Biofilm characteristics of globular biofilter in the ecological spur-dike and water quality improvement effect on Wangyu River

To improve the water quality of Wangyu River, which is the important diversion channel for Water Transfer from Yangtze River to Lake Taihu, a ecological spur-dike was constructed in Wangyu River, This project combined the traditional water conservancy engineering with the biofilm technology, which can not only slow velocity and settle down sediment but also degrade organic pollutants and absorption nutrients in river water by organisms in biofilm. After 39 days of the construction, biofilm characters on the surface of globular biofilter were performed five times to analyze the changing process of microbial community. In addition, 3 sites of water samples were also observed before and behind the spur-dike, and in the background of Wangyu River, it was found that spur-dike has good effect on water purification. Results show that 70 taxa of attaching organism were identified on the biofilter, and major divisions were Bacillariopyta 37, Chlorophyta 20 and Cyanophyta 7. Compared with the background values, the purification efficiency of SS, TP, TN and COD_Mn were at the range of 5.1%-61.2%, 16.4%-57.2%, 8.2%-17.7%, 1.6%-34.5%, respectively. This study provided support for the development of river ecosystem restoration projects of in the future.