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Recent Advances in Biochar Applications in Agricultural Soils: Benefits and Environmental Implications

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Recent Advances in Biochar Applications in Agricultural Soils: Benefits and Environmental Implications

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Biochar, a by‐product of biomass pyrolysis, has been suggested as a mean to combat climate change, and at the same time to achieve agricultural and environmental benefits. As one possible source of the components with high aromatic structure in soil humus, biochar is of great importance in increasing soil carbon storage and improving soil nutrient retention and nutrient availability, and in maintaining the balance of soil ecosystem. This paper briefly reviewed and synthesized recent findings and discussions regarding the production and characteristics of biochar, its effects on global climate change and particularly in relation to the environmental effects of biochar in soils. Agronomic benefits of biochar application are critically highlighted because researches show that biochar had varied effects on crop productivity thorough the different bio‐physical interactions between the biochar and the soils, which are deserved for further investigations. Potential pitfalls and knowledge gaps were briefly discussed on the environmental behavior and the effects of biochar in agricultural ecosystem.

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... Owning to carbon neutral characteristic, biomass-derived porous carbon for CO 2 capture could achieve decarbonization of emission-intensive industries/sectors and enable NETs for climate change abatement [30]. Commonly, converting biomass into porous carbons for CO 2 capture includes carbonization (pyrolysis, gasification, and hydrothermal) [15,22,24,25,27,[31][32][33][34][35][36][37][38][39][40], activation (physical and chemical) [37,38,, and surface modification (N, S, Mg, etc.) [42,45,68,69,71,73,[75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91] (Fig. 2a and b). ...
... Herein, three major thermochemical conversion processes (Fig. 2a), such as pyrolysis, gasification, and hydrothermal carbonization (HTC), are reviewed in the following sections, trying to demonstrate an overview of their advantages and limitations for CO 2 adsorption applications. Pyrolysis has been an alternative solution to convert biomass into high-value products such as biochar, bio-oil, and syngas, in the absence of oxygen at a temperature range of 300-900 • C [15,[26][27][28][29][30][31][32][33][34][35][36][37]. The types of pyrolysis process (slow, fast, and flash) depend on temperature, heating rate, and residence time. ...
... Physical and chemical activation is often employed for converting biomass, biochar and/or hydrochar into porous carbons, which show great potential and promising for CO 2 adsorption process (Fig. 2b) [18], [19,35,36], [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55], . Physical activation, a commonly cost-effective and eco-friendly activation method, could increase the porosity of biochar/hydorchar and increase the functional groups for improving the hydrophobicity and polarity. ...
Article
Adsorption CO2 capture technology has been regarded as one of the most promising approaches for effectively mitigating greenhouse gas (GHG), by which global warming could be controlled as well. The Intergovernmental Panel on Climate Change (IPCC) reported that the temperature increases should be kept within 1.5 • C other than 2 • C, implying that some more typical negative-emissions technologies (NETs) should be intensively investigated, such as the biomass-derived CO2 adsorption process driven by solar thermal energy. In this review, for the post-combustion CO2 capture, the biomass-derived CO2 temperature swing adsorption (TSA) combining the potential of low-grade thermal energy utilization was primarily addressed. In terms of adsorbent, adsorber, and adsorption process, the biomass-derived CO2 adsorption capture was reviewed as the main guideline to achieve the negative-emissions targets. The development of high-performance biomass-derived CO2 adsorbent was investigated firstly, including the thermo-chemical conversion techniques, activation treatment, and surface modification. Biomass-derived CO2 adsorption technology could be verified as one cost-effective and environment-friendly method for alleviating climate change. From the view of heat and mass transfer, the design and optimization of CO2 adsorber were also reviewed for high-efficiently achieving biomass-derived CO2 capture process. Thirdly, the system design for the entire process was discussed from the thermodynamics view, suggesting that the biomass-derived CO2 adsorption capture driven by low-grade solar thermal energy could become more preferable and feasible for commercial-scale application. Finally, concluding remarks and future perspectives for biomass-derived CO2 adsorption capture were addressed.
... Applied Soil Ecology 157 (2021) 103732 2019; Win et al., 2019). Their amendment can enrich the organic matter content in the soil, thus improving soil fertility (Xu et al., 2012). Biochar application also minimizes the soil acidity and increases EC (electrical conductivity) and CEC (cation exchange capacity) thus elevating nutrient availability (Laird et al., 2010). ...
... Peat was next to biochar in enhancing the bacterial survival efficiency. In mastering plant yield, biochar may act in two manners: directly, as a nutrient source by slow release of nutrients and indirectly, through improved retention of nutrients increase in soil water retention, soil pH, CEC, and microbial modification in soil population and function (Graber et al., 2010;Xu et al., 2012). ...
... Biochar-mediated improvements in the soil cation exchange capacity, and nutrient retention improved crop biomass and productivity (Schnell et al. 2012, Xu et al. 2012 as well as soil carbon contents (Lehmann et al. 2011). Other prominent effects of biochar on soil included improvement in particle size and bulk density, porosity and other physical properties, like soil structure and soil texture (Ding et al. 2016, Xu et al. 2012. ...
... Biochar-mediated improvements in the soil cation exchange capacity, and nutrient retention improved crop biomass and productivity (Schnell et al. 2012, Xu et al. 2012 as well as soil carbon contents (Lehmann et al. 2011). Other prominent effects of biochar on soil included improvement in particle size and bulk density, porosity and other physical properties, like soil structure and soil texture (Ding et al. 2016, Xu et al. 2012. Biochar also inhibited nitrogen volatilisation and improved soil N pool (McHenry 2011). ...
... It can adsorb pollutants in the soil as well as remediating contaminated soil (Arbestain and Leifeld, 2014;Xiong et al., 2017). Adding BC to the soil affects the soil structure, texture, porosity, particle size distribution, and density (Xu et al., 2012). The addition of BC increases the soil conductivity and cation exchange capacity (Laird et al., 2010). ...
... The addition of BC increases the soil conductivity and cation exchange capacity (Laird et al., 2010). Applying BC to soil can increase the soil nitrogen level and further increase the organic matter content to enhance the soil fertility (Xu et al., 2012). From an agricultural perspective, BC can fix fertilizers that are applied to soil and they are then released more slowly in the later stages of crop growth (Wang et al., 2018), which increases the effective period for fertilizer and improves the nutrient utilization efficiency . ...
Article
Biochar (BC) will gradually age over time after its application to soil due to the effects of environmental factors, such as long-term oxidation and acid rain. The changes in the physical and chemical properties and structure of BC after aging are not well understood. In this study, soil burial (S), oxidation (O), and acidification (A) methods were used to simulate the aging of walnut shell BC based on comparisons with fresh BC (F-BC). The differences in the physicochemical properties and structure of the BC before and after aging were studied using an elemental analyzer, scanning electron microscopy, and Fourier transform infrared spectroscopy. We found that the hydrophilicity of BC increased after aging whereas the aromaticity decreased. The surface pore structures were severely damaged on O-BC and A-BC compared with F-BC. Many clay particles were attached to the surface of BC. The adsorption performance of S-BC was not significantly lower than that of F-BC. According to the Langmuir model, the Q0 values for F-BC, S-BC, O-BC, and A-BC were determined as 33.78 mg g−1, 32.47 mg g−1, 18.62 mg g−1, and 19.12 mg g−1, respectively. Finally, based on the three types of aging processes, we analyzed the adsorption mechanism for BC after aging in its natural state and evaluated the environmental benefits of BC aging. Our results provide a theoretical basis for practical applications of BC aging in soil.
... Application of biochar to soil causes numerous soil changes, ranging from chemical, physical, and biological effects (Alemayehu et al., 2020). Biochar is recently well known organic components of an integrated nutrient supply system, which improve soil health, increase productivity and releases some amount of macro and micro nutrients (Xu et al., 2015). The ability of to retain nitrogen and prevent its leaching can increase nutrient use efficiency, there by maintains crop yield under small nitrogen application (Zhang, et al., 2015). ...
... This result is in agreement with Saarnio et al., (2012) who reported that biochar application integrated with fertilizer helps to increase in plant leaf number. Xu et al., (2015) also reported that there was a significant improvement of leaf photosynthesis and capacity on biochar amended soils, which they attributed to increased leaf number and soil available nitrogen. Koul (1997) reported that the level of fertilizer increased number of leaf per plant increased due to the ability of fertilizer that promoted leaf yield via cell division and elongation. ...
Article
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The study was carried out to evaluate the productivity of Chloris gayana and Panicum coloratum by application of different levels of coffee husk biochar and inorganic fertilizers (DAP and urea). The Experimental design was Randomized Complete Block Design (RCBD) with three replications. The treatments were T1=zero fertilizer application (control), T2= inorganic fertilizer using 100 kg DAP and 50 kg Urea, T3=5 t ha-1 biochar with 40 kg ha-1 inorganic fertilizer, T4=3 t ha-1 t biochar with 40 kg ha-1 inorganic fertilizer and T5=5 t ha-1 biochar with 100 kg ha-1 inorganic fertilizer for the two grass species. The result revealed that combined application of biochar and inorganic fertilizer significantly (<0.05) affected phonological variables, agronomical parameters, seed and biomass yields of Chloris gayana and Panicum coloratum measured at 4, 8 and 12 weeks after planting. Delayed days to 50% flowering (74 and 55 days) and 50% maturity (96 and 69 days) were obtained due to the application of 5 t ha-1 biochar with 100 kg ha-1 kg ha-1 inorganic fertilizer for Chloris gayana and Panicum coloratum, respectively. The highest plant height, leave length, number of tiller per plant and number of leaves per plant at all weeks were recorded for (T5) while the lowest was from T1 in both grass species. The study results indicated that the productivity of Chloris gayana and Panicum coloratum can be improved by the combined application of biochar and inorganic fertilizer. In future, application of biochar combined with inorganic fertilizer should be repeated at different seasons and agro ecology conditions.
... In terms of creating awareness about biochar, the community members can also be made aware that the benefits of using biochar outweigh the potential risks. This is because biochar remains stable with a high adsorption potential of contaminates [27,65,66]. Reduction in sanitation diseases can become preventive rather than having to pay medical bills when there is a diarrhoea or cholera outbreak, which in most cases is recurring if the underlying causes are not resolved or addressed. ...
Article
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Most people in rural areas in South Africa (SA) rely on untreated drinking groundwater sources and pit latrine sanitations. A minimum basic sanitation facility should enable safe and appropriate removal of human waste, and although pit latrines provide this, they are still contamination concerns. Pit latrine sludge in SA is mostly emptied and disposed off-site as waste or buried in-situ. Despite having knowledge of potential sludge benefits, most communities in SA are reluctant to use it. This research captured social perceptions regarding latrine sludge management in Monontsha village in the Free State Province of SA through key informant interviews and questionnaires. A key informant interview and questionnaire was done in Monontsha, SA. Eighty participants, representing 5% of all households, were selected. Water samples from four boreholes and four rivers were analyzed for faecal coliforms and E. coli bacteria. On average, five people in a household were sharing a pit latrine. Eighty-three percent disposed filled pit latrines while 17% resorted to closing the filled latrines. Outbreaks of diarrhoea (69%) and cholera (14%) were common. Sixty percent were willing to use treated faecal sludge in agriculture. The binary logistic regression model indicated that predictor variables significantly (p < 0.05) described water quality, faecal sludge management, sludge application in agriculture and biochar adaption. Most drinking water sources in the study had detections <1 CFU/100 mL. It is therefore imperative to use both qualitative surveys and analytical data. Awareness can go a long way to motivate individuals to adopt to a new change.
