波流式生态滤床氨氮去除效果及其微生物群落结构分析

Ammonia removal and the microbial community structure in wave-flowing ecological filtering bed

利用波流式生态滤床处理受污染的河水,考察了其对氨氮的去除效果和沿程污染物转化情况,并采用扫描电镜、高通量测序手段解析了波流式生态滤床不同时间和位置基质上生物膜的细菌群落组成,分析了波流式生态滤床小试反应器中硝化细菌和反硝化细菌的分布特点,以探讨其去除氨氮的机理.结果表明,反应器稳定运行以后,对氨氮平均去除率为74.83%,基质表面可以观察到大量微生物,不同时期优势细菌有较大不同.反应器前部主要发挥硝化作用,中部发挥反硝化作用,硝化菌的分布呈现上多下少、前多后少的特点,使得氨氮在前端被快速去除;中部以黄杆菌属(Flavobacterium)为代表的反硝化菌丰度较高,促进了反硝化作用的发挥,降低了出水中总氮浓度;不同部位样品中细菌多样性差别不大,微生物种群多样性随着水流方向呈现先增加,到后段减少的趋势.

Wave-flowing ecological filtering bed was used to treat the contaminated river water. The pollutant removal along the water flow,especially the removal of ammonia,was investigated. Scanning electron microscope and high-throughput sequencing were used to characterize the microbial morphologies and community structures on the filtering matrixes at different times and locations. The distributions of nitrifying and denitrifying bacteria in the reactor were analyzed to explore the ammonia removal mechanism. The results show that：（1） the average removal of ammonia nitrogen after the reactor start-up was74.83%,abundant microorganisms were observed on the surface of filter matrix,and the dominant bacteria were varied with time periods;（2）In the upper part of the reactor,nitrification predominated,while denitrification did in the middle part. The amount of nitrifying bacteria in the up-front were more than that in rare partr. The denitrifying bacteria were mainly predominated by Flavobacterium in the middle part of reactor;（3） Bacterial diversity firstly increased and then decreased along the water flow direction,though little difference of bacterial diversity was in different parts of the reactor.