This study focuses on empirical modeling of the strength characteristics of urban soils contaminated with heavy metals using machine learning tools and their subsequent stabilization with ordinary Portland cement(OPC)...This study focuses on empirical modeling of the strength characteristics of urban soils contaminated with heavy metals using machine learning tools and their subsequent stabilization with ordinary Portland cement(OPC).For dataset collection,an extensive experimental program was designed to estimate the unconfined compressive strength(Qu)of heavy metal-contaminated soils collected from awide range of land use pattern,i.e.residential,industrial and roadside soils.Accordingly,a robust comparison of predictive performances of four data-driven models including extreme learning machines(ELMs),gene expression programming(GEP),random forests(RFs),and multiple linear regression(MLR)has been presented.For completeness,a comprehensive experimental database has been established and partitioned into 80%for training and 20%for testing the developed models.Inputs included varying levels of heavy metals like Cd,Cu,Cr,Pb and Zn,along with OPC.The results revealed that the GEP model outperformed its counterparts:explaining approximately 96%of the variability in both training(R2=0.964)and testing phases(R^(2)=0.961),and thus achieving the lowest RMSE and MAE values.ELM performed commendably but was slightly less accurate than GEP whereas MLR had the lowest performance metrics.GEP also provided the benefit of traceable mathematical equation,enhancing its applicability not just as a predictive but also as an explanatory tool.Despite its insights,the study is limited by its focus on a specific set of heavy metals and urban soil samples of a particular region,which may affect the generalizability of the findings to different contamination profiles or environmental conditions.The study recommends GEP for predicting Qu in heavy metal-contaminated soils,and suggests further research to adapt these models to different environmental conditions.展开更多
There have been reports of potential health risks for people from hydrophobic organic pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorinated hydrocarbons(PCHs),and organophosphate flame retardants(O...There have been reports of potential health risks for people from hydrophobic organic pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorinated hydrocarbons(PCHs),and organophosphate flame retardants(OPFRs).When a contaminated site is used for residential housing or public utility and recreation areas,the soil-bound organic pollutantsmight pose a threat to human health.In this study,we investigated the contamination profiles and potential risks to human health of 15 PAHs,6 PCHs,and 12 OPFRs in soils from four contaminated sites in China.We used an in vitro method to determine the oral bioaccessibility of soil pollutants.Total PAHswere found at concentrations ranging from26.4 ng/g to 987 ng/g.PCHs(0.27-14.3 ng/g)and OPFRs(6.30-310 ng/g)were detected,but at low levels compared to earlier reports.The levels of PAHs,PCHs,and OPFRs released from contaminated soils into simulated gastrointestinal fluids ranged from 1.74%to 91.0%,2.51%to 39.6%,and 1.37%to 96.9%,respectively.Based on both spiked and unspiked samples,we found that the oral bioaccessibility of pollutantswas correlated with their logKow andmolecularweight,and the total organic carbon content and pH of soils.PAHs in 13 out of 38 contaminated soil samples posed potential high risks to children.When considering oral bioaccessibility,nine soils still posed potential risks,while the risks in the remaining soils became negligible.The contribution of this paper is that it corrects the health risk of soil-bound organic pollutants by detecting bioaccessibility in actual soils from different contaminated sites.展开更多
Rotating machinery is critical to industrial systems,necessitating robust anomaly detection(AD)to ensure operational safety and prevent failures.However,in real-world scenarios,monitoring data is typically unlabeled a...Rotating machinery is critical to industrial systems,necessitating robust anomaly detection(AD)to ensure operational safety and prevent failures.However,in real-world scenarios,monitoring data is typically unlabeled and often consists of normal samples contaminated with a small proportion of unknown anomalies.To address this,this paper proposes a diffusion-based AD method,Anomaly Detection Denoising Diffusion Probabilistic Model(AD-DDPM)for robust AD.The method employs a U-attention-net to capture local and global features and introduces a filtered contrastive mechanism to mitigate the impact of contaminated training data.By leveraging the probabilistic nature of diffusion models,AD-DDPM effectively models normal data distributions,achieving superior AD even with polluted samples.Experimental validation on fault simulation datasets demonstrates the method’s exceptional performance,outperforming traditional machine learning and deep learning baselines.The proposed approach offers a promising solution for reliable health monitoring in industrial settings.展开更多
The investigation of leachate-contaminated clay(LCC)is essential for landfill engineering assessment and achievement of sustainable development goals.Several static and dynamic laboratory tests,including unconfined co...The investigation of leachate-contaminated clay(LCC)is essential for landfill engineering assessment and achievement of sustainable development goals.Several static and dynamic laboratory tests,including unconfined compressive strength(UCS),California bearing ratio(CBR),and cyclic simple shear,are conducted.Cyclic simple shear experiments on LCCs were performed to evaluate the damping and shear modulus.The investigated factors are vertical load(VL),leachate content(LC),frequency(F),and shear strain(ShS)for LCC.Forensic-based investigation optimization(FBIO)and equilibrium optimizer algorithm(EOA)were utilized in addition to multiple types of ensemble models,including adaptive boosting(ADB),gradient boosting regression tree(GBRT),extreme gradient boosting(XGB) and random forest(RF).The comparison of the methods showed that GBRT-FBIO and XGB-EOA models outperformed other models for shear modulus and damping of LCC.The p-value less than 0.0001 shows the significance of the used models in the response surface methodology(RSM)method.展开更多
In recent years,there has been an intensifying focus within the soil contamination prevention and remediation sector,both domestically and internationally,on the off-site disposal of contaminated soils.The United Stat...In recent years,there has been an intensifying focus within the soil contamination prevention and remediation sector,both domestically and internationally,on the off-site disposal of contaminated soils.The United States and Japan,as pioneers in this field,have formulated and implemented a suite of policy standards and practical measures for the regional collaborative management of off-site soil disposal.This paper meticulously reviews and evaluates the existing research on the regional collaborative management of off-site soil disposal,analyzing the experiences and strategies of the United States and Japan from the perspectives of regulatory systems and practical implementation.In light of China’s specific circumstances,it proposes a series of strategic recommendations for the adaptation of these international experiences to the Chinese context.These include enhancement of Chinese legal standards for the regional collaborative management of contaminated land soil off-site disposal,improvement of risk control standards for soil pollution and specific regulations for off-site disposal,as well as delineation of objective criteria to define the scope of collaborative management.展开更多
