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Pollution of air, water, and soil is a pressing global issue with significant implications for environmental and human health. This research paper explores the various methods and technologies employed for the monitoring and remediation of pollutants in these three crucial environmental compartments. It discusses the challenges associated with pollution, the importance of effective monitoring, and the diverse strategies available for pollutant remediation. By synthesizing current research and technologies, this paper aims to provide insights into the state-of-the-art approaches for addressing pollution and promoting environmental sustainability [ABSTRACT FROM AUTHOR]

Cadmium-contaminated soil significantly threatens global food security and human health. This scenario gives rise to significant worries regarding widespread environmental pollution. Biochar and arbuscular mycorrhizal fungi (AMF) can effectively immobilize cadmium in the soil in an environmentally friendly way. Existing studies have separately focused on the feasibility of each in remediating polluted soil. However, their association during the remediation of cadmium-polluted soils remains unclear. This review paper aims to elucidate the potential of biochar, in conjunction with AMF, as a strategy to remediate soil contaminated with cadmium. This paper comprehensively analyzes the current understanding of the processes in cadmium immobilization in the soil environment by examining the synergistic interactions between biochar and AMF. Key factors influencing the efficacy of this approach, such as biochar properties, AMF species, and soil conditions, are discussed. The influences of biochar–AMF interactions on plant growth, nutrient uptake, and overall ecosystem health in cadmium-contaminated environments are highlighted. This review indicates that combining biochar and AMF can improve cadmium immobilization. The presence of AMF in the soil can create numerous binding sites on biochar for cadmium ions, effectively immobilizing them in the soil. Insights from this review contribute to a deeper understanding of sustainable and eco-friendly approaches to remediate cadmium-contaminated soils, offering potential applications in agriculture and environmental management. [ABSTRACT FROM AUTHOR]

Recent advances in the microbial degradation of persistent organic pollutants have the potential to mitigate the damage caused by anthropogenic activities that are harmfully impacting agriculture soil ecosystems and human health. In this paper, we summarize the pollution characteristics of neonicotinoid insecticides (NNIs) in agricultural fields in China and other countries and then discuss the existing research on screening for NNI-degrading functional bacterial strains, their degradation processes, the construction of microbial consortia, and strategies for their application. We explore the current needs and solutions for improving the microbial remediation rate of NNI-contaminated soil and how these solutions are being developed and applied. We highlight several scientific and technological advances in soil microbiome engineering, including the construction of microbial consortia with a broad spectrum of NNI degradation and microbial immobilization to improve competition with indigenous microorganisms through the provision of a microenvironment and niche suitable for NNI-degrading bacteria. This paper highlights the need for an interdisciplinary approach to improving the degradation capacity and in situ survival of NNI-degrading strains/microbial consortia to facilitate the remediation of NNI-contaminated soil using strains with a broad spectrum and high efficiency in NNI degradation. [ABSTRACT FROM AUTHOR]

A number of geochemical and epidemiological studies verified that the Lavrion urban and suburban area is highly contaminated and has affected to a variable degree the health of the inhabitants, presented in the first part of review on the Lavrion 'sagas'. In the second part of this review, emphasis is given to the challenge environmental scientists faced in communicating the scientific results to environmental managers and the public and state officials in order for them to understand the benefits of prioritising public health over wealth. Imminent remediation actions have been developed and proposed in order to secure a healthier life for the local population. The proposed integrated environmental management scheme was based on the findings of hazard and health risk assessment. The aim was not only to remediate the contaminated land, but also to inform the local population and authorities regarding the environmental hazards that they were facing, and the necessary safety measures that should be taken. However, the proposed lifestyle changes were viewed with scepticism from all stakeholders. This paper seeks to provide some answers to questions related to the obstacles that have prevented the implementation of the proposed remediation plan on a large scale by reporting on risk perception and response to scientific evidence by the affected community in Lavrion. It also underlines the significant role of SEGH in linking applied environmental research with the public. [ABSTRACT FROM AUTHOR]

