Phytoremediation In-situ Applications: In-situ Applications
Abstract
This book provides in-situ phytoremediation strategies that are particularly well suited for developing nations. Its goal is to promote the use of field-tested phytoremediation methods for removing soil and water pollutants from agricultural, industrial, military, and municipal sources. These strategies include using algae and a variety of aquatic and terrestrial plants. The book subsequently discusses the use of crops and native plants for phytoremediation, and how phytoremediation efforts impact the rhizosphere. After having finished the book, readers will be able to directly adapt the strategies described here for their specific purposes.
... Macrophytes used in phytoremediation of wastewater are usually characterised by high biomass accumulation and growth rates. Macrophyte species exhibiting these traits outside of their natural area are regarded as invasive, having the ability for rapid colonisation (Fletcher et al. 2020). Therefore, there is an important link between the use of aquatic plants in phytoremediation and strategies for the control of invasive plants (Fletcher et al. 2020). ...
... Macrophyte species exhibiting these traits outside of their natural area are regarded as invasive, having the ability for rapid colonisation (Fletcher et al. 2020). Therefore, there is an important link between the use of aquatic plants in phytoremediation and strategies for the control of invasive plants (Fletcher et al. 2020). It is more suitable to utilise these aquatic plants as part of an integrated strategic approach to prevent the spread of the plants while effectively degrading the suspended sediment, removing nutrients and metals and harvesting the biomass for economic benefit (Yan et al. 2016). ...
The objective of this research was to ascertain the best conditions for efficient applications of water lettuce, giant salvinia and water hyacinth in improving the quality of low strength domestic wastewater. Water quality assessment of the wastewater samples before (influent) and after treatment (effluent) with effect to retention times (6, 12 and 24 h) was analysed. The outcome of the study at 6 h retention showed that water lettuce (6.8–7.0 pH, 50.5% colour, 46.7% biochemical oxygen demand (BOD) and 37.8% chemical oxygen demand (COD)), giant salvinia (6.9–7.1 pH, 40.5% colour, 60% BOD and 43.2% COD) and water hyacinth (6.7–6.9 pH, 45.5% colour, 53% BOD and 35.1% COD) reduction values were achieved. At 12 h retention, water lettuce (6.6–7.0 pH, 57.2% colour, 77.1% BOD and 74.6% COD), giant salvinia (6.4–6.8 pH, 81.1% colour, 66.7% BOD and 72.2% COD) and water hyacinth (6.4–6.7 pH, 61.9% colour, 70% BOD and 61.1% COD) reduction values were achieved. Similarly, for 24 h retention, water lettuce (6.6–7.0 pH, 76.7% colour, 53.2% BOD and 70.3% COD), giant salvinia (6.6–7.0 pH, 91.4% colour, 74.7% BOD and 81.0% COD) and water hyacinth (6.4–6.9 pH, 74% colour, 58% BOD and 67.2% COD) reduction values were achieved. These findings indicated that the retention times of 12 and 24 h provided suitable conditions to break down the organic contaminants present in the shallow ponds. HIGHLIGHTS
Determine the ideal conditions for efficient applications of macrophytes in phytoremediation of treated domestic wastewater.;
The reduction rate of pollutants progressively increased, as the retention time and sampling period increased.;
The developed hydroponic ponds provided simple, cheap, and sustainable technology for tertiary treatment of wastewater within a short time.;
Heavy metal(loid)s and radionuclides are released into the environment by natural and anthropogenic activities. These contaminants have toxic effects on living organisms and human health. Therefore, finding a practical solution for eliminating and detoxifying these pollutants is of great importance. Over the past decades, several removal strategies have been proposed to address these environmental issues; however, biological-based methods, as low-cost, eco-friendly, and versatile technologies, have gained much attention among scientists. In this chapter, we discussed various bioremediation strategies including biotransformation, phytoremediation, and biotransformation. In addition, we investigated recent technologies, such as omics applications, nanotechnology, genetically modified plants and microorganisms, and bioreactors as well as their mechanism of interactions with toxic contaminants to better understand the processes involved in biological detoxification. Understanding these biological techniques, their efficiency and the mechanism of interactions would help us find practical solutions for removing such hazardous pollutants from the environment.
