With the rapid development of economy and the acceleration of urbanization, the river pollution
occurred continuously, which results in the river ecosystems damaged seriously. Vast quantities of
domestic and industrial wastewater flowed into the river, which leads to the water system become
severely polluted. Accordingly, the function of river as resources was lost and the urban ecology and
water environment are seriously deteriorated. The problems of urban river pollution and ecological
damage are becoming more and more critical. According to the statistics, by the early 20th century, there is not almost a complete natural river in the world [1]. Therefore, it is urgent to develop a cost effective
technique to manage the river water quality.