The efficacy and environmental effects of using metal-organic frameworks (MOFs) for the remediation of arsenic (As)-contaminated soil, a significant global problem, remain unclear. This study evaluated MIL-88A(Fe) and MIL101(Fe) coupled with ramie (Boehmeria nivea L.) for As-contaminated soil remediation. A soil incubation experiment revealed that 10,000 mg kg-1 MIL-88A(Fe) and MIL-101(Fe) reduced As bioavailability by 77.1 % and 65.0 %, respectively, and increased residual As fractions by 8 % and 7 % through Fe-As co-precipitation and adsorption. Divergent environmental effects emerged, which were probably due to differences in the framework structures and organic ligands: MIL-88A(Fe) improved soil urease activity and bacterial diversity, whereas MIL101(Fe) induced acidification (decreasing soil pH by 25 %) and salinity stress (elevating soil electrical conductivity (EC) by 946 %). A pot experiment showed that 1000 mg kg-1 MOFs enhanced ramie biomass via As immobilization, whereas 5000 mg kg-1 MIL-101(Fe) suppressed growth because exposure to the MOF caused root damage. The MOFs enriched Pseudomonas (As-oxidizing) and suppressed Dokdonella (pathogenic), enhancing plant resilience. Notably, 100 mg kg-1 MIL-101(Fe) increased As translocation to stems (14.8 %) and leaves (27.6 %). Hydroponic analyses showed that 50-200 mg L-1 MIL-101(Fe) mitigated As-induced chlorophyll degradation (elevating Soil and plant analyzer development (SPAD) by 12.8 %-28.3 %), whereas 500 and 1000 mg L-1 induced oxidative stress (reducing SPAD by 4.2 %-10.7 %). This study provides valuable insights into using Fe-based MOFs in soil remediation and highlights their beneficial and harmful effects.

Periphyton-based biofertilizer have a high potential for soil remediation, particularly for controlling soil salinization. This global environmental problem leads to low soil utilization and insufficient crop yields. Efficient and sustainable methods of managing saline soils are needed to reduce salinization and improve soil fertility and crop quality. Traditional methods such as physical mulching and chemical amendments, while improving soil conditions, exhibit limited effectiveness and may damage soil structure. This study aims to evaluate the feasibility of algae-based fertilizers in remediating saline-alkali soils and improving crop performance. The review delves into the and application prospects of algae-based fertilizers, highlighting their potential from both sustainable development and economic perspectives. It further advocates integrating other emerging technologies with the production and application of algae-based fertilizers to address the increasingly severe challenges posed by degraded soil resources and environmental instability. The review found that algal fertilizers are more environmentally friendly than traditional chemical fertilizers but are not inferior in function. This approach offers more efficient and sustainable solutions for managing saline-alkaline soils and effectively achieves sus-tainable agricultural production. Furthermore, it is necessary to conduct experimental research and monitoring evaluations of algal fertilizers to formulate scientific and rational fertilization plans to meet the increasingly serious challenges facing soil resources and unstable environments. The findings of this study will provide theoretical and technical support for using algae biofertilizers for soil remediation, improving crop quality and sequestering carbon.

Conventional in-situ light non-aqueous phase liquid (LNAPL) remediation techniques often face challenges of high costs and limited efficiency, leaving residual hydrocarbons trapped in soil pores. This study investigates the efficiency of an alcohol-in-biopolymer emulsion for enhancing diesel-contaminated soil remediation. The emulsion, formulated with xanthan gum biopolymer, sodium dodecyl sulfate surfactant, and the oil-soluble alcohol 1-pentanol, was evaluated through rheological tests, interfacial tension measurements, and onedimensional sand-column experiments under direct injection and post-waterflooding scenarios. The emulsion exhibited non-Newtonian shear-thinning behavior with high viscosity, ensuring stable propagation and efficient delivery of 1-pentanol to mobilize trapped diesel ganglia. It achieved 100 % diesel recovery within 1.2 PV during direct injection, outperforming shear-thinning polymer-only and polymer-surfactant solutions, which achieved recovery factors of 83.4-92.9 %. Post-waterflooding experiments also demonstrated 100 % diesel recovery within 1.3 PV, regardless of initial diesel saturation. Key mechanisms include reduced interfacial tension, diesel swelling and mobilization induced by 1-pentanol, and uniform displacement facilitated by the emulsion's viscosity. Additionally, the emulsion required lower injection pressures compared to more viscous alternatives, enhancing its injectability into the soil and reducing energy demands. These findings highlight the emulsion's potential to overcome conventional remediation limitations, offering a highly effective and sustainable solution for diesel-contaminated soils and groundwater.