To address cadmium pollution in China’s cultivated land, chitosan, inorganic and organic selenium were used to modify rice husk charcoal for cadmium inhibition. Basic physicochemical properties of rice husk carbons were characterized (BET, FTIR, XRD, Zeta potential). Kinetic and isothermal adsorption experiments studied the adsorption of Cd2+ by modified biochar under different pH and dosages. A350 and C350 had pore changes, and B350 had a smoother surface. The polarity and Zeta potential of A350, B350, and C350 differed. B350 and C350’s kinetic adsorption fit the pseudo second order model, A350’s fit both the pseudo first and second order. Their isothermal adsorption fit Langmuir (B350, C350) and Freundlich (A350). Intraparticle diffusion was three-stage with single-layer chemical adsorption. The pH increase raised removal and adsorption of CK350, A350, B350, and C350. The dosage increase hiked removal but cut unit adsorption. A350 had the highest max adsorption (57.845 mg/g). All modifications enhanced Cd2+ adsorption, and the effect could be altered by adjusting pH and dosage.
Innovative and sustainable environmental management strategies are urgently required to address the escalating global pollution crisis. Phytoremediation, which involves using plants to mitigate, remediate, or contain environmental contaminants, is a promising, cost-effective, and environmentally friendly alternative to conventional remediation methods. This review summarizes current research to elucidate the multifaceted roles of plants in pollution mitigation, detailing mechanisms such as phytoextraction, phytostabilization, phytodegradation, and rhizofiltration; we highlight successful case studies that demonstrate practical applications across diverse environments, such as the use of hyperaccumulator plants for heavy metal removal and genetically engineered species for organic pollutant degradation. Furthermore, this review explores recent technological advancements that have enhanced the effectiveness of phytoremediation, such as the integration of nanotechnology and genetic engineering. It also analyzes the economic and social implications of adopting plant-based pollution control strategies, emphasizing their potential for community involvement and socioeconomic benefits. Despite the promising outlook, we acknowledge the inherent challenges and limitations of phytoremediation, including public acceptance and scalability issues. Finally, we identify key opportunities for future research and innovative approaches that could expand the scope and impact of phytotechnologies in pollution mitigation. This comprehensive review underscores the potential of plants as both agents of environmental restoration and essential components of sustainable pollution management systems.
This study investigates the impact of varying biomass levels of Eichhornia crassipes (water hyacinth) and Pistia stratiotes (water lettuce) on the removal efficiency of nutrients, organic matter, and selected heavy metals from paint industry wastewater. The experiment was conducted using different biomass quantities of the aquatic plants to evaluate their phytoremediation capabilities. Changes in physicochemical parameters, nutrients, organic pollutants, and selected heavy metals were monitored over a 14-day period. At the end of week 1, water lettuce (WL) achieved removal efficiencies of 37.16%, 62.94%, and 38.47% for NO₃⁻, PO₄³⁻, and NH₃, respectively. Water hyacinth (WH) achieved removal efficiencies of 45.18%, 61.07%, and 45.86% for NO₃⁻, PO₄³⁻, and NH₃, respectively. Similarly, both plants significantly removed heavy metals, with WH achieving average removal efficiencies of 95.91%, 90.88%, and 67.68% for Cr, Pb, and Cu, respectively. WL achieved the highest average removal efficiencies of 90% and 88.9% for Zn and Cu, respectively. A statistically significant difference was observed among the biomass level treatments and heavy metal removal efficiencies (p < 0.05). The results indicate that both species effectively reduced nutrient, organic pollutant, and heavy metal concentrations, with higher biomass levels showing greater removal efficiencies. WH exhibited slightly better performance in removing all evaluated parameters in the wastewater treatment compared to WL. This study highlights the potential of these aquatic plants for phytoremediation applications in wastewater treatment systems. Optimization of biomass levels and operational conditions could enhance removal efficiencies and make the process more sustainable.
