Remediation Mechanisms Research Articles

Effect of scour remediation by solidified soil on lateral response of monopile supporting offshore wind turbines using numerical model

Offshore wind turbines supported by monopiles are inevitably influenced by scour, which will weaken the support provided by soils around and reduce the lateral capacity of the foundations, potentially leading to structure failures. In response, solidified soil is recognized as a promising solution for scour remediation, not only effectively filling the scour holes but also increasing the overall bearing capacity of the monopile. Nevertheless, the mechanism for scour remediation of solidified soil to increase the bearing capacity of the monopile is still unclear. Therefore, this paper mainly investigates the impact of solidified soil on the lateral bearing capacity of monopiles under various scour conditions and compares the effectiveness of different scour remediation methods (i.e., inverted conical remediation to half or all of scour hole and cylindrical remediation to half or all of scour hole). Firstly, the effect of solidified soil on lateral responses of monopile was investigated numerically. The overall load-displacement behavior, profile of bending moment and deflection versus depth of monopile under different scour stages and scour remediation conditions have been fully studied, in addition to the displacement field and failure mode of soil around monopile. It was found that solidified soil can greatly improve the lateral capacity and initial stiffness of monopile, and the cylindrical remediation to all of scour hole scenario showing the greatest improvement. After remediated by solidified soil, the resistance of soil around the monopile is greatly improved, and the rotation center position of monopile is moved up. Furthermore, a series of supplementary sensitivity analyses were conducted to study the effects of remediation parameters (i.e., elastic modulus and strength of solidified soil) and original soil parameter on lateral capacity of monopile.

The Mechanism for Remediation of Low-Permeable Soil Contaminated with Petroleum Hydrocarbons by Thermally-Enhanced Soil Vapor Extraction Combined with Sand Mixing

The Mechanism for Remediation of Low-Permeable Soil Contaminated with Petroleum Hydrocarbons by Thermally-Enhanced Soil Vapor Extraction Combined with Sand Mixing

Biochar remediates cadmium and lead contaminated soil by stimulating beneficial fungus Aspergillus spp.

An in-depth understanding of the micro-ecological mechanisms underlying the remediation of heavy metal-contaminated soils by biochar amendment is crucial for enhancing the efficacy of biochar-microbe combination. Nevertheless, this remediation mechanism remains elusive. Consequently, we performed a pot experiment to investigate the effects of biochar on soil fungal communities in a cadmium (Cd) and lead (Pb) contaminated soil. The results demonstrated that the amendment of biochar derived from rice straw significantly reshaped soil fungal communities, leading to the enrichment of members of the genus Aspergillus, which was found to correlate significantly with the remediation of heavy metal-contaminated soil. A representative of the targeted Aspergillus species (strain F8) was successfully isolated. The results of the pot experiments demonstrated that the inoculation with the isolate F8 can promote plant growth, immobilize soil Cd and Pb, and decrease tomato plant uptake of Cd and Pb. These results indicate that the enrichment of specific taxa induced by biochar amendment is associated with the remediation of heavy metal-contaminated soil. Therefore, this study provides new evidence to support the indirect mechanism of biochar in the remediation of heavy metal-contaminated soil by reshaping the soil microbiome.

Enhancing degradation of sulfamethoxazole by layered double hydroxide/carbon nanotubes catalyst via synergistic effect of photocatalysis/persulfate activation

A Co3Mn-LDHs and carbon nanotube (Co3Mn-LDHs/CNT) composite catalyst was constructed for permonosulfate (PMS) activation and degrading sulfamethoxazole (SMX) under Vis light irradiation. The introduction of CNTs into Co3Mn-LDHs facilitate the exciton dissociation and carrier migration, and the e− and h+ were readily separated from Co3Mn-LDHs/CNT in the photocatalysis process, which promoted the production rate of reactive oxygen species (ROS), so the Co3Mn-LDHs + Vis + PMS system exhibited better activity with an SMX degradation ratio of 61.25% than those of Co3Mn-LDHs + Vis system (42.30%) and Co3Mn-LDHs + PMS system (48.30%). After 10 cycles, the degradation rate of SMX only decreased by 7.16%, indicating the good reusability of the Co3Mn-LDHs/CNTs catalyst. The results of electron paramagnetic resonance (EPR) analysis and radical quenching experiments demonstrated that that the SO4•− played crucial role for SMX removal in Co3Mn-LDHs/CNTs + Vis + PMS system, and both e− and h+ made an important contribution to activating PMS to produce ROS. Overall, this work provided an excellent catalyst for photo-assisted PMS activation and suggested the activation mechanism for organic pollutant remediation.