This study presents a method for remediating soils contaminated by organic pollutants through the selective blocking of pores. This technique is based on the use of yield stress fluids, specifically concentrated biopolymer solutions, which, due to their distinctive rheological properties, preferentially flow through high-conductance flow paths. Following the injection of yield stress fluid, its presence redirects subsequent water flow towards the pores that are typically unswept during standard waterflooding. Laboratory experiments at the pore scale were conducted to validate this method and confirm previous findings from core-flooding experiments. Aqueous xanthan gum solutions were used as microscopic blocking agents in well-characterized micromodels exhibiting microscopic heterogeneities in pore size. The impact of polymer concentration, soil wettability and operating conditions (injection pressure and flow rate) on the residual pollutant saturation following treatment was analyzed, enabling the optimization of the remediation strategy. The use of xanthan gum as a blocking agent led to a significant improvement in pollutant removal compared to conventional waterflooding, delivering consistently better results across all cases studied. The method demonstrated strong performance in water-wet medium, with the average polymer concentration yielding the highest efficiency in pollutant removal.

Tetracycline (TC) is effectively used antibiotic in animal husbandry and healthcare, has damaged soil ecosystems due to its misuse and residues in the soil environment. Therefore, the main objective of this study was to abate TC in hyphosphere soil by inoculating soil with arbuscular mycorrhizal fungi (AMF) and to explore its potential mechanisms. The results showed that under TC stress, inoculation with AMF reduced the contents of soil organic carbon and total nitrogen, and increased the activities of beta-glucosidase and urease in hyphosphere soil. The relative abundance of bacterial genera such as Pseudomaricurvus in the hyphosphere soil increased significantly after AMF inoculation. In addition, four bacterial genera, Cellulosimicrobium, Roseibium, Citromicrobium, and Hephaestia, were uniquely present in AMF-inoculated soil, and the functional genes Unigene456231 and Unigene565663 were significantly enriched in the hyphosphere soil. This suggests that the reshaping of the bacterial community and the enrichment of functional genes in the hyphosphere soil led to changes in the bacterial community's functions, which promoted the gradual abatement of residual TC in the soil. It should be noted that this study was solely based on a single pot experiment, and its conclusions may have certain limitations in broader ecological application scenarios. Subsequent studies will further investigate the remediation effects under different environmental factors and field trials. This study provides new insights into the use of AMF as a biological agent for the remediation of TC-contaminated soils, offering new perspectives for promoting sustainable agricultural development.

Conventional pump-and-treat technologies have demonstrated limited effectiveness in remediating soils contaminated with light non-aqueous phase liquids (LNAPLs), such as petroleum hydrocarbons. Nonconventional in-situ flushing with shear-thinning fluids, such as polymers, offers a promising alternative. However, even with polymer flushing, residual LNAPL ganglia may remain trapped in porous media, requiring further improvement of the flushing fluid to enhance remediation efficiency. In this study, we present a novel alcohol-in-biopolymer emulsion developed to enhance the recovery of residual diesel oil from porous media. Batch experiments were conducted to evaluate the partitioning behavior of fifteen different alcohols between the aqueous and diesel phases. The results revealed that 1-pentanol preferentially partitions into the diesel phase rather than the aqueous phase, leading to an increase in diesel oil volume via a swelling mechanism. Furthermore, 1-pentanol forms a stable and homogeneous emulsion when combined with an aqueous solution of the biopolymer xanthan gum, and the surfactant sodium dodecyl sulfate. The emulsion demonstrated high stability for over 30 days, ensuring its suitability for prolonged remediation processes. Rheological experiments confirmed the emulsion's shear-thinning behavior, which ensures stable and uniform displacement within porous media. A two-dimensional cell packed with silica sand was used to evaluate the efficiency of the emulsion in removing residual diesel oil. The results demonstrated that the emulsion propagates uniformly throughout the porous media, effectively achieving complete removal of residual diesel within 1.15 pore volumes of injection. Porescale visualizations revealed the swelling and subsequent mobilization of entrapped diesel ganglia induced by the emulsion, further confirming its efficacy. These findings highlight the potential of this novel alcohol-inbiopolymer emulsion to significantly improve diesel oil recovery from contaminated soils.

Pyroligneous acids (PAs) amendments could reduce soil antibiotic resistance genes (ARGs) pollution, but their impacts on horizontal transformation of extracellular ARGs (eARGs) remain unclear. Here, a wood residues derived PA was selected to investigate its effect on ARG dissemination via transformation using a soil microcosm experiment and an in vitro transformation system. The PA application effectively decreased the abundances of representative ARGs and mobile genetic elements, demonstrating that the weakened horizontal gene transfer alleviated ARG pollution in the soil. PA showed an amount-dependent inhibition on the transformation as well as the three distilled fractions and chemical components, proving that their important roles in inhibiting eARG transformation. The relatively low-amount (1 mu L mL-1) of PA suppressed the transformation mainly by destroying the plasmid pBR322 structure, while the high-amount (10-100 mu L mL-1) of PA inhibited the transformation due to the inactivation of recipient Escherichia coli DH5 alpha by inducing oxidative stress and destroying cell membrane, and damages of plasmid by reducing eARGs abundance and broking the base deoxyribose, and phosphate skeletons. These findings expand the understanding of PA amendments mitigating ARG pollution in agricultural soils via inhibiting horizontal gene transformation, and also provide a practical strategy to remediate soil ARG pollution.