We investigated the individual and combined (CB) performances of four aquatic plant species, Eichhornia crassipes (water hyacinth, WH), Lemna minor (duckweed, DW), Nymphaea (water lily, WLY), and Pistia stratiotes (water lettuce, WL) in removing selected nutrients (PO43-, NO3–, NH3) and heavy metals (Cd, Cr, Cu, Pb, Zn) from well water for a 30-day duration while monitoring changes in the physicochemical properties (pH, salinity, conductivity, total dissolved solid TDS). WLY could not thrive beyond the 10th day, while other plants lasted the whole test period. All macrophytes leached PO43- into the water, showing negative removal efficiencies as follows: WH>CB>WL>WLY>DW. Likewise, WL, DW, and CB leached NO3– into the solution, whereas WH showed no observable difference between the initial and final concentrations, and WLY reduced the initial concentration (13.56 mg/L) by 87.5%. All plants recorded significant NH3 removal except WLY, which raised the concentration from 4.88 to 5.04 mg/L. Individual and combined macrophyte set-ups significantly removed Cr, Cu, Cd, Pb, and Zn. WL was most effective in removing Cr, Cu, and Zn, achieving removal efficiency of 86.8%, 84.56%, and 62.42%, respectively. Also, CB had the highest removal efficiency of 93.08% for Cd and 97.09% for Pb. In conclusion, understanding the nature of water contaminants and physiochemical properties is essential for selecting the appropriate macrophytes, solely or combined, for optimum growth and effective phytoremediation.
The prolonged duration of phytoremediation poses a risk of heavy metal dispersal to the surrounding environment. This study investigated a combined remediation approach for cadmium (Cd)- and arsenic (As)-contaminated soil by integrating phytoremediation with stabilization techniques. Bidens pilosa was utilized as the phytoremediator, and steel slag, pyrolusite, and FeSO4 were employed as stabilizing agents in the pot experiments. Key metrics such as soil moisture content, root length, plant height, and heavy metal concentrations in Bidens pilosa were measured to evaluate the remediation efficacy. Additionally, the bioavailability, leaching toxicity, and chemical forms of Cd and As, along with other soil properties, were analyzed. The results indicated that the optimal restoration effect was achieved by combining steel slag, pyrolusite, and FeSO4 with stabilizers in a ratio of 2:1:10. Additionally, the optimal dosage of these materials was found to be 9% by weight. Mechanistic studies, including heavy metal speciation analysis, X-ray photoelectron spectroscopy (XPS), and microbial community diversity analysis, revealed that the stabilization effects were primarily due to the interactions of anionic and cationic ions, chelation by organic acids secreted by plant roots, and enhanced microbial activity. A cost–benefit analysis demonstrated the technical, economic, and commercial viability of the combined remediation approach.
This review analyzes the main methods for cleaning up oil pollution in natural ecosystems, with a particular focus on the synergy between chemical and microbiological techniques for environmental remediation. While biological methods are a green and inexpensive soil remediation technique, they have a major limitation in their inability to clean up high concentrations of toxic contaminants. The poor performance of chemical methods stems from the high cost of chemicals and concerns over their negative and toxic effects on the environment. Physical methods also have high costs due to energy consumption and the need for additional treatment of gases generated during decontamination, making them ineffective for soil remediation. The main principle of bioremediation is based on microorganisms’ ability to degrade complex organic compounds, such as petroleum. This process is described in this review. This combination of methods allows for a higher level of decontamination of soil and water ecosystems, even against pollutants that are usually resistant to degradation, such as oil derivatives. While existing methods for cleaning oil-contaminated ecosystems are highly effective, they require significant material costs to implement. Additionally, the review discusses how the joint use of current and future biotechnology techniques can lead to the development of an effective set of strategies to protect soil and water systems from oil pollution. The reviewed studies show that a hybrid biotechnological approach is the most effective remediation method. When biological decontamination methods are adopted, the optimized combination of different remediation strategies can overcome the limitations of each technique, allowing efficiencies of even more than 70% to be achieved, given that the choice still depends on the type of contaminant, its concentration, and the properties of the receiving substrate.
