Domestic wastewater treatment using constructed wetland: an efficient and alternative way

Abstract

Constructed wetlands are engineered systems that are designed and constructed to utilize the natural process, involving vegetation, soil and their associated microbial assemblage to assist in treating different types of wastewater. Many different processes occur simultaneously inside the system to reduce the contaminant level in wastewater. The contaminants present in wastewater are mainly removed by filtration, sedimentation, biochemical interaction and microbial degradation. They are designed to take advantages of different processes that occur in the natural wetland but do so within a more controlled environment. Constructed wetlands have been used widely for the treatment of municipal, industrial and agricultural wastewater, as well as for urban storm water. In this study, Typha latifolia and Phragmites australis were used as vegetation for the reduction in the contaminant level present in the domestic wastewater using integrated set-up. An integrated set-up was constructed taking into account the EPA 1986 manual with dimension of 0.7 × 0.4 × 0.3 m. The flow rate adapted was 6 L/day with T. latifolia and P. australis as vegetation. For convincing flow of the wastewater, a bottom slope of 1% was also adapted. After the plants attained its full growth, the feed of domestic wastewater was given and the removal of pollutants and the vegetations was analyzed. For the removal of wastewater, the removal percentages of 75% of BOD and 70% of COD by T. latifolia as vegetation were obtained, and around 65% BOD and 70% COD removal percentages were obtained when P. australis was used as vegetation. The uptake of nitrate and phosphate is carried out in root, stem, and leaf, and thus presented and discussed.