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Veterinary antibiotics (VAs) are emerging contaminants in soils as they may pose high risks to the ecosystem and human health. Identifying VAs accumulation in soils is essential for assessing their potential risks. Therefore, we investigated the distribution of VAs in soils from vegetable fields and evaluated their potential ecological and antimicrobial resistance risks in the Chongqing region of the Three Gorges Reservoir area, China. Results indicated that twenty-six species of VAs, including nine sulfonamides (SAs), seven quinolones (QNs), four tetracyclines (TCs), four macrolides (MLs), and two other species of VAs were detected in soils, with their accumulative levels ranging from 1.4 to 3145.7 μg kg -1 . TCs and QNs were the dominant VAs species in soils with high detection frequencies (100% TCs and 80.6% for QNs) and accumulative concentration (up to 1195 μg kg -1 for TCs and up to 485 μg kg -1 for QNs). Risk assessment indices showed that VAs (specifically SAs, TCs, and QNs) in most vegetable soils would pose a medium to high risk to the ecosystem and antimicrobial resistance. Mixture of VAs posed a higher risk to soil organisms, antimicrobial resistance, and plants than to aquatic organisms. Modeling analysis indicated that socioeconomic conditions, farmers' education levels, agricultural practices, and soil properties were the main factors governing VAs accumulation and environmental risks. Farmers with a high educational level owned large-scale farms and were more willing to use organic fertilizers for vegetable production, which eventually led to high VAs accumulation in vegetable soil. These findings would provide a reference for sustainable agricultural and environmental production under the current scenario of chemical fertilizer substitution by organic products and green agricultural development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The Environmental Protection Agencies (EPAs) of Denmark, Sweden, Norway, Germany and the Netherlands submitted a proposal to the European Chemical Agency (ECHA) in February 2023 calling for a ban in the use of toxic industrial chemicals per- and polyfluoroalkyl substances (PFAS). These chemicals are highly toxic causing elevated cholesterol, immune suppression, reproductive failure, cancer and neuro-endocrine disruption in humans and wildlife being a significant threat to biodiversity and human health. The main reason for the submitted proposal is recent findings of significant flaws in the transition to PFAS replacements that is leading to a widespread pollution. Denmark was the first country banning PFAS, and now other EU countries support the restrictions of these carcinogenic, endocrine disruptive and immunotoxic chemicals. The proposed plan is among the most extensive received by the ECHA for 50 years. Denmark is now the first EU country to initiate the establishment of groundwater parks to try and protect its drinking water. These parks are areas free of agricultural activities and nutritious sewage sludge to secure drinking water free of xenobiotic including PFAS. The PFAS pollution also reflects the lack of comprehensive spatial and temporal environmental monitoring programs in the EU. Such monitoring programs should include key indicator species across ecosystems of livestock, fish and wildlife, to facilitate detection of early ecological warning signals and sustain public health. Simultaneously with inferring a total PFAS ban, the EU should also push for more persistent, bioaccumulative and toxic (PBT) PFAS substances to be listed on the Stockholm Convention (SC) Annex A such as PFOS (perfluorooctane sulfonic acid) that is currently listed on the SCs Annex B. The combination of these regulative restrictions combined with groundwater parks and pan-European biomonitoring programs, would pave the way forward for a cleaner environment to sustain health across the EU., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Discarded plastics and microplastics (MPs) in the environment are considered emerging contaminants and indicators of the Anthropocene epoch. This study reports the discovery of a new type of plastic material in the environment─plastic-rock complexes─formed when plastic debris irreversibly sorbs onto the parent rock after historical flooding events. These complexes consist of low-density polyethylene (LDPE) or polypropylene (PP) films stuck onto quartz-dominated mineral matrices. These plastic-rock complexes serve as hotspots for MP generation, as evidenced by laboratory wet-dry cycling tests. Over 1.03 × 10 8 and 1.28 × 10 8 items·m -2 MPs were generated in a zero-order mode from the LDPE- and PP-rock complexes, respectively, following 10 wet-dry cycles. The speed of MP generation was 4-5 orders of magnitude higher than that in landfills, 2-3 orders of magnitude higher than that in seawater, and >1 order of magnitude higher than that in marine sediment as compared with previously reported data. Results from this investigation provide strong direct evidence of anthropogenic waste entering geological cycles and inducing potential ecological risks that may be exacerbated by climate change conditions such as flooding events. Future research should evaluate this phenomenon regarding ecosystem fluxes, fate, and transport and impacts of plastic pollution.

Silver (Ag), a naturally occurring, rare and precious metal, is found in major minerals such as cerargyrite (AgCl), pyrargyrite (Ag 3 SbS 3 ), proustite (Ag 3 AsS 3 ), and stephanite (Ag 5 SbS 4 ). From these minerals, Ag is released into soil and water through the weathering of rocks and mining activities. Silver also enters the environment by manufacturing and using Ag compounds in electroplating and photography, catalysts, medical devices, and batteries. With >400 t of Ag NPs produced yearly, Ag NPs have become a rapidly growing source of anthropogenic Ag input in the environment. In soils and natural waters, most Ag is sorbed to soil particles and sediments and precipitated as oxides, carbonates, sulphides, chlorides and hydroxides. Silver and its compounds are toxic, and humans and other animals are exposed to Ag through inhalation of air and the consumption of Ag-contaminated food and drinking water. Remediation of Ag-contaminated soil and water sources can be achieved through immobilization and mobilization processes. Immobilization of Ag in soil and groundwater reduces the bioavailability and mobility of Ag, while mobilization of Ag in the soil can facilitate its removal. This review provides an overview of the current understanding of the sources, geochemistry, health hazards, remediation practices and regulatory mandates of Ag contamination in complex environmental settings, including soil and aquatic ecosystems. Knowledge gaps and future research priorities in the sustainable management of Ag contamination in these settings are also discussed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Potentially toxic elements (PTEs) pose a great threat to ecosystems and long-term exposure causes adverse effects to wildlife and humans. Cadmium induces a variety of diseases including cancer, kidney dysfunction, bone lesions, anemia and hypertension. Here we review the ability of plants to accumulate cadmium from soil, air and water under different environmental conditions, focusing on absorption mechanisms and factors affecting these. Cadmium possess various transport mechanisms and pathways roughly divided into symplast and apoplast pathway. Excessive cadmium concentrations in the environment affects soil properties, pH and microorganism composition and function and thereby plant uptake. At the same time, plants resist cadmium toxicity by antioxidant reaction. The differences in cadmium absorption capacity of plants need more exploration to determine whether it is beneficial for crop breeding or genetic modification. Identify whether plants have the potential to become hyperaccumulator and avoid excessive cadmium uptake by edible plants. The use of activators such as wood vinegar, GLDA (Glutamic acid diacetic acid), or the placement of earthworms and fungi can speed up phytoremediation of plants, thereby reducing uptake of crop varieties and reducing human exposure, thus accelerating food safety and the health of the planet., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Medical wastes include all solid and liquid wastes that are produced during the treatment, diagnosis, and immunisation of animals and humans. A significant proportion of medical waste is infectious, hazardous, radioactive, and contains potentially toxic elements (PTEs) (i.e., heavy metal (loids)). PTEs, including arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg), are mostly present in plastic, syringes, rubber, adhesive plaster, battery wastes of medical facilities in elemental form, as well as oxides, chlorides, and sulfates. Incineration and sterilisation are the most common technologies adopted for the safe management and disposal of medical wastes, which are primarily aimed at eliminating deadly pathogens. The ash materials derived from the incineration of hazardous medical wastes are generally disposed of in landfills after the solidification/stabilisation (S/S) process. In contrast, the ash materials derived from nonhazardous wastes are applied to the soil as a source of nutrients and soil amendment. The release of PTEs from medical waste ash material from landfill sites and soil application can result in ecotoxicity. The present study is a review paper that aims to critically review the dynamisms of PTEs in various environmental media after medical waste disposal, the environmental and health implications of their poor management, and the common misconceptions regarding medical waste., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2023. Published by Elsevier Ltd. All rights reserved.)