Phytoremediation is one of the effective technologies for removing pollutants from the aquatic environment. Toxic compounds such as chlorpyrifos can affect the physiological processes of aquatic plants, causing secondary oxidative stress in plant tissues. Macrophytes, like other organisms inhabiting the contaminated ecosystem, have developed a system of defense mechanisms, thanks to which plants can still exist in their natural ecosystem. Our research is a summary of the previously presented results of the effectiveness of purifying contaminated water with chlorpyrifos in the phytoremediation process and the second type of phytoremediation supported by microorganisms, which intensify the process of removing contaminants from the environment. This research concerned changes in nonenzymatic and enzymatic antioxidants in Canadian seaweed, needle spikerush and water mint caused by chlorpyrifos. The research determines changes in the total concentration of polyphenols, flavonoids and dyes (chlorophyll A, chlorophyll B, anthocyanins and carotenoids) as well as differences in the activity of guaiacol peroxidase and glutathione S-transferase. The analysis of the results showed an increase in the content of polyphenols and flavonoids. The reverse trend was observed in the case of the pigment content. The appearance of chlorpyrifos in the environment caused an increase in the activity of the examined enzymes. The process involving microorganisms that were obtained from places contaminated with pesticide proved to be more effective. This shows the cooperation of species living in an investigated ecosystem.
Global water security is critical for human health, well-being, and economic stability. However, freshwater environments are under increasing anthropogenic pressure and now, more than ever, there is an urgent need for integrated approaches that couple issues of water security and the remediation of degraded aquatic environments. One such strategy is the use of floating treatment wetlands (FTW), which are artificial floating mats that sustain and support the growth of macrophytes capable of removing nutrients from over-enriched waterbodies. In this study, we quantify a range of indicators associated with FTWs, planted with different vegetation community types (i.e., monocultures and polycultures) over the course of a three-year field-scale study. The composition of the two different types of FTWs changed significantly with a convergence in diversity and community composition between the two types of FTWs. Phytoremediation potential of the two FTW communities, in terms of nutrient standing stocks, were also similar but did compare favourably to comparable wild-growing plant communities. There were few substantial differences in invertebrate habitat provision under the FTWs, although the high incidence of predators demonstrated that FTWs can support diverse macroinvertebrate communities. This field-scale study provides important practical insights for environmental managers and demonstrates the potential for enhanced ecosystem service provision from employing nature-based solutions, such as FTWs, in freshwater restoration projects.
Saline ecosystems are often the target of spills and releases of pollutants such as metals, as many industrial companies settle in or around these areas. Metal pollution is a major threat for humans and ecosystems. In line with sustainable development, nature-based solutions and biological tools such as phytoremediation offer eco-friendly and low-cost solutions to remove metals or limit their spread in the environment. Many plant-growth-promoting (PGP) effects are frequently prospected in plant-associated microbes such as the production of auxins, siderophores, or extracellular polymeric substances to enhance phytoremediation. Halophytes are nowadays presented as good phytoremediators for metal-contaminated saline environments such as coastal regions, but little is known about the potential of their associated microbes in the bioaugmentation of this technique. Here, we review the studies that focused on halophytes-associated microbes and their plant-growth-promotion capacities. Moreover, we discuss the limitation and applicability of bioaugmented phytoremediation in saline ecosystems.
The release of inadequately treated urban wastewater is the main cause of environmental pollution of aquatic ecosystems. Among efficient and environmentally friendly technologies to improve the remediation process, those based on microalgae represent an attractive alternative due to the potential of microalgae to remove nitrogen (N) and phosphorus (P) from wastewaters. In this work, microalgae were isolated from the centrate stream of an urban wastewater treatment plant and a native Chlorella-like species was selected for studies on nutrient removal from centrate streams. Comparative experiments were set up using 100% centrate and BG11 synthetic medium, modified with the same N and P as the effluent. Since microalgal growth in 100% effluent was inhibited, cultivation of microalgae was performed by mixing tap-freshwater with centrate at increasing percentages (50%, 60%, 70%, and 80%). While algal biomass and nutrient removal was little affected by the differently diluted effluent, morpho-physiological parameters (FV/FM ratio, carotenoids, chloroplast ultrastructure) showed that cell stress increased with increasing amounts of centrate. However, the production of an algal biomass enriched in carotenoids and P, together with N and P abatement in the effluent, supports promising microalgae applications that combine centrate remediation with the production of compounds of biotechnological interest; for example, for organic agriculture.