Recent advances in the microbial degradation of persistent organic pollutants have the potential to mitigate the damage caused by anthropogenic activities that are harmfully impacting agriculture soil ecosystems and human health. In this paper, we summarize the pollution characteristics of neonicotinoid insecticides (NNIs) in agricultural fields in China and other countries and then discuss the existing research on screening for NNI-degrading functional bacterial strains, their degradation processes, the construction of microbial consortia, and strategies for their application. We explore the current needs and solutions for improving the microbial remediation rate of NNI-contaminated soil and how these solutions are being developed and applied. We highlight several scientific and technological advances in soil microbiome engineering, including the construction of microbial consortia with a broad spectrum of NNI degradation and microbial immobilization to improve competition with indigenous microorganisms through the provision of a microenvironment and niche suitable for NNI-degrading bacteria. This paper highlights the need for an interdisciplinary approach to improving the degradation capacity and in situ survival of NNI-degrading strains/microbial consortia to facilitate the remediation of NNI-contaminated soil using strains with a broad spectrum and high efficiency in NNI degradation.

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Contamination by heavy metals is a significant issue worldwide. In recent decades, soil heavy metals pollutants in China had adverse impacts on soil quality and threatened food security and human health. Anthropogenic inputs mainly generate heavy metal contamination in China. In this review, the approaches were used in these investigations, focusing on geochemical strategies and metal isotope methods, particularly useful for determining the pathway of mining and smelting derived pollution in the soil. Our findings indicate that heavy metal distribution substantially impacts topsoils around mining and smelting sites, which release massive amounts of heavy metals into the environment. Furthermore, heavy metal contamination and related hazards posed by Pb, Cd, As, and Hg are more severe to plants, soil organisms, and humans. It's worth observing that kids are particularly vulnerable to Pb toxicity. And this review also provides novel approaches to control and reduce the impacts of heavy metal pollution. Hydrometallurgy offers a potential method for extracting metals and removing potentially harmful heavy metals from waste to reduce pollution. However, environmentally friendly remediation of contaminated sites is a significant challenge. This paper also evaluates current technological advancements in the remediation of polluted soil, such as stabilization/solidification, natural attenuation, electrokinetic remediation, soil washing, and phytoremediation. The ability of biological approaches, especially phytoremediation, is cost-effective and favorable to the environment. [ABSTRACT FROM AUTHOR]

In situ chemical oxidation (ISCO) is a popular remediation technique for hydrocarbon-contaminated soil and groundwater. A range of oxidising agents and activators are available for ISCO; however, selection is usually based on contaminant destruction which is time-consuming and impacted by sample heterogeneity based on 1–10 g sample contaminant analysis. In this paper, we demonstrate the use of an automated respirometer, measuring CO2 production, as a rapid and reliable approach for activator type and concentration selection. The approach is demonstrated based on tests in matrices of different types (loam soil and sand). In both matrices, CO2 production was significantly increased following sodium persulphate (SPS) oxidation with iron activation in a concentration-dependant manner. Alkaline activation led to no increased CO2 production compared to SPS addition without activation. The approach will provide greater confidence in treatability testing and reagent efficiency in ISCO projects. [ABSTRACT FROM AUTHOR]

Cadmium-contaminated soil significantly threatens global food security and human health. This scenario gives rise to significant worries regarding widespread environmental pollution. Biochar and arbuscular mycorrhizal fungi (AMF) can effectively immobilize cadmium in the soil in an environmentally friendly way. Existing studies have separately focused on the feasibility of each in remediating polluted soil. However, their association during the remediation of cadmium-polluted soils remains unclear. This review paper aims to elucidate the potential of biochar, in conjunction with AMF, as a strategy to remediate soil contaminated with cadmium. This paper comprehensively analyzes the current understanding of the processes in cadmium immobilization in the soil environment by examining the synergistic interactions between biochar and AMF. Key factors influencing the efficacy of this approach, such as biochar properties, AMF species, and soil conditions, are discussed. The influences of biochar–AMF interactions on plant growth, nutrient uptake, and overall ecosystem health in cadmium-contaminated environments are highlighted. This review indicates that combining biochar and AMF can improve cadmium immobilization. The presence of AMF in the soil can create numerous binding sites on biochar for cadmium ions, effectively immobilizing them in the soil. Insights from this review contribute to a deeper understanding of sustainable and eco-friendly approaches to remediate cadmium-contaminated soils, offering potential applications in agriculture and environmental management.