Preparation of formic acid modified industrial zero-valent iron (FA-ZVIbm) for CdII-EDTA removal: CdII capturing and self-enhanced oxidative degradation of EDTA

Cadmium (Cd) contamination is highly toxic to human health, and the complexed Cd in wastewater is tricky to remove owing to its stable chelating structure. In this study, industrial zero-valent iron (ZVI) was modified by ball-milling with tiny formic acid (FA), and the as-prepared sample (FA-ZVIbm) was attempted in the treatment of CdII-ethylenediaminetetraacetic acid (CdII-EDTA). Little FA addition to ball-milling could dramatically improve the performance of FA-ZVIbm towards CdII-EDTA elimination and raise the elimination rate constant by more than 200 times. Results ascertained that the (HCOO)2FeII shell formed on FA-ZVIbm promoted CdII-EDTA decomplexation and activation of dissolved O2 to reactive oxygen species (ROS) for oxidative degradation of EDTA ligands. CdII-EDTA was instantly decomplexation by Fe3+ replacement, and the decomplexed Cd2+ was rapidly captured by FA-ZVIbm. At the same time, the EDTA ligands underwent oxidative degradation, avoiding the re-chelation ecological hazard. Interestingly, we found that replacement decomplexation has a synergistic mechanism for activating dissolved O2 to ROS, facilitating oxidative destruction of EDTA ligands. Furthermore, the FA-ZVIbm fixed-bed reactor could remediate CdII-EDTA contaminated environmental water one-stop, and the effluent stably meets the emission standards. This study demonstrated that FA-ZVIbm could be a viable approach for CdII-EDTA decontamination and clarified the remediation mechanism.

Between rhetoric and reality: effects of FIFA’s Human Rights Policy on its organisational structures and procedures

ABSTRACT In a ground-breaking development, The Fédération Internationale de Football Association (FIFA) responded to the global call for human rights protection within the sports world by adopting a Human Rights Policy. This policy represents a significant paradigm shift, redefining how sports organisations approach and advocate for equality, respect, and accountability in human rights. This article uses a single and explanatory qualitative case study approach to examine the effects of FIFA’s Human Rights Policy on the organisation. Data for this research were obtained through a documentary analysis of reports from FIFA’s Human Rights Advisory Board as well as eight semi-structured interviews with key stakeholders. The study sheds light on transformative changes across the administration of the organisation, its governance structures and decision-making procedures. By building on organisational change models, the study reveals a dual impact of FIFA’s Human Rights Policy. On the one hand, positive outcomes were identified, including significant organisational and administrative changes, increased resources, improvements in the FIFA World Cup bidding process and enhanced stakeholder engagement. On the other, challenges persist in fully integrating human rights throughout the organisation, particularly in leadership, governance structures, political decision-making, and remedy mechanisms.

Reduction and immobilization of Cr(VI)-contaminated soil using FeSO4 combined with (NH4)2HPO4: The remediation efficiency, mechanisms, and long-term stability

The chemical reduction technique is widely used to remediate Cr(VI)-contaminated soil due to its cost-effective and convenient operation. However, it also suffers from the "yellowing" issue and re-migration of Cr(VI) after on-site remediation. This study hence investigated a new combined treatment material, (NH4)2HPO4 and FeSO4, to enhance the immobilization of Cr(VI) in soil, ultimately inhibiting the "yellowing" phenomenon. The Cr(VI) remediation efficiency, mechanisms, and the long-term stability using FeSO4 with (NH4)2HPO4 were investigated. The Cr(VI) immobilization mechanisms were elucidated using the European Community Bureau of Reference (BCR) sequential extraction procedure, X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). The results suggested that, following the reduction of Cr(VI) to Cr(III) by FeSO4, the presence of (NH4)2HPO4 promoted the formation of residual Cr (CrPO4). At the optimal dose of FeSO4:(NH4)2HPO4:Cr(VI), 5:10:1, 88 % of the 450 mg/kg Cr(VI) in soil was reduced, all the HOAC-extractable Cr (58.67 %) disappeared, while the residual Cr was increased from 6.74 % to 50.61 %. The H2O2 oxidation and simulated rainfall experiments suggested that the extra addition of (NH4)2HPO4 significantly inhibited Cr reoxidation and leachability, possibly due to the formation of residue CrPO4 and FexCr1-x(OH)3, especially when the rainfall`s SO42-:NO3- ratio was 8:1. It is believed that the combination of FeSO4 and common synthetic fertilizer (NH4)2HPO4 is a promising method for in-situ remediation of Cr(VI)-contaminated soil due to its strong resistance to oxidation and acid rain erosion.