The effects of five amendments such as acetic acid（AA）, citric acid （CA）, ethylenediamine tetraacetic acid （EDTA）, sepiolite and phosphogypsum on growth and metal uptake of giant reed （Arundo donax L.） grown o...The effects of five amendments such as acetic acid（AA）, citric acid （CA）, ethylenediamine tetraacetic acid （EDTA）, sepiolite and phosphogypsum on growth and metal uptake of giant reed （Arundo donax L.） grown on soil contaminated by arsenic （As）, cadmium （Cd） and lead （Pb） were studied. The results showed that the shoot biomass of giant reed was enhanced by 24.8% and 15.0%, while superoxide mutase and catalase activities slightly varied when adding 5.0 mmol/kg CA and 2.5 mol/kg EDTA to soil as compared to the control, respectively. The concentrations of As, Cd and Pb in shoots were remarkably increased by the addition of 2.5 mmol/kg AA and CA, 5.0 mmol/kg EDTA, and 4.0 g/kg sepiolite as compared to the control. The accumulations of As and Cd were also significantly enhanced in the above condition, while the shoot Pb accumulation was noticeably enhanced by amending with 4.0 g/kg sepiolite and 8.0 g/kg phosphogysum, respectively. The results suggested that AA, CA and sepiolite could be used as optimum soil amendments for giant reed remediation system.展开更多
[Objective] The aim was to study on in-situ elimination effect on heavy metals in soil of the mining area by ramie （Boehmeria nivea （L.） Gaud.）. [Methods] Based on Xiangzhu No.3 and Zhongzhu No.1, we conducted res...[Objective] The aim was to study on in-situ elimination effect on heavy metals in soil of the mining area by ramie （Boehmeria nivea （L.） Gaud.）. [Methods] Based on Xiangzhu No.3 and Zhongzhu No.1, we conducted research on heavy metals contents of plants growing in soil of Qibao Mountain orefield in Liuyang, Hunan Province, and on characteristics of enrichment and transfer of heavy metals （Cu, Pb, Cd, Zn） under influence of the two ramie species. [Result] It was concluded that trend of Cu content in different parts of ramie was as follows： rootskinleafbone; trend of Pb was rootleafskinbone; trend of Cd was rootskinboneleaf; the trend of Zn was rootskinboneleaf. In farmland A （with low content of heavy metal）, for per square meter of plough horizon, effect of Zhong 1 on heavy metals transferring volume and the period for restoration of the soil into national standard one （Category Ⅲ of Environmental Quality Standard for Soil） have been concluded. Specifically, for Cu, the corresponding values were 3 404.44 mg and 8.59 y, respectively; for Pb, the values were 3 638.5 mg and 13.52 y; for Cd, the values were 720.48 mg and 1.49 y; for Zn, the values were 37 324.8 mg and 0.67 y. [Conclusion] Soil contaminated by Cu, Pb, Cd, and Zn in orefield can be rapidly restored by growing ramie.展开更多
[Objective] To study the remediation efficiency of red mud on Pb, Zn and Cd in the heavy metal contaminated paddy soil of mine area, to clarify its remediation mechanism and fertilizer efficiency on heavy metal contam...[Objective] To study the remediation efficiency of red mud on Pb, Zn and Cd in the heavy metal contaminated paddy soil of mine area, to clarify its remediation mechanism and fertilizer efficiency on heavy metal contaminated soil. [Method] The soil incubation experiment was conducted to study the effect of red mud on the pH values and electrical conductivity （EC）, and the remediation efficiency of red mud on lead （Pb）, zinc （Zn） and cadmium （Cd） in heavy metal contaminated soil. [Result] Red mud addition reduced the content of exchangeable Pb, Zn and Cd in the soil significantly. Compared with the control, when incubated for 30, 60 and 90 d with the red mud dosage of 4% （W/W）, the exchangeable Pb content was decreased by 39.25%, 41.38% and 50.19%; exchangeable Zn content was decreased by 49.26%, 57.32% and 47.16%; and exchangeable Cd content was decreased by 19.53%, 24.06% and 25.70%, respectively. The application of red mud had significant impact on the share of Pb, Zn and Cd contents in five forms, and different amounts of red mud application all reduced the proportion of exchangeable Pb, Zn and Cd to the total Pb, Zn and Cd. In addition, the proportion of exchangeable Pb, Zn and Cd to total Pb, Zn and Cd decreased with the increasing amount of red mud addition. [Conclusion] The study provided references for reasonable application of red mud and reduction of heavy metal pollution in paddy soil.展开更多
Microbe-assisted phytoremediation is of great significance for the remediation of soil contaminated with heavy metals(HMs),and probiotics are beneficial microorganisms that can improve soil structure and fertility and...Microbe-assisted phytoremediation is of great significance for the remediation of soil contaminated with heavy metals(HMs),and probiotics are beneficial microorganisms that can improve soil structure and fertility and promote plant growth.However,there are few studies on probiotics applied to remediate soil contaminated with HMs,and whether probiotics can improve the efficiency of phytoremediation still needs to be further investigated.This study aimed to investigate the effects of two kinds of probiotics,Lactobacillus casei(Lc)and Bacillus licheniformis(Bl),on activating the remediation potential of leaf mustard,Brassica juncea(L.)Czerniak.,for soil contaminated with Cd and Zn using incubation and pot experiments.The results showed that the addition of the two probiotics significantly reduced soil pH by 0.05–0.32 units and improved the available contents of soil HMs(by 15.3%–60.0%and 7.1%–23.8%for Cd and Zn,respectively)in the incubation experiment.After probiotic addition,available Cd and Zn contents in soil treated with 1×10^(9) colony forming units(cfu)mL^(-1) Bl were 1.65-and 1.66-folds of those in the control without probiotic,respectively,in the pot experiment.Meanwhile,soil alkaline phosphatase,urease,and sucrose activities were increased,indicating that soil microbial metabolic activities were also stimulated.Addition of Lc and Bl significantly improved the biomass and chlorophyll contents of leaf mustard.The contents of Cd and Zn in shoots and roots were significantly increased in the treatment with 1×10^(5) cfu mL^(-1) Lc.Furthermore,the activities of plant antioxidant enzymes,including superoxide dismutase,peroxidase,and catalase,were increased,and the content of plant malondialdehyde was reduced,indicating that the resistance of plants to HMs was enhanced.These results indicated that these two kinds of probiotics could enhance the availability of Cd and Zn directly in soil and promote the growth of leaf mustard,thereby increasing the efficiency of phytoremediation for HMs.The study provides a useful reference for probiotic-assisted phytoremediation of soil contaminated with HMs.展开更多
