Design And Application Of Urban Landscape River Circulating Purification Pilot Project

Water demand for cities have increased dramatically with a rapid development of urbanization.However,due to the pollution and the adverse impact of living and industrial production on waters,most urban scenic rivers have been polluted to different degrees,causing ecological imbalance and weakening the recovery of water system.The black-odor rivers,caused by pollution,will not only have an adverse effect on human health,but also on the development of social productive forces.Therefore,it is extremely essential to treat the polluted urban rivers.The paper conducts a study on the scenic rivers in Changzhou City,Base on the analysis of characteristics of an urban slow flow water body,a purification technology has been adopted and the demonstrate project has been built.The paper makes an analysis of the operating results through 915 days after the startup of the project.result shows that:at the early stage of the running of the purification devices,the level of total nitrogen concentration was reduced from 8.2mg/L to 2.6mg/L,with a removal efficiency of greater than 68.3%;the level of ammonia concentration was reduced from 7.13mg/L to 1.55mg/L,with a removal efficiency of greater than 78%;the level of total phosphorus concentration was reduced from 1.14mg/L to 0.24mg/L,with a removal efficiency of greater than 78%;and the chemical oxygen demand(COD)was reduced from 40 mg/L to 12.3 mg/L,with a removal rate of 69.3%.The water quality indexes of the scenic river met the standards of the "Environmental Quality Standards for Surface Water"(GB3838-2002)IV except for the level of total nitrogen concentration.At the later stage of the running of the purification devices,the removal rates of total nitrogen concentration,ammonia concentration,total phosphorus concentration and COD were 97.5%,98.23%,41.1%and 90.72%,respectively.However,the water quality was further deteriorated due to the input of external contamination.During the demonstrate project,the removal rates of total nitrogen concentration,ammonia concentration,total phosphorus concentration and COD all increased with the increase of their volume loading rate,and the removal rate of the pollutants was in extremely significant linear relationship with the volume loading rate..The effluent of the project return to the river,which not only removed the pollutants,but also improved the water quality and restored the river ecosystem to a certain extent;the purification devices have a strong anti-impact ability to initial rainwater pollution and other new pollution so that the system can be recovered in a short time.Since the building of the model project,the water quality around the University New Village was improved significantly.The scenic rivers change to be clean and clear and the ecosystem has been restored to some extent.The slow-flow water body recycling and purification technology,an remediation technology,can remove the pollutants in scenic rivers efficiently,which can not only improve the water quality of slow-flow water body,protect waters from deteriorating,and restore the damaged ecosystem,but also restore and control water pollution of the slow-flow water,especially for the urban scenic rivers.