... Biochar is produced through pyrolysis of different biomass types including those from forestry and agricultural crop residues, the organic portion of municipal solid wastes, invasive plant species, animal manures, and wood waste (Ghani et al., 2013;Jayawardhana et al., 2018;Tomczyk et al., 2020). Biochar in soil systems has a wide assortment of benefits such as reducing mobility and bioavailability of heavy metal(loids), improving soil nutrient content, increasing water holding capacity, providing habitat for microbial community, and minimizing greenhouse gas emissions through carbon sequestration (Kumarathilaka et al., 2018c;Xu et al., 2012). ...
... Biochar is produced through pyrolysis of different biomass types including those from forestry and agricultural crop residues, the organic portion of municipal solid wastes, invasive plant species, animal manures, and wood waste (Ghani et al., 2013;Jayawardhana et al., 2018;Tomczyk et al., 2020). Biochar in soil systems has a wide assortment of benefits such as reducing mobility and bioavailability of heavy metal(loids), improving soil nutrient content, increasing water holding capacity, providing habitat for microbial community, and minimizing greenhouse gas emissions through carbon sequestration (Kumarathilaka et al., 2018c;Xu et al., 2012). ...
Article
Arsenic (As) in rice agroecosystems causes a loss of both rice yield and quality of rice grains. In this study, an integrated approach of biochar (BC) and alternative water management is proposed to reduce As content while sustaining essential elemental concentrations in rice. The rice cultivar, Jayanthi, was grown, irrigated with 1 mg L − 1 of As-containing water, under rice hull BC (RBC)-flooded, RBC-intermittent, conventional flooded, and intermittent treatments. The RBC has increased rice yield by 11%− 19% in RBC-intermittent and-flooded treatments compared to the flooded treatment. Inorganic As content in rice tissues and abundance of Fe(III) reducing bacteria in the rhizosphere were lowered by 10%− 83% and 40-70%, respectively, in RBC-flooded,-intermittent, and intermittent treatments over flooded treatment. Essential elemental concentrations (Fe, Mn, Zn, Mg, and Ca) in unpolished rice grains increased by 45%− 329% in RBC-flooded and-intermittent treatments compared to flooded treatment. Overall, the integrated approach of RBC-intermittent practices has lowered inorganic As concentration in unpolished rice grains, while sustaining the levels of essential elements in rice grains, compared to other treatments. An integrated approach of RBC-intermittent practices is suggested for rice grown with As-contaminated water to improve the quality of rice, as well as tackling food-related malnutrition in people.
... Many studies have reported that biochar has an excellent ability to improve soil structure because of its high total porosity, low BD, and high specific surface area (Xu et al. 2012;Wu et al. 2014;Lehmann and Joseph 2015). Considering such characteristics, three kinds of biochar were applied to improve soil structure, decrease soil BD, boost total porosity and capillary porosity, and increase moisture adsorption coefficient, wilting moisture capacity, saturated water content, field capacity, and effective water limit. ...
Article
Full-text available
Biochar has been extensively used for the improvement of soil water retention. However, the effects of various biochars were not well determined. The objectives of this study were to investigate the effects of three biochars [biochars made from bamboo (Bambusaceae), rice straw (Oryza sativa), and tobacco stem (Nicotiana L.)] on soil physical properties and the water retention characteristics of red soil at southeast China. The air-dried soil samples were mixed with ratios of 2%, 5%, and 10% (w w−1) BC (bamboo biochar), RC (rice straw biochar), and TC (tobacco biochar), respectively, and evaluated for changes in soil bulk density (BD), soil saturated water content, field capacity, capillary porosity and soil hygroscopic coefficient. The results showed that BD decreased significantly with the application of the three types of biochar, total soil porosity and capillary porosity increased with the increase of the biochar ratio. The soil hygroscopic coefficient, wilting moisture capacity, saturated water content, and field capacity were significantly affected by the application of the three types of biochar. Compared with the other two treatments, the BC showed the best effects on soil water characteristics. BC treatments with addition ratios of 2%, 5%, and 10% significantly decreased BD by 6.55%, 18.03%, and 36.07%, respectively. Moreover, saturated water content and field capacity were increased by BC. BC treatments significantly increased the readily available water by 32.65%, 42.49%, and 50.01%, respectively. However, the increased non-readily available water induced by the high ratio of biochar addition was not easily utilized by plants. Our results suggested that the biochar amendment can improve soil structure, decrease soil BD, boost soil porosity and capillary porosity, and increase soil moisture constant, and 2–5% of BC was recommended in the field condition.
... It contributes to sequester carbon into the soil and improves soil properties to reduce greenhouse gas emissions (Lehmann, 2007;Laird et al, 2010;Collet and Rousseau, 2015;Naisse, 2015). Other studies show a beneficial effect of biochar on soil fertility and plant productivity when combined with fertilizer or manure (Novak et al, 2009;Badji, 2011;Xu et al, 2012;Manka'abusi et al, 2019;Akoto-Danso et al, 2019;Lompo et al, 2020). Biochar can be produced using different types of reactors including locally manufactured reactors and modern ones (International Biochar Initiative (IBI), 2013); Jeguirim and Limousy, 2017). ...
Article
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This study focused on the production and characterization of biochars from three types of crop residues comprising cotton stems, corn cobs and sorghum stems. The reactor used was a local cone kiln made from a 200-liter drum. The production parameters measured included the duration of pyrolysis, the amount of biochar produced and the production yield. The chemical characteristics of the biochars were determined using the usual analytical methods used for organic amendment analyses. According to the study, pyrolysis time, biochar quantities and production yields depended on the type of crop residues. The three types of biochar obtained showed high C/N values indicating that their use as soil amendment must be combined with mineral fertilizers to ensure good plant development and crop yield. The heavy metal contents of the three biochar types complied with the international standards recommended for biochars by the International Biochar Initiative (IBI) and by the European Biochar Certificate (EBC). The production and the use of Biochar from crop residues is an interesting alternative for sustainable soil fertility management in the Sahelian countries.
... Biochar characteristics such as the chemical composition, surface chemistry, particle and pore size distribution, and physical and chemical stabilization mechanisms in soils determine its effects on soil functions and faecal contaminants control [21]. Studies into biochar have demonstrated potentials for its use in increasing nutrient [19,70,[85][86][87][88] and water retention [89][90][91][92][93] in soils, filtering heavy metals [94,95], reducing transport of microbes [14,15,22], increasing C sequestration [96][97][98], infiltration, soil aeration, root development, soil density, cation exchange capacity (CEC), and pH value [99][100][101][102]. The direct influence on soil structure, distribution of pore size, and density of the soil improves water holding capacity, aeration, and permeability [91,103,104]. ...
Article
Full-text available
Faecal sludge management (FSM) in most developing countries is still insufficient. Sanitation challenges within the sub-Saharan region have led to recurring epidemics of water- and sanitation-related diseases. The use of pit latrines has been recognised as an option for on-site sanitation purposes. However, there is also concern that pit latrine leachates may cause harm to human and ecological health. Integrated approaches for improved access to water and sanitation through proper faecal sludge management are needed to address these issues. Biochar a carbon-rich adsorbent produced from any organic biomass when integrated with soil can potentially reduce contamination. The incorporation of biochar in FSM studies has numerous benefits in the control of prospective contaminants (i.e., heavy metals and inorganic and organic pollutants). This review paper evaluated the potential use of biochar in FSM. It was shown from the reviewed articles that biochar is a viable option for faecal sludge management because of its ability to bind contaminants. Challenges and possible sustainable ways to incorporate biochar in pit latrine sludge management were also illustrated. Biochar use as a low-cost adsorbent in wastewater contaminant mitigation can improve the quality of water resources. Biochar-amended sludge can also be repurposed as a useful economical by-product.
... They characterized and reported the release of nutrients and contaminants from types of biochar made from sugarcane bagasse, eucalyptus bark, and sewage sludge on 350-500 °C pyrolysis temperature. Biochar is an enriched carbon-based material and is the product of biomass pyrolysis and has profound impacts on improving soil carbon storage [18]. An important attribute of biochar is its cation exchange capacity (CEC) due to its large surface area and porosity which impact the soil biota and nutrient dynamics [6,19]. ...
Article
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Biochar produced from transforming bioresource waste can benefit sustainable agriculture and support circular bioeconomy. The objective of this study was to evaluate the effect of the application of biochar, produced from wheat straws, and a nitrification inhibitor, sourced from neem (Azadirachta indica), in combinition with the recommended synthetic fertilizer on soil properties, maize (Zea mays L.) plant growth characteristics, and maize grain yield and quality paramters. The nitrification inhibitor was used with the concentrations of 5 and 10 mL pot−1 (N1 and N2, respectively) with four levels of biochar (B0 = 0 g, B1 = 35 g, B2 = 70 g, B3 = 105 g, B4 = 140 g pot−1), one recommended nitrogen, phosphorous, and potassium syntactic fertilizer (250, 125, and 100 kg ha−1, respectively) treatment, and one control treatment. The results showed that the nitrification inhibitor enhanced crop growth while the application of biochar significantly improved soil fertility. The application of biochar significantly enhanced soil organic matter and soil nitrogen as compared with nitrogen–phosphorus–potassium treatment. The highest root length (65.43 cm) and root weight (50.25 g) were observed in the maize plants treated with B4 and N2 combinedly. The grain yield, total biomass production, protein content from biochar’s B4, and nitrogen–phosphorus–potassium treatments were not significantly different from each other. The application of 140 g biochar pot−1 (B4) with nitrification inhibitor (10 mL pot−1) resulted in higher crop yield and the highest protein contents in maize grains as compared to the control treatments. Therefore, the potential of biochar application in combination with nitrification inhibitor may be used as the best nutrient management practice after verifying these findings at a large-scale field study. Based on the experimental findings, the applied potential of the study treatments, and results of economic analysis, it can be said that biochar has an important role to play in the circular bioeconomy.
... The multifunctional properties of biochar showed the potential as a sorbent for organic and inorganic contaminants in soil and water. The greatest concern of organic contaminants such as pesticides, herbicides, polycyclic aromatic hydrocarbons, dyes, and antibiotics have been a concern due to its toxicity and accumulative properties [38]. In the soil medium, biochar has been used for heavy metal sequestration [39,40]. ...
Chapter
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Conversion of agricultural wastes into eco-friendly and low cost biochar is not only a smart recycling strategy but a panacea to environmental pollution management. Agricultural wastes biochar can be an effective alternative technique for controlling contaminants due to its low cost, high-efficiency, simple to use, ecological sustainability and reliability in terms of public safety. Biochars have made substantial breakthroughs in reducing greenhouse gases emissions, reducing soil nutrient leaching, sequester atmospheric carbon into the soil, increasing agricultural productivity, and reducing bioavailability of environmental contaminants. Recent advances in the understanding of biochars warrant a proper scientific evaluation of the relationship between its properties and impact on soil properties, environmental pollutant remediation, plant growth, yield, and resistance to biotic and abiotic stresses. The main factors controlling biochar properties include the nature of feedstock, heat transfer rate, residence time and pyrolysis temperature. Biochar efficacy in pollutants management largely depends on its elemental composition, ion-exchange capacity, pore size distribution and surface area, which vary with the nature of feedstock, preparation conditions and procedures. The chapter explored the possibility of using biochar from agricultural wastes as a suitable alternative for the remediation of environmental pollutants, soil conditioning and the long-term biochar application in the environment.
... The multifunctional properties of biochar showed the potential as a sorbent for organic and inorganic contaminants in soil and water. The greatest concern of organic contaminants such as pesticides, herbicides, polycyclic aromatic hydrocarbons, dyes, and antibiotics have been a concern due to its toxicity and accumulative properties [38]. In the soil medium, biochar has been used for heavy metal sequestration [39,40]. ...
