As a green remediation technology for complete remediation of contaminated soil, the combination of easily recoverable adsorbents and washing still faces challenges such as low remediation efficiency and unclear remediation mechanisms. Hence, the bis Schiff base functional group comprising sulfhydryl groups was loaded into the UiO-66 calcium alginate spheres (UiO-66-AMB-ACPs) to obtain efficient selective adsorption. The results of response surface optimization showed that the maximum removal of Pb and Cd from soil reached 69.73% and 82.63% by the combination of UiO-66-AMB-ACPs with acetic acid, of which about 95.55% and 60.31% were attributed to the adsorption. Factor interaction analysis demonstrated that solid-liquid ratio combined with either adsorbent dosage or acetic acid concentration significantly affected Cd adsorption rates. In the above system, Schiff bases,-SH, and carboxylic acids in UiO-66-AMB-ACPs compete for the Pb and Cd captured by acetic acid through chelation, ion exchange, and complexation, which assisted in maintaining the high desorption rate to further enhance the resolution process of acid-soluble and reduced Pb and Cd. The release of free acetic acid will again participate in the resolution of heavy metals, thus constituting an internal cycle of acetic acid. UiO-66-AMB-ACPs were maintained in a stable state during each of the 18 cycles. The remediated soil retained most of the plant nutrients, while the mobility of residual heavy metals was greatly inhibited. This technique showed promise for the total removal and recovery of Pb and Cd from contaminated soils with low damage and short time while immobilizing the residual heavy metals.

Rampant industrial growth and urbanization have caused a wide range of hazardous contaminants to be released into the environment resulting in several environmental issues that could eventually lead to ecological disasters. The unscientific disposal of urban and industrial wastes is a critical issue as it can cause soil contamination, bioaccumulation in crops, groundwater contamination, and changes in soil characteristics. This article explores the impact of various industrial and urban wastes, including petroleum hydrocarbons (PHs), coal-fired fly ash, municipal solid waste (MSW) and wastewater (MWW), and biomedical waste (BMW) on various types of soil. The contamination and impact of each of these wastes on soil properties such as compaction characteristics, plasticity, permeability, consolidation characteristics, strength characteristics, pH, salinity, etc is studied in detail. Most of the studies indicate that these wastes contain heavy metals, organics, and other hazardous compounds. When applied to the soil, PHs tend to cause large settlements and reduction in plasticity, while the effect of coal-fired fly ash varies as it mainly depends on the type of soil. From the studies it was seen that the long-term application of MWW improves the soil health and properties for agricultural purposes. Significant soil settlements were observed in areas of MSW disposal, and studies show that MSW leachate also alters soil properties. While the impacts of direct BMW disposal have not been extensively studied, few researchers have concentrated on utilizing certain components of BMW, like face masks and nitrile gloves to enhance the geotechnical characteristics of weak soil. Soil remediation is required to mitigate the contamination caused by heavy metals and PHs from these wates to improve the soil quality for engineering and agricultural purposes, avert bioaccumulation in crops, and pose less environmental and public risks, and ecotoxicity. Coal-fired fly ash and biomedical waste ash contain compounds that promote pozzolanic reactions in soil, recycling and reuse as soil stabilizers offer an effective strategy for their reduction in the environment, thus complying to sustainable practices. In essence, this study offers a contemporary information on the above aspects by identifying the gaps for future research and mitigation strategies of contaminated soils.

