南方典型水稻土镉(Cd)累积规律模拟  

Simulation Cadmium(Cd)Accumulation in Typical Paddy Soils in South China

作　　者：戴雅婷 傅开道 杨阳[2] 王美娥[2] 陈卫平[2,3] DAI Ya-ting;FU Kai-dao;YANG Yang;WANG Mei-e;CHEN Wei-ping(Institute of International Rivers and Eco-Security,Yunnan University,Kunming 650091,China;State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]云南大学国际河流与生态安全研究院,昆明650091 [2]中国科学院生态环境研究中心城市与区域国家重点实验室,北京100085 [3]中国科学院大学,北京100049

出　　处：《环境科学》2021年第1期353-358,共6页Environmental Science

基　　金：国家自然科学基金项目(41907353);中国科学院生态环境研究中心城市与区域生态国家重点实验室项目(SKLURE2020-2-5)。

摘　　要：模拟分析稻田系统镉(Cd)迁移途径和土壤Cd累积趋势有助于风险决策的科学性和合理性.本文以湖南省攸县为研究区,在多环境介质采样的基础上,构建土壤重金属污染物累积(PAM)模型,预测区域稻田土壤Cd累积趋势,结合Monte Carlo随机模拟方法评估不同修复措施的有效性和可持续性.结果表明在当前Cd输入模式下连续耕作50 a后,攸县稻田土壤Cd含量处于轻度污染的概率高达82.1%,平均累加量达到4.28μg·(kg·a)-1.敏感性分析显示大气沉降和水稻吸收是影响攸县水稻土Cd累积的关键输入和输出过程.多情景模拟结果显示减少秸秆还田、优化工矿企业布局(减少大气沉降)和清洁灌溉水的综合措施可使区域土壤Cd含量在50 a降低43.7%,轻度污染概率降低了80.6%,是稻田Cd污染风险防控的长期有效措施.The simulation analysis of the migration path and soil accumulation trend of Cd in paddy soil systems could contribute to improved scientific and reasonable risk decision-making.In this study,based on a regional survey of environmental media in Youxian County,Hunan Province,a pollutant accumulation model(PAM)was built to predict the cumulative trend of Cd in paddy soils.Combined with Monte Carlo simulation,the PAM model was used to evaluate the effectiveness and sustainability of various remediation measures.Results showed that the probability of Cd accumulation in paddy soils in Youxian County exceeded that of the national soil environmental quality standard by 2-fold and was up to 82.1%,and the average accumulation rate reached 4.28μg·(kg·a)-1 after 50 years of cultivation under current input pattern.Sensitivity analysis results showed that atmospheric deposition and rice uptake were the key processes affecting Cd accumulation in paddy soils.Results of a multi-scenario simulation showed that the comprehensive measures,such as reducing the straw returning,optimizing the layout of industrial and mining enterprises that reduce the atmospheric deposition of Cd,and cleaning irrigation water,could reduce the Cd accumulation in paddy soils by 43.7%and reduce the probability of light Cd pollution by 80.6%after 50 years,which would be an effective long-term measure to prevent and control Cd pollution risk in paddy soils.

关 键 词：水稻土 Cd累积风险 通量模型 Monte Carlo模拟 敏感性分析 

分 类 号：X53[环境科学与工程—环境工程]