Thermoacidophilic Cyanidiales maintain a competitive edge in inhabiting extreme environments enriched with metals. Here, species of Cyanidioschyzon merolae (Cm), Cyanidium caldarium (Cc), and Galdieria partita (Gp) were exploited to remove hexavalent chromium [Cr(VI)]. Cm and Gp could remove 168.1 and 93.7 mg g -1 of Cr(VI) at pH 2.0 and 7.0, respectively, wherein 89% and 62% of sorbed Cr on Cm and Gp occurred as trivalent chromium [Cr(III)]. Apart from surface-sorbed Cr(VI), the in vitro Cr(III) bound with polysaccharide and in vivo chromium(III) hydroxide [Cr(OH) 3 ] attested to the reduction capability of Cyanidiales. The distribution of Cr species varied as a function of sorbed Cr amount, yet a relatively consistent proportion of Cr(OH) 3 , irrespective of Cr sorption capacity, was found only on Cm and Cc at pH 2.0. In conjunction with TXM (transmission X-ray microscopy) images that showed less impaired cell integrity and possible intracellular Cr distribution on Cm and Cc at pH 2.0, the in vivo Cr(OH) 3 might be the key to promoting the Cr sorption capacity (≥ 152 mg g -1 ). Cyanidiales are promising candidates for the green and sustainable remediation of Cr(VI) due to their great removal capacity, the spontaneous reduction under oxic conditions, and in vivo accumulation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Herein, a one-step co-pyrolysis protocol was adopted for the first time to prepare a novel pyrogenic carbon-Cu 0 /Fe 3 O 4 heteroatoms (FCBC) in CO 2 ambiance to discern the roles of each component in PDS activation. During co-pyrolysis, CO 2 catalyzed formation of reducing gases by biomass which facilitated reductive transformation of Fe 3+ and Cu 2+ to Cu 0 and Fe 3 O 4 , respectively. According to the analysis, the resulting metal (oxide) catalyzed graphitization of biocharand decomposition of volatile substances resulting in an unprecedented surface area (1240 m 2/ g). The resulting FCBC showed greater structural defects and less electrical impedance. Batch experiments indicated that Rhodamine B (RhB) degradation by FCBC (100%) was superior to Fe 3 O 4 (50%) and Cu 0 /Fe 3 O 4 (76.4%) in persulfate (PDS) system, which maintained reasonable efficiency (75.6%-63.6%) within three cycles. The reactive oxygen species (ROS) associated with RhB degradation was identified by an electron paramagnetic resonance and confirmed by scavenging experiments. RhB degradation invoked both (sulfate and dominantly hydroxyl) radical and non-radical (singlet oxygen, 1 O 2 ) pathways. Regarding FCBC, Cu 0 can continuously react with Fe 3+ in Fe 3 O 4 to generate larger quantities of Fe 2+ , and both Cu 0 and Fe 2+ activated PDS to yield sulfate radicals which was quickly converted to hydroxyl radical. Besides, Cu 0 /Cu 2+ could complex with PDS to form a metastable complex, which particularly contributed to 1 O 2 generation. These cascade reactions by FCBC were reinforced by carbonyl group of biochar and favorable electron transfer ability. This work highlighted a new approach to prepare a magnetic and environment-benign heterogonous catalyst to remove organic pollutants in water., (Copyright © 2021. Published by Elsevier B.V.)

Lithium's (Li) ubiquitous distribution in the environment is a rising concern due to its rapid proliferation in the modern electronic industry. Li enigmatic entry into the terrestrial food chain raises many questions and uncertainties that may pose a grave threat to living biota. We examined the leverage existing published articles regarding advances in global Li resources, interplay with plants, and possible involvement with living organisms, especially humans and animals. Globally, Li concentration (<10-300 mg kg -1 ) is detected in agricultural soil, and their pollutant levels vary with space and time. High mobility of Li results in higher accumulation in plants, but the clear mechanisms and specific functions remain unknown. Our assessment reveals the causal relationship between Li level and biota health. For example, lower Li intake (<0.6 mM in serum) leads to mental disorders, while higher intake (>1.5 mM in serum) induces thyroid, stomach, kidney, and reproductive system dysfunctions in humans and animals. However, there is a serious knowledge gap regarding Li regulatory standards in environmental compartments, and mechanistic approaches to unveil its consequences are needed. Furthermore, aggressive efforts are required to define optimum levels of Li for the normal functioning of animals, plants, and humans. This review is designed to revitalize the current status of Li research and identify the key knowledge gaps to fight back against the mountainous challenges of Li during the recent digital revolution. Additionally, we propose pathways to overcome Li problems and develop a strategy for effective, safe, and acceptable applications., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this work., (© 2023 The Authors.)

Radionuclides released from nuclear contamination harm the environment and human health. Nuclear pollution spread over large areas and the costs associated with decontamination is high. Traditional remediation methods include both chemical and physical, however, these are expensive and unsuitable for large-scale restoration. Bioremediation is the use of plants or microorganisms to remove pollutants from the environment having a lower cost and can be upscaled to eliminate contamination from soil, water and air. It is a cheap, efficient, ecologically, and friendly restoration technology. Here we review the sources of radionuclides, bioremediation methods, mechanisms of plant resistance to radionuclides and the effects on the efficiency of biological adsorption. Uptake of radionuclides by plants can be facilitated by the addition of appropriate chemical accelerators and agronomic management, such as citric acid and intercropping. Future research should accelerate the use of genetic engineering and breeding techniques to screen high-enrichment plants. In addition, field experiments should be carried out to ensure that this technology can be applied to the remediation of nuclear contaminated sites as soon as possible., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Metal halide perovskite solar cells (PSCs) have gained extensive attention in the field of solar photovoltaic technology over the past few years. Despite being a remarkable alternative to fossil fuels, solar cells may have detrimental effects on the environment and human health owing to the use of toxic materials during manufacturing. Although modern metal-halide-based PSCs are stable and have encapsulation to prevent the release of potentially toxic materials into the environment, their destruction due to strong winds, hail, snow, landslides, fires, or waste disposal can result in the exposure of these materials to the environment. This may lead to the contamination of soil and groundwater, and uptake of potentially toxic elements by plants, subsequently affecting humans and other living organisms via food chain contamination. Despite worldwide concern, the environmental and ecotoxicological impacts of metal-halide-based PSCs have not been comprehensively surveyed. This review summarizes and critically evaluates the current status of metal-halide-based PSC production and its impact on environmental sustainability, food security, and human health. Furthermore, safe handling and disposal methods for the waste generated from metal-halide-based PSCs are proposed, with a focus on recycling and reuse. Although some studies have suggested that the amount of lead released from metal halide PSCs is far below the maximum permissible levels in most soils, a clear conclusion cannot be reached until real contamination scenarios are assessed under field conditions. Precautions must be taken to minimize environmental contamination throughout the lifecycle of PSCs until nontoxic and similarly performing alternative solar photovoltaic products are developed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Inc.)