Water pollution due to heavy metals has become a serious environmental concern due to their hazardous properties. Since conventional water remediation techniques are generally ineffective and non-environmentally friendly, phytoremediation has gained increasing attention from worldwide researchers and scientists due to its cost-effectiveness and environmental friendliness. Hence, this review first discussed soil and water remediations. Phytoremediation can be divided into five techniques to remove heavy metals from the polluted environment, namely, phytostabilization (phytosequestration), phytodegradation (phytotransformation), phytofiltration (rhizofiltration), phytoextraction (phytoaccumulation), and phytovolatilization. Four common floating aquatic plants (accumulator plants), such as duckweed (Lemna minor), water lettuce (Pistia stratiotes), water hyacinth (Eichhornia crassipes), and watermoss (Salvinia) were discussed in detail due to their great capability in absorbing the metal ions by their roots and further translocating the metal ions to the aerial parts. Furthermore, the parameter studies, such as optimum pH and temperature of the water, exposure duration, initial metal concentration, water salinity, and the addition of chelating agents, were evaluated. The absorption kinetics of the plants was discussed in detail. In short, phytoremediation is a promising green and sustainable water remediation approach. However, further research is necessary to enhance its practicability and performance at large-scale implementation.
The demand for traditional herbal medicines has grown exponentially worldwide in the twenty-first century. Much of this growth is in economically disadvantaged nations seeking sustainable and inexpensive options for treating endemic and emerging epidemic diseases. In wealthy nations, much of increased desire for medicinal plants is for the formulation of cosmetics and nutraceuticals. Research studies for identifying and confirming the effectiveness of medical plants is globally competitive. However, having an arsenal of effective medicinal plants is impractical without research that investigates the profitable cultivation of indigenous and non-native medicinal plants. Much of the medicinal plant cultivation research investigates the impacts of environmental stress factors on plant development and growth, leading to the discovery of physiological mechanisms that protect plants from unfavorable environmental conditions. Besides benefiting the plant, these mechanisms make the plant a candidate for phytoremediation, a viable option for removing pollutants from contaminated soil and water. The physiological mechanisms that contribute to phytoremediation are involved in extracting, immobilizing, or removing salts, metals, organic compounds and radionuclides from soil and water. In medicinal plants phytoremediation properties have the potential of precluding the safe use of the plant. In contrast, certain properties can allow the safe use of the plants for human consumption while removing contaminants from soil or water.
This research investigated four different species of aquatic macrophytes with natural occurrence in an urban environment highly anthropized in Southern Brazil. The aim of the research was to compare the phytoremediation potential among the species E. anagallis, H. grumosa, H. ranunculoides, and S. montevidensis through Pearson´s correlation analysis and cluster analysis, using the heavy metal content identified through HNO3 - HClO4 and phytoremediation indexes. The results highlighted the bioconcentration factor (BCF) of H. ranunculoides, with outstanding results for Cu BCF = 667.09, Zn BCF = 149.93, Cd BCF = 26.85, Cr BCF = 31.77, Ni BCF = 35.47, and Pb BCF= 126.29. Additionally, H. grumosa and S. montevidensis were also highlighted, considering the potential phytoremoval (g ha−1). Therefore, this study demonstrates the tolerance and potential for removal of heavy metals Cu, Cr, Cd, Pb, Ni, and Zn by the evaluated aquatic macrophyte species and elucidates the outstanding potential of application in phytoremediation purposes.
Contaminants of emerging concern (CECs) are primarily anthropogenic compounds found in water at trace concentrations and mostly still ignored. Pharmaceuticals and personal care products (PPCPs) are two popular categories of CECs. PPCPs are persistent in the environment and capable of disrupting the physiology of target receptors. PPCPs are reported to be overused daily and exposed to aquatic environment via multiple routes, including municipal and industrial effluent. Nevertheless, there is a lack of a comprehensive summary of PPCPs removal techniques, particularly in wastewater treatment plants (WWTPs). While WWTPs are inefficient at removing PPCPs, they serve as primary barriers to the spread of CECs. This paper reviews and highlights the conventional treatment technologies involved for PPCPs removal in WWTPs as well as comparison with phytotechnology in the wastewater treatment field to combat the disconcerting occurrence of PPCPs. Operating parameters in applying phytotechnology, including retention time and aeration requirement as well as major challenges for phytoremediation of PPCPs are evaluated. Fate of PPCPs (focused on ibuprofen and paracetamol) are discussed in detail during treatment using constructed wetland. The results validated concerns regarding the prevalence of PPCPs and the good potential of using constructed wetland as tertiary treatment in WWTP to avoid further spreading of PPCPs to the environment.
