Remediation Of Eutrophic Water And Mechanism Using Enhanced Constructed Wetlands

Currently, most rivers and lakes water in China are in moderate or serious eutrophic state. Frequently-used water remediation technology like physical and chemiscal methods requires high capital cost and causes many subsequent problems. Traditional activated sludge process is not suit for mechanism of groundwater pollution control. Eutrophic phenomena of groundwater involves a wide rang of watersheds and its mechanism is sophisticated. Till now, no effective strategies have been found to solve the problem. Nowdays, with conception of sustainable development, the idea of environment protection is chaging. People begin to relize the importance of ecological technology for water remediation like constructed wetland (CW) due to excellent performance, minimal capoital cost and ecological benefit.Most constructed wetlans adequately remove biochemical oxygen demands, total suspended solid and fecal coliform. However, most CWs may not adequately remove nitrogen and phosphorus; especialy can not remove ammonia effectively in winter and cold region. Low temperature offen causes internal ammonium release in CW. Presently, poor ability of nitrogen and phosphorus removal in low temprature is a significant problen for CW. Since most CWs can not satisfy requirement of steady removal performance and high loadings endurance, two enhanced constructed wetland processes are proposed based on natural characteristic of CW ecosystem: constructed wetland combined with ion-exchange and bioregeneration process (CW-IEBR), integrated constructed wetland (ICW). In CW-IEBR process, nitrogen and phosphorus removal are improved by ammonia adsorption using zeolite from wetland effluents during the colder winter months and ammonium-sorbed zeolite can be biologically regenerated during the summer months when temprature were more conducive for nitrafication. In integreted constructed wetland process, optimal combination of different flow wetlands and specific plant Pontedena cordata wer adopted to improve nitrogen and phosphorus removal in winter and spring moths.Nitrogen and phosphorus removal using the two enhanced CWs, feasility of...