ABSTRACT

The performance of photo-sequencing batch reactor (PSBR) in removing multiple antibiotics and nutrients from aquaculture wastewater as well as the antibiotic resistance genes (ARGs) proliferation were firstly investigated during the long-term experiments. The operational conditions (i.e. light intensity, light time, aeration and solid retention time) were optimised to realise the simultaneous removal of antibiotics and nutrients. It was found that, compared with traditional SBR, PSBR has similar nutrient removal rate and a 30% higher antibiotics removal rate due to the corporation of microalgae (Chlorella) and bacteria, and the absolute abundance of ARGs decreased by 78% in PSBR. Further investigation showed that PSBR had certain advantages in removing quinolones and the corresponding removal rate could reach up to 90%. In terms of the mechanisms, the possible metabolic pathway of antibiotic was analysed and the intermediate metabolites were different from that of the reported studies. The microbial communities were also affected by microalgae and the relative abundance of certain bacteria (such as members of the families Rhodocyclaceae and Burkholderiaceae), which were positively correlated with some ARGs, decreased in PSBR. This study provides an alternative and effective method to aquaculture wastewater treatment, which present high nutrients and antibiotics removal efficiencies and low ARGs transmission.

摘要

在长期实验中，首次研究了光序间歇反应器（PSBR）去除水产养殖废水中多种抗生素和营养物质的性能以及抗生素抗性基因（ARGs）的增殖。优化操作条件（即光照强度、光照时间、曝气和固体停留时间），实现抗生素和营养物质的同时去除。研究发现，与传统的 SBR 相比，PSBR 的养分去除率相近，由于微藻（小球藻）的加入，抗生素去除率提高了 30%。) 和细菌，而 PSBR 中 ARGs 的绝对丰度下降了 78%。进一步研究表明，PSBR在去除喹诺酮类药物方面具有一定的优势，相应的去除率可达90%。在机制方面，分析了抗生素可能的代谢途径，中间代谢物与报道的研究不同。微生物群落也受到微藻和某些细菌（如红环菌科和伯克霍尔德菌科的成员）的相对丰度的影响。)，与某些 ARG 呈正相关，在 PSBR 中降低。本研究为水产养殖废水处理提供了一种替代且有效的方法，该方法具有高营养物质和抗生素去除效率以及低 ARGs 传播。