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Cannabis sativa: A Plant Suitable for Phytoremediation and Bioenergy Production
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Phytoremediation has been gaining interest as a sustainable approach for management of the sites contaminated with toxic/hazardous substances. Several plants have been reported in the literature that have the potential for simultaneous execution of phytoremediation and production of useful products like biogas, bioethanol, biodiesel, charcoals, fibres, etc. during the process. Among several plant species, the present chapter has been focused on Cannabis sativa L., a multipurpose annual herbaceous plant species which has wide range of application as seed oil, industrial fibre, food, livestock feed, medicine as well as significant place in recreation, religious and spiritual practices. Cannabis sativa L. has the potential to serve as phytoremedial agent for removal of toxic metals from contaminated sites as well as yields high biomass which could be used for production of bioenergy. The energy yield of Cannabis sativa L. for biofuel and biogas production has been reported comparable to most of the energy crops. The present chapter provides an overview of the phytoremediation capacity of Cannabis sativa L. for resolving environmental issues of contaminated soil along with its potential abilities to generate bioenergy to meet energy demand of future generations.
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... Cannabis sativa L. are annual plants with a vegetation period of about four months and very rapid growth. Cultivated hemp reaches a height of up to 4 m [2]. There are two forms of hemp in Poland and Europe-dioecious and monoecious. ...
... Hemp can be used multi-directionally in biofuel production, energy production by combustion and in biomass production, as well as for pressing oil from the seeds and for biodiesel production. Hemp biomass can be gasified to produce methane, or parts of the stalks can be used to produce bioethanol [2]. ...
In this work, hemp (Cannabis sativa L.) stalks were pretreated with pyrrolidinium acetate [Pyrr][AC] to increase the availability of cellulose for cellulolytic enzymes and thus improve the production of 2G ethanol from reducing sugars. The process was carried out under different temperature and time conditions: The control sample was raw material and deionized water, and the second sample was kept at 21 °C for 24 h. The third sample was kept at 90 °C for 30 min, and the fourth sample was kept at the same temperature for 24 h. For each pretreatment, the extraction of lignin and hemicellulose was determined, as well as the change in biomass composition before and after pretreatment. The stalks of hemp seed contained 41.54% cellulose, 18.08% lignin and 28. 87% hemicellulose. [Pyrr][AC] used to dissolve seed hemp at 90 °C for 24 h was most effective in the extraction of this biopolymer, extracting 3.1% content. After enzymatic hydrolysis, the highest content of reducing sugars was found for samples of hemp stalks that were first pretreated with proton ionic liquid (PIL) and stirred at 90 °C for 24 h. On the other hand, the highest ethanol content (5.6 g/L) after fermentation and yeast viability (56.7%) after 72 h were obtained in samples pretreated at 90 °C and for 24 h.
... Cannabis sativa L. is a crop that regenerates the soil due to its deep root system, which enhances soil aeration and structure. Its phytoremediation properties, including high biomass production and the ability to tolerate and accumulate heavy metals from contaminated soils (Kumar et al., 2017), further contribute to environmental benefits. Additionally, repurposing discarded stems helps mitigate the harmful burning practices typically associated with their production. ...
Fibers are integral to the fashion industry, functioning as essential materials and cultural symbols within a global network of production and consumption. This paper adopts a planetary perspective, exploring fibers as dynamic material flows across human, non-human, living, and technological realms. Using Cannabis sativa L. stems as a case study, we examine their transformation from waste to resource, highlighting their potential role in a circular economy. This includes governance and ethical considerations, cultural histories, and the relationship between fibers and geographical locations where all these elements synergize. Understanding fibers holistically is crucial for fostering a sustainable future in fashion and embracing the inherent nobility of fiber.
... Kenaf, jute, cotton, flax, and hemp are fast-growing crops with the ability to increase their biomass and resistance against HMs [22][23][24][25]. Hemp is well known for its role in the cleaning of contaminated soils owing to its large biomass, long root system, and ability to uptake and accumulate HMs [26,27]. Jute is tolerant to metal stress, and is the second most important source of fiber after cotton [28]. ...
