作为全球第二大杀虫剂，新烟碱类农药（NEOs）已在全世界范围内广泛检出，天然水体是其重要的环境汇。研究表明，NEOs对非靶标生物具有毒性，在水中还可能降解成毒性更强的产物。然而，NEOs及其降解产物在水环境中的来源、迁移转化和传输等环境行为尚未厘清。本项目拟选择华南典型城市水链（污水厂-自来水厂-地表水）为研究对象，针对4种常见的NEOs及其降解产物开展如下研究：1）目标区域城市水链中污染水平及生态风险；2）典型水处理设施中的处理效率、消长动力学及关键单元中生物/非生物转化机制；3）水环境多介质中的相间迁移、归趋特征及驱动因素。我国是世界上最大的NEOs生产和使用国。该项目有望在探明我国城市水链中NEOs污染特征及消减规律方面取得新认识，在水处理设施的转化机制和水环境归趋的形成机理方法取得新成果。既为NEOs生态风险评估提供理论依据，也为国家制定合理的规管措施提供科学支撑。

As the second largest pesticides, neonicotinoids (NEOs) have been globally found in natural water which is the important environmental sinks of NEOs. Studies show that NEOs are toxic for a variety of non-target organisms, and their catabolites in water may be more toxic than parent chemical. However, environmental sources and behaviors of NEOs and their catabolites such as migration, transformation, and transmission in water environment have not been clarified yet. In this project, the water chain in typical cities of South China (i.e., waste water treatment plant - drinking water plants - surface water) are selected, and the following research is conduct on 4 commonly used NEOs and their degradation products. The aims of this project are to understand: 1) pollution level and ecological risk of NEOs in urban water chain from target areas; 2) treatment efficiency, growth kinetics, and biological/abiotic conversion mechanisms of NEOs in key units in typical water treatment facilities; and 3) inter-phase migration, fate and driving factors of NEOs in multi-medium water environment. China is the world's largest country on the production and use of NEOs. This project is expected to provide novelty information on contamination characteristics and abatement rules of NEOs in Chinese urban water chain, make new achievements in their transformation mechanism of water treatment facilities and the understanding of their fate in water bodies. Such findings will provide theoretical basis for ecological risk assessment of NEOs, simultaneously, will propose important scientific support for Chinese government.