Chapter
Full-text available
Conversion of agricultural wastes into eco-friendly and low cost biochar is not only a smart recycling strategy but a panacea to environmental pollution management. Agricultural wastes biochar can be an effective alternative technique for controlling contaminants due to its low cost, high-efficiency, simple to use, ecological sustainability and reliability in terms of public safety. Biochars have made substantial breakthroughs in reducing greenhouse gases emissions, reducing soil nutrient leaching, sequester atmospheric carbon into the soil, increasing agricultural productivity, and reducing bioavailability of environmental contaminants. Recent advances in the understanding of biochars warrant a proper scientific evaluation of the relationship between its properties and impact on soil properties, environmental pollutant remediation, plant growth, yield, and resistance to biotic and abiotic stresses. The main factors controlling biochar properties include the nature of feedstock, heat transfer rate, residence time and pyrolysis temperature. Biochar efficacy in pollutants management largely depends on its elemental composition, ion-exchange capacity, pore size distribution and surface area, which vary with the nature of feedstock, preparation conditions and procedures. The chapter explored the possibility of using biochar from agricultural wastes as a suitable alternative for the remediation of environmental pollutants, soil conditioning and the long-term biochar application in the environment.
... Its basic composition (carbon, nitrogen, potassium and magnesium) can provide nutrients and increase crop yields, thereby reducing fertilizer requirements. The application of biochar as a soil amendment leads to improvement of the physico-chemical quality of the soil [21][22][23]. ...
Article
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Contemporary farming practices and rapid industrialization over the last few decades, have raised significant soil and water pollution with extreme toxic effects to humans and ecosystems. The widespread and inefficient use of pesticides, which surpass the soil’s self purification capability, has accelerated soil pollution. In this study, wheat straw biochar was obtained using the traditional pyrolysis technique and its characterization; in addition, the adsorption efficiency of metribuzin was investigated. Biochars’ physical and chemical characteristics were qualified using scanning electron microscopy and Fourier transform infrared spectroscopy. A batch sorption test and liquid chromatography coupled with mass spectrometry were also used to assess the biochar efficiency. SEM and FTIR confirmed the highly reactive surfaces of biochar, establishing efficient biomass conversion in low-oxygen conditions. The adsorption process showed best fit with pseudo second-order kinetic and Langmuir models, suggesting a chemisorption procedure and monolayer-type removal. Regarding its environmental and agricultural application, wheat straw biochar can be advanced as a recommendation solution for further research, which is fundamental for soil rehabilitation and the immobilization of contaminations.
... It has been reported to improve adsorption-desorption and the degradation of pesticides in the soil (Khorram et al. 2016). According to Xu et al. (2012), the stability and absorbent properties of biochar make it a perfect remedy for polluted soils when used as a soil amendment, given that it can bind with toxicants, thus reducing their mobility. For example, Yu et al. (2009) revealed that the ability of biochar to sequester pesticide residues could result in reduced uptake of chlorpyrifos and carbofuran, two organic pesticides, by the spring onion (Allium cepa). ...
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Terrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.
... It is characterized by a highly porous structure and a high specific surface area, which can allow the adsorption and immobilization of pollutants from contaminated waters. The addition of biochar to a conventional substrate was reported to have beneficial effects for the enhancement of soil fertility [67], the alteration of microbial communities, and the promotion of plant growth [68]. Wood-chips are another natural material that can be easily found near agricultural activities and could be exploited for the leaching out of organic compounds, resulting in an increase of the organic concentration in CW influents, and in the enhancement of both nitrification and denitrification processes [69]. ...
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The implementation of nature-based solutions (NBSs) can be a suitable and sustainable approach to coping with environmental issues related to diffuse water pollution from agriculture. NBSs exploit natural mitigation processes that can promote the removal of different contaminants from agricultural wastewater, and they can also enable the recovery of otherwise lost resources (i.e., nutrients). Among these, nitrogen impacts different ecosystems, resulting in serious environmental and human health issues. Recent research activities have investigated the capability of NBS to remove nitrogen from polluted water. However, the regulating mechanisms for nitrogen removal can be complex, since a wide range of decontamination pathways, such as plant uptake, microbial degradation, substrate adsorption and filtration, precipitation, sedimentation, and volatilization, can be involved. Investigating these processes is beneficial for the enhancement of the performance of NBSs. The present study provides a comprehensive review of factors that can influence nitrogen removal in different types of NBSs, and the possible strategies for nitrogen recovery that have been reported in the literature.
... Biochar, a pyrolyzed product prepared from agricultural wastes [16,17], is considered to be a potential amendment material due to its relatively large surface area and micropore volume, high exchange capacity (CEC), and abundant surface functional groups [18][19][20][21]. Thus, the application of biochar in agriculture soil can increase the soil's pH, organic matter, CEC, and nutrient utilization [22][23][24]; mitigate greenhouse gas emissions [25]; and then reduce the mobility of pesticides and their degradation products from the soil to groundwater through pore filling, partitioning, the hydrophobic effect, H-bonding, electrostatic attraction, specific interaction, and surface precipitation [26][27][28][29]; such pesticides and their degradation products include pyrazosulfuron-ethyl [16], glyphosate [30], atrazine [31], and TCP [9]. Therefore, as an environmentally friendly soil amendment, biochar is progressively gaining attention from policy makers and scientific communities. ...
Article
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3,5,6-Trichloro-2-pyridinol (TCP), the main degradation production of the pesticide chlorpyrifos and the herbicide triclopyr, features anti-degradation and high water solubility that challenge the in situ prevention of the migration of TCP from soils to water bodies. Biochar is a widely used amendment, but previous studies focused on the low content of biochar application that restricted the off-site prevention. In this study, therefore, both experiments and models were employed to explore the destination of TCP in purple soil, an Entisol with low organic matter content, large pores, and high water conductivity in southwestern China with a high ratio of biochar applied. Soil columns were homogeneously packed by mixing biochar at 0, 1%, 2%, 3%, 4%, 5%, 7.5%, 10%, 15%, and 20%, then the impulsive input of the breakthrough curves was used to explore the adsorption and desorption process of TCP, and the release of adsorbed TCP was traced by Br−. Following the dynamic outflow during the adsorption processes was simulated using the cumulative distribution function of gamma distribution, and the release of TCP was simulated by coupling the mass balance equation and first-order decay kinetics equation. The results revealed that the adsorption ability of the soil increased exponentially with the content of mixed biochar, implying a much larger increment at high content. For the removal rate of 90%, e.g., the increment was about 20 mg/kg when the content of biochar was raised from 15% to 20%, while it was about 7 mg/kg when the content was raised from 0 to 5%. The dynamic release and the unreleasable TCP could be well simulated by the first-order decay kinetics equation and the logarithmic model, respectively. The releasable TCP showed an increase–decrease pattern, and the maximum was observed at a 5% biochar content. These results above will provide a systematic experimental scheme, model support, and data reference to control organic pollutants with high solubility, stability, and strong migration using biochar in an off-site pattern such as an ecological ditch system.
... Biochar has a beneficial effect on soil properties and plantmicrobial ecosystem by directly influencing soil's physicochemical properties, nutrient contents, and its capacity to accumulate nutrients and gradually release them into the soil solution (Dejene and Tilahun 2019). The processes involved are the addition of soluble nutrients present in the biochar (Xu et al. 2012), mineralization of the labile fractions from organically bound nutrients (Lehmann et al. 2009), and lowering nutrient losses (Martinsen et al. 2014). Due to high internal porosity, surface area, and the presence of polar and non-polar surface groups, biochar adsorbs organic molecules and other nutrients which are transformed into available forms (Yao et al. 2012) and have profound benefits for improving soil N and P in plants (Zhang et al. 2019). ...
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Biochar application variably affects nutrients availability, growth, and yield of crop plants based on their feedstock type and pyrolysis conditions. A pot experiment was carried out to evaluate the effect of biochars prepared from three different feed stocks viz. sugarcane filter cake (SF-BC), farmyard manure (FM-BC), and rice husk (RH-BC), on the availability of the plant nutrients in soil and the growth and nutrient uptake by maize crop (Zea mays L.). The biochars were applied separately to the soil at the rate of 0, 0.25, 0.5, and 1% separately, and the experiment was laid out according to two-factor factorial completely randomized design (CRD) maintaining three replications. Maize variety Monsanto-DK8031 was sown as the test crop. The concentration of total nitrogen (N), nitrate (NO3-N), ammonium (NH4-N), microbial biomass nitrogen (MBN), Olsen phosphorus (P), and extractable K increased with the addition of FM-BC, while the SF-BC increased soil microbial biomass phosphorus (MBP) and micronutrients (Zn, Mn, Cu, Fe) availability in the soil. Moreover, the biochar application significantly improved crop growth parameters (i.e., plant height, fresh plant weight and dry biomass) and also increased plant nutrient concentration and uptake. No negative impact of biochar was observed on plant growth or nutrients concentration. The macronutrient (total N, P, and K) contents and their uptakes were higher in plants grown with RH-BC, while the micronutrient (Mn, Cu, and Fe) contents were higher in plants grown with SF-BC. Biochar as an organic amendment has a great potential to improve soil fertility status and nutrients availability to crop plants in tropical alkaline soils; however, the effectiveness varies with the feed stock type and application rate.
... Many other studies have reported that with addition of biochar to soil improved the roots growth of mung beans (Vigna radiata L.) (Lehmann et al. 2011), subterranean clover (Trifolium subterraneum) (Solaiman, Murphy, and Abbott 2012), barely (Hordeum vulgare L.) (Bruun et al. 2014) and in maize (Free et al. 2010) that was attributed to better improvement in soil water retentions (Bruun et al. 2014;Haider et al. 2017) and also improved organic matter status of soil (Table 1). However, biochar application (4-6 t ha À1 ) to loamy soil not prominently improved the maize production that might be due to imbalance nutrient release from freshly prepared biochar (Zhang et al. 2010;Xu et al. 2012;Butnan et al. 2015), thus this treatment was eliminated from the field study. It has been found that biochar application increases the soil pH (Table 1) (Butnan et al. 2015;Rizwan et al. (2016), Imtiaz, Chhajro, and Huang 2016) which in return reduces the nutrients availability. ...
Article
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This study was designed to investigate the effect of biochar on maize production and nutrient retention with recommended full and half dose of nitrogen (N) and phosphorus (P) nutrition in loamy soil. In the first study, maize was grown in pots with four levels of biochar (0, 2, 4, and 6 t ha⁻¹) under two levels of NP fertilizer, viz. recommended (200–150 kg NP ha⁻¹) and it’s half (100–75 kg NP ha⁻¹) dose. The prominent improvement in plant roots traits, leaf area, plant growth, morphological and yield-related parameters were observed with addition of biochar at 2 and 4 t ha⁻¹; while, plant height, number of grains per cob, grains and biological yield decreased with biochar addition 6 t ha⁻¹ along with full dose of NP nutrition. In subsequent field studies, two levels of biochar along with control (0, 2, 4 t ha⁻¹) were investigated. The more improvement in root growth, leaf area and crop growth was observed when biochar was applied at 2 t ha⁻¹ with full NP nutrition. Biochar application at 2 t ha⁻¹ with full NP nutrition produced the highest grain yield (6.64 t ha⁻¹); however, biochar addition (2 t ha⁻¹) with half NP nutrition resulted in better grain yield than full dose of NP to enhance maize production as compared with full dose of NP without biochar. Therefore, biochar addition (2 t ha⁻¹) with half-recommended dose of NP prominently improved the maize productivity in loamy soil and serve as better in replacement of full dose of NP fertilizer.
... We also found that planting white clover on the soil surface and adding 5% biochar to ionic rare earth tailing soils (SBC2) could significantly increase the soil TN content and have positive effects on other nutrient contents. This improvement may have occurred because the strong adsorption capacity of biochar can effectively prevent the leaching of soil nutrients and prolong the retention time of soil nutrient elements (Xu et al., 2012;H. Zheng et al., 2013). ...