Heavy metal pollution is one of the most devastating abiotic factors, significantly damaging crops and human health. One of the serious problems it causes is a rise in cadmium (Cd) toxicity. Cd is a highly toxic metal with a negative biological role, and it enters plants via the soil–plant system. Cd stress induces a series of disorders in plants’ morphological, physiological, and biochemical processes and initiates the inhibition of seed germination, ultimately resulting in reduced growth. Fiber crops such as kenaf, jute, hemp, cotton, and flax have high industrial importance and often face the issue of Cd toxicity. Various techniques have been introduced to counter the rising threats of Cd toxicity, including reducing Cd content in the soil, mitigating the effects of Cd stress, and genetic improvements in plant tolerance against this stress. For decades, plant breeders have been trying to develop Cd-tolerant fiber crops through the identification and transformation of novel genes. Still, the complex mechanism of Cd tolerance has hindered the progress of genetic breeding. These crops are ideal candidates for the phytoremediation of heavy metals in contaminated soils. Hence, increased Cd uptake, accumulation, and translocation in below-ground parts (roots) and above-ground parts (shoots, leaves, and stems) can help clean agricultural lands for safe use for food crops. Earlier studies indicated that reducing Cd uptake, detoxification, reducing the effects of Cd stress, and developing plant tolerance to these stresses through the identification of novel genes are fruitful approaches. This review aims to highlight the role of some conventional and molecular techniques in reducing the threats of Cd stress in some key fiber crops. Molecular techniques mainly involve QTL mapping and GWAS. However, more focus has been given to the use of transcriptome and TFs analysis to explore the potential genomic regions involved in Cd tolerance in these crops. This review will serve as a source of valuable genetic information on key fiber crops, allowing for further in-depth analyses of Cd tolerance to identify the critical genes for molecular breeding, like genetic engineering and CRISPR/Cas9.
... However, hemp still offers a high potential to be used for phytoremediation purposes not only due to its fast growth in a variety of climates and soil types, its natural resistance to many biotic and abiotic stresses, and its well-known technique of cultivation (Small 2015;Fike 2016;Amaducci et al. 2015;Adesina et al. 2020;Żuk-Gołaszewska and Gołaszewski 2020), but also mostly due to its high aboveground biomass production (Kumar et al. 2017b;Todde et al. 2022). This fact leads to another very important aspect of why hemp could be grown in heavy metal-polluted soil; this is its multipurpose usage and extensive industrial utilization of all plant parts, even when they contain high amounts of heavy metals. ...
Hemp ( Cannabis sativa L.) is a multiuse plant, which has been abundantly studied for phytoremediation purposes in recent years. The majority of experiments were performed in greenhouses with potted plants where hemp showed promising results. Only few studies tested hemp on site in heavy metal–polluted agricultural soil in real environmental conditions and practical assessments of hemp phytoremediation feasibility are lacking. We conducted a comprehensive study using 2 legal industrial hemp varieties (Futura 75 and Tisza) at three differently polluted locations (heavily polluted location, HP; moderately polluted location, MP; and slightly polluted location, SP) in the heavy metal contaminated Celje valley in Slovenia and determined the content of Pb, Zn, and Cd in 5 plant organs/tissues. The yield of each organ/tissue was determined as well to enable us to calculate the phytoremediation potential (PP). On average, plants grown in the HP location accumulated the highest values of all examined elements, followed by plants from the MP location and plants from the SP location, showing that the content of heavy metals in soil influences the accumulation in plants. Accumulation of Pb/Zn/Cd by plant organs/tissues was distributed in the following order: inflorescences (Pb-4.10/Zn-92.8/Cd-0.50 mg/kg) > seeds (Pb-1.79/Zn-92.6/Cd-0.27 mg/kg) > roots (Pb-1.15/Zn-15.0/Cd-0.44 mg/kg) > stem bark (Pb-0.42/Zn-12.4/Cd-0.23 mg/kg) > stem woody core (Pb-0.34/Zn-4.6/Cd-0.15 mg/kg). The only exception was for Cd, where roots accumulated a higher value than seed, yet lower than inflorescences. PP was calculated by multiplying hemp tissue/organ yield by the relative concentrations of heavy metal. The highest PP for Pb and Cd were achieved at the HP location (3.80 and 0.23 g/ha/vegetation period). On the other hand, tissue/organ yield was more important for high PP of Zn, where the SP location reached the highest PP for Zn (148.5 g/ha/vegetation period) due to the highest yields. Only seeds from HP and MP locations accumulated a too high content of Pb; otherwise, all other fibers and seeds can be safely used in the textile and food industry. Results of this study showed that hemp cannot be considered an efficient plant for the phytomanagement of contaminated areas. Nevertheless, hemp cultivation in heavy metal–polluted agricultural soils seems feasible since the majority of tissues/organs were not contaminated and different products can be obtained from various parts of the hemp plant.