Mn-modified biochar could impact soil quality and metal(loid) migration in contaminated soils. However, the remediation efficiency, mechanism, and influencing factors of Mn-modified biochar on multi-metal(loid) contaminated soils were largely unknown. In this study, three Mn-modified biochar were prepared by using MnCl2-impregnated 2-impregnated rubber, tobacco rod, and coconut shell biochar, respectively. The remediation efficiency of Mn-modified biochar on Pb, As, Cd, Cu, and Zn contaminated soil was also compared. Our data revealed that the addition of Mn-modified biochar increased the effective cation exchange capacity (ECEC), organic matter (OM), alkaline hydrolyzed nitrogen (AHN), and the mobility of the nutrient Zn in the soil. Furthermore, Mn-modified rubber biochar and Mn-modified coconut shell biochar reduced acid extractable or Diethylenetriamine Pentaacetic Acid (DTPA) leached Pb, As, Cd, and Cu However, Mn-modified tobacco rod biochar increased the acid extractable or DTPA leached Pb, Cd, and Cu. The study showed that three Mn-modified biochars could effectively improve soil physicochemical properties and significantly increase soil nutrient activity. Mn-modified rubber and coconut shell biochar can effectively immobilize metal(loid)s and reduce their damage to soil. However, the Mnmodified tobacco rod biochar instead increased the mobility of metal(loid)s. The results indicate that feedstock is an important factor influencing the application of Mn-modified biochar and should be considered in the production.

Composite polymer materials as soil improvers are developed to enhance soil cohesion and aggregate stability. However, the improved soil still struggles to overcome the reduction in strength caused by day-to-day freeze-thaw (FT) cycle in the plateau area with large temperature difference. In this study, the natural power of FT cycle was used to drive the crosslinking of poly (vinyl alcohol) (PVA) and sodium alginate (SA) to form the interpenetrating networks of PVA-SA hydrogel. Then, this hydrogel was applied to stabilize the soil. The characterizations by FTIR, TGA, SEM and XRD indicated that the PVA-SA hydrogel had a porous, multi-channel and multi-chamber structure. Under the action of FT driving force, a series of studies including physical, chemical, water retention, direct shear, permeability, and aggregate stability were carried out on the soil with hydrogel applied. Compared to the control group, the data indicated that the cohesion of soil is significantly improved to 80 kPa. And the saturated hydraulic conductivity of the soil was reduced to 1/45 of the pre-modification rate, which had a positive impact on the water retention of the soil. What's more, the results revealed that the PVA-SA hydrogel had effects on the aggregate stability, the submerged soil with added PVA-SA hydrogel still had no sign of disintegration and its mass percentage was greater than 99% after 70 days. In a word, this composite material can effectively improve the cohesion and aggregate stability of the soil with the help of natural driving forces, which is potential to be used as remediation material for the plant layer in ecological restoration process.

Rapid economic development has led to an alarming increase in soil pollution by potentially toxic elements (PTEs), significantly reducing soil productivity and posing long-term threats to sustainable agriculture and human well-being. Over the past two decades, it has been observed that soil PTEs pollution has severely impacted biodiversity, with damage rates of 94.7 % in plants, 77.4 % in humans, and 68.4 % in animals. In response, various remediation technologies have been developed, considering factors such as practical applicability, treatment duration, and ecological safety. Microbial remediation has shown a PTEs removal efficiency ranging from 32.0 % to 95.2 %, while multi-technology combined remediation approaches have demonstrated broader efficacy, with removal rates ranging from 18.7 % to 381 %. However, the selection of a suitable remediation technology must also consider the cost to ensure efficient contaminant removal. This review provides a comprehensive overview of the local and international status, sources, and hazards associated with PTEs, as well as the environmental factors influencing their migration. It also examines the detoxification mechanisms of plants and microbial remediation and evaluates the strengths and weaknesses of physical, chemical, biological, and combined remediation methods. Furthermore, it underscores the requirements and opportunities for developing effective PTEs removal techniques. The insights presented here are crucial for agronomists in developing soil remediation strategies and for interdisciplinary research into integrated emission sources and pathogenesis, thereby enhancing efforts to safeguard the Earth's ecological environment.