人工湿地净化海水养殖外排水效果与微生物群落分析

利用实验室规模的复合垂直流人工湿地系统来处理海水养殖外排水,探讨了人工湿地对外排水中主要污染物指标氨氮、磷酸盐和COD的去除效果,并利用变形梯度凝胶电泳技术(DGGE)分析了人工湿地内部微生物的群落组成和结构特点。结果显示,人工湿地对海水养殖外排水中的氨氮、磷酸盐和COD去除效果显著,平均去除率分别为(92.82±3.27)%、(72.53±2.31)%、(66.04±8.23)%;人工湿地系统内微生物组成较为丰富,且不同位置存在着种属相同、数量不同的生态幅广泛的优势种;人工湿地下行流池微生物多样性指数(H′)比上行流池高,且沿水流方向呈下降趋势;人工湿地系统中距离越远相似性系数越小;海水养殖外排水人工湿地处理系统微生物种群包括变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)、疣微菌门(Verrucomicrobia)、硝化螺旋菌门(Nitrospirae)和厚壁菌门(Firmicutes),其中,主要的优势菌群属于变形菌门和拟杆菌门。

Removal Effect of Mariculture Wastewater and Analysis of Microbial Communities in Constructed Wetlands

Constructed wetland, a new technique of wastewater treatment, has been widely used in fresh aquaculture wastewater treatment but not in mariculture wastewater treatment. In present study, we established a laboratory scale integrated vertical-flow constructed wetland （IVCW） to purify the mariculture wastewater. We examined the removal efficiencies of the main pollutants such as ammonia nitrogen, phosphate and chemical oxygen demand （COD）, and explored the composition and structure of the bacteria community in IVCW using denaturating gradient gel electrophoresis （DGGE）. The results suggest that the IVCW efficiently removed ammonia nitrogen, phosphate and COD （92.82±3.27）%, （72.53±2.31）%and （66.04±8.23）%, respectively. The results show a variety of bacterial divisions in the IVCW. The quantities of the dominant species were different in each layer of the IVCW. The Shannon-Wiener （H￠） of the down-flow tank is higher than that of the up-flow tank and it shows a decreasing trend along the water flow. The Dice coefficient （Cs） of microbial community in each layer showed an inverse relationship between the distance along the water flow and Dice coefficient. Six known bacteria groups including Proteobacteria, Bacteroidetes, Actinobacteria, Verrucomicrobia, Nitrospirae and Firmicutes were observed in the IVCW, and Proteobacteria and Bacteroidetes were the dominant species. This study provide a theoretical reference for elucidating the removal mechanism of contructed wetlands.