Phytoremediation using the robust perennial grass Pennisetum purpureum has been researched as a substitute for traditional treatment approaches for arsenic (As) pollution remediation in the Constructed wetland system. In the current investigation, As absorption and removal through P. purpureum were measured and optimisation was done using Response surface methodology (RSM). To maximise the absorption and removal of As, the Box-Behnken design (BBD) was applied, with 3 key factors (As concentration in treatment sand: 5, 22, and 39 mg kg −1 ; exposure period: 14, 28, and 42 days; aeration rate: 0, 1, and 2 L min −1) in the optimisation. The estimated optimum conditions were 39 mg kg −1 As concentration, 42 days of retention time, and 0.18 L min −1 aeration rate, with an actual biological As accumulation and removal were 5,088.19 mg kg −1 dry weight (DW) and 91.45%, respectively. These amounts were comparable to the amount predicted through RSM 5,245.94 mg As kg −1 DW and 94.29%, respectively. The variance between the test and expected results was 3.10%, demonstrating that RSM could estimate the optimum biological accumulation of As correctly with relatively minimum error. Factors, like As concentration, retention time, and aeration rate, could influence the performance of arsenic phytoremediation through P. purpureum.
Urban development in south-eastern Europe has significant ecological consequences, such as a reduction in native plant diversity, the introduction of non-native species, and increased maintenance costs of urban green spaces. Achieving sustainable urban development requires a thorough understanding of the inventory of native plant species to better manage and conserve these areas. This study analyzed 806 vegetation surveys conducted in rural and urban areas over a 30-year period, identifying 450 plant species from 39 distinct plant communities. Our findings revealed generally low dominance index values in all communities, while Shannon diversity index values were particularly high, indicating rich species diversity despite urbanization pressures. Equality index values varied slightly, reflecting differences in species distributions. Principal component analysis (PCA) identified a substantial group of species with low abundance, which is essential for understanding and managing urban biodiversity. These findings have significant implications for urban planning and plant species conservation. Low dominance and high diversity suggest opportunities to improve urban green spaces by integrating diverse native species. In addition, the ecological and practical value of ruderal species, plants that thrive in disturbed environments, was emphasized, as well as their potential in medicine, phytoremediation, green roof design, and pollination services. Through directly correlating biodiversity indices with urban sustainability goals, our study provides useful insights for urban biodiversity management and the strategic integration of native plant species into urban landscapes.