The effects of soil selenium (Se) application on the enrichment and human exposure risk of heavy metals in the jute (Corchorus capsularis L.) leaf have attracted extensive attention. The jute was planted with or without soil Se addition for 265 days. The jute leaf was harvested seven times during the experiment to determine the content of lead (Pb), cadmium (Cd), and Se. The results showed that the enrichment ability ranked Cd > Se > Pb. Cd in the jute leaf exceeded the average pollutant limit in GB2762-2017 by 1.37 times without Se application. The Se application is conducive to an increase of Se by 88.11–202.79%, contrarily reducing Cd by 35.40–38.32% and Pb by 9.58–26.57%. In general, the risk quotients (HQ) of Cd and Pb were decreased and less than 1 with Se treatment. Thus, the human exposure risk of Cd and Pb is negligible when ingesting the jute leaf via diet. It is suggested that Se can be applied to inhibit the enrichment of Cd and Pb in the jute production process to reduce the potential exposure risk of Cd and Pb to the human body and increase economic and nutritional values by raising Se levels in the jute leaf.
This study was conducted to assess the phytoremediation potential of Pistia stratiotes for post-treatment of Ni(II) and Cr(III)-containing industrial wastewater effluents in mono (synthetic wastewater) and bimetallic systems (real wastewater). Differences were seen in metal uptake, growth performance, and metal accumulation of the plants. In the monometallic system, the highest removal efficiency was calculated as 77.50% for Cr(III) and 70.79% for Ni(II) at 5 mg L-1 concentration. At 1.25 mg L-1 concentration, the bioconcentration factor of P. stratiotes was calculated as 734.2 for Ni(II) and 799.0 for Cr(III). To assess the effects of metal stress on plants, photosynthetic pigments and percent growth rates were also investigated. The percent growth rate increased from 38.22 to 81.74% for Ni and decreased from 87.53 to 43.18% for Cr(III) when the metal concentrations increased from 1.25 to 5 mg L-1. Toxicity symptoms were less severe in plants exposed to low Ni concentrations. The greatest reduction in chlorophyll was observed at 5 mg L-1 Ni concentration. P. stratiotes showed better performance in the monometallic system. It was concluded based on present findings that P. stratiotes could potentially be used for the post-treatment of wastewaters containing Ni and Cr.Novelty Statement Previous phytoremediation studies were mostly conducted only in either mono- or multi-metallic systems. In this study, mono- and bimetallic systems were assessed together and the feasibility of research findings on a large scale was investigated in detail. Present findings may also aid in the development of phyto-remedial strategies and the identification of Ni and Cr toxicity in macrophytes. Pistia stratiotes are already known for its incredible potential in removing metals and other contaminants from wastewater effluents. However, most studies only present data regarding the plant performance in laboratory studies (synthetic wastewater), while this study provides some important additional information on natural effluent conditions, which transform the presented data more interesting from a practical point of view.
Hemp is a crop that in recent years has received renewed attention and been cultivated in numerous countries after having been abandoned by many during the twentieth century. This ‘rebirth’ is due to numerous factors: its favorable agronomical characteristics, its image of being a sustainable crop, and the plasticity of the products it can provide. However, due to its absence for a long time, there is a lack of expert knowledge on cultivating hemp. There is a lack of scientific knowledge regarding the specificities of its biology, and the strong interaction between genotype and environment remains a limiting factor of hemp cultivation, affecting both the yield and quality of the biomass produced. In this chapter, we have discussed the ins and outs of the cultivation of hemp through a scientific prism to address the principal factors, environmental and genotypic, that drive the agronomical characteristics of a hemp crop. Thereafter, we have focussed on the best crop management practices for optimizing hemp cultivation in terms of yield and quality parameters of the different fractions of the biomass that hemp can provide.KeywordsAgronomyCrop managementCultivationEcophysiologyIndustrial hemp
Some African countries have decriminalized cannabis production for medicinal purposes. This has resulted in the commercial cultivation of the once illegal crop from hidden areas to either indoor or outdoor gardens. Cannabis health and socio-economic effects have been widely researched while ignoring its environmental impacts on commercial-scale cultivation. The extensive production methods have both negative and positive impacts on the environment. It was established that though cannabis production has been legalized in a few African countries and thus grown extensively, it is still illegal in most countries and cultivated in hidden fields in forests and other public lands. Indoor cannabis cultivation involves manipulating light, humidity, temperature, and other factors to optimal levels. Cannabis cultivation has beneficial effects (soil improvement, bio-economy development, soil moisture maintenance, control of weeds emergence, organic matter accumulation) and adverse effects (loss and fragmentation of habitats, grading