Facilitating the coping and development of college students with mental disorders: a positive clinical psychology approach.

In serving college students with mental disorders, on-campus mental health professionals have been lacking integrative theoretical frameworks to guide their missions of prevention, remedy, and development facilitation. In the current paper, we propose the positive clinical psychology as a theoretically and practically valuable framework for these missions by narratively reviewing the preventive, remedial, and developmental mechanisms derived from the theory and summarizing the most recent empirical evidence that supports each mechanism. We further discuss why and how these mechanisms and findings can be applied to on-campus mental health services to facilitate the resilience and optimal development of college students with mental disorders. Particularly, the use of resilience-focused and strength-based intervention strategies are promoted for services.

Molecular Basis of Energy Crops Functioning in Bioremediation of Heavy Metal Pollution

Heavy metal pollution is a gradually growing environmental issue that hinders the growth and development of plants, and also destabilizes soil. Consequently, eco-friendly phytoremediation methods have gained traction, with energy crops emerging as a particularly effective solution. Energy crops not only provide high-quality plant materials for detoxification and remediation of heavy metal pollution, but also possess energy properties conducive to biofuel production. Therefore, this paper delves into the tolerance mechanism of energy crops towards heavy metal toxicity, elucidating processes such as root complex-mediated inhibition of metal migration and response to reactive oxygen species (ROS) through heavy metal-related proteins, enzyme systems, reactive nitrogen species (RNS), and hormones. Moreover, it summarizes the heavy metals remediation mechanisms of energy crops, including uptake, translocation, chelation, immobilization, and sequestration. This paper explores applications of energy crops in heavy metal pollution remediation, emphasizing the methods for efficient biochar remediation and biofuel generation. Furthermore, potential challenges in using energy crops for heavy metal pollution remediation are outlined. By systematically examining the function mechanisms and prospective applications of energy crops in heavy metal pollution bioremediation, this paper serves as a valuable reference for both research and practical implementation in this field.

Reductive Immobilization of Hexavalent Chromium in Soil Using Hydrazine – Kinetics, Process Optimization, Sonochemical Enhancement, and Cost Estimation

ABSTRACT The presence of hexavalent chromium in soil poses a grave hazard to the environment and human health. This study explores the effectiveness, mechanism, and economic viability of remediation of Cr(VI)-contaminated soil by hydrazine. Soil-phase batch kinetic experiments were performed to examine the feasibility of reducing Cr(VI) while finding the effects of relevant process parameters, such as initial Cr(VI) concentration, hydrazine dosage, pH, soil-to-water ratio, and temperature. The materials were thoroughly characterized to gain insight into the mechanism. TCLP tests were done to affirm the immobilization stability. Complete Cr(VI) reduction was achieved within 3 h using a moderate 326% excess of hydrazine at neutral pH. Sonication of the soil mixed with hydrazine using a probe-type sonicator accelerated the reduction of Cr(VI) to Cr(III). Kinetic data could be adequately fitted in a second-order rate model, where the rate constant shows a linear dependency on the soil-to-water ratio. Additionally, the logarithmic rate constant demonstrates linearity within the pH range. The leaching toxicity of Cr(VI) and Crtotal complied with the USEPA regulatory limit and remained stable for 75 d. Hydrazine alone and its combination with ultrasound are sustainable and economically feasible for effective remediation of Cr(VI)-contaminated soil. The statistical analysis using RSM indicated a 99.4% reduction, aligning closely with the calculated optimized value. The optimal process conditions are easy to implement for field application at a competitive cost compared to other reductants. A simplified economic analysis was done to check the competitive acceptability of the technique, considering the construction cost of the remediation plant and its daily operational and maintenance expenses. The results show that the proposed technique will be a competitive one for field applications for the remediation of soil contaminated with Cr(VI). The data and kinetic rate equation will be useful for the process design of the remediation of soil contaminated with Cr(VI).