Combined with the existing research, the research progress of biochar remediation of heavy metal pollution is reviewed. This paper focuses on the mechanism of biochar immobilization of heavy metals in soil, the effect of biochar on the absorption of heavy metals by plants, the research results of the application of biochar in field engineering, and the risks and shortcomings o£ biochar as a soil improver. Finally, it is hoped that on the premise of meeting safe production, the popularization of biochar should be promoted in agricultural production, rather than limited to scientific research. Start the life cycle assessment of biochar and establish a biochar life cycle database to provide a comprehensive and effective scientific basis for the future use of biochar. [ABSTRACT FROM AUTHOR]

[Objectives] This paper was aimed to study the remediation effects of phosphate-solubilizing fungi and bone char in different soils. [Methods] Three different types of lead-contaminated soils (neutral yellow brown soil, alkaline sand soil and acidic red soil)were mixed with the bone char sintered at different temperatures. We measured the contents of phosphorus and lead, and the remediation differences of different soils. The Pb bioavailability of lead-contaminated soil was then determined by planting non-heading Chinese cabbage. The application potential of compound remediation materials was confirmed by adding compound remediation agents to the soil with the best remediation effect. [Results] The bone char had the best effect of promoting the release of phosphorus in yellow brown soil, and the available phosphorus content was 64 times higher than that of the control, showing a high potential of lead remediation. The pH of yellow brown soil was neutral, and the available P in the soil would not be fixed by Ca, Fe, Al, etc., thus increasing the probability of its reaction with Pb. When bone char was solely used, the material treated at 200-300 ℃ had qualified remediation effect. We planted non-heading Chinese cabbage to verify the bioavailability of lead in yellow brown soil after bone char application. It was observed that addition of a certain proportion of bone char to yellow brown soil (the initial mass ratio of bone char to lead was over 0.5:1) could not only increase the absorption of phosphorus by 2.0 to 3.5 times, but also reduce the absorption of lead by non-heading Chinese cabbage(content of lead in pakchoi leaves was reduced by 70% to 80% compared with blank treatment). A composite of bone char and Aspergillus niger was further applied to yellow brown soil, and the effective lead was reduced to 14.36 mg·kg-1. In particular, the growth of the A. niger proved the remediation potential of the composite. [Conclusions] The composite of bone char and A. niger was suitable for lead remediation in neutral soils, and the suitable heating temperature for preparing bone char was 200-300 ℃. [ABSTRACT FROM AUTHOR]

As a result of urban transformation activities, natural disasters, regional and global wars, billions of tonnes of waste concrete occur. Therefore, the remediation process of waste concrete is one of the critical research topics of recent years. The sustainability concept provides a primary bridge between the demand for natural concrete material and the remediation process of waste concrete. Recycled aggregate and recycled concrete aggregate, which may be named sustainable materials, are obtained by the recycling process of waste concrete. Many experimental and numerical studies have been conducted in recent years to show that this sustainable material is an alternative product to natural aggregate. In this study, a comprehensive numerical simulation of foundation beams resting on soils incorporating conventional and sustainable materials has been performed. The foundation beams considered include some with conventional concrete properties and some with sustainable concrete properties. Additionally, the material conditions of soils are assessed, using six different mixed recycled aggregates as filling material. Based on the numerical simulation, the deflection, rotation, bending moment, shear force and spring force capacities of conventional and sustainable foundation beams resting on soils exhibited slightly different behaviour depending on the recycled concrete aggregate and mixed recycled aggregate ratios. Finally, comparing the numerical simulation results of soil–structural interaction members incorporating conventional and sustainable materials indicated that the soil–structure interaction modeling process applied to conventional foundation beams resting on soils is also valid for sustainable members. [ABSTRACT FROM AUTHOR]