Contamination of paddy soils with potentially toxic elements (PTEs) has become a severe environmental issue. Application of functionalized biochar for rice cultivation has been proposed as an effective means to reduce environmental risks of these PTEs in paddy soils. This work was undertaken to seek the positive effects of a rice husk-derived silicon (Si)-rich biochar (Si-BC) and a pig carcass-derived phosphorus (P)-rich biochar (P-BC), as well as their Fe-modified biochars (Fe-Si-BC and Fe-P-BC) on the enzyme activity and PTE availability in an As-Cd-Pb-contaminated soil. A rice cultivation pot trial was conducted using these functionalized biochars as soil amendments for the alleviation of PTE accumulation in rice plants. Results showed that Si-BC decreased the concentrations of As in rice grain and straw by 59.4 % and 61.4 %, respectively, while Fe-Si-BC significantly (P < 0.05) enhanced plant growth, increasing grain yield (by 38.6 %). Fe-Si-BC significantly (P < 0.05) elevated Cd and Pb accumulation in rice plants. P-BC enhanced the activities of dehydrogenase, catalase, and urease, and reduced grain-Pb and straw-Pb by 49.3 % and 43.2 %, respectively. However, Fe-P-BC reduced plant-As in rice grain and straw by 12.2 % and 51.2 %, respectively, but increased plant-Cd and plant-Pb. Thus, Fe-modified Si- and P-rich biochars could remediate paddy soils contaminated with As, and enhance the yield and quality of rice. Application of pristine P-rich biochar could also be a promising strategy to remediate the Pb-contaminated paddy soils and limit Pb accumulation in rice., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This review aims to provide an overview of the sources and reactions of persistent organic pollutants (POPs) and surfactants in soil and sediments, the surfactant-enhanced solubilisation of POPs, and the unintended consequences of surfactant-induced remediation of soil and sediments contaminated with POPs. POPs include chemical compounds that are recalcitrant to natural degradation through photolytic, chemical, and biological processes in the environment. POPs are potentially toxic compounds mainly used in pesticides, solvents, pharmaceuticals, or industrial applications and pose a significant and persistent risk to the ecosystem and human health. Surfactants can serve as detergents, wetting and foaming compounds, emulsifiers, or dispersants, and have been used extensively to promote the solubilization of POPs and their subsequent removal from environmental matrices, including solid wastes, soil, and sediments. However, improper use of surfactants for remediation of POPs may lead to unintended consequences that include toxicity of surfactants to soil microorganisms and plants, and leaching of POPs, thereby resulting in groundwater contamination., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2022. Published by Elsevier B.V. All rights reserved.)

Rice grown in soils contaminated with arsenic (As) and lead (Pb) can cause lower rice yield and quality due to the toxic stress. Herein, we examined the role of functionalized biochars (raw phosphorus (P)-rich (PBC) and iron (Fe)-modified P-rich (FePBC)) coupled with different irrigation regimes (continuously flooded (CF) and intermittently flooded (IF)) in affecting rice yield and accumulation of As and Pb in rice grain. Results showed that FePBC increased the rice yield under both CF (47.4%) and IF (19.6%) conditions, compared to the controls. Grain As concentration was higher under CF (1.94-2.42 mg kg -1 ) than IF conditions (1.56-2.31 mg kg -1 ), whereas the concentration of grain Pb was higher under IF (0.10-0.76 mg kg -1 ) than CF (0.12-0.48 mg kg -1 ) conditions. Application of PBC reduced grain Pb by 60.1% under CF conditions, while FePBC reduced grain As by 12.2% under IF conditions, and increased grain Pb by 2.9 and 6.6 times under CF and IF conditions, respectively, compared to the controls. Therefore, application of the multiple-functionalized biochar can be a promising strategy for increasing rice yield and reducing the accumulation of As in rice grain, particularly under IF conditions, whereas it is inapplicable for remediation of paddy soils contaminated with Pb., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Microplastics are among the major contaminations in terrestrial and marine environments worldwide. These persistent organic contaminants composed of tiny particles are of concern due to their potential hazards to ecosystem and human health. Microplastics accumulates in the ocean and in terrestrial ecosystems, exerting effects on living organisms including microbiomes, fish and plants. While the accumulation and fate of microplastics in marine ecosystems is thoroughly studied, the distribution and biological effects in terrestrial soil call for more research. Here, we review the sources of microplastics and its effects on soil physical and chemical properties, including water holding capacity, bulk density, pH value as well as the potential effects to microorganisms and animals. In addition, we discuss the effects of microplastics in combination with other toxic environmental contaminants including heavy metals and antibiotics on plant growth and physiology, as well as human health and possible degradation and remediation methods. This reflect is an urgent need for monitoring projects that assess the toxicity of microplastics in soil and plants in various soil environments. The prospect of these future research activities should prioritize microplastics in agro-ecosystems, focusing on microbial degradation for remediation purposes of microplastics in the environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

