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Mineral materials as feasible amendments to stabilize heavy metals in polluted urban soils

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Journal of Environmental Sciences 2011年第4期23卷 607-615页

作者： Mingkui Zhang Jincheng Pu Zhejiang Provincial Key Laboratory of Subtropical soil and Plant Nutrition College of Environmental and Resource Sciences Zhejiang University Hangzhou 310058 China.

Four minerals, agricultural limestone （AL）, rock phosphate （RP）, palygorskite （PG）, and calcium magnesium phosphate （CMP）, were evaluated by means of chemical fractions of heavy metals in soils and concentrations of heavy metals in leachates from columns to determine their ability to stabilize heavy metals in polluted urban soils. Two urban soils （calcareous soil and acidic soil） polluted with cadmium, copper, zinc and lead were selected and amended in the laboratory with the mineral materials） for 12 months. Results indicated that application of the mineral materials reduced exchangeable metals in the sequence of Pb, Cd Cu Zn. The reduction of exchangeable fraction of heavy metals in the soils amended with different mineral materials followed the sequence of CMP, PG AL RP. Reductions of heavy metals leached were based on comparison with cumulative totals of heavy metals eluted through 12 pore volumes from an untreated soil. The reductions of the metals eluted from the calcareous soil amended with the RP, AL, PG and CMP were 1.98%, 38.89%, 64.81% and 75.93% for Cd, 8.51%, 40.42%, 60.64% and 55.32% for Cu, 1.76%, 52.94%, 70.00% and 74.12% for Pb, and 28.42%, 52.74%, 64.38% and 49.66% for Zn. Those from the acidic soil amended with the CMP, PG, AL, and RP were 25.65%, 68.06%, 78.01% and 79.06% for Cd, 26.56%, 49.64%, 43.40% and 34.68% for Cu, 44.44%, 33.32%, 61.11% and 69.44% for Pb, and 18.46%, 43.77%, 41.98% and 40.68% for Zn. The CMP and PG treatments were superior to the AL and RP for stabilizing heavy metals in the polluted urban soils.

关键词： heavy metals polluted soil chemical fraction chemical immobilization mineral materials

The application and progress of bioelectrochemical systems (BESs) in soil remediation: A review

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Green Energy & Environment 2021年第1期6卷 50-65页

作者： Tian Li Ruixiang Li Qixing Zhou MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringNankai UniversityNo.38 Tongyan RoadJinnan DistrictTianjin300350China

soil pollution endangers human health and ecological balance,which is why finding a highly efficient way to deal with pollutants is *** method is an environmentally friendly treatment *** systems(BESs),which combine electrochemistry with biological methods,have been widely used to remediate polluted environments,including wastewater,sludge,sediment,and *** BESs,redox reactions occur on electrodes with electroactive bacteria,which convert pollutants into low-polluting or nonpolluting *** BESs being a promising technology in the remediation field,the decontamination mechanisms and applications in soil conducted by BESs have attracted much ***,to better understand the research progress of BESs,this paper mainly summarizes the mechanism of different classified *** applications of microbial fuel cells(MFCs)in four pollutants(petroleum,heavy metals,pesticides,antibiotics)and the possible applications of microbial electrolysis cells(MECs)in soil are *** main problems in BESs and possible future development directions are also evaluated.

关键词： polluted soil Bioelectrochemical systems Remediation Application

Cadmium Release in Contaminated soils due to Organic Acids

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Pedosphere 2004年第2期14卷 223-228页

作者： LIAOMin XIEXiao-Mei DepartmentofResourcesScience CollegeofEnvironmentalandResourceSciencesZhejiangUniversityHangzhou310029（China）.E-mail：liaomin@***

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 (= 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 ***, 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.

关键词： artificially contaminated soil cadmium organic acid polluted soil release

Toxicity threshold of lead(Pb) to nitrifying microorganisms in soils determined by substrate-induced nitrification assay and prediction model

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Journal of Integrative Agriculture 2017年第8期16卷 1832-1840页

作者： ZHENG Han CHEN Li LI Ning LIU Bin MENG Nan WANG Meng CHEN Shi-bao Key Laboratory of Plant Nutrition and Fertilizer Ministry of Agriculture/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences Institute of Plant Protection and Environmental Protection Beijing Academy of Agriculture and Forestry Science

Lead （Pb） contamination has often been recorded in Chinese field soils. In recent years, efforts have been made to inves- tigate Pb toxicity thresholds in soils with plant growth and microbial assays. However, the influence of soil properties on Pb toxicity impacts on soil microbial processes is poorly understood. In this study ten soils with different properties were collected in China to investigate the relationships between thresholds of Pb toxicity to soil microbes and soil properties. The effect of soil leaching on Pb toxicity was also investigated to determine the possible influence of added anions on Pb toxicity during dose-response tests. Toxicity was inferred by measuring substrate-induced nitrification in leached and non-leached soils after Pb addition. We found that soil microbe Pb toxicity thresholds （ECx, x=10, 50） differed significantly between the soils; the 10% inhibition ratio values （ECI0） ranged from 86 to 218 mg kg-1 in non-leached soils and from 101 to 313 mg kg in leached soils. The 50% inhibition ratio values （EC50） ranged from 403 to 969 mg kg^-1 in non-leached soils and from 494 to 1 603 mg kg^-1 in leached soils. soil leaching increased EC50 and EC50 values by an average leaching factor （LF） of 1.46 and 1.33, respectively. Stepwise multiple regression models predicting Pb toxicity to soil microbes were developed based on ECx and soil properties. Based on these models, soil pH and organic carbon are the most important soil properties af- fecting Pb toxicity thresholds （R2〉0.60）. The quantitative relationship between Pb toxicity and soil properties will be helpful for developing soil-specific guidance on Pb toxicity thresholds in Chinese field soils.

关键词： dose-response lead (Pb) polluted soil substrate-induced nitrification

Lead and Mercury Contamination Assoc=atea with Artisanal Gold Mining in Anka, Zamfara State, North Western Nigeria： The Continued Unabated Zamfara Lead Poisoning

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Journal of Earth Science and Engineering 2013年第11期3卷 764-775页

作者： Lar Uriah Tsuwang Kenneth Gusikit Rhoda Mangs Ayuba Department of Geology University of Jos Jos P.M.B. 2084 Nigeria

A total of 24 soil samples were collected from areas around Artisanal Gold and associated Pb-Zn-Cu sulfide mining and mineral processing sites in the Anka mining district of Zamfara State, NW Nigeria. The samples were geochemically analyzed with the main objective of assessing the degree of Pb and Hg pollution in the environment resulting from the mining and mineral ore processing activities in the mining district and to consider the effect on human health. The assessment of the degree of pollution or toxicity was based on the Igeo （index of geoaccummulation） and EF （enrichment factor） where the former gives a quantitative pollution class with respect to the quality of the medium analyzed, while the latter differentiates between metals originating from anthropogenic activities and those from natural processes. The geochemical results show that the concentrations of Pb and Hg especially at the mineral processing sites significantly exceed the established thresholds （4,152 ppm and 12.92 ppm respectively）. The calculated EF values for both Pb and Hg revealed that the soils from the entire mining district are extremely enriched in these elements, essentially originating from the anthropogenic activities （EF= 〉〉 40）. Lead and Mercury are toxic heavy metals with documented long-lasting adverse human health effects. These calls for efficient bioremediation measures for the removal of Pb and Hg from the contaminated soils that take into account the geochemical peculiarities of the mining district.

关键词： Lead mercury polluted soil environment human health gold artisanal mining.