' The aim of this study was to clean up toxic element polluted soil in Madaka, Niger State, Nigeria. Standard techniques were used to determine the soil physicochemical properties. To aid the plants (Melissa officinalis L and Sida acuta) during the remediation process, standard methods were used to make chicken dropping vermicompost and goat manure vermicompost. M. officinalis L mopped up toxic elements in the first location (Angwan Kawo), with concentrations of cadmium, arsenic, and lead ranging from 0.007 to 0.33 mg/kg, 0.09 to 4.39 mg/kg, and 0.07 to 10.35 mg/kg, respectively, while toxic elements, cadmium, arsenic, and lead in S. acuta, ranged from 0.002 to 0.43 mg/kg, 0.27 to 3.79 mg/ kg, and 1.68 to 10.7 mg/kg, respectively. The two plants mopped up toxic elements at different rates in the second location of the polluted soil (Angwan Magiro). Cadmium, arsenic, and lead concentrations in M. officinalis L ranged from 0.03 to 0.41 mg/kg, 0.65 to 4.65 mg/kg, and 1.93 to 11.49 mg/kg, respectively, while toxic element concentrations in S. acuta ranged from 0.06 to 0.66 mg/kg, 0.68 to 4.64 mg/kg, and 1.53 to 11.53 mg/kg, respectively. Melissa officinalis L and Sida acuta were found to be the most suitable plants for phytoextraction of toxic element-contaminated sites because their bioconcentration factor, translocation factor, and biological accumulation coefficient were all greater than one (> 1), and both plants had bioconcentration and translocation factor < 1; they were also classified as phytostabilizers. As a result, the plants could be used to clean up Madaka soil polluted with toxic element. [ABSTRACT FROM AUTHOR]

Oil contamination has become a primary environmental concern due to increased exploration, production, and use. When oil enters the soil, it may attach or adsorb to soil particles and stay in the soil for an extended period, contaminating the soil and surrounding areas. Nanoparticles have been widely used for the treatment of organic pollutants in the soil. Surfactant foam has effectively been employed to remediate various soil contaminants or recover oil compounds. In this research, a mixture of biosurfactant foam/nanoparticle was utilized for remediation of oil-contaminated soil. The results demonstrated that the biosurfactant/nanoparticle mixture and nitrogen gas formed high-quality and stable foams. The foam stability depended on the foam quality, biosurfactant concentration, and nanoparticle dosage. The pressure gradient change in the soil column relied on the flowrate (N2 gas + surfactant/nanoparticle mixture), foam quality, and biosurfactant concentration. The optimal conditions to obtain good quality and stable foams and high oil removal efficiency involved 1 vol% rhamnolipid, 1 wt% nanoparticle, and 1 mL/min flowrate. Biosurfactant foam/nanoparticle mixture was effectively used to remediate oil-contaminated soil, whereas the highest treatment efficiency was 67%, 59%, and 52% for rhamnolipid biosurfactant foam/nanoparticle, rhamnolipid biosurfactant/nanoparticle, and only rhamnolipid biosurfactant, respectively. The oil removal productivity decreased with the increase of flowrate due to the shorter contact time between the foam mixture and oil droplets. The breakthrough curves of oil pollutants in the soil column also suggested that the foam mixture's maximum oil treatment efficiency was higher than biosurfactant/nanoparticle suspension and only biosurfactant. [ABSTRACT FROM AUTHOR]