There is a growing concern about human health of residents living in areas where mining and smelting occur. In order to understand the exposure to the potentially toxic elements (PTEs), we here identify and examine the cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) in scalp hair of residents living in the mining area (Bayan Obo, n = 76), smelting area (Baotou, n = 57) and a reference area (Hohhot, n = 61). In total, 194 hair samples were collected from the volunteers (men = 87, women = 107) aged 5-77 years old in the three areas. Comparing median PTEs levels between the young and adults, Ni levels were significantly higher in adults living in the smelting area while Cr was highest in adults from the mining area, no significant difference was found for any of the elements in the reference area. From the linear regression model, no significant relationship between PTEs concentration, log 10 (PTEs), and age was found. The concentrations of Ni, Cd, and Pb in hair were significantly lower in the reference area when compared to both mining and smelting areas. In addition, Cu was significantly higher in the mining area when compared to the smelting area. Factor analysis (FA) indicated that men and women from the smelting area (Baotou) and mining area (Bayan Obo), respectively, had different underlying communality of log10(PTEs), suggesting different sources of these PTEs. Multiple factor analysis quantilized the importance of gender and location when combined with PTEs levels in human hair. The results of this study indicate that people living in mining and/or smelting areas have significantly higher PTEs (Cu, Ni, Cd, and Pb) hair levels compared to reference areas, which may cause adverse health effects. Remediation should therefore be implemented to improve the health of local residents in the mining and smelting areas., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Land use impacts from agriculture, industrialization, and human population should be considered in surface water quality management. In this study, we utilized an integrated statistical analysis approach mainly including a seasonal Mann-Kendall test, clustering analysis, self-organizing map, Boruta algorithm, and positive matrix factorization to the assessment of the interactions between land use types and water quality in a typical catchment in the Huai River Basin, China, over seven years (2012-2019). Spatially, water quality was clustered into three groups: upstream, midstream, and downstream/mainstream areas. The water quality of upstream sites was better than of mid-, down-, and mainstream. Temporally, water quality did not change significantly during the study period. However, the temporal variation in water quality of up-, down-, and mainstream areas was more stable than in the midstream. The interactions between land use types and water quality parameters at the sub-basin scale varied with seasons. Increasing forest/grassland areas could substantially improve the water quality during the wet season, while nutrients such as phosphorus from cropland and developed land was a driver for water quality deterioration in the dry season. Water area was not a significant factor influencing the variations of ammonia nitrogen (NH 3 -N) and total phosphorus (TP) in the wet or dry season, due to the intensive dams and sluices in study area. The parameters TP, and total nitrogen (TN) were principally linked with agricultural sources in the wet and dry seasons. The parameters NH 3 -N in the dry season, and chemical oxygen demand (COD Cr ) in the wet season were mainly associated with point source discharges. Agricultural source, and urban point source discharges were the main causes of water quality deterioration in the study area. Collectively, these results highlighted the impacts of land use types on variations of water quality parameters in the regulated basin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Soil acidification in managed ecosystems such as agricultural lands principally results from the increased releasing of protons (H + ) from the transformation reactions of carbon (C), nitrogen (N) and sulphur (S) containing compounds. The incorporation of liming materials can neutralize the protons released, hence reducing soil acidity and its adverse impacts to the soil environment, food security, and human health. Biochar derived from organic residues is becoming a source of carbon input to soil and provides multifunctional values. Biochar can be alkaline in nature, with the level of alkalinity dependent upon the feedstock and processing conditions. This review covers the fundamental aspects of soil acidification and of the use of biochar to address constraints related to acidic soil. Biochar is increasingly considered as an effective soil amendment for reducing soil acidity owing to its liming potential, thereby enhancing soil fertility and productivity in acid soils. The ameliorant effect on acid soils is mainly because of the dissolution of carbonates, (hydro)-oxides of the ash fraction of biochar and potential use by microorganisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In the recent decades, the area of seasonal water (SEW) has substantially increased at the global scale. To evaluate nutrient dynamics in aquatic ecosystems, previous studies have analyzed the determining factors of sediment nutrient content and stoichiometry on whole sediment profiles without depth separation on SEW sites. Such a methodology assumes that SEW sediment is a uniform unit and its nutrient dynamics are regulated by the same mechanism at various depths (uniformity assumption). We tested this assumption using sediment samples from six depth increments of 154 sediment profiles (1 m depth) on SEW sites at Shengjin Lake in subtropical China. We measured sediment total nitrogen (STN), total phosphorus (STP), nutrient fractions, and the molar ratio of STN to STP (R SNP ), and investigated their determining factors at various depths. STN, STP, and R SNP were averaged at 1.34 g/kg, 0.55 g/kg, and 5.43, respectively, and all gradually decreased with depth. STN was positively affected by moisture and flooding duration in all depth increments. Instead, the major determining factors of STP changed from particle size at 0-20 cm of depth to pH and electrical conductivity at 30-100 cm of depth. These vertical patterns have close connections with sediment nutrient fractions since sediment N fractions did not shift along profile depths (i.e., over 99 % of STN was organic N) but sediment P fractions did (the percentage of Fe-P and Al-P decreased by 6.25 % but those of Ca-P increased by 4.31 % along the sediment depth gradient). The major determining factors of R SNP showed no obvious vertical patterns because they frequently varied along depth gradients. The results demonstrate that SEW sediment is not a uniform unit and the determining factors of nutrient dynamics change with depth. Our study highlights the importance of improved methodological reflection in studies addressing sediment nutrient dynamics on SEW sites., Competing Interests: Declaration of competing interest None., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Irrigation of carbonate-rich agricultural soils with arsenic (As)-contaminated water leads to the accumulation of As in these soils. In this regard, there is an opportunity to adsorb and fix the As in soil and decrease the As transportation to the plants and subsequently the human food chain. So, the present study aimed to investigate the adsorption-desorption characteristics of As in calcareous soils and the potential of As fixation over time. First, to achieve this purpose, 53 soil samples were gathered from the study site and after the laboratory analysis, the soils were categorized into four groups based on their physicochemical properties. Then, four representative samples of these groups were selected, namely soil 1, soil 2, soil 3, and soil 4. Afterward, the As adsorption-desorption was investigated in a lab-scale batch experiment. Next, the effect of age was assessed by incubating the As-adsorbed soils for 60 days, and to study the impact of temperature, the adsorption was performed at four temperature levels (10, 20, 30, and 40 °C). Finally, the isotherm models were fitted to experimental data, and the amount of loosely and tightly held As was quantified. Results revealed that the As adsorption isotherms were L-type, in which As adsorption increased with the increase of As loading. The double-site Langmuir (DSL) estimated that a limited amount of As was adsorbed on high-energy surfaces and a large amount of As was adsorbed on low-energy surfaces. Desorption results showed that a significant amount of As desorbed immediately; however, the desorption significantly decreased with the increase of age, especially at low equilibrium concentrations. By aging the loosely held As transformed into non-labile forms so that in soils 1, 2, 3, and 4, the fraction of As adsorbed on high-energy surfaces increased from 72.5, 93.2, 63.2, and 123 mg/kg to 167, 141, 70.6, and 196 mg/kg, respectively, and the fraction of As adsorbed on low-energy surfaces decreased from 397, 256, 202, and 317 mg/kg to 182, 238, 173, and 172 mg/kg, respectively (after aging for 60 days). Aging proved to be a promising solution for decreasing As transport into the human food chain and could be employed for crops with longer irrigation cycles. ΔH ad values were positive and varied from 9.26 to 13.0 kJ/mol, confirming the endothermic nature of adsorption. ΔG ad values were negative and varied from - 18.8 to - 22.8 kJ/mol at all temperatures, demonstrating the spontaneous nature of adsorption., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The unpredictable climatic perturbations, the expanding industrial and mining sectors, excessive agrochemicals, greater reliance on wastewater usage in cultivation, and landfill leachates, are collectively causing land degradation and affecting cultivation, thereby reducing food production globally. Biochar can generally mitigate the unfavourable effects brought about by climatic perturbations (drought, waterlogging) and degraded soils to sustain crop production. It can also reduce the bioavailability and phytotoxicity of pollutants in contaminated soils via the immobilization of inorganic and/or organic contaminants, commonly through surface complexation, electrostatic attraction, ion exchange, adsorption, and co-precipitation. When biochar is applied to soil, it typically neutralizes soil acidity, enhances cation exchange capacity, water holding capacity, soil aeration, and microbial activity. Thus, biochar has been was widely used as an amendment to ameliorate crop abiotic/biotic stress. This review discusses the effects of biochar addition under certain unfavourable conditions (salinity, drought, flooding and heavy metal stress) to improve plant resilience undergoing these perturbations. Biochar applied with other stimulants like compost, humic acid, phytohormones, microbes and nanoparticles could be synergistic in some situation to enhance plant resilience and survivorship in especially saline, waterlogged and arid conditions. Overall, biochar can provide an effective and low-cost solution, especially in nutrient-poor and highly degraded soils to sustain plant cultivation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Potentially toxic elements (PTEs) can be released during mining operations and ore processing. The pollution and health risk related to PTEs in total suspended particulates (TSPs) around the largest polymetallic rare earth mining area (Bayan Obo) and smelting area (Baotou) in Inner Mongolia, China, were evaluated. PTEs in the hair of the elderly living in these two areas and a reference area (Hohhot) were also examined. Relationships between PTEs in TSPs and hair with categorical factors (location, gender, etc.) were also modeled. Multivariate statistical analyses were carried out to analyze the possible sources of the PTEs in TSPs. The bubble maps of the concentrations of PTEs indicated that high concentrations of PTEs were near the industrial area where smelting plants and power plants were located. In addition, health risks were assessed for adults in the mining and smelting area. The carcinogenic risk of Cr was high for residents in the study areas. Also, the residents were exposed to a non-carcinogenic risk of Ni. Significant mean value differences were observed between PTEs in the hair of the elderly in Baotou and Hohhot. Results of the linear regression model indicated that around 31 % of the Pb in hair could be explained by the linear regression model, it could be affected by Ni and Zn in TSPs, but location, gender, and sampling time showed no significant contribution. Age was not significantly associated with the PTEs levels in hair in Baotou and Bayan Obo. The results provide important scientific evidence for a better understanding of the effects of PTEs in TSPs in polymetallic ore mining and smelting areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The pollution risks due to the soil migration of toxic metal(loid)s (TMs) are a greatly hazard to ecological environment as well as animal and human health. Previous studies have primarily focused on surface contamination while deep soil layers often contain dangerous levels of TMs. We used restored wheat and rice farmlands from aquaculture ponds as a case study to examine the ecological risk and distribution of TMs in soil profiles. The elements Cu, Zn, Cr, Cd, Hg and As were markedly enriched in the 60-180 cm soil layers of restored farmland, and their concentrations decreased in the several depths as follows: 120-180 cm > 60-120 cm > 0-60 cm. Concentrations of TMs were 9.5-128 % greater in the restored farmlands relative to farmlands not exposed to aquaculture practices. Cadmium and mercury were the most serious contaminants and increased the overall ecological risk. The subsoil of wheat farming system had the highest pollution risk versus the restored rice farmland at 60-120 cm due to elevated levels of Cu, Zn and Pb. Toxic metal(loid)s might be derived from natural sources in deep soil of conventional farmland whereas aquaculture practices were found to constitute the major contribution in the subsoil of restored farmland. Our results indicated that the TMs that were buried in deep soil layers migrated upward and were a significant pollution risk. Urgent actions should be taken to identify and alleviate the contamination sources of these deep soils in addition to the conventional leaching and migration processes of surface contaminants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