The physicochemical interacting mechanisms and real-time spectral induced polarization monitoring of lead remediation by an aeolian soil

Compared to traditional lead-remediating materials, natural-occurring paleosol is ubiquitous and could be a promising alternative due to its rich content in calcite, a substance known for its lead-removal ability via carbonate dissolution-PbCO3 precipitation process. Yet, the capability of paleosol to remediate aqueous solutions polluted with heavy metals, lead included, has rarely been assessed. To fill this gap, a series of column permeation experiments with influent Pb2+ concentrations of 2000, 200, and 20 mg/L were conducted and monitored by the spectral induced polarization technique. Meanwhile, the SEM-EDS, XRD, XPS, FTIR and MIP tests were carried out to unveil the underlying remediation mechanisms. The Pb-retention capacity of paleosol was 1.03 mmol/g. The increasing abundance of Pb in the newly-formed crystals was confirmed to be PbCO3 by XRD, SEM-EDS and XPS. Concurrently, after Pb2+ permeation, the decreasing calcite content in paleosol sample from XRD test, and the appearance of Ca2+ in the effluent confirmed that the dissolution of CaCO3 followed by the precipitation of PbCO3 was the major mechanism. The accumulated Pb (i.e., the diminished Ca) in paleosol was inversely proportional (R2 >0.82) to the normalized chargeability (mn), an SIP parameter denoting the quantity of polarizable units (primarily calcite).

Mechanisms for synergistically enhancing cadmium remediation performance of biochar: Silicon activation and functional group effects

This work proposes an advanced biochar material (β-CD@SiBC) for controllable transformation of specific silicon (Si) forms through endogenous Si activation and functional group introduction for efficient cadmium (Cd) immobilization and removal. The maximum adsorption capacity of β-CD@SiBC for Cd(II) reached 137.6 mg g−1 with a remarkable removal efficiency of 99 % for 200 mg L−1Cd(II). Moreover, the developed β-CD@SiBC flow column exhibited excellent performance at the environmental Cd concentration, with the final concentration meeting the environmental standard for surface water quality (0.05 mg L−1). The remediation mechanism of β-CD@SiBC could be mainly attributed to mineral precipitation and ion exchange, which accounted for 42 % and 29 % of the remediation effect, respectively, while functional group introduction enhanced its binding stability with Cd. Overall, this work proposes the role and principle of transformation of Si forms within biochar, providing new strategies for better utilizing endogenous components in biomass.

Protecting the patient’s data in the 21st century healthcare industry: Is the African continent ready for the digital space?

To ensure proper healthcare services and automation, including minimising medical errors and providing faster and more efficient healthcare, the medical field is experiencing innovative technological trends. They include automated patient records, hospital management system software, telemedicine, and the use of artificial intelligence devices. These innovations exist in more than just the global north, as they are slowly finding residence in African countries. Focusing on automated patient record, the article examines existing data protection legal frameworks in Africa to ascertain whether they provide effective remedy mechanisms patients can access should a breach occur. Taking cognisance of the current African Continental Free Trade Area Agreement (AfCFTA) aimed at creating a single market for goods and services; it is evident that healthcare services might have a continental approach. Thus, the article adopts a continental, regional, and national perspective. Using doctrinal method, the article compares the African Union Data Protection Convention with the European Union General Data Protection Regulation to draw lessons from the European Union Experience. The article finds that strengthened national mechanisms might provide the requisite remedy mechanisms patients can access to ensure enforcement of their rights to data protection.

Biochar-bacteria-plant combined potential for remediation of oil-contaminated soil.

Oil pollution is a common type of soil organic pollution that is harmful to the ecosystem. Bioremediation, particularly microbe-assisted phytoremediation of oil-contaminated soil, has become a research hotspot in recent years. In order to explore more appropriate bioremediation strategies for soil oil contamination and the mechanism of remediation, we compared the remediation effects of three plants when applied in combination with a microbial agent and biochar. The combined remediation approach of Tagetes erecta, microbial agent, and biochar exhibited the best plant growth and the highest total petroleum hydrocarbons degradation efficiency (76.60%). In addition, all of the remediation methods provided varying degrees of restoration of carbon and nitrogen contents of soils. High-throughput sequencing found that microbial community diversity and richness were enhanced in most restored soils. Some soil microorganisms associated with oil degradation and plant growth promotion such as Cavicella, C1_B045, Sphingomonas, MND1, Bacillus and Ramlibacter were identified in this study, among which Bacillus was the major component in the microbial agent. Bacillus was positively correlated with all soil remediation indicators tested and was substantially enriched in the rhizosphere of T. erecta. Functional gene prediction of the soil bacterial community based on the KEGG database revealed that pathways of carbohydrate metabolism and amino acid metabolism were up-regulated during remediation of oil-contaminated soils. This study provides a potential method for efficient remediation of oil-contaminated soils and thoroughly examines the biochar-bacteria-plant combined remediation mechanisms of oil-contaminated soil, as well as the combined effects from the perspective of soil bacterial communities.