Antimony smelting activities damage the soil and vegetation surroundings while generating economic value. However, no standardized methods are available to diagnose the extent of soil degradation at antimony smelting sites. This study developed a standardized framework for assessing soil quality by considering microbial-induced resilience and heavy metal contamination at Xikuangshan antimony smelting site. The soil resilience index (SRI) and soil contamination index (SCI) were calculated by Minimum Data Set and geo-accumulation model, respectively. After standardized by a multi-criteria quantitative procedure of modified Nemerow's pollution index (NPI), the integrated assessment of soil quality index (SQI), which is the minimum of SRINPI and SCINPI, was achieved. The results showed that Sb and As were the prominent metal(loid) pollutants, and significant correlations between SQI and SRI indicated that the poor soil quality was mainly caused by the low level of soil resilience. The primary limiting factors of SRI were Fungi in high and middle contaminated areas, and Skermanella in low contaminated area, suggesting that the weak soil resilience was caused by low specific microbial abundances. Microbial regulation and phytoremediation are greatly required to improve the soil quality at antimony smelting sites from the perspectives of pollution control and resilience improvement. This study improves our understanding of ecological effects of antimony smelting sites and provides a theoretical basis for ecological restoration and sustainable development of mining areas. (c) 2024 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Cadmium (Cd) is an abiotic stressor negatively affecting plant growth and reducing crop productivity. The effects of Cd (25 mu M) and of pre-soaking seeds with salicylic acid (SA) (500 mu M) on morphological, physiological, and glycerolipid changes in two cultivars of wheat (Triticum aestivum L. 'Tosunbey' and 'Cumhuriyet') were explored. Parameters measured were length, fresh and dry biomass, Cd concentration, osmotic potential (psi), lipid peroxidation, and polar lipid species in roots and leaves, as well as leaf chlorophyll a, carotenoids, and fv/fm. Fresh biomass of roots and leaves and leaf length were strongly depressed by Cd treatment compared to the control, but significantly increased with SA + Cd compared to Cd alone. Cd reduced leaf levels of chlorophyll a, carotenoids, and fv/fm, compared to controls. Treatment with SA + Cd increased pigment levels and fv/fm compared to Cd alone. Cd treatment led to a decrease in DW of total membrane lipids in leaves and depressed levels of monogalactosyldiacylglycerol and phosphatidic acid in leaves and roots of both cultivars. The effects of SA priming and SA + Cd treatment on lipid content and composition were cultivar-specific, suggesting that lipid metabolism may not be a primary target underlying SA remediation of the damaging effects of Cd on wheat growth and development.

Heavy metals (HM) are toxic to the microbiota of agricultural soils because they affect the development of bacteria and fungi that promote plant growth and are agents of biological control of pathogenic organisms. In this regard, fungi ofthe genus Trichoderma have these functions in plants, but like other organisms, HM affects their growth and biological activity. This article reviews the lithogenic and anthropogenic sources of generation of HM Cu, Cr-VI, Pb, and Cd, the tolerance mechanisms, and the antioxidant response to oxidative damage in Trichoderma caused by HM. It was identified that in some agricultural soils, the HM content increases mainly due to irrigation with wastewater and the intensive use of agrochemicals, such as pesticides and fertilizers. In Trichoderma, the tolerance mechanisms to Cu, Cr-VI, Pb, and Cd include biosorption, bioaccumulation, and biotransformation. In contrast, studies of the antioxidant response of Trichoderma to oxidative stress caused by MP are scarce. In the case of Cu and Cr, a relationship between changes in antioxidant enzyme activity and a decrease in the oxidation of cell membrane lipids is reported. This represents an opportunity to understand the toxic effect of MP on fungi of the genus Trichoderma, which is part of the biotic soil community.

Soil pollution caused by potentially toxic transition metals has become a worldwide environmental issue. Geogenic processes and anthropogenic activities are two important sources of soil pollution. Soils may inherit toxic transition metals from parent materials; however, soil pollution mostly results from industrial and agricultural activities. Contamination by transition metals can be indicated by the changes in chemical, biochemical, and microbial properties of soils and plant responses. The target of this research is removing transition metals of chromium (Cr), manganese (Mn), iron (Fe), zinc (Zn), tungsten (W), cadmium (Cd) from soil due to nanomaterial-based boron nitride nanocage (B5N10-nc). The electromagnetic and thermodynamic attributes of toxic transition metals trapped in B5N10-nc was depicted by materials modeling. The encapsulation of these elements occurs via chemisorption. It has been studied the behavior of trapping of Cr, Mn, Fe, Zn, W, Cd by B5N10-nc for sensing the soil metal cations. B5N10-nc was designed in the existence of transition metals (Cr, Mn, Fe, Zn, W, Cd). Case characterization was performed by DFT method. The nature of covalent features for these complexes has represented the analogous energy amount and vision of the partial density of states between the p states of boron and nitrogen in B5N10-nc with d states of transition metals in X B5N10-nc complexes (X= Cr, Mn, Fe, Zn, W, Cd). Furthermore, the nuclear magnetic resonance (NMR) analysis indicated the notable peaks surrounding Cr, Mn, Fe, Zn, W, Cd through the trapping in the B5N10-nc during atom detection and removal from soil; however, it can be seen some fluctuations in the chemical shielding treatment of isotropic and anisotropy tensors. Based on the results in this research, the selectivity of toxic metal, metalloid and nonmetal elements adsorption by B5N10-nc (atom sensor) have been indicated as: Cd > Zn > Fe > Cr > Mn approximate to W. In this article, it is proposed that toxic metal, metalloid and nonmetal elements-adsorbed might be applied to design and expand the optoelectronic specifications of B5N10-nc for generating photoelectric instruments toward soil purification.