A comprehensive evaluation of the effects of cerium on plants is lacking even though cerium is extensively applied to the environment. Here, the effects of cerium on plants were meta-analyzed using a newly developed database consisting of approximately 8500 entries of published data. Cerium affects plants by acting as oxidative stressor causing hormesis, with positive effects at low concentrations and adverse effects at high doses. Production of reactive oxygen species and its linked induction of antioxidant enzymes (e.g. catalase and superoxide dismutase) and non-enzymatic antioxidants (e.g. glutathione) are major mechanisms driving plant response mechanisms. Cerium also affects redox signaling, as indicated by altered GSH/GSSG redox pair, and electrolyte leakage, Ca 2+ , K + , and K + /Na + , indicating an important role of K + and Na + homeostasis in cerium-induced stress and altered mineral (ion) balance. The responses of the plants to cerium are further extended to photosynthesis rate (A), stomatal conductance (g s ), photosynthetic efficiency of PSII, electron transport rate, and quantum yield of PSII. However, photosynthesis response is regulated not only by physiological controls (e.g. g s ), but also by biochemical controls, such as via changed Hill reaction and RuBisCO carboxylation. Cerium concentrations <0.1-25 mg L -1 commonly enhance chlorophyll a and b, g s , A, and plant biomass, whereas concentrations >50 mg L -1 suppress such fitness-critical traits at trait-specific concentrations. There was no evidence that cerium enhances yields. Observations were lacking for yield response to low concentrations of cerium, whereas concentrations >50 mg Kg -1 suppress yields, in line with the response of chlorophyll a and b. Cerium affects the uptake and tissue concentrations of several micro- and macro-nutrients, including heavy metals. This study enlightens the understanding of some mechanisms underlying plant responses to cerium and provides critical information that can pave the way to reducing the cerium load in the environment and its associated ecological and human health risks., Competing Interests: Declaration of competing interest E.A. is the Managing Editor of the Virtual Special Issue in which this article is published; however, he was not involved in the peer-review process of this article. The authors declare that they have no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The contamination of soil with organic pollutants has been accelerated by agricultural and industrial development and poses a major threat to global ecosystems and human health. Various chemical and physical techniques have been developed to remediate soils contaminated with organic pollutants, but challenges related to cost, efficacy, and toxic byproducts often limit their sustainability. Fortunately, phytoremediation, achieved through the use of plants and associated microbiomes, has shown great promise for tackling environmental pollution; this technology has been tested both in the laboratory and in the field. Plant-microbe interactions further promote the efficacy of phytoremediation, with plant growth-promoting bacteria (PGPB) often used to assist the remediation of organic pollutants. However, the efficiency of microbe-assisted phytoremediation can be impeded by (i) high concentrations of secondary toxins, (ii) the absence of a suitable sink for these toxins, (iii) nutrient limitations, (iv) the lack of continued release of microbial inocula, and (v) the lack of shelter or porous habitats for planktonic organisms. In this regard, biochar affords unparalleled positive attributes that make it a suitable bacterial carrier and soil health enhancer. We propose that several barriers can be overcome by integrating plants, PGPB, and biochar for the remediation of organic pollutants in soil. Here, we explore the mechanisms by which biochar and PGPB can assist plants in the remediation of organic pollutants in soils, and thereby improve soil health. We analyze the cost-effectiveness, feasibility, life cycle, and practicality of this integration for sustainable restoration and management of soil.

The release dynamics and mobilization of geogenic Ni, Co, and Cr in serpentine paddy soils under fluctuating redox conditions have not yet been well studied. Here we investigated the release dynamics of Cr, Co, and Ni and controlling factors (e.g., Fe, Mn, Mg, Cl - , PO 4 3- , SO 4 2- , and dissolved organic carbon (DOC)) in a geogenic-contaminated serpentine soil under wide range of redox potential (E H ) changes. The effects of re-oxidation process have been also investigated. The soil was incubated for 28 days and E H was controlled from oxidation (+200 mV) to reduction (-200 mV) and re-oxidation (+240 mV) using a microcosm setup in duplicates. The slurry pH increased, along with decreasing E H . The average concentration of dissolved Co (17.1-23.6 μg L -1 ) decreased under low E H /high pH and vice versa. The average concentration of dissolved Cr decreased sharply from 624 μg L -1 to 54.4 μg L -1 with decreasing E H from +200 mV to 0 mV and the associated increase of pH from 7.8 to 8.5; then, it was constant around 24.5 μg L -1 . Concentration of dissolved Ni was lower (73.5-84.6 μg L -1 ) under high E H at the first week of incubation; then, increased to 108.5 μg L -1 under low E H (-200 mV); thereafter, increased more at the end up to 124.5 μg L -1 at high E H (+240 mV), because of the pH decrease. A factor analysis identified that Cr and Co formed one group with Mn and Mg, while Ni was clustered together with Cl - , DOC, and SO 4 2- . This indicates that the redox-induced release dynamic of Cr and Co was mainly governed by MnMg compounds, while the release of Ni was mainly affected by the aliphatic compounds of DOC and the redox chemistry of chlorides and sulfur in this soil. The re-oxidation increased the mobilization of Ni and Co and did not affect the release of Cr. These findings suggest that the redox-induced mobilization of geogenic Co, Ni, and Cr from soil to water in serpentine rice soils should be considered due to the high solubility and thus the associated bioavailability and potential environmental and human health risks, when such metal-enriched soils will be used for agricultural flood-dry cycle systems., Competing Interests: Declaration of competing interest There is no conflict of interest for this study., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Rare earth elements (REEs) concentrated in soils have attracted increasing attention about their impact on soil health as emerging contaminants. However, the sources of REEs enriched in soils are diverse and need to be further investigated. Here, surface soil samples were collected from southern Jiangxi Province, China. REEs contents and soil physicochemical properties were determined, and cerium (Ce) and europium (Eu) anomalies were calculated. Moreover, we established a model to further identify the main sources of REEs accumulation in the studied soils. Results show that the abundance of soil REEs reveals larger spatial variation, suggesting spatially heterogeneous distribution of REEs. The median content of light REEs in soils (154.5 mg kg -1 ) of the study area was higher than that of heavy REEs and yttrium (35.8 mg kg -1 ). In addition, most of the soil samples present negative Ce anomalies and all the soil samples present negative Eu anomalies implying the combined effect of weathering and potential exogenous inputs on soil REEs. Positive matrix factorization modeling reveals that soil REEs content is primarily influenced by soil parent materials. Potential anthropogenic sources include mining-related leachate, traffic exhaust, and industrial dust. These results demonstrate that the identification of sources of soil REEs is an important starting point for targeted REEs sources management and regulation of excessive and potentially harmful REEs levels in the soil., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

