Use of wetland to purify polluted stream network for a city water source
以河网作为城市水源的污染问题和湿地净化

JX City,located in the Yangtze River delta,takes drinking water from a stream network.In recent years,the water quality has declined rapidly because of the economic development in upstream areas.Stream networks have many pollution sources and complicated hydrodynamics that are difficult to control and threaten regional water safety.The JX City built an "ecological water purification wetland" in front of the water plant as the final barrier.The wetland has an area of 110 hm2,including a pretreatment zone,root-channel purification zone,water level rising and aeration zone,and deep purification zone.The wetland significantly improves water quality,and the removal rate of ammonia nitrogen was 32.5 %.This wetland system has other functions of ecological service,such as water storage buffering,urban air refreshing,habitats for wildlife and recreation site for the residents.