养殖废水中典型抗生素的藻类去除效能及机制研究

Adverse effects of residual antibiotics in intensive high density agricultural production (e.g poultry，livestock，and fish farming) were revealed, including reducing microbial biomass and activity，altering microbial community structure and diversity, inducing antibiotic resistance genes in contaminated environments. The potential risks of antibiotics in the environment have been increasingly recognized in their influence on ecosystem safety and human health. In recent years, wastewater treatment by algae biotechnology, which can couple with biofuel production, has an applicable potential in the culture wastewater treatment. Previous studies on algae and pollutants have mainly focused on the removals of nitrogen and phosphorus, little work has been done so far on algae for the removals of organic contaminants, especially antibitics. The studies on the removal efficiency and mechanism of selected antibiotics in culture effluents by algae, are beneficial to the safety of farmed products quality and the sustainable development of food animal production. In this project, the interaction including sorption/desorption, degradation, accumulation and transformation between algae and antibiotics will be investigated in detail. The suitable algae species with a high efficiency of antibiotics removal will be collected in culture wastewater. After isolation and purified cultivation, these algae species will be further investigated for the removal process and mechanisms of selected antibiotics in culture wastewater. The algal responses to antibiotics will also be evaluated by measuring algal growth, algal ultrastructure, enzymatic activity and photosynthetic parameters such as photosynthetic pigment and chlorophyll ?uorescence. The influencing factors, such as temperature, pH values, light intensity, concentrations of organic matter and nutrients, initial density of algae and culture mode, will be explored. Batch experiments will be carried out to investigate the simultaneous removal of antibiotics, nitrogen, phosphorus and heavy metals by various algae species. The cultural conditions will further be optimized to improve the removal efficiencies of multiple contaminants.In addition, the rapid and cheap technique for algae harvest will be developed. This study is helpful to the understanding of the application of algae biotechnology in culture wastewater. As an environment friendly wastewater treatment process, this algae biotechnology, is hopefully to decrease the traditional treatment load and realize the low-energy consumption.

集约化养殖业的快速发展导致养殖区环境抗生素种类和含量逐年增加，从而给生态安全和人类健康带来潜在风险。近年来，藻类生物技术因具有废水处理和生物产能的双重功效而被广泛应用于养殖废水处理。然而以往的研究多集中在藻类对氮磷的去除研究，尚缺少对废水中残留抗生素等有机污染物的去除研究。开展藻类对养殖区抗生素去除效能和机制的研究，对于保障养殖产品的质量安全，确保养殖业可持续健康发展具有重大现实意义。本项目旨在研究藻类对抗生素的吸附、降解、累积和转移作用，甄别和获取高效去除抗生素的藻种，考察藻细胞在抗生素胁迫下的生理特征响应，阐明藻类对抗生素的去除过程和机制及环境因素对藻类去除效能的影响；进一步研究藻类对养殖废水中抗生素、氮磷和重金属等复合污染物的同步去除作用。通过优化培养条件以提高复合污染物的去除效能，并开发廉价快速的藻类收获方法。为降低传统处理负荷，形成低能耗的环境友好型绿色废水处理技术提供理论依据。

近年来集约化养殖业的快速发展导致环境中残留抗生素种类和含量逐年增加，从而给生态安全和人类健康带来潜在风险。藻类生物技术因具有废水处理和生物产能的双重功效而被广泛应用于养殖废水处理。以往的研究多集中在藻类对氮磷的去除研究，尚缺少对废水中残留抗生素等有机污染物的去除研究。本项目首先建立了复杂环境介质中抗生素的提取、净化和仪器分析方法，能满足养殖环境中痕量级八大类43种抗生素的定性和定量分析。运用建立的固相萃取-高效液相色谱-串联质谱法测定了养殖区废水中残留抗生素的分布特征，发现大环内酯类、喹诺酮类和磺胺类抗生素具有较高的环境残留。分别从海水和淡水环境中甄别和筛选出具有去除抗生素能力的两种绿藻，眼点拟微球藻和近头状伪蹄型藻，以环境检出率和浓度较高的红霉素、诺氟沙星及磺胺嘧啶进行室内暴露实验结果发现，抗生素对藻类生长表现出“低促高抑”现象，低浓度抗生素能提高叶绿素a含量，促进光合作用，而在高浓度胁迫下，藻细胞严重受损，光合活性、电子传递、酶活性等均受到强烈抑制。红霉素对两种藻的抑制作用要大于诺氟沙星和磺胺嘧啶；在低浓度暴露下，眼点拟微球藻和近头状伪蹄型藻对诺氟沙星和磺胺嘧啶的去除过程符合一级动力学方程，生物转化及生物降解是藻类去除这两种抗生素的主要途径。对诺氟沙星和磺胺嘧啶的降解产物分别进行了鉴定，并推导了其降解途径及降解机理。证实了藻类对废水中总氮总磷、重金属和抗生素的同步去除具有一定的效果。探讨了利用多种果皮废弃物的水解液兼养培养微藻生产生物柴油的可行性。该项目的研究成果可为藻类污水处理技术去除新型有机污染物及藻类产能技术的应用提供理论依据，对保障养殖产品的质量安全，确保养殖业可持续健康发展具有重大现实意义。本项目已正式发表学术论文12篇，其中SCI论文11篇，中文核心期刊论文1篇，培养博士后1名，研究生7名，青年学术骨干4名。