This study investigates the long-term effects of landfill leachate contamination on soil hydraulic conductivity and shear strength parameters over a 12-month period, addressing the current lack of comprehensive long-term experimental data in this field. Laboratory permeability tests and direct shear tests were performed on sandy clayey silt samples contaminated with leachate at concentrations ranging from 5% to 25%. Microstructural and mineralogical analyses were conducted using SEM and XRD to identify the mechanisms behind observed changes. The results identify a critical threshold at 15% contamination where soil behavior transitions from granular to cohesive characteristics, marked by significant changes in both hydraulic and mechanical properties. Hydraulic conductivity increases at low contamination levels but decreases significantly at higher levels, while friction angle shows an immediate reduction from 36.5 degrees to 31-31.5 degrees and cohesion exhibits a three-phase evolution pattern, reaching peak increases of 151.5% at 15% contamination. The hydraulic conductivity changes are controlled by contamination level rather than exposure time, maintaining stable values throughout the testing period, whereas shear strength parameters demonstrate more complex temporal evolution patterns. These findings provide essential parameters for landfill design and stability assessment, demonstrating how leachate concentration affects long-term soil behavior through mineral formation and structural modification.

Heavy metal contamination in water and soil presents a growing global issue that poses significant risks to environmental integrity and human well-being. Various heavy metals, including arsenic (As), lead (Pb), mercury (Hg), cadmium (Cd), and chromium (Cr), contaminate ecosystems. These metals enter the environment through both natural processes and human activities such as coal mining, leather production, metal processing, agriculture, and industrial waste disposal. With their high toxicity and tendency to accumulate in organisms, heavy metals induce oxidative stress in cells, resulting in organelle damage. This toxicity can lead to genetic mutations and histone alterations. Given the severe effects of heavy metals, urgent actions are required to eliminate them from polluted soil and water. While physicochemical techniques like membrane filtration, precipitation, oxidation, and reduction exist, they have limitations. Hence, there is a pressing need to devise environmentally friendly and cost-efficient approaches for heavy metal removal. This article examines heavy metal contamination in water and soil, its adverse impacts, and the cleanup of heavy metals using eco-friendly methods. [GRAPHICAL ABSTRACT]

Significant efforts have been made to develop environmentally friendly remediation methods to restore petroleum-damaged ecosystems. One such approach is cultivating plant species that exhibit high resistance to contamination. This study aimed to assess the impact of petroleum-derived soil pollutants on the photosynthetic performance of selected plant species used in green infrastructure development. A pot experiment was conducted using both contaminated and uncontaminated soils to grow six plant species under controlled conditions. Biometric parameters and chlorophyll a fluorescence measurements were taken, followed by statistical analyses to compare plant responses under stress and control conditions. This study is the first to simultaneously analyze PF, DF, and MR820 signals in plant species exposed to petroleum contamination stress. The results demonstrated that petroleum exposure reduced the activity of both PSII and PSI, likely due to increased nonradiative energy dissipation in PSII antenna chlorophylls, decreased antenna size, and/or damage to the photosynthetic apparatus. Additionally, petroleum contamination affected the electron transport chain efficiency, limiting electron flow between PSII and PSI. The most resistant species to petroleum-induced stress were Lolium perenne, Poa pratensis, and Trifolium repens.

Purpose Manganese (Mn) is crucial in low concentrations but can become toxic in soils and sediments, affecting plants and animals. Understanding how plants inoculated with arbuscular mycorrhizal fungi (AMF) tolerate Mn is crucial for the application of these microorganisms in the remediation of contaminated soils. Despite recognized benefits in various plant species, assessing plant-AMF interaction effectiveness in mitigating Mn toxicity is crucial for undocumented plants. Methods Acacia mangium Willd. plants were inoculated with an AMF native to a Mn mining area and grown in soil with increasing Mn levels (0, 200, and 400 mg kg(-1)) to evaluate the effects of inoculation on plant growth and plant-AMF association strategies to reduce Mn toxicity. Results Inoculation with AMF resulted in beneficial effects, minimizing Mn toxicity and enhancing plant growth, despite reduced mycorrhizal colonization and AMF spore levels in the soil. Non-inoculated plants exposed to 400 mg kg(-1) of Mn exhibited significant reductions in shoot dry mass (64.9%), number of leaves (25%), and root length (24%) compared to AMF-inoculated plants. Mn concentration was higher in the roots of AMF-inoculated plants at all Mn levels, indicating a restriction in Mn transport to the shoot, thus minimizing damage and promoting plant growth. Energy-dispersive spectroscopy identified Mn, potassium, phosphorus, iron and calcium in AMF spores, suggesting their protective role against Mn phytotoxicity and adaptability of this species of microorganism under stress conditions. Conclusion The native AMF inoculation reduces toxicity and improves the growth of A. mangium Willd. under high levels of Mn in the soil.