and burying of streams; sedimentation, eutrophication, water contamination, and greenhouse gas emissions) on the environment. Cannabis is a high-value crop that can improve national economies through exports and the livelihoods of individual farmers at the local level, despite the adverse impacts it may have on the environment. Most studies on the environmental effects of cannabis cultivation have been conducted in Europe and North America. There is thus still a gap in this aspect in Africa. Given the double-edged effects of cannabis cultivation, it is pertinent that scientists address the environmental effects of cannabis cultivation in Africa, and design strategies to minimize the risks associated with its cultivation, and inform the development of regulations for the growing cannabis industry in Africa. This review focuses on cultivation methods, physiological factors for growth, and the effects of cannabis growing on the environment. Also, the review deals with how to increase the yields and quality of different varieties of cannabis.KeywordsAfricaCultivationCannabisEnvironment impactPhysiological factors
Soils contaminated by potentially toxic elements (PTEs) as a result of anthropogenic activities such as mining are a problem due to the adverse effects on human and environmental health, making it necessary to seek sustainable strategies to remediate contaminated areas. The objective of this study was to evaluate the species Clidemia sericea D. Don for the phytoremediation of soils contaminated with PTEs (Hg, Pb, and Cd) from gold mining activities. The study was conducted for three months, with soils from a gold mining area in northern Colombia, and seeds of C. sericea, under a completely randomized experimental design with one factor (concentration of PTEs in soil) and four levels (control (T0), low (T1), medium (T2), and high (T3)), each treatment in triplicate, for a total of twelve experimental units. Phytotoxic effects on plants, bioconcentration (BCF), and translocation (TF) factors were determined. The results obtained for the tissues differed in order of metal accumulation, with the root showing the highest concentration of metals. The highest values of bioconcentration (BCF > 1) were presented for Hg at T3 and Cd in the four treatments; and of translocation (TF > 1) for Hg and Pb at T0 and T1; however, for Pb, the TF indicates that it is transferable, but it is not considered for phytoextraction. Thus, C. sericea demonstrated its potential as a phytostabilizer of Hg and Cd in mining soils, strengthening as a wild species with results of resistance to the stress of the PTEs evaluated, presenting similar behavior and little phytotoxic affectation on the growth and development of each of the plants in the different treatments.
A novel thickening agent from wild taro corms was investigated in the preparation of the printing paste for the screen-printing of silk fabric with acid dye. The concentrations of thickening agent, acid dyestuff, and citric acid and steaming fixation time were explored. Printed silk fabric quality was evaluated by determining different parameters: color values (L*, a*, b*), color strength (K/S), color fastness, and physical properties, whereas print paste quality was evaluated by measuring the viscosity. The results revealed that the printing paste, comprising the thickening agent prepared from the modified starch of wild taro corms, can be applied for printing silk fabric using acid dye. The fastness properties of the printed samples were found to be fair to good. The printed fabric also had decreased tensile and tear strength compared to the original fabric. An increase in stiffness (bending length) of printed silk fabric also occurred. The overall study showed that using the new proposed thickening agent was confirmed at the semi-industrial scale.
Similar to other organisms, plants establish interactions with a variety of microorganisms in their natural environment. The plant microbiome occupies the host plant’s tissues, either internally or on its surfaces, showing interactions that can assist in its growth, development, and adaptation to face environmental stresses. The advance of metagenomics and metatranscriptomics approaches has strongly driven the study and recognition of plant microbiome impacts. Research in this regard provides comprehensive information about the taxonomic and functional aspects of microbial plant communities, contributing to a better understanding of their dynamics. Evidence of the plant microbiome’s functional potential has boosted its exploitation to develop more ecological and sustainable agricultural practices that impact human health. Although microbial inoculants’ development and use are promising to revolutionize crop production, interdisciplinary studies are needed to identify new candidates and promote effective practical applications. On the other hand, there are challenges in understanding and analyzing complex data generated within a plant microbiome project’s scope. This review presents aspects about the complex structuring and assembly of the microbiome in the host plant’s tissues, metagenomics, and metatranscriptomics approaches for its understanding, covering descriptions of recent studies concerning metagenomics to characterize the microbiome of non-model plants under different aspects. Studies involving bio-inoculants, isolated from plant microbial communities, capable of assisting in crops’ productivity, are also reviewed.