In the present study, the phytochemical content and the antioxidant activity in the inflorescences of the monoecious hemp cultivar Codimono grown in southern Italy were assessed, and their elicitation was induced by foliar spray application of 50 mg/L and 250 mg/L of chitosan (CHT) at three different molecular weights (low, CHT L; medium, CHT M; high CHT H). The analysis of the phytochemical profile confirmed that cannabinoids were the most abundant class (54.2%), followed by flavonoids (40.3%), tocopherols (2.2%), phenolic acids (1.9%), and carotenoids (1.4%). Cannabinoids were represented almost exclusively by cannabidiol, whereas cannabigerol and Δ⁹-tetrahydrocannabinol were detected at very low levels (the latter was below the legal limit of 0.3%). The most abundant flavonoids were orientin and vitexin, whereas tocopherols were mainly represented by α-tocopherol. The antioxidant activity was found to be positively correlated with flavonoids and tocopherols. Statistical analysis revealed that the CHT treatments significantly affected the phytochemical content and the antioxidant activity of hemp inflorescences. Notably, a significant increase in the total phenolic content (from +36% to +69%), the α-tocopherol (from +45% to +75%) and β+γ-tocopherol (from +35% to +82%) contents, and the ABTS radical scavenging activity (from +12% to +28%) was induced by all the CHT treatments. In addition, treatments with CHT 50 solutions induced an increase in the total flavonoid content (from +12% to +27%), as well as in the vitexin (from +17% to +20%) and orientin (from +20% to +30%) contents. Treatment with CHT 50 L almost always resulted in the greatest increases. Overall, our findings indicated that CHT could be used as a low-cost and environmentally safe elicitor to improve the health benefits and the economic value of hemp inflorescences, thus promoting their employment in the food, pharmaceutical, nutraceutical, and cosmetic supply chains.
Environmental pollution is the result of the indiscriminate discharge of materials into the ecosphere that may reduce the quality of life. Plants have the potential to express environmental stress caused by pollutants, which makes them viable indicators. Moreover, the high sensitivity of some plant taxa towards major environmental pollutants including heavy metals qualifies them as biomonitors and managers. With increasing pollution rates due to globalization and exacerbated by the predictable and unpredictable effects of climate change, there is a need to find sustainable ways to enhance the absorption, degradation, and removal of pollutants using easily and readily available resources like plants. This chapter highlights plant roles in green chemistry as environmental managers, provide examples, and describes their mechanisms of action, limitations, and potential for future developments.
A field study was conducted to evaluate the efficacy of the sunflower plant for phytoremediation of
contaminated soils in the absence and presence of organic soil amendments (compost and vermicompost).
Tested organic amendments significantly influenced the uptake of Pb, Zn and Cd by the sunflower plant. The
compost and vermicompost treatments significantly reduced the heavy metals concentration in the sunflower
seeds, meals and oils, but the effect differed among them. There was a dose effect of the amendments as
well. The 40 t/da compost and 20 t/da treatment led to decreased heavy metal contents in the sunflower oil
below the regulated limits. The possibility of further industrial processing will make sunflower an economically
interesting crop for farmers applying the phytoremediation technology.
Giant reed (Arundo donax) and Miscanthus spp. were tested to evaluate their tolerance and phytoremediation capacity in soils contaminated with heavy metals. Giant reed was tested under 450 and 900 mg Zn kg−1, 300 and 600 mg Cr kg−1, and 450 and 900 mg Pb kg−1 contaminated soils, while the Miscanthus genotypes M. × giganteus, M. sinensis, and M. floridulus were tested on 450 and 900 mg Zn kg−1 contaminated soils, along 2 years. Giant reed biomass production was negatively affected by the contamination; however, yield reduction was only significant under 600 mg Cr kg−1 soil. Zn contamination reduced significantly M. × giganteus production but not M. sinensis or M. floridulus yields. Yet, M. × giganteus was also the most productive. Both grasses can be considered as indicators, once metal concentration in the biomass reflected soil metal concentration. Regarding giant reed experiments, higher modified bioconcentration factors (mBCFs, 0.3–0.6) and translocation factors (TFs, 1.0–1.1) were obtained for Zn, in the contaminated soils, followed by Cr (mBCFs, 0.2–0.4, belowground organs; TFs, 0.2–0.4) and Pb (mBCFs, 0.06–0.07, belowground organs; TFs, 0.2–0.4). Metal accumulation also followed the same pattern Zn > Cr > Pb. Miscanthus genotypes showed different phytoremediation potential facing similar soil conditions. mBCFs (0.3–0.9) and TFs (0.7–1.5) were similar among species, but highest zinc accumulation was observed with M. × giganteus due to the higher biomass production. Giant reed and M. × giganteus can be considered as interesting candidates for Zn phytoextraction, favored by the metal accumulation observed and the high biomass produced. A. donax and Miscanthus genotypes showed to be well suited for phytostabilization of heavy metal contamination as these grasses prevented the leaching of heavy metal and groundwater contamination.