Efficient and innovative nano-catalytic oxidation technologies offer a breakthrough in removing emerging contaminants(ECs)from water,surpassing the limitations of traditional methods.Environmental functional materials...Efficient and innovative nano-catalytic oxidation technologies offer a breakthrough in removing emerging contaminants(ECs)from water,surpassing the limitations of traditional methods.Environmental functional materials(EFMs),particularly high-end oxidation systems using eco-friendly nanomaterials,show promise for absorbing and degrading ECs.This literature review presents a comprehensive analysis of diverse traditional restoration techniques-biological,physical,and chemical-assessing their respective applications and limitations in pesticide-contaminated water purification.Through meticulous comparison,we unequivocally advocate for the imperative integration of environmentally benign nanomaterials,notably titanium-based variants,in forthcoming methodologies.Our in-depth exploration scrutinizes the catalytic efficacy,underlying mechanisms,and adaptability of pioneering titanium-based nanomaterials across a spectrum of environmental contexts.Additionally,strategic recommendations are furnished to surmount challenges and propel the frontiers of implementing eco-friendly nanomaterials in practical water treatment scenarios.展开更多
Chemical leaching techniques have been proven effective in removing heavymetal contaminants fromsoil using various leaching agents.Previous research has shown that both singleagent and composite leaching systems have ...Chemical leaching techniques have been proven effective in removing heavymetal contaminants fromsoil using various leaching agents.Previous research has shown that both singleagent and composite leaching systems have been applied for the remediation of chromiumcontaminated soils,with varying degrees of success depending on soil type and contaminant form.However,the removal rate of total chromium(Cr)and hexavalent chromium(Cr(Ⅵ))often fluctuates based on the chemical composition of the leaching agents,as well as the soil’s physicochemical properties,such as pH and Cr speciation stability.Therefore,this study investigates the effectiveness of 20 composite leaching systems,including deionized water,lime water,calcium chloride,sodium carbonate,and sodium phosphate,through soil column leaching tests.The aim was to evaluate their impact on soil pH,total Cr,and Cr(Ⅵ)removal,and to examine the transformation of various Cr species during the leaching process.Results reveal that lime water and sodium phosphate were particularly effective in stabilizing Cr(Ⅵ)and neutralizing soil pH,while total Cr removal amount ranged from 197.4 mg/kg to 1671.6 mg/kg and Cr(Ⅵ)removal amount ranged from 113.2mg/kg to 316.8mg/kg.We also find that using 0.2 mol/L citric acid,0.1 mol/L hydrochloric acid,and 1.2 mL/g lime solution adjusted soil pH to 7.37,with average removal efficiencies of 34.6%.for total Cr and 72.7%for Cr(Ⅵ).Overall,our results suggest that the combined use of lime water and sodium phosphate is an effective strategy for remediating chromium-contaminated soil,particularly for stabilizing unleached Cr and adjusting soil pH.展开更多
Cadmium(Cd)contamination of soil is a global environmental issue.Traditional remediation techniques such as immobilization,leaching,and phytoextraction have numerous shortcomings,which has led to growing interest in t...Cadmium(Cd)contamination of soil is a global environmental issue.Traditional remediation techniques such as immobilization,leaching,and phytoextraction have numerous shortcomings,which has led to growing interest in the development of low-cost,high-efficiency,and environmentally friendly agents for removing Cd from soil.In this study,four magnetite(Fe_(3)O_(4))/polyaniline(PANI)nanocomposites,Fe_(3)O_(4)(1.0)/PANI,Fe_(3)O_(4)(1.5)/PANI,Fe_(3)O_(4)(2.0)/PANI,and Fe_(3)O_(4)(2.5)/PANI,were developed using 4 mL aniline monomer and 1.0,1.5,2.0,and 2.5 g Fe_(3)O_(4),respectively,and used as remediation agents with magnetic separation and regeneration capabilities.The Cd adsorption isotherms showed a better fit to the Langmuir model,with Fe_(3)O_(4)(1.5)/PANI exhibiting the highest Cd adsorption capacity of 47.62 mg g^(-1) at 25℃.Then,Fe_(3)O_(4)(1.5)/PANI was used to remediate four Cd-contaminated soils typical in China(black,brown,cinnamon,and red),all with a Cd content of 180 mg kg^(-1) after spiking.The results showed that the total Cd removal efficiency was satisfactory at 25.25%–38.91%and the exchangeable Cd removal efficiency was 36.03%on average.In addition,soil basic properties did not show significant changes after remediation.Regarding the regeneration performance,a higher total Cd removal efficiency(27.89%–44.96%)was achieved after the first regeneration cycle of Fe_(3)O_(4)(1.5)/PANI.After two regeneration cycles,Fe_(3)O_(4)(1.5)/PANI exhibited decreased total Cd removal efficiency compared to after the first regeneration,but its efficiency remained above 95%of or higher than those of virgin Fe_(3)O_(4)(1.5)/PANI.The synthetic process of Fe_(3)O_(4)/PANI was simple and cost-effective,and Fe_(3)O_(4)/PANI exhibited a high Cd removal efficiency with easy recovery and recyclability.Therefore,Fe_(3)O_(4)/PANI is a promising solution for the sustainable and efficient remediation of Cd-contaminated soils,especially for the reclamation of highly contaminated development land.展开更多
Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area a...Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area and porous structure.It works by attracting and binding HM ions to its surface.Okoubaka is known for its medicinal properties and some studies suggest it has detoxifying effects.However,its specific role in HM removal would likely involve binding mechanisms like other plant-based materials.This study examines the efficiency of activated charcoal,charred versus uncharred Okoubaka plant materials,eggshells and oxalic acid to remove HMs like copper,lead,and zinc from contaminated water.展开更多
Cement-based composite grouting materials were used to construct grouting cutoff wall for heavy metal contaminated soil in non-ferrous metal mining areas. Cement, fly ash, and slag as principal ingredients were mixed ...Cement-based composite grouting materials were used to construct grouting cutoff wall for heavy metal contaminated soil in non-ferrous metal mining areas. Cement, fly ash, and slag as principal ingredients were mixed with water glass in different ways to produce three composite grouting materials. In order to investigate the effect of water glass mixing ratio, Baume degree, fly ash and slag contents on the mechanical properties of the composite grouting materials, particularly their gel time and compressive strength, the beaker-to-beaker method of gel time test and unconfined compressive strength test were conducted. In addition, the phase composition and microstructure of the composite grouting materials were analyzed by the X-ray diffraction（XRD） and scanning electron microscope（SEM） techniques. The test results show that their gel time increases when water glass mixing ratio and Baume degree increase. The gel time increases dramatically when fly ash is added, but decreases slightly if fly ash is partly replaced by slag. When the mixing ratio of water glass is below 20%, their compressive strength increases with the increases of the ratio; when the ratio is above 20%, it significantly decreases. The compressive strength also tends to increase as Baume degree increases, and improves if fly ash and slag are added.展开更多