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The disordered mining of ion‐type rare soil has caused significant ecological and environmental problems. Arbuscular mycorrhizal fungi (AMF) can promote soil quality, providing new ideas about the ecological restoration of degraded soil. In this study, the degraded ion‐type rare earth tailing soils in Xinfeng County, southern Jiangxi Province, was used as a research object. The soil was subjected to different restoration methods (biochar + fly ash + surface vegetation planting) for 2 yr. A total of six treatments were set up in this experiment, and the phospholipid fatty acid method was used to determine the microbial community structure and biomass of the rhizosphere soil of navel oranges [Citrus sinensis (L.) Osbeck] treated with different amounts of biochar (0, 1, and 5%) plus surface mulching (Trifolium repens L.) or soil without plants. Additionally, a pot experiment was conducted to study the effects of single and double inoculation of AMF (Septoglomus viscosum and Claroideoglomus claroideum) on plant growth and soil improvement under various P levels (0 and 50 mg kg–1) in ion‐type rare soil. The results showed that the microbial biomass (fungi, Gram‐positive bacteria, Gram‐negative bacteria, actinomycetes, AMF, and protozoa) when T. repens was present was noticeably higher than that when T. repens was not present. In particular, the biomass of the AMF under the T. repens treatment with 5% biochar (1.28 nmol g–1) was 34.38% higher than that under the 5% biochar treatment without plants (p < .05). Furthermore, the pot experiments showed that AMF inoculation significantly increased the plant biomass, single AMF inoculation significantly increased soil P in the absence of basal P, and double inoculation significantly increased the glomalin (a component of soil organic matter) content. Our findings indicated that the soil microbial biomass was greatly affected by planting T. repens and adding biological modifiers. These composite remediation methods could provide an increasing number of C sources for the soil microbial community and could effectively improve soil quality and plant growth. We conducted a novel study on the effect of arbuscular mycorrhizal fungi (AMF) on restoration of degraded soil in ionized rare earth mining area. Soil microbial biomass was greatly affected by Trifolium repens and biological modifier. The inoculation of AMF had a significant contribution to the soil organic matter pool. The composite remediation modes could effectively improve soil quality and plant growth.
... Biochar is also a promising adsorbent for the remediation of contaminated soils, due to its high capacity to retain organic and inorganic species [14]. The high adsorption capacity is linked to its high specific surface, porosity, and diversity of functional groups [12,15]. ...
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Growing environmental pollution in recent decades has been generating potentially toxic elements (PTE) which pose an ongoing threat to terrestrial and aquatic ecosystems and human health, especially in mining areas. Biochar and PTE-tolerant species have been used in soil remediation as they are environmentally friendly alternatives. This study aimed to assess the influence of açaí seed biochar (Euterpe oleracea Mart), impregnated with iron (BFe) or not (BC), on the bioavailability of PTEs, in a multi-contaminated soil from a gold (Au) mining area in the Amazon, using Ipomea asarifolia as a plant test since it was naturally growing on the tailings. BC increased the soil pH while BFe reduced. Biochars increased PTEs in the oxidizable fraction (linked to soil organic matter). The use of BC and BFe improved the immobilization of PTEs and BC increased arsenic (As) in the easily soluble fraction in the soil. Moreover, plants grown with biochars showed lower dry matter yield, higher concentrations of PTEs and lower nutrient content than the control treatment. According to the phytoextraction and translocation factors, Ipomea asarifolia can be classified as a species with potential for phytostabilization of Zn and tolerant to other PTEs, mainly As.
... Several benefits have been reported from its use in faecal sludge waste management which include a reduction in faecal bacteria pathogens like faecal coliforms and E.coli (Mohanty et al., 2014); excreta dehydration associated with its high water adsorption (Mohanty et al., 2014;Rogers et al., 2018); higher nutrients exchanges, increases in pH and reduced nitrogen leaching (Bai et al., 2018;Aghoghovwia et al., 2022); barrier for organic and inorganic contaminants percolation towards groundwater sources (Mohanty et al., 2014). Biochar also has the potential to serve as an active soil C sink because it has a high fraction of recalcitrant C and can therefore remain stable for hundreds to thousands of years (Xu et al., 2015). The high recalcitrant C fraction also reduces the need for the regeneration process of biochar in soils as the active colloidal sites for adsorption can slowly exchange sorbed organic and inorganic elements into solution (Dai et al., 2019). ...
Article
Biochar is a valuable treatment option for faecal sludge management (FSM). However, the sanitation application rates of biochar in FSM are not well established. There is also a gap in knowledge about the effect of actual raw sewage effluent and sludge on organic and inorganic contaminants migration of biochar treated soil. This study investigated the concentration and migration rates of N, P, E. coli and faecal coliform bacteria through different soil-bed biochar column treatments leached with raw faecal sludge and sewage effluent. Forty-four soil-bed leaching columns with pinewood biochar rates at 5, 10 and 20 t/ha were set at the Bloemspruit wastewater plant, South Africa. The pinewood biochar used had a pH of 10.21, total C composition of 92%, surface area of 517 m²/g, and a pore size of 1.7 nm. It was found that the 20 t biochar per ha treatment with faecal sludge increased water retention (flows of 33 mm/hr. at 0 t/ha compared to 0.8 mm/hr. at 20 t/ha) and leachates purification. High detections were observed for faecal coliforms and E.coli above 4331 CFU/100 mL from the effluent and faecal sludge in soils without biochar. Detection of E.coli at 20 t/ha decreased to 1 CFU/100 mL while the faecal coliforms still had counts above 10 CFU/ 100 mL. The results showed a decreasing rate of nitrates, phosphates, zinc and copper with an increasing biochar application rate. Pinewood biochar showed significant removal efficiencies of bacteria (between 89 – 98%) and nitrates and phosphates (between 68 – 98%). Significant differences were seen at P < 0.05 between the means of the treatments with and without biochar. The results from the study show that pinewood biochar applied at rates between 5 and 20 t/ha has a high organic and inorganic contaminants reduction potential for FSM.
... It was observed that from an acidic nature of the soil, it was significantly changed into a slightly alkaline in nature from a pH value 5.93 -7.51. However, biochar with an initial alkaline pH value is suitable as an amendment for acidic, degraded soil, because it might lead to nutrient deficiencies in plant, when soil gets too alkaline 36 . ...
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Poultry litter char (PLC) is one of the high valued fertilizer rich in nutrients and locally available, however, limited published data are available on its effects on crops and soil properties. The study was conducted to determine the optimum rate of poultry litter char enhancing growth and yield of corn and evaluate its effect on the physico-chemical properties of degraded upland soil. Five treatments using 0, 2.5, 5, 10, 20 tons of PLC ha-1 were used in a randomized complete block design with three replications. The results showed that poultry litter char application significantly increased the plant height, resulted to earlier tasseling, fruiting and harvesting of corn and increased their yield particularly number of fruits, fruit yield, ear length, weight of 1000 seeds and stover yield as well. In addition, corn tissue was found to have a considerable amount of nitrogen and phosphorus. On the other hand, addition of PLC significantly improved the physico-chemical properties of degraded soil such as reduction of soil strength, increased soil porosity and soil water holding capacity and increased pH, % OC, total N, Extractable P, Exchangeable K and Ca. The study recommends an application rate of 20 t ha-1 of PLC to improve the growth and yield of corn and enhance the properties of highly degraded soil and 2.5 t ha-1 PLC to gain a higher return on investment.
... In slow carbonization, the precursor was pyrolyzed for a longer duration with a heating rate of less than 10°C/min within the temperature range of 300-800°C, while on the other hand, in the fast carbonization, the precursor was pyrolyzed for a shorter span with the heating rate of around <300°C /min in the temperature range 400-600°C (Mohan et al., 2014;Xu et al., 2012). Further, a slow heating rate and low carbonization temperature of <500°C leads to the formation of the coke, whereas a high carbonization temperature at a faster heating rate increases the volatiles yield. ...
Article
Due to rapidly deteriorating water resources, the world is looking forward to a sustainable alternative for the remediation of noxious pollutants such as heavy metals and organic and gaseous contaminants. To address this global issue of environmental pollution, nanoporous carbon materials (NPCMs) can be used as a one-stop solution. They are widely applied as adsorbents for many toxic impurities and environmental contaminants. The present review provides a detailed overview of the role of different synthesis factors on the porous characteristics of carbon materials, activating agents, reagent-precursor ratio and their potential application in the remediation. Findings revealed that synthetic parameters result in the formation of microporous NPCMs (SBET: >4000 m³/g; VTotal (cm³/g) ≥ 2; VMicro (cm³/g) ≥ 1), micromesoporous (SBET: >2500 m³/g; VTotal (cm³/g) ≥ 1.5; VMicro (cm³/g) ≥ 0.7) and mesoporous (SBET: >2500 m³/g; VTotal (cm³/g) ≥ 1.5; VMicro (cm³/g) ≥ 0.5) NPCMs. Moreover, it was observed that a narrow pore size distribution (0.5–2.0 nm) yields excellent results in the remediation of noxious contaminants. Further, chemical activating agents such as NaOH, KOH, ZnCl2, and H3PO4 were compared. It was observed that activating agents KОН, H3PO4, and ZnCl2 were generally used and played a significant role in the possible large-scale production and commercialization of NPCMs. Thus, it can be interpreted that with a well-planned strategy for the synthesis, NPCMs with a “tuned” porosity for a specific application, in particular, microporosity for the accumulation and adsorption of energetically important gases (CO2, CH4, H2), micro-mesoporosity and mesoporosity for high adsorption capacity for towards metal ions and a large number of dyes, respectively.
... Biochar results from biomass pyrolysis under the limited presence or complete absence of oxygen at temperatures greater than 250 • C. Because of its stability and absorbent properties, some view biochar amendment as a means to mitigate the effects of chemicals in soils [14,15]. Such toxicity mitigating abilities have been shown after soil amendment in the cases of the spring onion Allium cepa exposed to carbofuran and chlorpyrifos [16], the potworm Enchytraeus albidus exposed to imidacloprid and silver nanoparticles [17] and several earthworms species exposed to fomesafen, chlorantraniliprole, mesotrione, and imidacloprid [15,[18][19][20]. ...
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Despite several known beneficial attributes, biochar is suspected to cause harm to soil organisms when present in relatively high quantities in the soil. To determine the potential detrimental effects of biochar, for 96 h, we exposed the earthworm Eisenia fetida to 0, 2, 4 and 8 mg glyphosate (GLY) per kg in non-amended and biochar-amended soil at rates of 5, 10 and 15%. The results indicated that in non-amended soil, survival was significantly decreased in the highest GLY concentration. Although no median lethal concentration (LC50) could be computed due to the lack of sufficient mortality, in the absence of biochar, a lethal concentration 10% (LC10) of 5.540 mg/kg and a lethal concentration 20% (LC20) of 7.067 mg/kg were calculated. In the biochar-amended soil, no mortality occurred in the control and GLY treatments for all three biochar amendment rates. Biomass results showed significant biomass loss in the highest GLY treatment in the absence of biochar, with an effective concentration of 10% (EC10) of 5.23 mg/kg and an effective concentration of 20% (EC20) of 6.848 mg/kg. In the amended soil, overall, slight non-significant increases in biomass were recorded and no effective concentrations could be calculated due to the lack of significant biomass loss. The assessment of neurotoxicity via the activity of acetylcholine esterase (AChE) showed no change in AchE due to GLY in all the non-amended treatments. However, in the biochar-amended treatments, statistically high levels of AchE occurred (p < 0.05) even in the control (in the absence of GLY). The assessment of oxidative stress through catalase (CAT) activity, showed similar results with no significant effects of GLY alone on CAT activity, but rather dramatic increases in activity in the control and GLY treatments in the biochar-amended soil, with one significant increase in the 10% amended in 8 mg GLY/Kg (p < 0.05). Such significant increases in both AChE and CAT were only observed in soil amended with 10 and 15% biochar. Our findings show that although seemingly beneficial for whole body endpoints, biomarker responses indicate that a biochar amendment higher than 5% adds considerable additional stress to earthworms and should be avoided.