In the UK, the widespread presence of elemental contaminants such as arsenic and nickel in contaminated sites and more widely release of platinum group metals into the biosphere are growing concerns. Phytoremediation has the potential to treat land contaminated with these elements at low cost. An integrated approach combining land remediation with post-process biomass to energy conversion and high value element recovery is proposed to enhance the financial viability of phytoremediation. An analytical review of plant species suitable for the phytoremediation of nickel, Arsenic and platinum group metals is reported. Additionally, a preliminary model is developed to assess the viability of the proposed approach. A feasibility appraisal using Monte Carlo simulation to analyse project risk suggests high biomass yield plant species can significantly increase the confidence of achieving financial return from the project. The order of financial return from recovering elements was found to be: Ni > Pt > As. Crown
Soils and wastes enriched with heavy metals may present ecological and human health risks. A considerable number of mining areas exist in Brazil, where high levels of metals have been found. However, studies of bioaccessibility of metals in soils/tailings from these areas are scarce, despite their potential informational contribution concerning exposure risks of residents near these areas. This study evaluated tailings collected from four sites of a zinc smelting area located in Brazil with aims to: (1) evaluate the presence of metals of potential concern; (2) investigate Cd and Pb bioaccessibility; and (3) determine the desorption kinetics of Cd and Pb. High concentrations of total Cd and Pb (up to 1743 mg Cd kg(-1) and 8675 mg Pb kg(-1)) and great variability were found in the tailings, indicating the importance of adequate planning for their final disposal, in order to avoid contamination in the surrounding environment. Cadmium and Pb bioaccessibility percentages in the intestinal phase were less than 47 and 4 %, respectively, which represents significant fractions not available for absorption in the intestinal tract. However, this material has to be monitored since its bioaccessibility may increase with eventual physicochemical changes, releasing Cd and Pb. Desorption kinetics experiments revealed that Pb in the samples remained in less labile fractions, whereas Cd was found in more labile fractions, which is in accordance with the bioaccessibility results.
Heavy metal contamination coming from different pathways to an agricultural area • Identification of areas of the highest contamination using a zero to ten score • Spatial extrapolation to detect hotspots regarding trace elements • Multivariate statistical analysis to identify contamination sources G R A P H I C A L A B S T R A C T a b s t r a c t Hazard element contamination coming from coal power plants is something obvious, but when this contamination is accompanied by other contamination sources, such as, urban, coal mining and farming activities the study gets complicated. This is the case of an area comprised in the southern part of Santa Catarina state (Brazil) with the largest private power plant generator. After the elemental analysis of 41 agricultural soils collected in an extensive area around the thermoelectric (from 0 to 47 km), the high presence of As, Co, Cr, Cu, Fe, Mn, Mo, Pb, Sb, Sn, Tl, V and Zn was found in some specific areas around the power plant. Nevertheless, as the NWAC (Normalized-and-Weighted Average Concentration) confirmed, only soils from one site were classified as of very high concern due to the presence of potential toxic elements. This site was located within the sedimentation basin of the power plant. The spatial distribution obtained by kriging in combination with the analysis of the data by Principal Component Analysis (PCA) revealed three important hotspots in the area according to soil uses and geographic localization: the thermoelectric, its area of influence due to volatile compound deposition, and the area comprised between two urban areas. Farming practice turn out to be an important factor too for the quantity of hazard element stored in soils.