To solve ecological and toxicological issues related to some synthetic dyestuffs, the potential application of a new thickening agent from wild taro corms and natural indigo dye in the screen printing process of woven cotton and knitted fabrics was investigated in this study. For this purpose, effects of the dye, thickening agent, thiourea dioxide, and sodium hydroxide concentrations were varied and investigated with respect to the color yield, fastness, and physical properties. Results revealed that the printing paste comprising the thickening agent prepared from the modified starch of wild taro corms can be applied for the printing of cotton fabric using natural indigo dye. The colorfastness to washing, water, and perspiration of the printed samples was found to be good to very good, whereas the colorfastness to light and rubbing was mostly at good and fair, respectively. The printed fabric also had increased tensile strength, tear strength, bursting strength, and stiffness compared to the original fabric.
Bioaugmentation in the form of artificial mycorrhization of plant roots and bacterial inoculation has been successfully implemented in several fields including soil remediation or activated sludge treatment. Likewise, bioaugmentation seems a promising approach to improve the functioning of treatment wetlands, considering that natural mycorrhization has been detected in treatment wetlands and that bacteria are the main driver of contaminant degradation processes. However, to date, full scale implementation seems to be rare. This review synthesizes the effects of bioaugmentation on different types of treatment wetlands, to a large extent performed on a microcosm (< 0.5 m²) or mesocosm scale (0.51 to 5 m²). While inoculation with arbuscular mycorrhizal fungi tended to show a positive effect on the growth of some wetland plants (e.g. Phragmites australis), the mechanisms underlying such positive effects are not well understood and the effects of upscaling to full scale treatment wetlands remain unknown. Bacterial inoculation tended to promote plant growth and pollutant degradation, but longer term data is required.
Heavy metals (HMs) in soil, air, and water environments effect human health. These HMs cannot be degraded in soil and they can only be transformed from one state to another. Food and energy resources such as coal, oil, petrol, etc. are gradually diminishing due to ever increasing demand and consumption, world faces crisis. There is an urgent need to address these problems by reclaiming the waste/polluted land for food and energy production. Various physicochemical remediation strategies are being proposed, developed, and tested but they are all very costly and only applicable to small contaminated sites. During the past two decades or so, plant-based phytoremediation technology is rapidly evolving as a promising new tool to address the issue with the potential to remediate HM contaminated soils in a sustainable manner. Plants, labeled as phyto-tolerant or phyto-accumulators, surviving on such contaminated soils reduce the toxicity by preventing their translocation or destroying the contaminants by sequestration by synthesizing thiol-containing HM-binding proteins (nano-molecules) and peptides (phytochelators or PCs) which modulate internal levels of metal concentration between deficient and toxic levels. But such plants are very slow growing, producing small biomass, and the process taking a long time to effectively remediate such soils. To overcome limitations of using such plants, plants capable of high biomass production and tolerating multiple HMs, such as non-food bioenergy crops (Vetiver and Hamp), are required. This plant-based remediation strategy can further be enhanced with the use of both plants and rhizosphere microbes like arbuscular mycorrhizal fungi (AMF) and plant growth-promoting bacteria. The combination of three components, i.e. high biomass producing plant, soil, and its rhizosphere harboring plant growth-promoting rhizobial (PGPR) microbiota, particularly AMF, will further improve the process of nano-phytoremediation of HM contaminated soils. This mini review focuses on how phytoremediation, nanotechnology, AMF and PGPR technologies can be merged together to form an integrated nano-mycorrhizo-phytoremediation (NMPR) strategy which synergistically achieve the goal of remediation of soil contaminants and improve the phytoremediation performance of bioenergy plants grown on HM polluted soils. This review also identifies the urgent need to conduct field-scale application of this strategy and use it as potential tool for reestablishing plant cover and population diversity during restoration of derelict land post-industrial/mining activities.
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