... These characteristics are not uniform-they change based on properties of the feedstock, burning temperature, production method, time and environmental conditions (Zhao et al. 2013;Ahmed et al. 2016). One of the most important properties of biochar is its high organic carbon content, primarily concentrated in highly stable aromatic compounds resistant to microbial decay (Xu et al. 2012). This property serves as a base for proposing biochar as a suitable carbon sequestration medium. ...
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Protection and appropriate management of forests is one of the key instruments for climate change adaptation. Soil amendments with biochar have shown to be promising in achieving this goal; however, the evaluation of its long-term effects on forest soils has largely been neglected. To assess the advantages and drawbacks of biochar in forest soils, data from relict charcoal hearths (RCH) can be a potent tool as they show changes in soil properties after up to several hundred years. RCHs can be found in places of former metallurgical hot spots and their presence leaves characteristic formations identifiable on a large scale using laser detection technologies. Forest soils with biochar amendment show an increase in base cations, shift towards more alkaline pH, smaller bulk density and seem to be especially beneficial to hostile environments. Sites with favourable conditions may show little to no improvement or may even be adversely affected. Still, with proper investigation, areas with affordable feedstock materials and poor forest soils—such as spruce monocultures of Central Europe—may benefit from biochar amendments and continue to do so in the long term.
... Due to its potential to mitigate climate change, it is conducive to food security and undertakes the management of organic waste, and has significantly been developed worldwide (Nsamba et al., 2015). Over the past decade, the application of biochar has shown its advantages in soil properties, crop growth, and environmental protection (Xu et al., 2012;Carter et al., 2013;Stavi and Lal, 2013;Wilson, 2014;Oliveira et al., 2017;Gayathri et al., 2021;Nguyen et al., 2021). However, soil conditions and fertilizer management affect the utilization of biochar in soil (Jha et al., 2010). ...
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Biochar is a kind of organic matter that can be added into the soil as a soil amendment to improve its quality. What are the effects of using biochar on purple soil and soybeans? Can the use of biochar reduce the use of fertilizers? This is our concern. Therefore, we carried out this study. The objectives of our study were to evaluate the effects of biochar, inorganic and organic fertilizer application on plant growth, chlorophyll content, photosynthetic gas exchange, and yield of soybean as well as fertility and microbial community in purple soil, and to appraise the possible reduction rate of inorganic fertilizer under the biochar application. A pot experiment was conducted with three levels of biochar, two levels of inorganic fertilizer, and two levels of organic fertilizer in a randomized complete block. The results indicated that the low rate of biochar together with half rate of inorganic fertilizer and organic fertilizer increased the plant growth of soybean. Meanwhile, the chlorophyll content, root growth, and yield of soybean were increased by 16.61, 197.73, and 96.7%, respectively, with biochar compared with no biochar. The high rate of biochar with half rate of inorganic fertilizer and organic fertilizer can promote the exchange of photosynthetic gas in soybean, and the photosynthetic rate increased by 45.25% compared with the blank control. At the full pod stage, the nitrogen content, phosphorus content, and potassium content of the whole plant under the high rate of biochar were 28.35, 13.65, and 28.78%, respectively, higher than that of the blank control. The application of biochar increased nitrogen, phosphorus, and potassium uptake of soybean. The high rate of biochar with half rate of inorganic fertilizer and organic fertilizer can improve soil nutrient content and soil microbial community. Compared with no biochar treatments, total organic carbon (TOC) increased by 740.28%, and cation exchange capacity (CEC) increased by 54.17%. Phospholipid fatty acid (PLFA) increased by 65.22%, and all kinds of soil microorganisms increased to varying degrees. In conclusion, the application of biochar can reduce the use of organic and inorganic fertilizers, improve the agronomic traits and yield of soybean, and play a positive role in soil nutrients and soil microorganisms.
... As a renewable fuel, the inherent properties of biochar make it an excellent product or additive for carbon sequestration, soil amendment, bioprocesses and wastewater treatment [6][7][8][9][10]. Recently, the use of biochar has expanded into more advanced applications, such as electrode fabrication and catalyst preparation [11]. ...
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Nano-biochar presents superior physicochemical properties over bulk biochar such as highly stable and unique nanostructure, high catalytic activity and large specific surface area. A comprehensive understanding of the current nano-biochar research is required while progressing to real-world implementations, including preparation, characteristic properties and targeted applications. This paper provides a state-of-the-art review on nano-biochar research for (1) definition and production methodologies, (2) compositions and properties, (3) high-value applications and performances, (4) environmental concerns, and (5) implications to conventional biorefineries and perspectives. Following a sequence of biochar preparation, size reduction and screening, nano-biochar can be obtained for high-value applications such as a high-performance adsorbent, a carrier of biocatalysts, electrodes in electrochemistry and additives. Compared with bulk biochar, nano-biochar performs better in general uses such as wastewater treatment and soil amendment and promises high-value applications in emerging areas such as electrochemistry and biocatalysis. This review highlights that the preparation of nano-biochar from conventional bioenergy and biorefinery technologies such as thermochemical liquefaction and gasification is promising to generate adding values, contributing to enhanced techno-economic feasibility. Integrating nano-biochar preparation and application with conventional biofuel production is thus highly recommended as a future research endeavour.
Thesis
The biochar is a by-product produced from the pyrolyzing an organic feedstock, mainly biomass, through a thermochemical process with limited or without the presence of oxygen. The application of biochar goes back to approximately 2000 years ago knowing that it was practiced mainly in ancient Amazonia. In order to determine the growth of the science in the area of the biochar application as a soil additive, a scientometric study was performed in the Web of Science core collection with the advance search of some specific keywords and the total number of 2123 English documents were retrieved published from 2000 to 2018. These bibliographic records were then analyzed regarding some scientometric criteria such as publication type, publication year, contributing country, keyword analysis, author analysis, cited authors, cited journals, categories, and cited documents. The obtained results in this regard demonstrated that despite many research performed in this field, the need regarding more collaboration among the researchers globally and overcoming matters regarding the proper feedstock, pyrolysis condition, and toxic behavior of the biochar is still greatly felt in order to commercialize the biochar application as a soil amendment. Moreover, as a case study, one type of biochar was pyrolyzed from the secondary sludge of the wastewater treatment of pulp and paper mill industry. Further, the produced biochar was analyzed regarding its chemical and physical characteristics. The performed analysis revealed that the biochar was porous and possesses an irregular microstructure. Also, it was in high pH and electric conductivity. Further on, an incubation test was conducted on the soil incubated with biochar as the additive. To provide a comparison, a liming agent was also applied in different soil samples. The amended soil samples with the liming agent were also kept in the incubation. Thereafter the incubation period, which was 21 days, it was observed that the biochar has the capacity to alter the pH, electrical conductivity, and the water holding capacity of the soil while with the liming agent only the pH increased significantly and no considerable modifications were observed in the other measured parameters.Furthermore, a phytotoxicity analysis regarding the germination of the seeds and their growth was conducted via the application of Lepidium sativum seeds (for germination test) and Lolium perenne seeds (for growth test). The obtained results in this regard demonstrated the non-toxic effect of the biochar addition on the seed germination. Also, thereafter the conduction of the growth test, it was observed that the biochar with the corresponding dose of 2.5% w/w enhanced the crop yield significantly in comparison to the collected soil via providing the crops with more dry-weight and height. While the crop obtained from the amended soil with the biochar higher doses had a negative effect on the crop yield. The liming agent did not significantly increase the crop yield as well. However, more research regarding the potentially toxic elements uptake by plants grown in the amended soil with biochar is considered to be crucial for a safe application of such an amendment.
Article
In recent years, the recycling of low-cost and wide-source biomass has caused great concern. The obtained biomass-derived porous carbon (BDPC) is widely used as the electrode material of new energy storage device in the field of electrochemistry due to its unique properties such as large specific surface area, developed pore structure, acid and alkali resistance, excellent conductivity, and adjustable pore size. At the same time, efficient energy storage devices have been gradually developed and upgraded. Various hybrid supercapacitors (sodium ion, potassium ion, lithium ion, zinc ion, etc.) are widely used as new green energy equipment in hybrid power vehicles and portable electronic products. In this review, various activation methods and mechanisms are introduced in detail, and the application and research progress of biomaterials in electrochemical energy storage in the past three years are reviewed. The effects of different activation processing methods on the surface modification and micromachining of the obtained carbon materials on the electrochemical performance are briefly discussed. Finally, this paper summarizes the current research status of biomass-derived porous carbon in energy storage, potential future development directions and current challenges to promote the application of biomass-derived porous carbon materials in various fields, which provide useful insights for further development and utilization of biomass.
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A sustainable management of environment and agriculture is crucial to protect soil, water, and air during intensified agriculture practices as well as huge industrial and transportation activities. A promising tool to address these challenges could be the application of biochar, a carbonaceous product of biomass pyrolysis. The efficiency of biochar could be improved through physical, chemical and microbial procedures. Engineered biochar could then be applied for various applications ranging from sustainable agriculture to pollution remediation and catalytic reactions. Biochar engineering allows achieving biochar properties which are optimum for specific applications and/or under specific conditions. This would lead to harnessing the favorable features of biochar and to enhance its efficiency while simultaneously minimizing the existing tradeoffs. This review covers the production and applications of engineered biochar by summarizing great deals of research and knowledge on the field. Unlike previous reviews, herein biochar physical and chemical properties and the factors affecting them (i.e., biomass nature and pyrolysis conditions) have been discussed in detail. Moreover, the contributions of each physical and chemical activation/modification methods to improving biochar characteristics with respect to environmental applications have been specifically scrutinized. By providing the state-of-the-art knowledge about engineered biochar production, properties, and applications, this review aims to help research in this field for identification of the culprits that must be addressed in future experiments.
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The investigation of renewable, cost-effective, and environmentally gracious electrode materials with high adsorption, fast ion/electron transport, and tunable surface chemistry is immediately desirable for the development of next-generation biocompatible energy-storage devices. In recent years, biomass-derived carbon electrode materials for energy storage have attracted significant attention because of their widespread availability, renewable nature, and low cost. More importantly, their inherent uniform and precise biological structures can be utilized as templates for fabricating electrode materials with controlled and well-defined geometries. The current review mainly spotlights on recent research progress towards biomass derived carbon electrode materials include plant, fruit, vegitable, animal waste, and microorganism based carbon electrode materials for supercapacitor applications. And over view of different synthesis methods for conversion and activation of biomass waste are discussed. Furthermore, summary and future research trends in this filed are projected.
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The aim of this study is to evaluate the effects of biochar on the plant’s growth. A pot experiment was carried out in our study. Rice straw-derived biochar were charred at two heating temperatures (400 °C/800 °C) and two oxygen-limited atmospheres (CO2/N2), respectively. The FESEM/EDS technique (field emission scanning electron microscopy with X-ray energy-dispersive spectroscopy) was used to study soils, biochar and plant samples. FESEM images indicated that the structure of the biochar was highly heterogeneous with larger macropores, which can enhance soil porosity. Fine soil mineral particles blocked the biochar inner pores and channels after returning biochar to soil. EDS analysis indicated that the Al and Fe contents increased on the surface of biochar after their returning, which reduced the toxicity of Al and Fe in the soil. The returning straw directly inhibited the growth of leaf-used lettuce. Four returning biochar all significantly improved leaf-used lettuce growth, and the effects of biochar prepared under 400 °C and a CO2 atmosphere were better than those prepared under 800 °C and a N2 atmosphere. Changes of nitrogen content in the biochar before and after their returning were consistent with the improvement of soil available nitrogen, and plant growth was positively correlated with the nitrogen content of biochar. This study explored the impact of biochar on soil nutrients and revealed the mechanism of biochar returning to the field to promote plant growth. It is of great significance in studying and improving the characteristics of soil nutrients.