Knowledge graph and development hotspots of biochar as an emerging aquatic antibiotic remediator: A scientometric exploration based on VOSviewer and CiteSpace

As an emerging material in the field of environmental remediation, biochar produced by carbonisation of organic solid waste has been widely used in the remediation of antibiotic wastewater due to its environmental friendliness and excellent adsorption properties. This study analyses the current literature in the field in a comprehensive and scientific manner using CiteSpace and VOSviewer technologies. Between 2011 and 2023, a total of 1162 papers were published in this domain, spanning three distinct stages: applied methods, mechanism investigation, and enhanced improvement. The results of keyword clustering indicate that the remediation of antibiotics complexed with multiple pollutants by biochar is the main research topic, followed by the remediation of antibiotics by biochar in combination with other technologies. Furthermore, drawing from current research hotspots in antibiotic remediation using biochar, this study identified the pivotal mechanisms involved: (1) The primary mechanisms by which raw biochar remediates antibiotics include π-π electron donor-acceptor interactions, hydrophobic interactions, electrostatic interactions, hydrogen-bonding, and pore filling. (2) Steam activation, acid/base, metal salt/metal oxide, and clay mineral modification can improve the physical/chemical properties of biochar, enhancing its adsorptive removal of antibiotics. (3) Biochar activated persulfate and degraded antibiotics via free radical pathways (SO4−•, •OH and O2−•) as well as non-free radical pathways (1O2 and electron transfer). In addition, the challenge and prospect of biochar engineering applications for antibiotic remediation lies in improving the main mechanism of antibiotic remediation by biochar. The prospective utilization of biochar in enhancing the remediation of antibiotic-related pollutants holds tremendous value for the future.

Microbiological Mechanisms of Collaborative Remediation of Cadmium-Contaminated Soil with Bacillus cereus and Lawn Plants.

Severe cadmium contamination poses a serious threat to food security and human health. Plant-microbial combined remediation represents a potential technique for reducing heavy metals in soil. The main objective of this study is to explore the remediation mechanism of cadmium-contaminated soil using a combined approach of lawn plants and microbes. The target bacterium Bacillus cereus was selected from cadmium-contaminated soil in mining areas, and two lawn plants (Festuca arundinacea A'rid III' and Poa pratensis M'idnight II') were chosen as the target plants. We investigated the remediation effect of different concentrations of bacterial solution on cadmium-contaminated soil using two lawn plants through pot experiments, as well as the impact on the soil microbial community structure. The results demonstrate that Bacillus cereus promotes plant growth, and the combined action of lawn plants and Bacillus cereus improves soil quality, enhancing the bioavailability of cadmium in the soil. At a bacterial suspension concentration of 105 CFU/mL, the optimal remediation treatment was observed. The removal efficiency of cadmium in the soil under Festuca arundinacea and Poa pratensis treatments reached 33.69% and 33.33%, respectively. Additionally, the content of bioavailable cadmium in the rhizosphere soil increased by up to 13.43% and 26.54%, respectively. Bacillus cereus increased the bacterial diversity in the non-rhizosphere soil of both lawn plants but reduced it in the rhizosphere soil. Additionally, the relative abundance of Actinobacteriota and Firmicutes, which have potential for heavy metal remediation, increased after the application of the bacterial solution. This study demonstrates that Bacillus cereus can enhance the potential of lawn plants to remediate cadmium-contaminated soil and reshape the microbial communities in both rhizosphere and non-rhizosphere soils.

Effects of nitrogen regulation on heavy metal phytoextraction efficiency (Leucaena leucocephala): Application of a nitrogen fertilizer and a fungal agent