This work proposes a facile methodology for producing porous biochar material (ABC) from açaí kernel residue, produced by chemical impregnation with ZnCl2 (1:1) and pyrolysis at 650.0 °C. The characterization was achieved using several techniques, and the biochar material was employed as an adsorbent to remove catechol. The results show that ABC carbon has hydrophilic properties. The specific surface area and total pore volume are 1315 m2·g−1 and 0.7038 cm3·g−1, respectively. FTIR revealed the presence of oxygenated groups, which can influence catechol adsorption. The TGA/DTG indicated that the sample is thermally stable even at 580 °C. Adsorption studies showed that equilibrium was achieved in <50 min and the Avrami kinetic model best fits the experimental data, while Freundlich was observed to be the best-fitted isotherm model. Catechol adsorption on ABC biochar is governed by van der Waals forces and microporous and mesoporous filling mechanisms. The Qmax is 339.5 mg·g−1 (40 °C) with 98.36% removal of simulated effluent, showing that açaí kernel is excellent biomass to prepare good biochar that can be efficiently used to treat real industrial effluents.

Nanoplastics are drawing a significant attention as a result of their propensity to spread across the environment and pose a threat to all organisms. The presence of nanoplastics in water is given attention nowadays as the transit of nanoplastics occurs through the aquatic ecosphere besides terrestrial mobility. The principal removal procedures for macro-and micro-plastic particles are effective, but nanoparticles escape from the treatment, increasing in the water and significantly influencing the society. This critical review is aimed to bestow the removal technologies of nanoplastics from aquatic ecosystems, with a focus on the treatment of freshwater, drinking water, and wastewater, as well as the importance of transit and its impact on health concerns. Still, there exists a gap in providing a collective knowledge on the methods available for nanoplastics removal. Hence, this review offered various nanoplastic removal technologies (microorganism-based degradation, membrane separation with a reactor, and photocatalysis) that could be the practical/effective measures along with the traditional procedures (filtration, coagulation, centrifugation, flocculation, and gravity settling). From the analyses of different treatment systems, the effectiveness of nanoplastics removal depends on various factors, source, size, and type of nanoplastics apart from the treatment method adopted. Combined removal methods, filtration with coagulation offer great scope for the removal of nanoplastics from drinking water with >99 % efficiency. The collected data could serve as base-line information for future research and development in water nanoplastics cleanup., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Neonicotinoid (NEO) pesticides have become a potential risk to ecological safety and human health after application. The combined use of biochar and organic fertilizer (OF) is a promising approach to reduce pesticide adverse effects and improve soil fertility in agricultural soils. However, the combined remediation effects of biochar and OF on immobilization and dissipation of NEOs in soils have not previously been systematically investigated. In this study, biochars derived from peanut shell prepared at low/high pyrolysis temperatures (PS400 and PS900) were combined with composted chicken manure (CCM) as an example for OF to remediate contaminated soils toward six typical NEOs, nitenpyram (NIT), thiamethoxam (THIA), clothianidin (CLO), imidacloprid (IMI), acetamiprid (ACE), thiacloprid (THI). Results shown that both biochars and CCM were effective in improving soil sorption capacity and immobilization efficiency. The Freundlich affinity parameters (K f ) of NEOs in soils increased 7.2-12.0 times after the combined remediation of biochar and CCM, and the K f of six NEOs had negative correlation with their lipophilicity (p < 0.05), which followed by THI > ACE ≈ IMI > CLO > THIA > NIT. Meanwhile, NEOs-abiotic degradation was accelerated by biochar, CCM and their combined addition by adjusting soil pH and stimulating hydrolysis action. Biotic degradation was dominant in NEOs dissipation processes in amended soils, and the contribution ratios of biotic degradation (CR bio ) were in the range of 25.4-99.0%. The combined use of biochar and CCM selectively stimulated the relative abundance of NEOs-degraders, which simplified abiotic degradation of -NO 2 -containing NEOs (viz., NIT, THIA, CLO, and IMI), but inhibited -C≡N-containing NEOs (viz., ACE and THI). The combined remediation provided a strategy for immobilizing NEOs and facilitating dissipation of -NO 2 -containing NEOs in soils. The results in this study provide valuable information for policymakers and decision-makers to choose appropriate soil remediation approaches with respect to the NEO types., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

High-technology rare earth elements (REEs) as emerging contaminants have potentially hazardous risks for human health and the environment. Investigating the sorption of REEs on soils is crucial for understanding their migration and transformation. This study evaluated the sorption mechanisms and influencing factors of the rare earth element yttrium (Y) on paddy soil via integrated batch sorption experiments and theoretical modeling analysis. Site energy distribution theory (SEDT) combined with kinetics, thermodynamics, and isotherm sorption models were applied to illustrate the sorption mechanism. In addition, the effects of phosphorus (P), solution pH, particle size of soil microaggregates, and initial Y content on the sorption processes were evaluated by self-organizing map (SOM) and Boruta algorithm. The sorption kinetic behavior of Y on paddy soil was more consistent with the pseudo-second-order model. Thermodynamic results showed that the Y sorption was a spontaneous endothermic reaction. The generalized Langmuir model well described the isotherm data of Y sorption on heterogeneous paddy soil and soil microaggregates surface. The maximum sorption capacity of Y decreased with increasing soil particle size, which may be related to the number of sorption sites for Y on paddy soil and soil microaggregates, as confirmed by SEDT. The heterogeneity of sorption site energy for Y was the highest in the original paddy soil compared with the separated soil microaggregates. The SOM technique and Boruta algorithm highlighted that the initial concentration of Y and coexisting phosphorus played essential roles in the sorption process of Y, indicating that the addition of phosphate fertilizer may be an effective way to reduce the Y bioavailability in paddy soil in practice. These results can provide a scientific basis for the sustainable management of soil REEs and a theoretical foundation for the remediation of REEs-contaminated soils., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