Measuring the reduction of in vitro bioaccessible (IVBA) Pb from the addition of phosphate amendments has been researched for more than 20 years. A range of effects have been observed from increases in IVBA Pb to almost 100% reduction. This study determined the mean change in IVBA Pb as a fraction of total Pb (AC) and relative to the IVBA Pb of the control soil (RC) with a random effects meta-analysis. Forty-four studies that investigated the ability of inorganic phosphate amendments to reduce IVBA Pb were identified through 5 databases. These studies were split into 3 groups: primary, secondary, and EPA Method 1340 based on selection criteria, with the primary group being utilized for subgroup analysis and meta-regression. The mean AC was approximately -12% and mean RC was approximately -25% for the primary and secondary groups. For the EPA Method 1340 group, the mean AC was -5% and mean RC was -8%. The results of subgroup analysis identified the phosphorous amendment applied and contamination source as having a significant effect on the AC and RC. Soluble amendments reduce bioaccessible Pb more than insoluble amendments and phosphoric acid is more effective than other phosphate amendments. Urban Pb contamination associated with legacy Pb-paint and tetraethyl Pb from gasoline showed lower reductions than other sources such as shooting ranges and smelting operations. Meta-regression identified high IVBA Pb in the control, low incubated soil pH, and high total Pb with the greater reductions in AC and RC. In order to facilitate comparisons across future remediation research, a set of minimum reported data should be included in published studies and researchers should use standardized in vitro bioaccessibility methods developed for P-treated soils. Additionally, a shared data repository should be created for soil remediation research to enhance available soil property information and better identify unique materials. [ABSTRACT FROM AUTHOR]

Per‐ and polyfluoroalkyl substances (PFASs), also known as "forever chemicals," are manmade chemicals that have been increasingly detected in various geological settings since the early 2000s. The soil and subsurface environments are the geological media commonly affected by PFAS. We conducted a comprehensive review of peer‐reviewed articles published from 2010 through 2022 concerning the fate and transport of PFAS in subsurface environments. This review is organized into different subsections, covering the basics of PFAS properties and how they affect the occurrence, fate, and transport of PFAS, the fundamental processes affecting subsurface transport and fate of PFAS, and mathematical models for describing and predicting PFAS transport behaviors. Mechanisms governing PFAS transport in the subsurface environment, including the sorption of PFAS at the air‐water interface, solid‐water interface, and nonaqueous phase liquids‐water interface, were explored in detail. Challenges and future research priorities are identified to better mitigate the global challenges of PFAS contamination. Plain Language Summary: Per‐ and polyfluoroalkyl substances (PFASs) are a group of manmade chemicals used in a multitude of applications and commercial products (clothing, cookware, cosmetics, personal care products, fire extinguishers, etc.). Their widespread use has, however, lead to increasing release and distribution in terrestrial and aquatic ecosystems. PFAS, due to their unique properties, are very persistent in the environment as they do not degrade easily. Unfortunately, they are also toxic to organisms, including humans. In this review, we discuss the omnipresence of PFAS in water and soil and explain how PFAS move through subsurface media. There are thousands of different PFAS compounds, and only few of them have been studied in more detail and their transport behavior is known. PFAS tend to accumulate at the air‐water interface in the vadose zone. Generally, PFAS with long carbon chains are retained in soils more strongly than short‐chain compounds. Negatively charged PFAS are more mobile in soils than neutral and positively charged PFAS, and thus can readily pollute groundwater. Nonetheless, due to their persistence and slow desorption, even more strongly sorbed PFAS can be a sustained source for groundwater pollution. We finally identify challenges and future research needs to address the emerging threat of PFAS contamination of the environment. [ABSTRACT FROM AUTHOR]

