Exploring the Role of Ecological Groin in Improving River Water Quality: A Case Study in Wangyu River, China

Abstract

The ecological groin being built using elastic filter bulb with biologic filler, has received attention in the community for its role in improving stream water quality through altering stream hydrodynamics, intercepting sediment and thereby reducing the sediment-attached nutrients. As an important watercourse for the project Transferring Yangtse River into Taihu Lake, Wangyu River, was chosen in this study to investigate the effect of ecological groin based on two sampling campaigns in April 2012. The results showed that suspended solid (SS) and total phosphorus (TP) concentration in the water decreased significantly after the ecological groin. The SS and TP concentration in the surface, intermediate and bottom water decreased after the ecological groin by 53.5% and 12.7%, 44.0 %and 14.5%, and 35.5% and 9.3%, respectively, which were greatly related to the facts that ecological groin favored sedimentation and that the total particulate phosphorus accounted for up to 75.0% of TP in the water. Comparatively, TN concentration in the surface, intermediate and bottom water decreased after the ecological groin by 5.6%, 2.4% and 5.1%, respectively. The findings of this study enable us to gain insight into the role of ecological groin in improving river water quality.