There are scarce data about the accumulation pattern and risk assessment of potentially toxic elements (PTEs) in soil and associated potential ecological risks, especially in less-developed countries. This study aims to assess the pollution levels and potential ecological risks of PTEs (As, Cr, Cd, Cu, Ni, Mn, Pb and Zn) in wastewater-irrigated arable soils and different edible-grown plants in selected areas of Vehari, Pakistan. The results revealed that the values of PTEs in soil samples were higher than their respective limit values by 20% for As, 87% for Cd, 15% for Cu, 2% for Cr, 83% for Mn, 98% for Fe, and 7% for Zn. The values of soil risk indices such as the potential ecological risk (PERI >380 for all samples), pollution load index (PLI >4 for 94% of studied samples), and degree of contamination (Dc > 24 for all samples) showed severe soil contamination in the study area. Some vegetables exhibited a high metal accumulation index (e.g., 8.1 for onion), signifying potential associated health hazards. Thus, long-term wastewater irrigation has led to severe soil contamination, which can pose potential ecological risks via PTE accumulation in crops, particularly Cd. Therefore, to ensure food safety, frequent wastewater irrigation practices need to be minimized and managed in the study area., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Abandoned gold mining spoils pose socio-environmental, human, and animal health impacts and threaten sustainability of mineral extraction. Green trials and ecological solutions are required to effectively remediate these contaminated soils and mitigate the associated risks. Here, we carried out a pot experiment using a highly contaminated soil (mean total As = 5104.0 mg/kg) collected from an abandoned mine spoil in Ghana. We aimed to quantify the impacts of compost, iron oxide, and poultry manure on the mobilization, fractionation, and uptake of As by ryegrass (Lolium perenne). The soil amendments were applied at a rate of 5% (w/w) each, separately or in combination. We extracted the mine spoil soil readily-bioavailable As and specific-sorbed As, and determined the As contents in plant and the uptake after harvest. The plant transfer indices for soil-to-root (bioconcentration factor, BCF), soil-to-shoot (bioaccumulation concentration- BAC), and root-to-shoot (translocation factor- TF) were also calculated. Addition of manure increased the mining readily-bioavailable As by 243% and specific-sorbed As by 38%, as compared to the control. Manure addition further aided root As-uptake by 134%, whilst its combination with compost increased uptake by 101%. Lone addition of manure and in combination with compost resulted in BCF above 1, indicating increased As-phytostability. The presence of carbon and iron in the roots of the ryegrass sorbed or precipitated As limited its soil-to-shoot and root-to-shoot transfer. These findings indicate that manure alone and in combination with compost can be used to augment the phytoremediation efficiency of ryegrass in the As-contaminated spoil., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Exploring the responses of greenhouse gas (GHG) emissions to land use conversion or reversion is significant for taking effective land use measures to alleviate global warming. A global meta-analysis was conducted to analyze the responses of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) emissions to land use conversion or reversion, and determine their temporal evolution, driving factors, and potential mechanisms. Our results showed that CH 4 and N 2 O responded positively to land use conversion while CO 2 responded negatively to the changes from natural herb and secondary forest to plantation. By comparison, CH 4 responded negatively to land use reversion and N 2 O also showed negative response to the reversion from agricultural land to forest. The conversion of land use weakened the function of natural forest and grassland as CH 4 sink and the artificial nitrogen (N) addition for plantation increased N source for N 2 O release from soil, while the reversion of land use could alleviate them to some degree. Besides, soil carbon would impact CO 2 emission for a long time after land use conversion, and secondary forest reached the CH 4 uptake level similar to that of primary forest after over 40 years. N 2 O responses had negative relationships with time interval under the conversions from forest to plantation, secondary forest, and pasture. In addition, meta-regression indicated that CH 4 had correlations with several environmental variables, and carbon-nitrogen ratio had contrary relationships with N 2 O emission responses to land use conversion and reversion. And the importance of driving factors displayed that CO 2 , CH 4 , and N 2 O response to land use conversion and reversion was easily affected by NH 4 + and soil moisture, mean annual temperature and NO 3 - , total nitrogen and mean annual temperature, respectively. This study would provide enlightenments for scientific land management and reduction of GHG emissions., (© 2022 John Wiley & Sons Ltd.)

Main Conclusion: Drought may be efficiently managed using the following strategies: prevention, mitigation, readiness, recovery, and transformation. Biotechnological interventions may become highly important in reducing plants' drought stress in order to address key plant challenges such as population growth and climate change. Drought is a multidimensional construct with several triggering mechanisms or contributing factors working at various spatiotemporal scales, making it one of the known natural catastrophes. Drought is among the causes of hunger and malnutrition, decreasing agricultural output, and poor nutrition. Many deaths caused in children are due to hunger situations, and one in four children face stunted growth. All this hunger and malnutrition may be responsible for the reduction in agricultural productivity caused due to the drought situations affecting food security. Global Hunger Index has been accelerating due to under-nutrition and under-5 deaths. Drought has been covering more than 20% of the world's agricultural areas, leading to significantly less food production than what is required for consumption. Drought reduces soil fertility and adversely affects soil biological activity reducing the inherent capacity of the soil to support vegetation. Recent droughts have had a much greater effect on people's lives, even beyond causing poverty and hunger. Drought may have substantial financial consequences across the globe it may cause a severe impact on the world economy. It is a natural feature of the environment that will appear and disappear as it has in history. Due to increasing temperatures and growing vulnerabilities, it will undoubtedly occur more often and seriously in the coming years. To ensure sustainable socio-economic and social development, it is critical to reducing the effects of potential droughts worldwide using different biotechnological interventions. It's part of a long-term growth plan, and forecasting is essential for early warnings and global hunger management., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The current study was designed to investigate whether application of irradiated chitosan (ICn), a recently established plant growth promoter, can prove effective in alleviating arsenic (As) stress in peppermint, a medicinally important plant. This study investigated how foliar application of ICn alleviated As toxicity in peppermint ( Mentha piperita L.). Peppermint plants were treated with ICn (80 mg L -1 ) alone or in combination with As (10, 20, or 40 mg kg -1 of soil, as Na 2 HAsO 4 ·7H 2 O) 40 days after transplantation (DAT), and effects on the growth, photosynthesis, and antioxidants were assessed at 150 DAT as stress severely decreases plant growth, affects photosynthesis, and alters enzymatic (ascorbate peroxidase, superoxide dismutase) and non-enzymatic (glutathione) antioxidants. When applied at 40 mg kg -1 , ICn significantly decreased the content of essential oil (EO) and total phenols in peppermint by 13.8 and 16.0%, respectively, and decreased phenylalanine ammonia lyase (PAL) and deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) activities by 12.8 and 14.6%, respectively. Application of ICn mitigated the disadvantageous effects caused by As toxicity in peppermint by enhancing activities of antioxidative enzymes and photosynthesis and increased accretion of secondary metabolism products (EOs and phenols). An enhancement of total phenols (increased by 17.3%) and EOs (36.4%) is endorsed to ICn-stimulated enhancement in the activities of PAL and DXR (65.9 and 28.9%, respectively) in comparison to the control. To conclude, this study demonstrated that foliar application of ICn (80 mgL -1 ) effectively promoted the growth and physiology of peppermint and eliminated As-induced toxicity to achieve high production of EO-containing crops grown in metal-contaminated soils., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ahmad, Dar, Khan, Ahmad, Rinklebe, Chen and Ahmad.)

Biochar amendment to paddy soils was promising to mitigate mercury (Hg) accumulation in rice; thus, it was applied to reduce human Hg exposure via rice consumption. However, how biochar affects Hg mobilization and MeHg formation in soil under changed redox potential (E h ) conditions remained unknown. Here, we explored the change of dissolved total Hg (DTHg) and dissolved MeHg (DMeHg), and their controlling biogeochemical factors in a soil with(out) biochar amendment under changing E h conditions using biogeochemical microcosm. Biochar amendment resulted in a widen E h range (-300 to 400 mV) compared to the control (-250 to 350 mV), demonstrating that biochar promoted reduction-oxidization reactions in soil. Biochar amendment enhanced Hg mobilization by mediating reductive dissolution of Fe/Mn (hydr)oxides. Thus, the increased Hg availability promoted MeHg formation in the soils. Biochar amendment changed the soil organic matter (SOM) composition. Positive correlations between the relative abundance of LIPID (lipids, alkanes/alkenes), ALKYL (alkylaromatics), and suberin and MeHg concentrations indicate that these SOM groups might be related to MeHg formation. Biochar enhanced the releasing and methylation of Hg by promoting the mobilization of Fe(oxyhydr)oxides and alternation of carbon chemistry under dynamic E h conditions. There is an unexpected environmental risk associated with biochar application to paddy soils under dynamic E h condition, and one should be aware this risk when applying biochar aiming to minimize human Hg exposure health risks via rice consumption., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