The present study utilizes the covalent-crosslinking method to immobilize the laccase enzyme on magnetic iron nanoparticles and further assess its potential in degrading chlorpyrifos in pesticide spiked soil. The soil texture analysis revealed the presence of clay, silt and sand accounting to 7.1%, 14.3%, and 78.6%, respectively. The degradation of chlorpyrifos in spiked soil using laccase enzyme immobilized magnetic iron nanoparticles was measured for 60 days in a batch process. The results revealed a gradual increase in degradation efficiency showing around 29.3%, 43.8%, 56.3%, and 67.3% at the 20th, 30th, 40th, and 50th day of incubation. A maximum degradation of 83.6% was observed on the 60th day of incubation. Intermediate products 2,4-bis(1,1 dimethylethyl) phenol, 1,2 benzenedicarboxylic acid, bis(2-methyl propyl) ester and piperidine confirmed the degradation of chlorpyrifos in soil. The piperidine originated in the chromatogram between 20–40 days of incubation and diminished later. Chlorpyrifos degradation followed pseudo first-order kinetics with a R2 of 0.96. Further, the nanoparticles showed no negative impact on soil bacterial population during the antibacterial assay. The study confirms the degradation of chlorpyrifos in contaminated soil using laccase-immobilized nanoparticles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Various iron-based catalysts used in SR-AOPs for soil remediation were summarized. • Iron-based catalysts exhibit considerable potential in SR-AOPs for soil remediation. • The mechanisms of iron-based catalysts that remove pollutants in soil were analyzed. • The properties of soil would be negatively affected after SR-AOPs treatment. • The applications of iron-based catalysts for SR-AOPs in soil remediation were presented. Accumulation of multiple organic pollutants in the soil is a huge threat to ecological systems and health of human beings. Iron-based catalysts, such as zero-valent iron (ZVI) catalysts, iron oxide catalysts, and supported iron-based catalysts are widely used in sulfate radicals (SO 4 •−)-based advanced oxidation process (SR-AOPs) for soil remediation as a result of their environmental friendliness, extensiveness, and low cost, etc. In recent years, SR-AOPs using iron-based catalysts have arousing attention for the degradation/mineralization of organic pollutants in polluted soil. It helps to accelerate the transformation of contaminants, as well as sustainable remediation and adaptability to complex soil environments. This paper concentrates on the progresses of the Fe-based catalysts in SR-AOPs for organically contaminated soil. General persulfate activation process and the radical free radicals generation are summarized in soil remediation. The changes of physicochemical properties (e.g. , organic matter, naturally occurring minerals, pH, and microbial community) in soil after SR-AOPs treatment are particularly discussed. The applications of Fe-based catalysts for SR-AOPs in soil remediation are thoroughly investigated from the perspective of the internal interaction among pollutants, catalysts, and soil. Finally, the existing challenges for SR-AOPs by Fe-based catalysts used in soil remediation are proposed. [ABSTRACT FROM AUTHOR]

The management of heavy metal contaminated soil has received extensive research attention. In this study, a novel immobilization agent (SiO2@Fe3O4@C-COOH) was combined with traditional immobilization agents (TIAs), i.e., CaO, organic matter (OM), and calcium superphosphate (CSP), and used to remediate Pb-contaminated soil. The immobilization effects of Pb in soil was evaluated through pot experiments involving wheat cultivation. The results indicated that SiO2@Fe3O4@C-COOH delivered a higher Pb immobilization efficiency than did TIAs such as CaO, OM, and CSP. The application of SiO2@Fe3O4@C-COOH in combination with TIAs (CaO, OM, and CSP) synergistically enhanced the Pb immobilization efficiency of the soil to 85.10%. Further, joint application in a 54.19% reduction of Pb content in wheat roots, a 65.78% reduction in stems, and a 47.96% in leaves. Thus, the combined application of SiO2@Fe3O4@C-COOH and TIAs significantly reduced the bioavailability of Pb, achieved the purpose of Pb stabilization and soil remediation, and has the potential for wide-spread application in the remediation of Pb-contaminated soils. [ABSTRACT FROM AUTHOR]