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This study aims to improve the quality and quantity of winter wheat by using the potential of combining the use of cold plasma and waste biorefinery products for improving wheat yield. Plasma was applied by a radio frequency (RF) plasma reactor operated with air for 180 s and 50 W. The waste biorefinery products, including pyroligneous acid, biochar, and azolla compost, were used as plant nutrition. The effects of cold plasma treatment and waste biorefinery products were determined by measuring plant photosynthesis, grain yield, and content of chlorophyll, carotenoids, anthocyanin, protein, and starch. The experiment was conducted during the cropping seasons 2016−18 in a randomized complete block design with four replications. The combination of cold plasma and pyroligneous acid increased the grain yield up to 40.0%. The photosynthesis rate was improved up to 39.3%, and total chlorophyll content up to 48.3% in both years. Seed plasma treatment combined with biochar application increased the starch content by 36.8%. Adding azolla compost increased the protein content by 35.4%. Using seed plasma treatment with biochar increased the microbial biomass carbon by 16.0%. The application of plasma and azolla compost increased the microbial biomass nitrogen by 29.0%.
Chapter
The global modern challenges of climate change, natural resources scarcity, waste overproduction, management and processing, etc., need to be examined under the circular economy principles. As such, biochar is considered as an abundant, cost effective, and universal organic amendment widely advantaged by the agriculture sector. Biomass waste constitutes the main feedstock for the production of biochar through thermochemical conversion. Toward this, tomato, a popular food commodity, is widely cultivated and consumed around the world and is examined as a case study for biochar production. The production and reuse of tomato waste biochar is therefore discussed, taking into account its chemical composition (e.g., cellulose and hemicellulose content). The main conditions of biochar production such as the final temperature, residence time, heating rate, flow, etc., are depicted next to the potential activation for improving its physiochemical properties. Toward this effort, the employment of various analytical techniques is necessary (e.g., SEM, EDX, FT-IR, TG, etc.) for biochar quality monitoring. Furthermore, examples of tomato-derived biochar valorization as an organic amendment in agriculture are reviewed. Finally, the chapter is concluded by a life cycle analysis, highlighting the benefits of biochar production from food processing residues.
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Currently, little is known about systematic comparisons of sludge products obtained from different sludge treatment processes in terms of land use. Moreover, it is worth evaluating whether the sludge produced from the co-treatment of industrial wastewater and domestic sewage can be applied to land use. In this study, three sludge products derived from the same municipal sludge—sludge biochar (SSB), dried sludge (DSS), and sludge compost (SSC)—were added to silty loam (SL) at a 20% mass ratio to assess their effects on soil structure, properties, and fertility. Chinese cabbage was planted as a model crop and its growth and physiological state were monitored. The experimental results showed that the water retention of the soil was significantly related to its porosity, and the moisture in the three sludge products-modified soil mainly existed in the form of free water. The addition of three sludge products increased the total porosity of SL. SSC enhanced the water retention of SL by increasing the capillary porosity, and SSB improved the gas permeability of SL by increasing the non-capillary porosity. The three sludge products all increased the content of large particles in the soil and improved the stability of the aggregates of SL. Among them, SSB and DSS had significant effects on improving the stability of the aggregates. Although the addition of the three sludge products improved the fertility of SL, compared with that of DSS and SSC, the addition of SSB made the growth indices of Chinese cabbage the best, indicating that SSB can effectively maintain soil nutrients. The heavy metal test results of Ni showed that SSB had a good stabilizing effect on heavy metals. Therefore, compared with drying and composting, pyrolysis of municipal sludge is more suitable for SL improvement.
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In an ever-growing attempt to reduce the excessive anthropogenic CO2 emissions, several CO2 capture technologies have been developed in recent years. Adsorption using solid carbonaceous materials is one of the many promising examples of these technologies. Carbon-based materials, notably activated carbons, are considered very attractive adsorbents for this purpose given their exceptional thermal stability and excellent adsorption capacities. More importantly, the ability to obtain activated carbons from agricultural wastes and other biomass that are readily available makes them good candidates for several industrial applications ranging from wastewater treatment to CO2 adsorption, among others. Activated carbons from biomass can be prepared using various techniques, resulting in a range of textual properties. They can also be functionalized by adding nitrogen-based groups to their structure that facilitates faster and more efficient CO2 capture. This review provides a detailed overview of the recent work reported in this field, highlighting the different preparation methods and their differences and effects on the textual properties such as pore size, surface area, and adsorption performance in terms of the CO2 adsorption capacity and isosteric heats. The prospect of activated carbon functionalization and its effect on CO2 capture performance is also included. Finally, the review covers some of the pilot-plant scale processes in which these materials have been tested. Some identified gaps in the field have been highlighted, leading to the perspectives for future work.
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Cadmium (Cd), a potent heavy metal, causes a significant reduction in plant growth and its yield by interfering with the plant's mineral nutrition and, primarily, by inducing Cd-induced oxidative damage. Cd mobilization at the soil-root interface is also very important in context of its bioavailability to plants. Therefore, an experiment was carried out to evaluate the mitigating role of iron-enriched biochar (Fe-BC) on Cd accumulation in soil and Cd toxicity in radish plants. Radish seeds were sown in pots, and two levels of Cd (0 and 0.75 mg kg −1) and two levels of Fe-BC (0 and 0.5%) were applied. Cd stress significantly reduced radish fresh and dry biomass production, which was due to high production of malondialdehyde (36%) and increase in cell membrane permeability (twofold) relative to control. Moreover, Cd stress considerably reduced chlorophyll concentrations and uptake of some essential nutrients, such as Ca, K, and Fe. Contrarily, Fe-BC application ameliorated Cd toxicity by triggering the activation of antioxidant enzymes (catalase and ascorbate pe-roxidase), primary and secondary metabolite accumulation (protein and phenolics concentrations), and by improving plant mineral nutrition under Cd treatment, compared with Cd treatment only. The ability of biosorbent material (Fe-BC) to adsorb the Cd ion on its surface and its immobilization from Cd-polluted soil to plant root was determined by using Langmuir and Freundlich isotherm models. Interestingly, Cd concentration was found in soil as diethylenetriamine (DTPA)-extractable soil Cd on radish root, but not reported in radish shoot with Cd+Fe-BC treatment, compared to Cd treatment; suggesting that Fe-BC treatment has a potential to provide extra strength to the root and shoot, and plays an important role in regulation ionic and redox homeostasis under Cd stress.
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Landfill leachate is the liquid formed by the decomposition of waste in the landfill and infiltration of water through that waste. It contains high concentrations of ammonia and organic contaminants (measured in terms of chemical oxygen demand, COD). Biochar, produced from woody residues separated from municipal waste, was used for the reduction of COD of the leachate. The produced biochar was characterized by scanning electron microscopy, Raman spectroscopy, Brunauer–Emmett–Teller surface area analysis and x-ray photoelectron spectroscopy. By following response surface methodology and specifically the Box–Behnken design, the optimum conditions and effects of time, temperature and biochar dosage were determined. It was stated that biochar dosage was the most influential factor, whereas adsorption time and temperature had a lesser effect on the process. The optimum conditions for COD removal from the leachate were the following: treatment time 140 min, temperature 31 °C and biochar dosage of 1.95 g, where a 75.5% COD removal was achieved. At these conditions, the NH4+-N concentration was reduced by 23%. The spent biochar sample was regenerated by successively washing it with HF, ethanol and NaOH, and the regenerated sample achieved COD removal rates of 71%, indicating the potential for multiple uses.
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Knowledge of pesticides fate in tropical soils and how it could be affected by pyrolyzed biomass as amendment is limited. Combining conventional and radiotracer methods, as well as risk assessment tools, the effects of several charred agrowastes on the sorption, persistence, and ecological risk of the herbicides bromacil (BMC) and diuron (DRN) were evaluated in a tropical agricultural soil under laboratory conditions. Pineapple stubble (PS), palm oil fiber (PF), and coffee hull (CH) were charred at 300 (torrefied) and 600 °C (biochar) and applied to the soil at 10 and 20 t ha⁻¹ rates. The sorption coefficients (Koc) in unamended soil for BMC and DRN were 18.4 and 212.1 L kg⁻¹, respectively. The addition of torrefied PS and PF caused a 3 to 4-fold increment in BMC sorption and a 3 to 6-fold change in DRN’s sorption. The only biochar that affected the sorption was PS that increased DRN’s sorption 3.5 times. The application of coffee hull materials had no significant effect. In terms of degradation (half-life, DT50), for unamended soil BMC’s degradation (300 days) was limited compared to DRN (73 days). Alternatively, biodegradation (mineralization half-life time, MT50) was 1278 d for BMC and 538 for DRN. While only PF and CH torrefied increased BMC’s persistence, all the torrefied affected DRN´s persistence. However, despite the observed effects, the predicted ecological risk was not mitigated. Our results highlight the need for scientific evidence on the use of pyrolyzed organic amendments to assess potential benefits and prevent unintended impacts in tropical agroecosystems.
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Biochar is a carbonized biomass that can be used as a soil amendment. However, the exclusive use of biochar may present some limitations, such as the lack of nutrients. Thus, biochar enrichment techniques have made it possible to obtain biochar-based fertilizers (BCFs), with great potential to improve soil fertility. Nevertheless, there is still a lack of information about the description, advantages, and limitations of the methods used for biochar enrichment. This review provides a comprehensive overview of the production methods of enriched biochar and its performance in agriculture as a soil amendment. Studies demonstrate that the application of BCF is more effective in improving soil properties and crop yields than the exclusive application of pure biochar or other fertilizers. The post-pyrolysis method is the most used technique for enriching biochar. Future studies should focus on understanding the mechanisms of the long-term application of BCFs.
Chapter
Both natural and anthropogenic activities have increased heavy metal (HM) contamination in the soil. HM has negative effects on the environment, agricultural productivity and human health through the soil-crop-food chain. The remediation of HM is needed to ensure sustainable crop growth, and maintain the natural ecosystem on unpolluted soils. Many methods for the remediation of polluted soils have been developed, but they are expensive and laborious. Moreover, secondary pollution also affects the soil microbial community. The exploitation of biological and organic amendments, like arbuscular mycorrhiza fungi (AMF) and biochar (BC), are costeffective and environmentally-friendly approaches to plant growth and phytoremediation in polluted soils. The individual role of AMF and/or BC for the remediation of contaminated soils has been reported in the literature, but studies regarding their combined effects are still limited, and there remains a large knowledge gap regarding their connection. This chapter highlights the potential benefits, tolerance and implementation of AMF and BC interactive use in the remediation of polluted soils and plant nutrition in sustainable agriculture.
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Rising wastes due to all round development can emphatically be seen in today’s world. Cutting edge and innovative waste processing technologies such as integration of anaerobic digestion (AD) with thermochemical processes (pyrolysis, gasification and hydrothermal carbonization) are required to decrease the adverse effects of wastes on environment and health, and to enhance the resource efficiency. The coupling of two or more technologies can not only offset the limitations of each other but can also act as a driving force to encourage the circular economy. This paper delivers an evaluation on the viability of integrating AD with thermochemical processes. The versatility of pyrochar (biochar) is examined as a means to promote it for multiple applications. The concept of integrated process design is proposed to pave a way for future research. This article throws light on different areas of waste valorization via coupling of thermal and biological routes to boost it as a possibly sustainable and green technology.
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Excessive land use has a series consequences on the degradation of land function and exerts tremendous pressure on the ecological environment. Farming, mining, and heavy metal pollution have resulted in many negative effects on soils. Biochar has become a hot research topic in the fields of agriculture, environment, and energy as an environmentally friendly soil improver in recent years. The application of biochar for both agricultural and environmental benefits has been studied and reviewed extensively. However, there are limited reviews on the structures of biochar and other biochar applications. This paper provides an overview of recent advances in the effects of the various physicochemical properties of biochar and biochar utilizations including its use as catalyst, soil amendment, water retention, contaminant adsorbent, gas storage, ion exchange, and soil microbial activity. Discussions on biochar on the physical, chemical, biological properties after amendment to the soil and preparation condition. However, the negative effects of biochar in preparations and applications need to be recognized through scientific observation and research. It is anticipated that further research on biochar amendment will increase the understanding on the interactions of biochar with soils, review the negative effects of biochar and it should be alleviated as much as possible.