[Objective] The remediation effect of the plant to Cd-contaminated soil was studied. [Method] By taking simulation test and field test, the ryegrass （Lolium perenne L.） was planted, and the remediation effect of the...[Objective] The remediation effect of the plant to Cd-contaminated soil was studied. [Method] By taking simulation test and field test, the ryegrass （Lolium perenne L.） was planted, and the remediation effect of the plant to contaminated sites was studied. [Result] The ryegrass was planted in the eluotropic soil for 0-60 d, Cd content in the soil showed a rapid decreasing trend; after 60 d, the enrich- ment ability of the plant to Cd gradually weakened over time; after 75 d of phytore- mediation, the Cd content in the soil decreased greatly, and the remediation effi- ciency was 90.66%. [Conclusion] Ryegrass remediation technology had good reme- diation effect to Cd-contaminated soil.展开更多
[Objective] The aim was to research phytoremediation effects on soils with combined pollution. [Method] With simulation experiment, the test selected plants suitable for phytoremediation in soils polluted with Pb-Cd, ...[Objective] The aim was to research phytoremediation effects on soils with combined pollution. [Method] With simulation experiment, the test selected plants suitable for phytoremediation in soils polluted with Pb-Cd, PAHs, and Pb-Cd-PAHs,respectively and ryegrass was grown to explore phytoremediation on contaminated sites by adjusting bio-availability. [Result] After 70 d growing of ryegrass, the content of available Pb in contaminated soils was 375.26 mg/kg, the content of Cd was 4.9mg/kg after 90 d, and the content of B [a]P was 0.60 mg/kg after 100 d, which were all lower compared with soil limits. [Conclusion] Ryegrass is a suitable plant for phytoremediation.展开更多
Restoration of contaminated soil and groundwater could be divided into two phases. The first phase takes aim at reducing human being＇s health risks by active remediation, while the second phase aims at eliminating ec...Restoration of contaminated soil and groundwater could be divided into two phases. The first phase takes aim at reducing human being＇s health risks by active remediation, while the second phase aims at eliminating ecological risks by natural attenuation （NA）. Because of cost-effective and sustainable cleanup, monitored natural attenuation （MNA） and enhanced natural attenuation （ENA） have been gaining more attention recently, especially in the respects of ecological risk-oriented contaminated land management and a follow-up measure after active remediation. The uses and procedures of MNA for contaminated site cleanup and remediation in USA and EU were introduced firstly, and then possible applications of MNA in China were suggested. More developments and practices of MNA and ENA for managing contaminated sites in China are expected.展开更多
To screen out a series of ideal plants that can effectively remedy contaminated soils by heavy metals is the main groundwork of phytoremediation engineering and the first step of its commercial application on a large ...To screen out a series of ideal plants that can effectively remedy contaminated soils by heavy metals is the main groundwork of phytoremediation engineering and the first step of its commercial application on a large scale. In this study, accumulation and endurance of 45 weed species in 16 families from an agricultural site were in situ examined by using the pot-culture field experiment, and the remediation potential of some weed species with high accumulation of heavy metals was assayed. The results showed that Solanum nigrum and Conyza canadensis can not only accumulate high concentration of Cd, but also strongly endure to single Cd and Cd-Pb-Cu-Zn combined pollution. Thus 2 weed species can be regarded as good hyperaccumulators for the remediation of Cd-contaminated soils. Although there were high Cd-accumulation in Artemigia selengensis, Znula britannica and Cephalanoplos setosum, their biomass was adversely affected due to action of heavy metals in the soils. If the problem of low endurance to heavy metals can be solved by a reinforcer, 3 weed species can be perhaps applied commercially.展开更多
There is limited information on the release behavior of heavy metals fromnatural soils by organic acids. Thus, cadmium release, due to two organic acids (tartrate andcitrate) that are common in the rhizosphere, from s...There is limited information on the release behavior of heavy metals fromnatural soils by organic acids. Thus, cadmium release, due to two organic acids (tartrate andcitrate) that are common in the rhizosphere, from soils polluted by metal smeltersor tailings andsoils artificially contaminated by adding Cd were analyzed. The presence of tartrate or citrate at alow concentration (<= 6 mmol L^(-1) for tartrate and <= 0.5 mmol L^(-1) for citrate) inhibited Cdrelease, whereas the presence of organic acids in high concentrations (>= 2 mmol L^(-1) for citrateand >= 15 mmol L^(-1) for tartrate) apparently promoted Cd release. Under the same conditions, theCd release in naturally polluted soils was less than that of artificially contaminatedsoils.Additionally, as the initial pH rose from 2 to 8 in the presence of citrate, a sequentialvalley and then peak appeared in the Cd release curve, while in the presence of tartrate the Cdrelease steadily decreased. In addition, Cd release was clearly enhanced as the electrolyteconcentration of KNO_3 or KC1 increased in the presence of 2 mmol L^(-1) tartrate. Moreover, ahigher desorption of Cd was shown with the KCl electrolyte compared to KNO_3 for the sameconcentration levels. This implied that the bioavailability of heavy metals could be promoted withthe addition of suitable types and concentrations of organic acids as well as reasonable fieldconditions.展开更多
Cadmium contamination of soil is a global issue and in-situ remediation technology as a promising mitigation strategy has attracted more and more attention.Many nanomaterials have been applied for the in-situ remediat...Cadmium contamination of soil is a global issue and in-situ remediation technology as a promising mitigation strategy has attracted more and more attention.Many nanomaterials have been applied for the in-situ remediation of cadmium-contaminated soil due to their excellent properties of the nano-scale size effect.In this work,recent research progress of various nanomaterials,including carbon nanomaterials,metal-based nanomaterials and nano mineral materials,in the removal of cadmium and in-situ remediation of cadmiumcontaminated soil were systematically discussed.Additional emphases were particularly laid on both laboratory and field restoration effects.Moreover,the factors which can affect the stability of cadmium,main interaction mechanisms between nanomaterials and cadmium in the soil,and potential future research direction were also provided.Therefore,it is believed that this work will ultimately contribute to the myriad of environmental cleanup advances,and further improve human health and sustainable development.展开更多
基金funded by the Natural Science Foundation of China(Grant No.52090084)was partially supported by the Sand Hazards and Opportunities for Resilience,Energy,and Sustainability(SHORES)Center,funded by Tamkeen under the NYUAD Research Institute Award CG013.