Lead (Pb) and cadmium (Cd) have been identified as the primary contaminants in soil, posing potential health threats. This study aimed to examine the effects of applying a nitrogen fertilizer and a fungal agent Trichoderma harzianum J2 (nitrogen alone, fungi alone, and combined use) on the phytoremediation of soils co-contaminated with Pb and Cd. The growth of Leucaena leucocephala was monitored in the seedling, differentiation, and maturity stages to fully comprehend the remediation mechanisms. In the maturity stage, the biomass of L. leucocephala significantly increased by 18% and 29% under nitrogen-alone (NCK+) and fungal agent-alone treatments (J2), respectively, compared with the control in contaminated soil (CK+). The remediation factors of Pb and Cd with NCK+ treatment significantly increased by 50% and 125%, respectively, while those with J2 treatment increased by 73% and 145%, respectively. The partial least squares path model suggested that the nitrogen-related soil properties were prominent factors affecting phytoextraction compared with biotic factors (microbial diversity and plant growth). This model explained 2.56 of the variation in Cd concentration under J2 treatment, and 2.97 and 2.82 of the variation in Pb concentration under NCK+ and J2 treatments, respectively. The redundancy analysis showed that the samples under NCK+ and J2 treatments were clustered similarly in all growth stages. Also, Chytridiomycota, Mucoromucota, and Ciliophora were the key bioindicators for coping with heavy metals. Overall, a similar remediation mechanism allowed T. harzianum J2 to replace the nitrogen fertilizer to avoid secondary pollution. In addition, their combined use further increased the remediation efficiency.

Sustainable removal of organic pollutants using biochar based ZnO composites: Experimental and theoretical studies of remediation process

The tailoring of biochar to enhance its remediation efficiency for removal of pollutants from water has been a hot topic these days. Fabricating two different biochar materials using metal oxide nano particles in four ratios has been done in this work. The synthesized materials have been characterized by XRD, surface functional groups were analyzed using FTIR and XPS, band gap calculation were carried out using Tauc's method, recombination of charges was studied using photoluminescence spectroscopy, morphological, textural properties and elemental analysis was done using SEM, BET, TGA, EIS and EDX analysis. The removal of organic pollutants including phenol, dibutyl phthalate and gallic acid up to 91.6 %, 84 % and 95 % was observed employing these composites. The band gap reduction from 3.1 eV to 2.5 eV and 2.8 eV was observed in case of ZW(1–10) and ZP(1–10) respectively. The formation of Zn-O-C bond in the composite could be possible reasons for the band gap reduction and excellent performance exhibited by the composite. The results highlight the influence of functional groups on the efficiency of synthesized material. Furthermore, density functional theory (DFT) calculations were performed using Gaussian16 software to propose the adsorption mechanism for the observed results. The energy calculation for different binding modes were carried out. Theoretical findings agreed with the empirically demonstrated remediation mechanism.

Research Enhancing Acidic Mine Wastewater Purification: Innovations in Red Mud-Loess.

This study investigates the adsorption of cadmium (Cd) by red mud-loess mixed materials and assesses the influence of quartz sand content on permeability. Shear tests are conducted using various pore solutions to analyze shear strength parameters. The research validates solidification methods for cadmium-contaminated soils and utilizes SEM-EDS, FTIR, and XRD analysis to elucidate remediation mechanisms. The findings suggest that the quartz sand content crucially affects the permeability of fine-grained red mud-loess mixtures. The optimal proportion of quartz sand is over 80%, significantly enhancing permeability, reaching a coefficient of 6.7 × 10-4 cm/s. Insufficient quartz sand content of less than 80% fails to meet the barrier permeability standards, leading to a reduced service life of the engineered barrier. Adsorption tests were conducted using various pore solutions, including distilled water, acidic solutions, and solutions containing Cd, to evaluate the adsorption capacity and shear characteristics of the red mud-loess mixture. Additionally, the study examines the behavior of Cd-loaded red mud-loess mixtures in various pore solutions, revealing strain-hardening trends and alterations in cohesiveness and internal friction angle with increasing Cd concentrations. The analysis of cement-red mud-loess-solidified soil demonstrates enhancements in soil structure and strength over time, attributed to the formation of crystalline structures and mineral formations induced by the curing agent. These findings provide valuable insights into the remediation of cadmium-contaminated soils.

The Research Progress of Biochar for Heavy Metal Soil Remediation was Briefly Discussed

Due to its structural advantages, biochar has developed pore structure, large porosity, surface potential energy, and more oxygen and nitrogen functional groups on the surface, which can adsorb and solidified heavy metals and organic pollutants in contaminated soil to achieve the purpose of repairing contaminated soil. At the same time, adding an appropriate amount of biochar to the soil can also enhance soil nutrition and improve water retention performance, and promote the good development of microbial systems. At present, it has become a research hotspot of contaminated soil remediation. In this paper, the preparation technology of biochar, the remediation mechanism of biochar and heavy metal pollutants, as well as the development prospect and precautions are described, in order to provide theoretical reference for the study of biochar in soil remediation.