太阳光强化降解水中抗生素与雌激素机理研究

The micro pollutants of antibiotics and estrogens in aquaculture water is a matter of concern to food safety and human health. Iron, humus and dissolved organic matters are important photoactive species in waters. It is very important for the treatment of water using solar energy. This project intends to combine the simulative experiments of solar photochemical reactions in plate system and field experiments in a breeding farms in Hubei respectively. The type of breeding farms is typical freshwater aquaculture systems. The photoactive compounds from the aquaculture systems will be detected and the reactive oxygen species produced in photochemical reactions will be determined and its sources will be identified according to the photoactive compounds. Typical antibiotics and estrogens will be selected as organic contaminants to investigate the photodegradation and its mechanisms of micro pollutants in aquaculture water, which helps to reveal the environmental processes and mechanisms of those micro pollutants and provide new method of enhanced removal. The response surface method will be used for the optimization of reaction conditions and the enhancement mechanisms could be achieved through regulating hydraulics and photochemical influencing factors to improve the removal efficiency of solar detoxification of antibiotics and estrogens. This project aims to provide basis to the application of solar energy to strengthen the self-purification function of aquaculture waters, reduce water pollution and promote energy conservation and natural resource use.

水产养殖水体中抗生素与雌激素等微污染物关乎食品安全与人群健康,水产养殖水体中含有铁、腐殖质和溶解有机质等重要的天然光活性物种，利用清洁能源太阳光强化处理水产养殖废水具有重要的现实意义。本项目拟通过薄层斜板式太阳光光化学模拟系统实验和养殖场现场实验结合，对湖北省武汉市东湖渔场养殖系统中的光活性体系进行甄别，检测太阳光光化学反应产生的活性氧类物种并查清其来源，研究养殖水中典型抗生素与雌激素的光降解及机制，既揭示污染物的环境过程与机理，又指导其强化去除方法，并利用响应面法优化反应条件，从而通过调控由强化机制决定的水力学与光化学影响因子提高太阳光对抗生素与雌激素的去除效率。本项目研究为利用太阳能强化水体自净功能，缓解水产养殖水体污染，促进节能减排和自然资源利用提供一定应用基础。

抗生素作为一类新兴污染物在环境水体中不断被监测到。这类污染物因具有“假”持久性并能引起环境菌群的抗药性而受到广泛关注。氯霉素类抗生素广泛应用于水产养殖，是环境中特别是在水产养殖区及附近水域中普遍存在的抗生素，研究其环境转化、归趋和生态风险具有重要意义。表层水体中，光化学降解是抗生素类污染物的主要消减方式。本项目通过薄层斜板式太阳光光化学模拟系统实验，探究华中科技大学校内湖溪河中氯霉素的光降解。主要是研究了活性氧化物种ROS浓度变化、活性氧化物种对抗生素的去除贡献程度、底物初始浓度、其他物质对光降解的影响、以及光降解过程中水样总有机碳和水样毒性变化。研究发现，CAP的光解符合光解一级动力学公式，CAP初始浓度升高会导致光解速率一定程度的下降；溶液pH在6-9的范围内对CAP的光解没有明显影响；随着溶液中氯离子浓度的增加，氯霉素的光降解效率和初始降解速率也会逐渐增加；在铵根离子浓度范围为0 ~ 800mg /L时，NH4+对氯霉素的降解效率和初始转化速率没有明显影响，但当铵根离子浓度达到1000mg /L时，降解效率从64.6%下降到52.06%；随着腐殖质浓度的增加，CAP光降解效率跟初始光降解速率也降低；65.91%的氯霉素是进行了直接光降解，6.82%的氯霉素是由生成的羟基自由基转化的，27.27%的氯霉素是由于单线态氧转化；经过一段时间的光照，湖溪河水样中TOC的呈下降趋势，毒性明显降低，最终低于可检测毒性阈值。