title: Performance of pond-wetland complexes as a preliminary processor of drinking water sources.
abstract: Shijiuyang Constructed Wetland (110 hm(2)) is a drinking water source treatment wetland with primary structural units of ponds and plant-bed/ditch systems. The wetland can process about 250,000 tonnes of source water in the Xincheng River every day and supplies raw water for Shijiuyang Drinking Water Plant. Daily data for 28 months indicated that the major water quality indexes of source water had been improved by one grade. The percentage increase for dissolved oxygen and the removal rates of ammonia nitrogen, iron and manganese were 73.63%, 38.86%, 35.64%, and 22.14% respectively. The treatment performance weight of ponds and plant-bed/ditch systems was roughly equal but they treated different pollutants preferentially. Most water quality indexes had better treatment efficacy with increasing temperature and inlet concentrations. These results revealed that the pond-wetland complexes exhibited strong buffering capacity for source water quality improvement. The treatment cost of Shijiuyang Drinking Water Plant was reduced by about 30.3%. Regional rainfall significantly determined the external river water levels and adversely deteriorated the inlet water quality, thus suggesting that the "hidden" diffuse pollution in the multitudinous stream branches as well as their catchments should be the controlling emphases for river source water protection in the future. The combination of pond and plant-bed/ditch systems provides a successful paradigm for drinking water source pretreatment. Three other drinking water source treatment wetlands with ponds and plant-bed/ditch systems are in operation or construction in the stream networks of the Yangtze River Delta and more people will be benefited.
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: wdwangh@yahoo.com.
authors.forename: Weidong
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Zhongqiong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Jiaxing Water Conservancy Investment Co. Ltd., Jiaxing 314033, China.
authors.forename: Rongbin
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Jiaxing Water Conservancy Investment Co. Ltd., Jiaxing 314033, China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Jiaxing Jiayuan Water Supply and Drainage Co. Ltd., Jiaxing 314001, China.
authors.forename: Xinfeng
authors.initials: X
authors.lastname: Yu
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Chengqing
authors.initials: C
authors.lastname: Yin
mesh_terms: D060766:Drinking Water; D061005:Ponds; D011891:Rain; D013696:Temperature; D013997:Time Factors; D060753:Water Quality; D014881:Water Supply / Q000592:standards; D053833:Wetlands
chemical_list: D060766:Drinking Water
keywords: Constructed root channel technology; Plant-bed/ditch system; Pond–wetland combination; Semi-subsurface flow wetland; Weighted comprehensive water quality index