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Bio-char has the ability to isolate carbon in soils and concurrently improve plant growth and soil quality, high energy density and also it can be used as an adsorbent for water treatment. In the current work, the characteristics of four different types of bio-chars, obtained from slow pyrolysis at 375 °C, produced from hard-, medium-, thin- and paper-shelled walnut residues have been studied. Bio-char properties such as proximate, ultimate analysis, heating values, surface area, pH values, thermal degradation behavior, morphological and crystalline nature and functional characterization using FTIR were determined. The pyrolytic behavior of bio-char is studied using thermogravimetric analysis (TGA) in an oxidizing atmosphere. SEM analysis confirmed morphological change and showed heterogeneous and rough texture structure. Crystalline nature of the bio-chars is established by X-ray powder diffraction (XRD) analysis. The maximum higher heating values (HHV), high fixed carbon content and surface area obtained for walnut shells (WS) samples are found as ~ 18.4 MJ kg−1, >80% and 58 m2/g, respectively. Improvement in HHV and decrease of O/C and H/C ratios lead the bio-char samples to fall into the category of coal and confirmed their hydrophobic, carbonized and aromatized nature. From the Fourier transform infra-red spectroscopy (FTIR), it is observed that there is alteration in functional groups with increase in temperature, and illustrated higher aromaticity. This showed that bio-chars have high potential to be used as solid fuel either for direct combustion or for thermal conversion processes in boilers, kilns and furnace. Further, from surface area and pH analysis of bio-chars, it is found that WS bio-chars have similar characteristics of adsorbents used for water purifications, retention of essential elements in soil and carbon sequestration.
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The ever-increasing rise in the global population coupled with rapid urbanization demands considerable consumption of fossil fuel, food, and water. This in turn leads to energy depletion, greenhouse gas emissions and wet wastes generation (including food waste, animal manure, and sewage sludge). Conversion of the wet wastes to bioenergy and biochar is a promising approach to mitigate wastes, emissions and energy depletion, and simultaneously promotes sustainability and circular economy. In this study, various conversion technologies for transformation of wet wastes to bioenergy and biochar, including anaerobic digestion, gasification, incineration, hydrothermal carbonization, hydrothermal liquefaction, slow and fast pyrolysis, are comprehensively reviewed. The technological challenges impeding the widespread adoption of these wet waste conversion technologies are critically examined. Eventually, the study presents insightful recommendations for the technological advancements and wider acceptance of these processes by establishing a hierarchy of factors dictating their performance. These include: i) life-cycle assessment of these conversion technologies with the consideration of reactor design and catalyst utilization from lab to plant level; ii) process intensification by integrating one or more of the wet waste conversion technologies for improved performance and sustainability; and iii) emerging machine learning modeling is a promising strategy to aid the product characterization, optimization of system design for the specific to the bioenergy or biochar application.
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Climate change such as an increase in temperature, a change in rainfall patterns, an increase in extreme weather events, and an increase in sea level will affect the agricultural sector, including land degradation. Land degradation can take the form of a decrease in soil fertility, so the use of suboptimal land needs to be applied technology that can increase nutrient availability, and at the same time mitigate the impacts of climate change. The research objective was to obtain technology that could increase soil fertility through the substitution of inorganic fertilizers with organic fertilizer from poultry combined with rice husk biochar in wet suboptimal land. The research was conducted in Sungai Rengas Village, Sungai Kakap District, Kubu Raya Regency, West Kalimantan Province, Indonesia. The method used in this study was an experimental method in the form of a completely randomized design (CRD). The treatment in this study was the application of 5 tons of poultry manure per hectare with 5 tons of rice husk biochar per hectare, so that 7 treatment combinations were obtained, namely treatment A, B, C, D, E, F, and G. The results showed that the combination of 5 tonnes/ha of quail manure with 5 tonnes/ha of rice husk biochar had a significant effect on increasing soil fertility and growth of corn plants and can reduce the use of inorganic fertilizers by 25% to 75% of the recommended dosage.
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Sequestration of atmospheric carbon to the soil is a challenging task for the scientific community to mitigate the rising concentration of atmospheric carbon dioxide (CO2). Biochar, due to its aromatic structure and long mean residence time in the soil (more than 100 years) has the potential for long-term carbon sequestration in the soil. The trend obtained from the meagre published literature raised our hopes of achieving the goal of enhancing the productivity of different crops along with environmental sustainability. According to an estimate, global production of black carbon has been reported between 50 and 270 Tg yr–1, with as much as 80% of this remaining as residues in the soil. Biochar decomposition rate is slow in the soil, which indicates that it could be the possible answer to mitigation of elevated atmospheric CO2. It is reported that black carbon can produce significant benefits when applied to agricultural soils in combination with some fertilizers. Increase in crop yield to the tune of 45–250% has been reported by application of biochar along with chemical fertilizers. Soil water retention properties, saturated hydraulic conductivity and nutrients availability increased with the application of biochar. Biochar application reduced CO2 respiration, nitrous oxide and methane production, and decreased dissipation rate of herbicide in the soil.
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A series of short-term greenhouse experiments and laboratory incubations were conducted to evaluate the effect of macadamia (Macadamia integrifolia Maiden & Betche) nut shell (MNS) charcoal with varying volatile matter (VM) content on soil properties and plant growth in two tropical soils. Lettuce (Lactuca sativa L.) and corn (Zen mays L.) were planted in an Andisol amended with four rates of MNS charcoal (0, 5, 10, and 20% w/w) containing relatively high Vie! content (225 g kg(-1)) with and without N fertilizer. Increasing rates of charcoal without N caused a significant decline in both lettuce and corn growth. Corn growth declined significantly with or without N at the two highest charcoal rates. In a third experiment, corn growth also declined significantly in an Ultisol amended with the MNS charcoal (5% w/w) with and without fertilizers. In a fourth experiment, charcoals with high VM (225 g kg(-1)) showed negative effects on plant growth while the low-VM (63.0 g kg(-1)) charcoal supplemented with fertilizer showed a significant positive effect on corn growth. Results from the 2-wk incubation experiments showed that high-VM charcoal caused a significant decline in soil NH(4)(+)-N and a significant increase in soil respiration compared with the soil amended with low-VM charcoal and the soil alone. We propose that phenolic compounds and other products in the high-VM charcoal stimulated microbial growth and immobilization of plant-available N. Our results demonstrate that VM content appears to be an important property of charcoal that has short-term effects on soil N transformations and plant growth. Longer incubation experiments and field trials are needed to further elucidate the role of charcoal VM content on soil processes and plant growth.
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A pot trial was carried out to investigate the effect of biochar produced from greenwaste by pyrolysis on the yield of radish (Raphanus sativus var. Long Scarlet) and the soil quality of an Alfisol. Three rates of biochar (10, 50 and 100 t/ha) with and without additional nitrogen application (100 kg N/ha) were investigated. The soil used in the pot trial was a hardsetting Alfisol (Chromosol) (0-0.1 m) with a long history of cropping. In the absence of N fertiliser, application of biochar to the soil did not increase radish yield even at the highest rate of 100 t/ha. However, a significant biochar x nitrogen fertiliser interaction was observed, in that higher yield increases were observed with increasing rates of biochar application in the presence of N fertiliser, highlighting the role of biochar in improving N fertiliser use efficiency of the plant. For example, additional increase in DM of radish in the presence of N fertiliser varied from 95% in the nil biochar control to 266% in the 100 t/ha biochar-amended soils. A slight but significant reduction in dry matter production of radish was observed when biochar was applied at 10 t/ha but the cause is unclear and requires further investigation. Significant changes in soil quality including increases in pH, organic carbon, and exchangeable cations as well as reduction in tensile strength were observed at higher rates of biochar application (> 50 t/ha). Particularly interesting are the improvements in soil physical properties of this hardsetting soil in terms of reduction in tensile strength and increases in field capacity
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Preventing radioactive pollution is a troublesome problem but an urgent concern worldwide because radioactive substances cause serious health‐related hazards to human being. The adsorption method has been used for many years to concentrate and remove radioactive pollutants; selecting an adequate adsorbent is the key to the success of an adsorption‐based pollution abatement system. In Taiwan, all nuclear power plants use activated carbon as the adsorbent to treat radiation‐contaminated air emission. The activated carbon is entirely imported; its price and manufacturing technology are entirely controlled by international companies. Taiwan is rich in bamboo, which is one of the raw materials for high‐quality activated carbon. Thus, a less costly activated carbon with the same or even better adsorptive capability as the imported adsorbent can be made from bamboo. The objective of this research is to confirm the adsorptive characteristics and efficiency of the activated carbon made of Taiwan native bamboo for removing 131I gas from air in the laboratory. The study was conducted using new activated carbon module assembled for treating 131I‐contaminated air. The laboratory results reveal that the 131I removal efficiency for a single‐pass module is as high as 70%, and the overall efficiency is 100% for four single‐pass modules operated in series. The bamboo charcoal and bamboo activated carbon have suitable functional groups for adsorbing 131I and they have greater adsorption capacities than commercial activated carbons. Main mechanism is for trapping of radioiodine on impregnated charcoal, as a result of surface oxidation. When volatile radioiodine is trapped by potassium iodide‐impregnated bamboo charcoal, the iodo‐compound is first adsorbed on the charcoal surface, and then migrates to iodide ion sites where isotope exchange occurs.