文摘This study focuses on empirical modeling of the strength characteristics of urban soils contaminated with heavy metals using machine learning tools and their subsequent stabilization with ordinary Portland cement(OPC).For dataset collection,an extensive experimental program was designed to estimate the unconfined compressive strength(Qu)of heavy metal-contaminated soils collected from awide range of land use pattern,i.e.residential,industrial and roadside soils.Accordingly,a robust comparison of predictive performances of four data-driven models including extreme learning machines(ELMs),gene expression programming(GEP),random forests(RFs),and multiple linear regression(MLR)has been presented.For completeness,a comprehensive experimental database has been established and partitioned into 80%for training and 20%for testing the developed models.Inputs included varying levels of heavy metals like Cd,Cu,Cr,Pb and Zn,along with OPC.The results revealed that the GEP model outperformed its counterparts:explaining approximately 96%of the variability in both training(R2=0.964)and testing phases(R^(2)=0.961),and thus achieving the lowest RMSE and MAE values.ELM performed commendably but was slightly less accurate than GEP whereas MLR had the lowest performance metrics.GEP also provided the benefit of traceable mathematical equation,enhancing its applicability not just as a predictive but also as an explanatory tool.Despite its insights,the study is limited by its focus on a specific set of heavy metals and urban soil samples of a particular region,which may affect the generalizability of the findings to different contamination profiles or environmental conditions.The study recommends GEP for predicting Qu in heavy metal-contaminated soils,and suggests further research to adapt these models to different environmental conditions.
基金supported by the National Key Research and Development Program of China(No.2019YFC1804604)Basic and Applied Basic Research Foundation of Guangdong Province(No.2021A1515010018).
文摘There have been reports of potential health risks for people from hydrophobic organic pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorinated hydrocarbons(PCHs),and organophosphate flame retardants(OPFRs).When a contaminated site is used for residential housing or public utility and recreation areas,the soil-bound organic pollutantsmight pose a threat to human health.In this study,we investigated the contamination profiles and potential risks to human health of 15 PAHs,6 PCHs,and 12 OPFRs in soils from four contaminated sites in China.We used an in vitro method to determine the oral bioaccessibility of soil pollutants.Total PAHswere found at concentrations ranging from26.4 ng/g to 987 ng/g.PCHs(0.27-14.3 ng/g)and OPFRs(6.30-310 ng/g)were detected,but at low levels compared to earlier reports.The levels of PAHs,PCHs,and OPFRs released from contaminated soils into simulated gastrointestinal fluids ranged from 1.74%to 91.0%,2.51%to 39.6%,and 1.37%to 96.9%,respectively.Based on both spiked and unspiked samples,we found that the oral bioaccessibility of pollutantswas correlated with their logKow andmolecularweight,and the total organic carbon content and pH of soils.PAHs in 13 out of 38 contaminated soil samples posed potential high risks to children.When considering oral bioaccessibility,nine soils still posed potential risks,while the risks in the remaining soils became negligible.The contribution of this paper is that it corrects the health risk of soil-bound organic pollutants by detecting bioaccessibility in actual soils from different contaminated sites.
基金supported by The National Natural Science Foundation of China under Grant(5247512)National Key Lab of Aerospace Power System and Plasma Technology Foundation(APSPT202304002).
文摘Rotating machinery is critical to industrial systems,necessitating robust anomaly detection(AD)to ensure operational safety and prevent failures.However,in real-world scenarios,monitoring data is typically unlabeled and often consists of normal samples contaminated with a small proportion of unknown anomalies.To address this,this paper proposes a diffusion-based AD method,Anomaly Detection Denoising Diffusion Probabilistic Model(AD-DDPM)for robust AD.The method employs a U-attention-net to capture local and global features and introduces a filtered contrastive mechanism to mitigate the impact of contaminated training data.By leveraging the probabilistic nature of diffusion models,AD-DDPM effectively models normal data distributions,achieving superior AD even with polluted samples.Experimental validation on fault simulation datasets demonstrates the method’s exceptional performance,outperforming traditional machine learning and deep learning baselines.The proposed approach offers a promising solution for reliable health monitoring in industrial settings.
文摘The investigation of leachate-contaminated clay(LCC)is essential for landfill engineering assessment and achievement of sustainable development goals.Several static and dynamic laboratory tests,including unconfined compressive strength(UCS),California bearing ratio(CBR),and cyclic simple shear,are conducted.Cyclic simple shear experiments on LCCs were performed to evaluate the damping and shear modulus.The investigated factors are vertical load(VL),leachate content(LC),frequency(F),and shear strain(ShS)for LCC.Forensic-based investigation optimization(FBIO)and equilibrium optimizer algorithm(EOA)were utilized in addition to multiple types of ensemble models,including adaptive boosting(ADB),gradient boosting regression tree(GBRT),extreme gradient boosting(XGB) and random forest(RF).The comparison of the methods showed that GBRT-FBIO and XGB-EOA models outperformed other models for shear modulus and damping of LCC.The p-value less than 0.0001 shows the significance of the used models in the response surface methodology(RSM)method.
基金supported by the National Social Science Foundation of China(Grant No.20&ZD091)the National Social Science Fund on the Spirit of the Sixth Plenary Session of the 19th Central Committee of the Communist Party of China(Grant No.22ZDA109)+1 种基金the 2024 Innovative Talents International Cooperation Training Program of the China Scholarship Council(Grant No.202406720002)the the 2024 Hunan Provincial Education Department Graduate Innovation Research Project(Grant No.CX20240485).
文摘In recent years,there has been an intensifying focus within the soil contamination prevention and remediation sector,both domestically and internationally,on the off-site disposal of contaminated soils.The United States and Japan,as pioneers in this field,have formulated and implemented a suite of policy standards and practical measures for the regional collaborative management of off-site soil disposal.This paper meticulously reviews and evaluates the existing research on the regional collaborative management of off-site soil disposal,analyzing the experiences and strategies of the United States and Japan from the perspectives of regulatory systems and practical implementation.In light of China’s specific circumstances,it proposes a series of strategic recommendations for the adaptation of these international experiences to the Chinese context.These include enhancement of Chinese legal standards for the regional collaborative management of contaminated land soil off-site disposal,improvement of risk control standards for soil pollution and specific regulations for off-site disposal,as well as delineation of objective criteria to define the scope of collaborative management.
