Stabilization in the remediation of heavy metal contaminated soils has been gaining prominence because of its cost-effectiveness and rapid implementation. In this study, microbial properties such as microbial communit...Stabilization in the remediation of heavy metal contaminated soils has been gaining prominence because of its cost-effectiveness and rapid implementation. In this study, microbial properties such as microbial community and enzyme activities, chemical properties such as soil pH and metal fraction, and heavy metal accumulation in spinach （Spinacia oleracea） were considered in assessing stabilization remediation effectiveness using sepiolite. Results showed that soil pH values increased with rising sepiolite concentration. Sequential extraction results indi- cated that the addition of sepiolite converted significant amounts of exchangeable fraction of Cd and Pb into residual form. Treatments of sepiolite were observed to reduce Cd and Pb translocation from the soil to the roots and shoots of spinach. Concentrations of Cd and Pb exhibited 12.6%-51.0% and 11.5%-46.0% reduction for the roots, respectively, and 0.9%-46.2% and 43.0%- 65.8% reduction for the shoots, respectively, compared with the control group. Increase in fungi and actinomycete counts, as well as in catalase activities, indicated that soil metabolic recovery occurred after sepiolite treatments.展开更多
The effects of immobilization remediation of Cd-contaminated soils using sepiolite on soil pH, enzyme activities and microbial communities, TCLP-Cd （toxicity characteristic leaching procedure-Cd） concentration, and ...The effects of immobilization remediation of Cd-contaminated soils using sepiolite on soil pH, enzyme activities and microbial communities, TCLP-Cd （toxicity characteristic leaching procedure-Cd） concentration, and spinach （Spinacia oleracea） growth and Cd uptake and accumulation were investigated. Results showed that the addition of sepiolite could increase soil pH, while the TCLP-Cd concentration in soil was decreased with increasing sepiolite. The changes of soil enzyme activities and bacteria number indicated that a certain metabolic recovery occurred after the sepiolite treatments, and spinach shoot biomass increased by 58.5%-65.5% in comparison with the control group when the concentration of sepiolite was ~ 10 g/kg. However, the Cd concentrations in the shoots and roots of spinach decreased with an increase in the rate of sepiolite, experiencing 38.4%-59.1% and 12.6%--43.6% reduction, respectively, in contrast to the control. The results indicated that sepiolite has the potential for success on a field scale in reducing Cd entry into the food chain.展开更多
基金This work was supported by National High Technol- ogy Research and Development Program of China （Grant No. 2012AA101404-5） and the National Natural Science Foundation of China （Grant Nos. 21107056 and 21177068）. The authors would also like to thank the Special Fund for Agro-scientific Research in the Public Interest （No. 201203045）.
文摘Stabilization in the remediation of heavy metal contaminated soils has been gaining prominence because of its cost-effectiveness and rapid implementation. In this study, microbial properties such as microbial community and enzyme activities, chemical properties such as soil pH and metal fraction, and heavy metal accumulation in spinach （Spinacia oleracea） were considered in assessing stabilization remediation effectiveness using sepiolite. Results showed that soil pH values increased with rising sepiolite concentration. Sequential extraction results indi- cated that the addition of sepiolite converted significant amounts of exchangeable fraction of Cd and Pb into residual form. Treatments of sepiolite were observed to reduce Cd and Pb translocation from the soil to the roots and shoots of spinach. Concentrations of Cd and Pb exhibited 12.6%-51.0% and 11.5%-46.0% reduction for the roots, respectively, and 0.9%-46.2% and 43.0%- 65.8% reduction for the shoots, respectively, compared with the control group. Increase in fungi and actinomycete counts, as well as in catalase activities, indicated that soil metabolic recovery occurred after sepiolite treatments.
基金supported by the National Natural Science Foundation of China (No. 2117706840901154+2 种基金21107056)the Program for Distinguished Scholar and Innovative Team of MOA (No. 2012-jcrc-xym)the Central Public Research Institutes Basic Funds for Research and Development (No.2011-szjj-syb)
文摘The effects of immobilization remediation of Cd-contaminated soils using sepiolite on soil pH, enzyme activities and microbial communities, TCLP-Cd （toxicity characteristic leaching procedure-Cd） concentration, and spinach （Spinacia oleracea） growth and Cd uptake and accumulation were investigated. Results showed that the addition of sepiolite could increase soil pH, while the TCLP-Cd concentration in soil was decreased with increasing sepiolite. The changes of soil enzyme activities and bacteria number indicated that a certain metabolic recovery occurred after the sepiolite treatments, and spinach shoot biomass increased by 58.5%-65.5% in comparison with the control group when the concentration of sepiolite was ~ 10 g/kg. However, the Cd concentrations in the shoots and roots of spinach decreased with an increase in the rate of sepiolite, experiencing 38.4%-59.1% and 12.6%--43.6% reduction, respectively, in contrast to the control. The results indicated that sepiolite has the potential for success on a field scale in reducing Cd entry into the food chain.