Arsenic (As) is highly toxic in its inorganic form. It is naturally presented at elevated levels in the groundwater of a number of countries and contaminates drinking water sources, generating numerous health and environmental problems. Current methodologies for its remediation have deficiencies which fuel the constant exploration of new alternatives. Therefore, the development of robust methodologies for the evaluation of potential remediation technologies are not only timely but also highly needed. In this study we have investigated the use of a rice plant species as a means to evaluate the efficacy of As remediation using sulfidated zerovalent iron nanoparticles (S-nZVI). The obtained results show that addition of S-nZVI to soils had a beneficial impact to plant growth in the presence of As(V) and As(III) concentrations between 10 and 50 ppm. Positive effects were also found for plant biomass and chlorophyll content in the plants. Moreover, evaluation of As uptake by plants showed that the application of S-nZVI reduced the amount of both As(V) and As(III) in shoots and increased the amount of As in the roots. Studies on the Fe and P content in shoot and root after exposure to As with and without the nanoparticles demonstrated that nanoparticles remain mainly in the roots and that P uptake by plants was not significantly affected, suggesting that S-nZVI treatment is safe for plants at the assayed doses. These results overall confirm the method as robust and reliable for demonstrating the reduction of the bioavailability of As in soil by S-nZVI sequestration. [ABSTRACT FROM AUTHOR]

The issue of heavy metal and metaloid (HMM) contamination continues to attract attention owing to their non-biodegradable nature and toxicity to almost all living organisms. Facilitating immobilization of HMMs in plants, face growing concerns as a result of global pollution challenge accompanying wobble climate patterns. Thus, reducing the HMM concentrations below the allowable limits is the key to safer food sustainability. Several studies are underway to develop methods having clear modes of action for removing HMMs from soil and wastewater. Engineered and incorporated practices are used to recover HMMs; some of which are very simple, such as applying agricultural (bioadsorption) and industrial waste, while some of them are complex, such as solvent extraction, phytoremediation, remediation by microbial communities, green separation by hydrogel polymers, immobilization, or principal nanotechnology techniques. However, most of these methods are insufficient for various reasons including incomplete removal of HMMs (poor efficiency), the necessity for extra reagents/high energy, the large amounts of waste production that could be difficult to eliminate later on, and production of unwanted toxic waste. In this review, different methods were compared to each other such as remediation methods that include biology-based methods and nanotechnology methods. Biology-based methods include phytoremediation, immobilization technique with the chelating agent, and low-cost bioabsorbents. Molecular and nanotechnology techniques were applied for enhancing the remediation process and open up new opportunities for remediation of heavy metal. Hydrogels and agricultural waste as new methods for the removal of water pollutants cannot apply for the heavy metal removal at nanoscale. Analyses of toxicity of the nanoparticles are essential for industries to provide healthy products for consumers. Therefore, the present study compared the advantages and disadvantages of the latest management strategies integrated to lower the HMM contamination levels in the soil and built barriers against ultimate transmission along the food chain. [ABSTRACT FROM AUTHOR]

Biochar is most commonly considered for its use as a soil amendment, where it has gained attention for its potential to improve agricultural production and soil health. Twenty years of near exponential growth in investigation has demonstrated that biochar does not consistently deliver these benefits, due to variables in biochar, soil, climate, and cropping systems. While biochar can provide agronomic improvements in marginal soils, it is less likely to do so in temperate climates and fertile soils. Here, biochar and its coproducts may be better utilized for contaminant remediation or the substitution of nonrenewable or mining-intensive materials. The carbon sequestration function of biochar, via conversion of biomass to stable forms of carbon, does not depend on its incorporation into soil. To aid in the sustainable production and use of biochar, we offer two conceptual decision trees, and ask: What do we currently know about biochar? What are the critical gaps in knowledge? How should the scientific community move forward? Thoughtful answers to these questions can push biochar research towards more critical, mechanistic investigations, and guide the public in the smart, efficient use of biochar which extracts maximized benefits for variable uses, and optimizes its potential to enhance agricultural and environmental sustainability. [ABSTRACT FROM AUTHOR]