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Natural organic biomass burning creates black carbon which forms a considerable proportion of the soil’s organic carbon. Due to black carbon’s aromatic structure it is recalcitrant and has the potential for long-term carbon sequestration in soil. Soils within the Amazon-basin contain numerous sites where the ‘dark earth of the Indians’ (Terra preta de Indio, or Amazonian Dark Earths (ADE)) exist and are composed of variable quantities of highly stable organic black carbon waste (‘biochar’). The apparent high agronomic fertility of these sites, relative to tropical soils in general, has attracted interest. Biochars can be produced by ‘baking’ organic matter under low oxygen (‘pyrolysis’). The quantities of key mineral elements within these biochars can be directly related to the levels of these components in the feedstock prior to burning. Their incorporation in soils influences soil structure, texture, porosity, particle size distribution and density. The molecular structure of biochars shows a high degree of chemical and microbial stability. A key physical feature of most biochars is their highly porous structure and large surface area. This structure can provide refugia for beneficial soil micro-organisms such as mycorrhizae and bacteria, and influences the binding of important nutritive cations and anions. This binding can enhance the availability of macro-nutrients such as N and P. Other biochar soil changes include alkalisation of soil pH and increases in electrical conductivity (EC) and cation exchange capacity (CEC). Ammonium leaching has been shown to be reduced, along with N2O soil emissions. There may also be reductions in soil mechanical impedance. Terra preta soils contain a higher number of ‘operational taxonomic units’ and have highly distinctive microbial communities relative to neighbouring soils. The potential importance of biochar soil incorporation on mycorrhizal fungi has also been noted with biochar providing a physical niche devoid of fungal grazers. Improvements in soil field capacity have been recorded upon biochar additions. Evidence shows that bioavailability and plant uptake of key nutrients increases in response to biochar application, particularly when in the presence of added nutrients. Depending on the quantity of biochar added to soil significant improvements in plant productivity have been achieved, but these reports derive predominantly from studies in the tropics. As yet there is limited critical analysis of possible agricultural impacts of biochar application in temperate regions, nor on the likelihood of utilising such soils as long-term sites for carbon sequestration. This review aims to determine the extent to which inferences of experience mostly from tropical regions could be extrapolated to temperate soils and to suggest areas requiring study. KeywordsBiochar-Black carbon-Biochar-Carbon sequestration-Charcoal-Climate change
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The application of biochar (biomass-derived black carbon) to soil has been shown to improve crop yields, but the reasons for this are often not clearly demonstrated. Here, we studied the effect of a single application of 0, 8 and 20tha−1 of biochar to a Colombian savanna Oxisol for 4years (2003–2006), under a maize-soybean rotation. Soil sampling to 30cm was carried out after maize harvest in all years but 2005, maize tissue samples were collected and crop biomass was measured at harvest. Maize grain yield did not significantly increase in the first year, but increases in the 20tha−1 plots over the control were 28, 30 and 140% for 2004, 2005 and 2006, respectively. The availability of nutrients such as Ca and Mg was greater with biochar, and crop tissue analyses showed that Ca and Mg were limiting in this system. Soil pH increased, and exchangeable acidity showed a decreasing trend with biochar application. We attribute the greater crop yield and nutrient uptake primarily to the 77–320% greater available Ca and Mg in soil where biochar was applied. KeywordsBiochar-Colombia-Crop yield-Exchangeable acidity-Maize-Oxisol-Tropical savannas
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Biochar can play a key role in nutrient cycling, potentially affecting nitrogen retention when applied to soils. In this project, laboratory experiments were conducted to investigate the adsorption properties of bamboo charcoal (BC) and the influence of BC on nitrogen retention at different soil depths using multi-layered soil columns. Results showed that BC could adsorb ammonium ion predominantly by cation exchange. Ammonium nitrogen (NH4 +-N) concentrations in the leachate of the soil columns showed significant differences at different depths after ammonium chloride application to the columns depending on whether BC had been added. Addition of 0.5% BC to the surface soil layer retarded the downward transport of NH4 +-N in the 70-day experiment, as indicated by measurements made during the first 7days at 10cm, and later, in the experimental period at 20cm. In addition, application of BC reduced overall cumulative losses of NH4 +-N via leaching at 20cm by 15.2%. Data appeared to suggest that BC could be used as a potential nutrient-retaining additive in order to increase the utilization efficiency of chemical fertilizers. Nonetheless, the effect of BC addition on controlling soil nitrogen losses through leaching needs to be further assessed before large-scale applications to agricultural fields are implemented. KeywordsBamboo charcoal-Nitrogen leaching-Nitrogen retention-Ammonium nitrogen-Adsorption
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Interactions between biochar, soil, microbes, and plant roots may occur within a short period of time after application to the soil. The extent, rates, and implications of these interactions, however, are far from understood. This review describes the properties of biochars and suggests possible reactions that may occur after the addition of biochars to soil. These include dissolution–precipitation, adsorption–desorption, acid–base, and redox reactions. Attention is given to reactions occurring within pores, and to interactions with roots, microorganisms, and soil fauna. Examination of biochars (from chicken litter, greenwaste, and paper mill sludges) weathered for 1 and 2 years in an Australian Ferrosol provides evidence for some of the mechanisms described in this review and offers an insight to reactions at a molecular scale. These interactions are biochar- and site-specific. Therefore, suitable experimental trials—combining biochar types and different pedoclimatic conditions—are needed to determine the extent to which these reactions influence the potential of biochar as a soil amendment and tool for carbon sequestration.
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Black Carbon (BC) may significantly affect nutrient retention and play a key role in a wide range of biogeochemical processes in soils, especially for nutrient cycling. Anthrosols from the Brazilian Amazon (ages between 600 and 8700 yr BP) with high contents of biomass derived BC had greater potential cation exchange capacity (CEC measured at pH 7) per unit organic C than adjacent soils with low BC contents. Synchrotron-based near edge X-ray absorption fine structure (NEXAFS) spectroscopy coupled with scanning transmission X-ray microscopy (STXM) techniques explained the source of the higher surface charge of BC compared with non-BC by mapping cross-sectional areas of BC particles with diameters of 10 to 50 mm for C forms. The largest cross-sectional areas consisted of highly aromatic or only slightly oxidized organic C most likely originating from the BC itself with a characteristic peak at 286.1 eV, which could not be found in humic substance extracts, bacteria or fungi. Oxidation significantly increased from the core of BC particles to their surfaces as shown by the ratio of carboxyl-C/aromatic-C. Spotted and non-continuous distribution patterns of highly oxidized C functional groups with distinctly different chemical signatures on BC particle surfaces (peak shift at 286.1 eV to a higher energy of 286.7 eV) indicated that non-BC may be adsorbed on the surfaces of BC particles creating highly oxidized surface. As a consequence of both oxidation of the BC particles themselves and adsorption of organic matter to BC surfaces, the charge density (potential CEC per unit surface area) was greater in BC-rich Anthrosols than adjacent soils. Additionally, a high specific surface area was attributable to the presence of BC, which may contribute to the high CEC found in soils that are rich in BC.
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We conducted laboratory and greenhouse experiments to determine whether charcoal derived from the ponderosa pine/Douglas-fir ecosystem may influence soil solution chemistry and growth of Koeleria macrantha, a perennial grass that thrives after fire. In our first experiment, we incubated forest soils with a factorial combination of Douglas-fir wood charcoal generated at 350°C and extracts of Arctostaphylos uva-ursi with and without the addition of glycine as a labile N source. These results showed that charcoal increased N mineralization and nitrification when glycine was added, but reduced N mineralization and nitrification without the addition of glycine. Charcoal significantly reduced the solution concentration of soluble phenols from litter extracts, but may have contributed bioavailable C to the soil that resulted in N immobilization in the no-glycine trial. In our second experiment, we grew K. macrantha in soil amended with charcoal made at 350°C from ponderosa pine and Douglas-fir bark. Growth of K. macrantha was significantly diminished by both of these charcoal types relative to the control. In our third experiment, we grew K. macrantha in soil amended with six concentrations (0, 0.5, 1, 2, 5, and 10%) of charcoal collected from a wildfire. The data showed increasing growth of K. macrantha with charcoal addition, suggesting some fundamental differences between laboratory-generated charcoal and wildfire-produced charcoal. Furthermore, they suggest a need for a better understanding of how temperature and substrate influence the chemical properties of charcoal.
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Rapid turnover of organic matter leads to a low efficiency of organic fertilizers applied to increase and sequester C in soils of the humid tropics. Charcoal was reported to be responsible for high soil organic matter contents and soil fertility of anthropogenic soils (Terra Preta) found in central Amazonia. Therefore, we reviewed the available information about the physical and chemical properties of charcoal as affected by different combustion procedures, and the effects of its application in agricultural fields on nutrient retention and crop production. Higher nutrient retention and nutrient availability were found after charcoal additions to soil, related to higher exchange capacity, surface area and direct nutrient additions. Higher charring temperatures generally improved exchange properties and surface area of the charcoal. Additionally, charcoal is relatively recalcitrant and can therefore be used as a long-term sink for atmospheric CO, Several aspects of a charcoal management system remain unclear, such as the role of microorganisms in oxidizing charcoal surfaces and releasing nutrients and the possibilities to improve charcoal properties during production under field conditions. Several research needs were identified, such as field testing of charcoal production in tropical agroecosystems, the investigation of surface properties of the carbonized materials in the soil environment, and the evaluation of the agronomic and economic effectiveness of soil management with charcoal.
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Production of biochar (the carbon (C)-rich solid formed by pyrolysis of biomass) and its storage in soils have been suggested as a means of abating climate change by sequestering carbon, while simultaneously providing energy and increasing crop yields. Substantial uncertainties exist, however, regarding the impact, capacity and sustainability of biochar at the global level. In this paper we estimate the maximum sustainable technical potential of biochar to mitigate climate change. Annual net emissions of carbon dioxide (CO(2)), methane and nitrous oxide could be reduced by a maximum of 1.8 Pg CO(2)-C equivalent (CO(2)-C(e)) per year (12% of current anthropogenic CO(2)-C(e) emissions; 1 Pg=1 Gt), and total net emissions over the course of a century by 130 Pg CO(2)-C(e), without endangering food security, habitat or soil conservation. Biochar has a larger climate-change mitigation potential than combustion of the same sustainably procured biomass for bioenergy, except when fertile soils are amended while coal is the fuel being offset.
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Biochar, a solid coproduct from the thermochemical production of bioenergy, has been reported to increase nutrient availability in soils through increased cation retention and decreased phosphate adsorption. The objectives of this study were to determine biochar effects on N and P availability in the presence and absence of external nutrient inputs. Biochar was obtained from hydrothermal pyrolysis of corn cobs at 305 degree C with 20 min of retention time. Biochar was added to two soils at three biochar rates (0, 2, and 20 g/kg) in combination with either two N rates (0 and 100 mg/kg) or two P rates (0 and 20 mg/kg) and incubated for 56 days. Soils were extracted for Mehlich-3 P and KCl-extractable NO3-N and NH4-N at 0, 3, 10, 17, 28, and 56 days after soil amendment. Biochar application at 20 g/kg increased NH4-N concentrations by 1.1 to 4.8 mg/kg during the first 10 days and consistently decreased NO3-N recovery by 5 to 10 mg/kg for the duration of the study. Biochar decreased Mehlich-3 P concentrations in soil by 0.9 mg/kg in the absence of P additions and increased Mehlich-3 P concentrations by 3.3 mg/kg when added with a P source. Furthermore, biochar increased Mehlich-3-extractable P by 5.4 mg/kg in the soil when applied with N fertilizer. Results indicate that biochar-amended soils may need additional N after biochar addition to maximize crop production
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a b s t r a c t A field trial was performed to investigate the effect of biochar at rates of 0, 10 and 40 t ha −1 on rice yield and CH 4 and N 2 O emissions with or without N fertilization in a rice paddy from Tai Lake plain, China. The paddy was cultivated with rice (Oryza sativa L., cv. Wuyunjing 7) under a conventional water regime. Soil emissions of CH 4 and N 2 O were monitored with a closed chamber method throughout the whole rice growing season (WRGS) at 10 day intervals. Biochar amendments of 10 t ha −1 and 40 t ha −1 increased rice yields by 12% and 14% in unfertilized soils, and by 8.8% and 12.1% in soils with N fertilization, respectively. Total soil CH 4 -C emissions were increased by 34% and 41% in soils amended with biochar at 40 t ha −1 compared to the treatments without biochar and with or without N fertilization, respectively. However, total N 2 O emissions were sharply decreased by 40–51% and by 21–28%, respectively in biochar amended soils with or without N fertilization. The emission factor (EF) was reduced from 0.0042 kg N 2 O-N kg −1 N fertilized with no biochar to 0.0013 kg N 2 O-N kg −1 N fertilized with biochar at 40 t ha −1 . The results show that biochar significantly increased rice yields and decreased N 2 O emission, but increased total CH 4 emissions. Summary calculations based on this experiment data set provide a basis for estimating the potential reductions in GHG emissions that may be achieved by incorporating biochar into rice paddy soils in south-eastern China.
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Surface soils were collected in the aquatic–terrestrial ecotone (ATE) of Yongnianwa wetland, downstream of Haihe River basin of North China in June of 2007. Samples were subjected to a total digestion technique before they were analyzed for total concentrations of Cr, Cu, Ni, Pb, and Zn to investigate their pollution levels in the ATE. The contamination index, integrated contamination index, geoaccumulation index, toxic units, and sum of toxic units were adopted to assess the heavy metal contamination levels and ecotoxicity, respectively. The results showed all the selected element concentrations in upland soils of the ecotone were relatively higher than those in the lowland soils. No Cr pollution was observed in all soil samples, but almost all samples were slightly polluted by Cu, Ni, Pb, and Zn except for Site 1. The contamination indexes and geoaccumulation indexes consistently presented no contamination for Site 1 and slight contamination for other sites. The ΣTUs increased from lowland to upland, but the whole level of toxicity in this ecotone was relatively low.