It is estimated that over 700,000 tons of synthetic dyes are produced annually, 15% of which are emitted as effluents. These highly stable dyes enter the world water ecosystems and stay in the environment, and eventually cause adverse impacts to the environment. Current wastewater treatment methods, such as filtration, coagulation, and chemical oxidation, have sideeffects, including toxic residue formation, membrane fouling, bioaccumulation, and secondary pollutant formation. Given the issues mentioned, it is necessary to study how to improve the degradation of synthetic dye with a cost-effective and ecofriendly approach. Natural oxidation provides a greener option. Recently, Deuteromycetes fungus Myrothecium verrucaria G-1 (M. verrucaria G-1) has shown great potential in producing high level of dye oxidase. This study aims to generate a dye oxidase hyperproducer, 3H6 from M. verrucaria G-1 by using atmospheric and room temperature plasma (ARTP) coupled with ultraviolet (UV) irradiation. This method increases oxidase production by nearly 106.15%. After a simple precipitation and dialysis, this mutant oxidase increases by 1.97-fold in a specific activity with dye degradation rates at 70% for Mmethylene blue (MB) and 85% for Congo red (CR). It is found that the genetic stability of 3H6 remains active for ten generations. The size of oxidase is 65 kDa, and optimum temperature for reaction is 30 °C with 4.5 pH. This study presents that the first combined mutagenesis approach by ARPT-UV on fungus species generates an impressive increment of acid dye oxidases production. As such, this method presents a cost-effective alternative to mitigate hazardous dye pollution., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Environmental pollution by mercury is a world-wide problem. Particularly floodplain ecosystems are frequently affected. One example is the Elbe River in Germany and its catchment areas; large amounts of Hg from a range of anthropogenic and geogenic sources have been accumulated in the soils of these floodplains. They serve as sink for Hg originating from the surface water of adjacent river. Today, the vastly elevated Hg contents of the floodplain soils at the Elbe River often exceed even the action values of the German Soil Conservation Law. This is especially important as Hg polluted areas at the Elbe River achieve several hundred square kilometres. Thus, authorities are coerced by law to conduct an appropriate risk assessment and to implement practical actions to eliminate or reduce environmental problems. A reliable risk assessment particularly with view to organisms (vegetation as green fodder and hay production, grazing and wild animals) to avoid the transfer of Hg into the human food chain, requires an authentic determination of Hg fluxes and their dynamics since gaseous emissions from soil to atmosphere are an important pathway of Hg. However, reliable estimates of Hg fluxes from the highly polluted floodplain soils at the Elbe River and its tributaries, and its influencing factors are scarce. For this purpose, we have developed a new method to determine mercury emissions from soils at various sites. Our objectives were i) to quantify seasonal variations of total gaseous mercury (TGM) fluxes for floodplain soils at the Elbe River, ii) to provide insights into physico-chemical processes regulating these TGM fluxes, and iii) to quantify the impacts of the controlling factors soil temperature and soil water content on Hg volatilization from a typical contaminated floodplain soil within soil microcosm experiments under various controlled temperature and moisture conditions. Our study provides insight into TGM emissions from highly Hg-polluted floodplain soils in Germany and that those emissions are an underestimated problem. Current needs for reliable risk assessments, the induced implications for authorities, and future challenges will be discussed. The presented data will contribute to a better understanding of seasonal dynamics of Hg fluxes and its controlling factors. This presentation should be of large interest for a wide international audience, such as environmental scientists and managers, applied ecologists, and authorities.

Trace elements are potentially toxic to human life and the environment. Element toxicity depends on chemical associations in soils. Therefore, determining the chemical form of an element in soils is important to evaluate its mobility and bioavailability. Initial soil development in river floodplains influences soil properties, processes and therefore behavior of trace elements. In this study, three different floodplain soils sampled at three rivers (Nile/Egypt, Elbe/Germany and Penios/Greece) were used to link soil development and properties to the geochemical fractions and mobility of some trace elements. Sequential extraction was used to fractionate five trace elements (Cd, Cu, Ni, Pb and Zn) into five operationally defined groups: water soluble + exchangeable, carbonate, Fe-Mn oxide, organic, and residual. German soil showed the highest total concentration of the studied elements (except Ni). The Greek soil had the greatest amount of Ni. The residual fraction was the abundant pool for the studied elements examined in the Egyptian and Greek soils while the non-residual fraction was the dominant pool for all elements in the German soil. A significant amount (71- 94%) of all elements was present in German soil in the potentially available fraction: non-residual fraction, while the amount of this fraction ranged between 9 and 39 % in Greek soil and between 9 and 34 % in Egyptian soil. These suggest that the potential availability of the studied trace elements was extremely high in German soil compared to the Egyptian and Greek soil. In the German soil, most of the non-residual Cd, Ni and Zn were bounded with the Fe-Mn oxide fraction, while Cu and Pb distributed in the organic fraction. While in the Egyptian and Greek soils Fe-Mn oxide fraction was the abundant pool for the studied elements except for Cd, in which the exchangeable and the carbonate fractions had the greatest amount of Cd. Assuming that mobility and bioavailability of these elements are related to their solubility and geochemical forms, and that they decrease in the order of extraction sequence, the apparent mobility and potential bioavailability for the studied elements in the soils were: Cu > Cd > Ni ≥ Pb = Zn in Egyptian soil, Cd > Cu > Pb> Ni = Zn in Greek soil and Cd > Zn> Pb> Cu > Ni in German soil.

Land treatment has become an essential waste management practice. Therefore, soil becomes a major source of contaminants including organic chemicals and potentially toxic elements (PTEs) which enter the food chain, primarily through leaching to potable water sources, plant uptake, and animal transfer. A range of soil amendments are used to manage the mobility of contaminants and subsequently their bioavailability. Various soil amendments, like desorbing agents, surfactants, and chelating agents, have been applied to increase contaminant mobility and bioavailability. These mobilizing agents are applied to increase the contaminant removal though phytoremediation, bioremediation, and soil washing. However, possible leaching of the mobilized pollutants during soil washing is a major limitation, particularly when there is no active plant uptake. This leads to groundwater contamination and toxicity to plants and soil biota. In this context, the present review provides an overview on various soil amendments used to enhance the bioavailability and mobility of organic and inorganic contaminants, thereby facilitating increased risk when soil is remediated in polluted areas. The unintended consequences of the mobilization methods, when used to remediate polluted sites, are discussed in relation to the leaching of mobilized contaminants when active plant growth is absent. The toxicity of targeted and non-targeted contaminants to microbial communities and higher plants is also discussed. Finally, this review work summarizes the existing research gaps in various contaminant mobilization approaches, and prospects for future research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Globally, the valorisation of food waste into digestate through the process of anaerobic digestion is becoming increasingly popular. As a result, a large amount of food-waste digestate will need to be properly utilised. The utilisation of anaerobic digestion for fertiliser and alternative uses is essential to obtain a circular bioeconomy. The review aims to examine the environmental management of food-waste digestate, the value of digestate as a fertiliser and soil conditioner, and the emerging uses and improvements for post-anaerobic digestion reuse of digestate. Odour emissions, contaminants in food waste, emission and leaching of nutrients into the environment, and the regulations, policies, and voluntary initiatives of anaerobic digestion are evaluated in the review. Food-waste digestate can provide essential nutrients, carbon, and bio-stimulants to soils and increase yield. Recently, promising research has shown that digestates can be used in hydroponic systems and potentially replace the use of synthetic fertilisers. The integration of anaerobic digestion with emerging uses, such as extraction of value-added products, algae cultivation, biochar and hydrochar production, can further reduce inhibitory sources of digestate and provide additional economic opportunities for businesses. Moreover, the end-product digestate from these technologies can also be more suitable for use in soil application and hydroponic use., (Copyright © 2022 Elsevier Ltd. All rights reserved.)