title: Modelling cadmium contamination in paddy soils under long-term remediation measures: Model development and stochastic simulations.
abstract: A pollutant accumulation model (PAM) based on the mass balance theory was developed to simulate long-term changes of heavy metal concentrations in soil. When combined with Monte Carlo simulation, the model can predict the probability distributions of heavy metals in a soil-water-plant system with fluctuating environmental parameters and inputs from multiple pathways. The model was used for evaluating different remediation measures to deal with Cd contamination of paddy soils in Youxian county (Hunan province), China, under five scenarios, namely the default scenario (A), not returning paddy straw to the soil (B), reducing the deposition of Cd (C), liming (D), and integrating several remediation measures (E). The model predicted that the Cd contents of soil can lowered significantly by (B) and those of the plants by (D). However, in the long run, (D) will increase soil Cd. The concentrations of Cd in both soils and rice grains can be effectively reduced by (E), although it will take decades of effort. The history of Cd pollution and the major causes of Cd accumulation in soil were studied by means of sensitivity analysis and retrospective simulation.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors.forename: Meie
authors.initials: M
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China. Electronic address: wpchen@rcees.ac.cn.
authors.forename: Weiping
authors.initials: W
authors.lastname: Chen
mesh_terms: D002104:Cadmium / Q000032:analysis* / Q000378:metabolism; D002681:China; D004787:Environmental Pollution / Q000032:analysis*; D052918:Environmental Restoration and Remediation; D008962:Models, Theoretical; D009010:Monte Carlo Method; D012275:Oryza / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D013269:Stochastic Processes
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium
keywords: Heavy metals; Mass balance model; Monte Carlo simulation; PAM-HMs; Risk prediction; Soil pollution; Stochastic model