基金Project (2012BAC09B04) supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of ChinaProject (2010-277-027) supported by Science and Technology Foundation of Environmental Protection in Hunan Province,ChinaProject (2011SK3262) supported by Science and Technology Planning of Hunan Province,China
文摘The effects of five amendments such as acetic acid（AA）, citric acid （CA）, ethylenediamine tetraacetic acid （EDTA）, sepiolite and phosphogypsum on growth and metal uptake of giant reed （Arundo donax L.） grown on soil contaminated by arsenic （As）, cadmium （Cd） and lead （Pb） were studied. The results showed that the shoot biomass of giant reed was enhanced by 24.8% and 15.0%, while superoxide mutase and catalase activities slightly varied when adding 5.0 mmol/kg CA and 2.5 mol/kg EDTA to soil as compared to the control, respectively. The concentrations of As, Cd and Pb in shoots were remarkably increased by the addition of 2.5 mmol/kg AA and CA, 5.0 mmol/kg EDTA, and 4.0 g/kg sepiolite as compared to the control. The accumulations of As and Cd were also significantly enhanced in the above condition, while the shoot Pb accumulation was noticeably enhanced by amending with 4.0 g/kg sepiolite and 8.0 g/kg phosphogysum, respectively. The results suggested that AA, CA and sepiolite could be used as optimum soil amendments for giant reed remediation system.
基金Supported by National Programs for High Technology Research and Development of China(2007AA061001)Talent Introduction Project Supported by Hunan Agricultural University Project(07YT03)~~
文摘[Objective] The aim was to study on in-situ elimination effect on heavy metals in soil of the mining area by ramie （Boehmeria nivea （L.） Gaud.）. [Methods] Based on Xiangzhu No.3 and Zhongzhu No.1, we conducted research on heavy metals contents of plants growing in soil of Qibao Mountain orefield in Liuyang, Hunan Province, and on characteristics of enrichment and transfer of heavy metals （Cu, Pb, Cd, Zn） under influence of the two ramie species. [Result] It was concluded that trend of Cu content in different parts of ramie was as follows： rootskinleafbone; trend of Pb was rootleafskinbone; trend of Cd was rootskinboneleaf; the trend of Zn was rootskinboneleaf. In farmland A （with low content of heavy metal）, for per square meter of plough horizon, effect of Zhong 1 on heavy metals transferring volume and the period for restoration of the soil into national standard one （Category Ⅲ of Environmental Quality Standard for Soil） have been concluded. Specifically, for Cu, the corresponding values were 3 404.44 mg and 8.59 y, respectively; for Pb, the values were 3 638.5 mg and 13.52 y; for Cd, the values were 720.48 mg and 1.49 y; for Zn, the values were 37 324.8 mg and 0.67 y. [Conclusion] Soil contaminated by Cu, Pb, Cd, and Zn in orefield can be rapidly restored by growing ramie.
基金Supported by the National Natural Science Foundation of China(50874046)the National High-tech Research and Develop Program of China(863 Program)(2010AA065203)the Science and Technology Project of Education Bureau of Hunan Province,China(08A032)~~
文摘[Objective] To study the remediation efficiency of red mud on Pb, Zn and Cd in the heavy metal contaminated paddy soil of mine area, to clarify its remediation mechanism and fertilizer efficiency on heavy metal contaminated soil. [Method] The soil incubation experiment was conducted to study the effect of red mud on the pH values and electrical conductivity （EC）, and the remediation efficiency of red mud on lead （Pb）, zinc （Zn） and cadmium （Cd） in heavy metal contaminated soil. [Result] Red mud addition reduced the content of exchangeable Pb, Zn and Cd in the soil significantly. Compared with the control, when incubated for 30, 60 and 90 d with the red mud dosage of 4% （W/W）, the exchangeable Pb content was decreased by 39.25%, 41.38% and 50.19%; exchangeable Zn content was decreased by 49.26%, 57.32% and 47.16%; and exchangeable Cd content was decreased by 19.53%, 24.06% and 25.70%, respectively. The application of red mud had significant impact on the share of Pb, Zn and Cd contents in five forms, and different amounts of red mud application all reduced the proportion of exchangeable Pb, Zn and Cd to the total Pb, Zn and Cd. In addition, the proportion of exchangeable Pb, Zn and Cd to total Pb, Zn and Cd decreased with the increasing amount of red mud addition. [Conclusion] The study provided references for reasonable application of red mud and reduction of heavy metal pollution in paddy soil.
基金supported by the Science and Technology Overall Innovation Project of Shaanxi Province,China(No.2016 KTCQ03-20)the Scientific Research Foundation Project of Quzhou University,China(No.KYQD006224002).
文摘Microbe-assisted phytoremediation is of great significance for the remediation of soil contaminated with heavy metals(HMs),and probiotics are beneficial microorganisms that can improve soil structure and fertility and promote plant growth.However,there are few studies on probiotics applied to remediate soil contaminated with HMs,and whether probiotics can improve the efficiency of phytoremediation still needs to be further investigated.This study aimed to investigate the effects of two kinds of probiotics,Lactobacillus casei(Lc)and Bacillus licheniformis(Bl),on activating the remediation potential of leaf mustard,Brassica juncea(L.)Czerniak.,for soil contaminated with Cd and Zn using incubation and pot experiments.The results showed that the addition of the two probiotics significantly reduced soil pH by 0.05–0.32 units and improved the available contents of soil HMs(by 15.3%–60.0%and 7.1%–23.8%for Cd and Zn,respectively)in the incubation experiment.After probiotic addition,available Cd and Zn contents in soil treated with 1×10^(9) colony forming units(cfu)mL^(-1) Bl were 1.65-and 1.66-folds of those in the control without probiotic,respectively,in the pot experiment.Meanwhile,soil alkaline phosphatase,urease,and sucrose activities were increased,indicating that soil microbial metabolic activities were also stimulated.Addition of Lc and Bl significantly improved the biomass and chlorophyll contents of leaf mustard.The contents of Cd and Zn in shoots and roots were significantly increased in the treatment with 1×10^(5) cfu mL^(-1) Lc.Furthermore,the activities of plant antioxidant enzymes,including superoxide dismutase,peroxidase,and catalase,were increased,and the content of plant malondialdehyde was reduced,indicating that the resistance of plants to HMs was enhanced.These results indicated that these two kinds of probiotics could enhance the availability of Cd and Zn directly in soil and promote the growth of leaf mustard,thereby increasing the efficiency of phytoremediation for HMs.The study provides a useful reference for probiotic-assisted phytoremediation of soil contaminated with HMs.
基金supported by the Research Platform Open Fund Project of Zhejiang Industry and Trade Vocation College(No.Kf202203)the Scientific Research Project of CCCC First Harbor Engineering Company Ltd.(No.2022-7-2)+3 种基金the National Natural Science Foundation of China(No.22406142)the Fellowship of China National Postdoctoral Program for Innovative Talents(No.BX20230262)the Fellowship of China Postdoctoral Science Foundation(No.2023M732636)the Shanghai Post-doctoral Excellence Program(No.2023755).