The assessment of soil quality and characterization of potential risks to the environment and human health can be a very difficult task due to the heterogeneity and complexity of the matrix, the poor understanding about the fate of contaminants in the soil matrix, scarcity of toxicological/ecotoxicological data and variability of guidelines. In urban soils these difficulties are enhanced by the patchy nature of urban areas and the presence of complex mixtures of organic and inorganic contaminants resulting from diffuse pollution caused by urban activities (e.g. traffic, industrial activity, and burning of carbon sources for heating). Yet, several tools are available which may help to assess the risks of soil contamination in a simpler, cost effective and reliable way. Within these tools, a tiered risk assessment (RA) approach, first based on a chemical screening in combination with geostatistical tools, may be very useful in urban areas. However, there is still much to improve and a long way to go in order to obtain a reliable RA, especially in the case of hydrophobic organic compounds such as polycyclic aromatic hydrocarbons (PAHs). This paper aims at proposing a RA framework to assess the environmental and human health risks of PAHs present in urban soils, based on existing models. In addition, a review on ecotoxicological, toxicological, and exposure assessment data was made, as well as of the existing soil quality guidelines for PAHs that can be used in the RA process.
The level, distribution, compositional pattern and possible sources of polycyclic aromatic hydrocarbons (PAHs) in Lanzhou urban soil of Northwest China were investigated in this study. The total level of 22 PAHs ranged from 115 to 12,100µgkg(-1) and that of 16 priority PAHs from 82.4 to 10,900µgkg(-1). Seven carcinogenic PAHs generally accounted for 6.18-57.4% of total 22 PAHs. Compared with data from those reported about urban areas, PAH contamination in Lanzhou urban soils was moderate. Among different functional areas, higher level of PAHs was found along roadsides and in the industrial district (p<0.01), while lower levels were detected in the commercial, park and residential districts. The composition of PAHs was characterized by high molecular weight PAHs (≥4 rings), among which fluoranthene, benz[a]anthracene and phenanthrene were the most dominant components. Correlation analysis suggested that low molecular weight PAHs and high molecular weight PAHs originated from different sources and further corroborated that TOC was an important factor in the accumulation of PAHs in soil. Isomer ratios and principal component analysis indicated that PAHs in urban soil derived primarily from emissions resulting from the combustion of biomass, coal and petroleum products. Toxic equivalent concentrations (BaPeq) of soil PAHs ranged from 6.12 to 1302µgBaPeqkg(-1), with a mean of 138µgBaPeqkg(-1). The results suggested that human exposure to those soils which polluted by high concentrations of PAHs through direct ingestion or inhalation of suspended soil particles probably poses a significant risk to human health from the carcinogenic effects of PAHs.
The present study was planned to delineate the role of antioxidants and different functional groups of Ricinus communis and Brassica juncea in the tolerance mechanisms toward cadmium (Cd) for phytoremediation. Application of Cd caused a reduction in dry biomass of 53.84% and 26.58% in root and 45.33% and 33.84% in shoots of B. juncea and R. communis, respectively. Antioxidant enzymes, namely superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, glutathione reductase and glutathione-S-transferase, and metabolites (proline) increased in both the species due to Cd exposure. The metal caused substantial changes in the functional groups present in the roots and leaves of the plants. A number of new peaks appeared in the Cd-treated plants, which indicate the production of the compounds responsible for the metal tolerance of these plants. R. communis has been found to possess a good antioxidant defense system against Cd stress and may be used for the phytoremediation of metal-contaminated soils in place of edible crops, which enhance the risk of contaminating the food chain. It has been observed that R. communis accumulated 213.39 and 335.68 mg Cd in roots and shoots, respectively, whereas B. juncea accumulated 28.19 and 310.15 mg Cd in the roots and shoots, respectively.