Applications of Constructed Wetlands for Wastewater Treatment

During the past decades, the high cost of conventional treatment processes has produced much economic pressure and they are not as natural methods as we expected. Thus, engineers begin to search for some creative, cost effective, and environmentally sound ways to treat wastewaters. Constructed wetland is a man made system which provides us many benefits and it is a very attractive way for many wastewaters treatment applications. Its mechanism of treatment is useing physical, chemical and biological processes separately or corporately. High efficiency of removal can be achieved for many kinds of contaminants, such as suspended solids, organic carbon, nitrogen, phosphorus, metals, and toxic organic compounds. And this kind of system could be used by a large range of users including governmental departments and agro-based industries in treating wastewaters before it is discharge into natural waterways. Except above virtues, constructed wetlands also serve as a wildlife sanctuary and provide habitat for wildlife, which satisfy us on the ecology aspect. This wastewater treatment system also can recreate publics, and can be an attractive destination for tourists or be a basic education center about natural ecosystem for researchers to study as well. However, constructed wetlands still have some limitations, for example, they cannot treat wastewaters with very high concentrations of contaminants and its treatment efficiency is considerably affected by climate or environmental conditions. What is more, compared with other traditional processes, it always takes longer time during the treatment process. Nevertheless, constructed wetlands treatment is considered to be the best choice for many kinds of wastewater treatment or pretreatment of wastewaters because of the low build and maintenance costs, high removal efficiency of contaminations, and simplicity of operation.