文摘Efficient and innovative nano-catalytic oxidation technologies offer a breakthrough in removing emerging contaminants(ECs)from water,surpassing the limitations of traditional methods.Environmental functional materials(EFMs),particularly high-end oxidation systems using eco-friendly nanomaterials,show promise for absorbing and degrading ECs.This literature review presents a comprehensive analysis of diverse traditional restoration techniques-biological,physical,and chemical-assessing their respective applications and limitations in pesticide-contaminated water purification.Through meticulous comparison,we unequivocally advocate for the imperative integration of environmentally benign nanomaterials,notably titanium-based variants,in forthcoming methodologies.Our in-depth exploration scrutinizes the catalytic efficacy,underlying mechanisms,and adaptability of pioneering titanium-based nanomaterials across a spectrum of environmental contexts.Additionally,strategic recommendations are furnished to surmount challenges and propel the frontiers of implementing eco-friendly nanomaterials in practical water treatment scenarios.
基金supported by the National Key Research and Development Program of China(No.2023YFC3707902)China Postdoctoral Science Foundation(No.2024M752168)+1 种基金Jiangsu Funding Programfor Excellent Postdoctoral Talent(No.2024ZB393)the National Natural Science Foundation of China(No.42407126).
文摘Chemical leaching techniques have been proven effective in removing heavymetal contaminants fromsoil using various leaching agents.Previous research has shown that both singleagent and composite leaching systems have been applied for the remediation of chromiumcontaminated soils,with varying degrees of success depending on soil type and contaminant form.However,the removal rate of total chromium(Cr)and hexavalent chromium(Cr(Ⅵ))often fluctuates based on the chemical composition of the leaching agents,as well as the soil’s physicochemical properties,such as pH and Cr speciation stability.Therefore,this study investigates the effectiveness of 20 composite leaching systems,including deionized water,lime water,calcium chloride,sodium carbonate,and sodium phosphate,through soil column leaching tests.The aim was to evaluate their impact on soil pH,total Cr,and Cr(Ⅵ)removal,and to examine the transformation of various Cr species during the leaching process.Results reveal that lime water and sodium phosphate were particularly effective in stabilizing Cr(Ⅵ)and neutralizing soil pH,while total Cr removal amount ranged from 197.4 mg/kg to 1671.6 mg/kg and Cr(Ⅵ)removal amount ranged from 113.2mg/kg to 316.8mg/kg.We also find that using 0.2 mol/L citric acid,0.1 mol/L hydrochloric acid,and 1.2 mL/g lime solution adjusted soil pH to 7.37,with average removal efficiencies of 34.6%.for total Cr and 72.7%for Cr(Ⅵ).Overall,our results suggest that the combined use of lime water and sodium phosphate is an effective strategy for remediating chromium-contaminated soil,particularly for stabilizing unleached Cr and adjusting soil pH.
基金financially supported by the National Natural Science Foundation of China(No.41807116)the Natural Science Foundation of Fujian Province,China(Nos.2023J01418,2019J05035,and 2022N0024)+2 种基金the Scientific and Technological Innovation Project of China Metallurgical Geology Bureau(No.CMGBKY202301)the Independent Innovation Foundation of Tianjin University and Fuzhou University,China(No.TF2023-3)the Fuzhou University Testing Fund of Precious Apparatus,China(No.2023T014).
文摘Cadmium(Cd)contamination of soil is a global environmental issue.Traditional remediation techniques such as immobilization,leaching,and phytoextraction have numerous shortcomings,which has led to growing interest in the development of low-cost,high-efficiency,and environmentally friendly agents for removing Cd from soil.In this study,four magnetite(Fe_(3)O_(4))/polyaniline(PANI)nanocomposites,Fe_(3)O_(4)(1.0)/PANI,Fe_(3)O_(4)(1.5)/PANI,Fe_(3)O_(4)(2.0)/PANI,and Fe_(3)O_(4)(2.5)/PANI,were developed using 4 mL aniline monomer and 1.0,1.5,2.0,and 2.5 g Fe_(3)O_(4),respectively,and used as remediation agents with magnetic separation and regeneration capabilities.The Cd adsorption isotherms showed a better fit to the Langmuir model,with Fe_(3)O_(4)(1.5)/PANI exhibiting the highest Cd adsorption capacity of 47.62 mg g^(-1) at 25℃.Then,Fe_(3)O_(4)(1.5)/PANI was used to remediate four Cd-contaminated soils typical in China(black,brown,cinnamon,and red),all with a Cd content of 180 mg kg^(-1) after spiking.The results showed that the total Cd removal efficiency was satisfactory at 25.25%–38.91%and the exchangeable Cd removal efficiency was 36.03%on average.In addition,soil basic properties did not show significant changes after remediation.Regarding the regeneration performance,a higher total Cd removal efficiency(27.89%–44.96%)was achieved after the first regeneration cycle of Fe_(3)O_(4)(1.5)/PANI.After two regeneration cycles,Fe_(3)O_(4)(1.5)/PANI exhibited decreased total Cd removal efficiency compared to after the first regeneration,but its efficiency remained above 95%of or higher than those of virgin Fe_(3)O_(4)(1.5)/PANI.The synthetic process of Fe_(3)O_(4)/PANI was simple and cost-effective,and Fe_(3)O_(4)/PANI exhibited a high Cd removal efficiency with easy recovery and recyclability.Therefore,Fe_(3)O_(4)/PANI is a promising solution for the sustainable and efficient remediation of Cd-contaminated soils,especially for the reclamation of highly contaminated development land.
基金The Sherman Fairchild Foundation Undergraduate Research GrantThe National Science Foundation Award#1912400:HBCU-UP Implementation Project:Improving Minority Participation and Completion through STEM at Dillard University(IMPACTS@DU Ⅱ)Dillard University Endowed Professorship,funds。
文摘Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area and porous structure.It works by attracting and binding HM ions to its surface.Okoubaka is known for its medicinal properties and some studies suggest it has detoxifying effects.However,its specific role in HM removal would likely involve binding mechanisms like other plant-based materials.This study examines the efficiency of activated charcoal,charred versus uncharred Okoubaka plant materials,eggshells and oxalic acid to remove HMs like copper,lead,and zinc from contaminated water.
