模拟巢湖敌敌畏和氯菊酯的迁移转化和生态风险

发布时间：2019-05-29 08:31

【摘要】：近年来,随着有机磷农药和拟除虫菊酯类杀虫剂的大量使用,环境问题引起的各种危害也得到普遍关注。为了认识这类污染物在目标环境中的污染水平和环境中迁移转化归趋,以及对生态破坏程度。本研究结合了两种模型:多介质逸度模型和物种敏感性分布模型,以敌敌畏和氯菊酯为研究对象模拟了稳态假设下敌敌畏和氯菊酯在巢湖生态系统各环境介质中的浓度分布、迁移通量和去除途径,对各个输入参数作了敏感性分析和不确定性分析,进一步建立了污染物的物种敏感性分布模型,对敌敌畏和氯菊酯在稳定条件下的生物的潜在风险做了评估,预测出生态系统中保护95%物种不受威胁的最大年输入量。结果表明,敌敌畏在大气相、水体相、沉积物相中的浓度分别为5.39×10~(-13)mol·m~(-3)、1.56×10~(-8) mol·m~(-3)和9.76×10~(-11) mol·m~(-3),氯菊酯在大气相、水体相、沉积物相中的浓度分别为3.99×10~(-1)6mol·m~(-3)、5.63×10~(-11)mol·m~(-3)和1.95×10~(-5)mol·m~(-3)。大气中的敌敌畏主要是通过挥发作用进入,通过吸收作用输出,而氯菊酯主要以挥发形式进入,空气颗粒物干沉降消减;水体中敌敌畏通过平流输出和水向底泥扩散为主消减,氯菊酯主要通过底泥沉降和底泥向水扩散消减,两者均以平流输入为主进入;沉积物中敌敌畏的输入输出过程主要是通过扩散作用,氯菊酯主要以沉降形式进入,通过底泥再悬浮和掩埋消减。此外,SSD模型预测的敌敌畏和氯菊酯的HC5浓度值分别为3.46 ng·L~(-1)和2.20×10-2ng·L~(-1),远高于多介质模型预测的水体浓度。当输入巢湖水体的敌敌畏和氯菊酯年输入量分别低于2.75和943 t·a~(-1)的情况下,巢湖水体中95%的物种不会受到威胁。
[Abstract]:In recent years, with the extensive use of organophosphorus pesticides and pyrethroid pesticides, various hazards caused by environmental problems have been paid more and more attention. In order to understand the pollution level of this kind of pollutants in the target environment, the migration and transformation trend in the environment, and the degree of ecological damage. In this study, two models, multi-medium fugacity model and species sensitivity distribution model, were combined to simulate the concentration distribution of dichlorvos and permethrin in various environmental media of Chaohu Lake ecosystem under steady state assumption. The sensitivity analysis and uncertainty analysis of each input parameter were carried out, and the species sensitivity distribution model of pollutants was further established. The potential risk of dichlorvos and permethrin in stable conditions was assessed and the maximum annual input of protected 95% species in the ecosystem was predicted. The results show that the concentrations of dichlorvos in atmospheric phase, water phase and sediment phase are 5.39 脳 10 ~ (- 13) mol 路m ~ (- 3), 1.56 脳 10 ~ (- 8) mol 路m ~ (- 3) and 9.76 脳 10 ~ (- 11) mol 路m ~ (- 3), respectively. The concentrations of permethrin in atmospheric phase, water phase and sediment phase are 3.99 脳 10 ~ (- 1) 6mol 路m ~ (- 3), 5.63 脳 10 ~ (- 11) mol 路m ~ (- 3) and 1.95 脳 10 ~ (- 5) mol 路m ~ (- 3), respectively. Dichlorvos in the atmosphere mainly enter through volatilization and output through absorption, while permethrin mainly enters in the form of volatilization, and the dry deposition of air particles decreases. Dichlorvos in water mainly decreased through advection output and water diffusion to sediment, and permethrin mainly decreased through sediment sedimentation and sediment diffusion to water, both of which were mainly entered by advection input. The input and output process of dichlorvos in sediments is mainly through diffusion, permethrin mainly enters in the form of sedimentation, and subtracts through sediment resuspension and burying. In addition, the HC5 concentrations of dichlorvos and permethrin predicted by SSD model are 3.46 ng 路L ~ (- 1) and 2.20 脳 10 ~ (- 2ng 路L ~ (- 1), respectively, which are much higher than those predicted by the multi-medium model. When the annual inputs of dichlorvos and permethrin are less than 2.75 t 路a ~ (- 1) and 943 t 路a ~ (- 1), respectively, 95% of the species in Chaohu Lake will not be threatened.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X592;X524

【参考文献】