Using a constructed wetland for non-point source pollution control and river water quality purification: a case study in Taiwan

摘要

The Kaoping River Rail Bridge Constructed Wetland, which was commissioned in 2004, is onenof the largest constructed wetlands in Taiwan. This multi-function wetland has been designednfor the purposes of non-point source (NPS) pollutant removal, wastewater treatment, wildlifenhabitat, recreation, and education. The major influents of this wetland came from the localndrainage trench containing domestic, agricultural, and industrial wastewaters, and effluents fromnthe wastewater treatment plant of a paper mill. Based on the quarterly investigation results fromn2007 to 2009, more than 96% of total coliforms (TC), 48% of biochemical oxygen demand (BOD),nand 40% of nutrients (e.g. total nitrogen, total phosphorus) were removed via the constructednwetland system. Thus, the wetland system has a significant effect on water quality improvementnand is capable of removing most of the pollutants from the local drainage system before theynare discharged into the downgradient water body. Other accomplishments of this constructednwetland system include the following: providing more green areas along the riversides, offeringnmore water assessable eco-ponds and eco-gardens for the public, and rehabilitating the naturalnecosystem. The Kaoping River Rail Bridge Constructed Wetland has become one of the mostnsuccessful multi-function constructed wetlands in Taiwan. The experience obtained from thisnstudy will be helpful in designing similar natural treatment systems for river water qualitynimprovement and wastewater treatment.