基金Projects(41472278,41202220)supported by the National Natural Science Foundation of ChinaProject(20120022120003)supported by the Research Fund for the Doctoral Program of Higher Education,China+1 种基金Project(51900265647)supported by the Beijing Higher Education Young Elite Teacher Project,ChinaProject(2652012065)supported by the Fundamental Research Funds for the Central Universities,China
文摘Cement-based composite grouting materials were used to construct grouting cutoff wall for heavy metal contaminated soil in non-ferrous metal mining areas. Cement, fly ash, and slag as principal ingredients were mixed with water glass in different ways to produce three composite grouting materials. In order to investigate the effect of water glass mixing ratio, Baume degree, fly ash and slag contents on the mechanical properties of the composite grouting materials, particularly their gel time and compressive strength, the beaker-to-beaker method of gel time test and unconfined compressive strength test were conducted. In addition, the phase composition and microstructure of the composite grouting materials were analyzed by the X-ray diffraction（XRD） and scanning electron microscope（SEM） techniques. The test results show that their gel time increases when water glass mixing ratio and Baume degree increase. The gel time increases dramatically when fly ash is added, but decreases slightly if fly ash is partly replaced by slag. When the mixing ratio of water glass is below 20%, their compressive strength increases with the increases of the ratio; when the ratio is above 20%, it significantly decreases. The compressive strength also tends to increase as Baume degree increases, and improves if fly ash and slag are added.
基金Supported by the Prospective Research Project of Industry-University-Research Cooperation in Jiangsu Province(BY2014037-21)~~
文摘[Objective] The remediation effect of the plant to Cd-contaminated soil was studied. [Method] By taking simulation test and field test, the ryegrass （Lolium perenne L.） was planted, and the remediation effect of the plant to contaminated sites was studied. [Result] The ryegrass was planted in the eluotropic soil for 0-60 d, Cd content in the soil showed a rapid decreasing trend; after 60 d, the enrich- ment ability of the plant to Cd gradually weakened over time; after 75 d of phytore- mediation, the Cd content in the soil decreased greatly, and the remediation effi- ciency was 90.66%. [Conclusion] Ryegrass remediation technology had good reme- diation effect to Cd-contaminated soil.
基金Supported by Unified Research with Industry-University-Research Cooperation(BY2014037-21)~~
文摘[Objective] The aim was to research phytoremediation effects on soils with combined pollution. [Method] With simulation experiment, the test selected plants suitable for phytoremediation in soils polluted with Pb-Cd, PAHs, and Pb-Cd-PAHs,respectively and ryegrass was grown to explore phytoremediation on contaminated sites by adjusting bio-availability. [Result] After 70 d growing of ryegrass, the content of available Pb in contaminated soils was 375.26 mg/kg, the content of Cd was 4.9mg/kg after 90 d, and the content of B [a]P was 0.60 mg/kg after 100 d, which were all lower compared with soil limits. [Conclusion] Ryegrass is a suitable plant for phytoremediation.
文摘Restoration of contaminated soil and groundwater could be divided into two phases. The first phase takes aim at reducing human being＇s health risks by active remediation, while the second phase aims at eliminating ecological risks by natural attenuation （NA）. Because of cost-effective and sustainable cleanup, monitored natural attenuation （MNA） and enhanced natural attenuation （ENA） have been gaining more attention recently, especially in the respects of ecological risk-oriented contaminated land management and a follow-up measure after active remediation. The uses and procedures of MNA for contaminated site cleanup and remediation in USA and EU were introduced firstly, and then possible applications of MNA in China were suggested. More developments and practices of MNA and ENA for managing contaminated sites in China are expected.
文摘To screen out a series of ideal plants that can effectively remedy contaminated soils by heavy metals is the main groundwork of phytoremediation engineering and the first step of its commercial application on a large scale. In this study, accumulation and endurance of 45 weed species in 16 families from an agricultural site were in situ examined by using the pot-culture field experiment, and the remediation potential of some weed species with high accumulation of heavy metals was assayed. The results showed that Solanum nigrum and Conyza canadensis can not only accumulate high concentration of Cd, but also strongly endure to single Cd and Cd-Pb-Cu-Zn combined pollution. Thus 2 weed species can be regarded as good hyperaccumulators for the remediation of Cd-contaminated soils. Although there were high Cd-accumulation in Artemigia selengensis, Znula britannica and Cephalanoplos setosum, their biomass was adversely affected due to action of heavy metals in the soils. If the problem of low endurance to heavy metals can be solved by a reinforcer, 3 weed species can be perhaps applied commercially.
基金Project supported by the National Key Basic Research Support Foundation of China (No. 2002CB410804) and the National Natural Science Foundation (No. 40201026).
文摘There is limited information on the release behavior of heavy metals fromnatural soils by organic acids. Thus, cadmium release, due to two organic acids (tartrate andcitrate) that are common in the rhizosphere, from soils polluted by metal smeltersor tailings andsoils artificially contaminated by adding Cd were analyzed. The presence of tartrate or citrate at alow concentration (<= 6 mmol L^(-1) for tartrate and <= 0.5 mmol L^(-1) for citrate) inhibited Cdrelease, whereas the presence of organic acids in high concentrations (>= 2 mmol L^(-1) for citrateand >= 15 mmol L^(-1) for tartrate) apparently promoted Cd release. Under the same conditions, theCd release in naturally polluted soils was less than that of artificially contaminatedsoils.Additionally, as the initial pH rose from 2 to 8 in the presence of citrate, a sequentialvalley and then peak appeared in the Cd release curve, while in the presence of tartrate the Cdrelease steadily decreased. In addition, Cd release was clearly enhanced as the electrolyteconcentration of KNO_3 or KC1 increased in the presence of 2 mmol L^(-1) tartrate. Moreover, ahigher desorption of Cd was shown with the KCl electrolyte compared to KNO_3 for the sameconcentration levels. This implied that the bioavailability of heavy metals could be promoted withthe addition of suitable types and concentrations of organic acids as well as reasonable fieldconditions.
基金supported by the National Key Research and Development Program(2018YFD0800300,2016YFC1400600)Natural Science Foundation of China(U1607111)+3 种基金the Hundred Talent program of CAS(2010–735)the Project for Science and Technology Service of Chinese Academy of Sciences(KFJ-EWSTS-016)Ningbo Natural Science Foundation(202003N4002)the Zhejiang Province Financial Support(LGF19D060001,R5110230)。
文摘Cadmium contamination of soil is a global issue and in-situ remediation technology as a promising mitigation strategy has attracted more and more attention.Many nanomaterials have been applied for the in-situ remediation of cadmium-contaminated soil due to their excellent properties of the nano-scale size effect.In this work,recent research progress of various nanomaterials,including carbon nanomaterials,metal-based nanomaterials and nano mineral materials,in the removal of cadmium and in-situ remediation of cadmiumcontaminated soil were systematically discussed.Additional emphases were particularly laid on both laboratory and field restoration effects.Moreover,the factors which can affect the stability of cadmium,main interaction mechanisms between nanomaterials and cadmium in the soil,and potential future research direction were also provided.Therefore,it is believed that this work will ultimately contribute to the myriad of environmental cleanup advances,and further improve human health and sustainable development.
