| 典型有机氯农药在珠三角地区多介质环境中的归趋模拟 |
| 摘要点击 2228 全文点击 763 投稿时间：2017-08-18 修订日期：2017-10-07 |
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| 中文关键词 p,p'-DDT γ-HCH Ⅳ级环境多介质逸度模型 温度变化 珠三角 |
| 英文关键词 p,p'-DDT γ-HCH level Ⅳ multimedia fugacity model temperature change Pearl River Delta |
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| 中文摘要 |
| 本研究以p，p'-DDT与γ-HCH为目标污染物，通过建立Ⅳ级环境多介质逸度模型，模拟目标污染物在高温高湿气候条件下珠三角地区从1952~2030年的79年间在环境介质中迁移转化随时间和温度变化的规律.模拟结果较好地反映了p，p'-DDT与γ-HCH浓度随农药施用和禁用等农业政策而经时变化的情况：持续施用导致p，p'-DDT与γ-HCH在气、水、土、底泥中的浓度随时间逐年增加；有机氯农药被禁止使用，则导致二者浓度逐渐下降并趋于稳定；预测到2030年p，p'-DDT在气、水、土、泥中的浓度分别为6.1×10-12、3.2×10-9、6.07×10-7和8.72×10-7 mol·m-3；γ-HCH的浓度则分别为3.37×10-11、1.14×10-8、1.21×10-6和4.18×10-7 mol·m-3.通过将温度设计为变量参数对模型进行校正后的模拟值比恒温模拟值更接近实测值.结果表明，在整个环境介质中出现有机氯农药由大气分别向土壤和水体、土壤向水体、水体向底泥传输的规律，并最终赋存于土壤和底泥中；有机氯农药排放量、降解速率、温度及辛醇-水分配系数Kow是模型主要的敏感参数；不确定性分析显示整体参数的改变对大气模拟浓度影响最大；有机氯农药在环境中的浓度分布存在季节性差异，温度变化会影响有机氯农药在环境中的分配. |
| 英文摘要 |
| A level Ⅳ multimedia fugacity model was established to simulate the fate of p,p'-DDT and γ-HCH in special climatic conditions, such as in the high temperature and humidity environment of the Pearl River Delta, China. The law of migration and transformation of p,p'-DDT and γ-HCH were approached by the Ⅳ multimedia fugacity model, corrected for time and temperature change during 1952-2030. The simulation results showed a better response of the variation of pollutant concentrations to the changes in the pesticide application policy; the concentrations of these two targets in air, water, soil, and sediment were found continuing to increase with the growth of application rates, and decreased with the prohibition in the use of pesticide. We predicted that concentrations will decrease to 6.1×10-12, 3.2×10-9, 6.07×10-7, and 8.72×10-7 mol·m-3 for p,p'-DDT, and to 3.37×10-11, 1.14×10-8, 1.21×10-6, and 4.18×10-7 mol·m-3 for γ-HCH, in air, water, soil, and sediment, respectively, by 2030. The output values of the Ⅳ multimedia fugacity model corrected by designating temperature as a variable parameter, was closer to the survey results than the simulation results obtained by using the model with a constant temperature parameter. The results also showed the pattern of organochlorine pesticides transformation in the whole environmental media in the study area as follow:the pollutants transferred from air to soil, air to water, soil to water, and from water to sediment, and were lastly stored in the soil and sediment. The results of sensitivity analysis indicated that the emission rate, degradation rate, temperature, and lgKow had significant influences on the concentrations of p,p'-DDT and γ-HCH in all the above-mentioned environmental medias. Uncertainty analysis showed that changes in the whole parameter sets had great impact on air concentrations. There were seasonal variations in the distribution of organochlorine pesticide concentrations, and temperature change had influence on its partition in the environment. |
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