Study on suitability of single and hybrid constructed wetland for treating sewage for a small community

Abstract

In this study an attempt is made to study the comparison of effectiveness of single constructed wetland and hybrid constructed wetland for treating wastewater. Single constructed wetland is made with Phragmites Australis. The flow of water is vertical. Hybrid constructed wetland is made with vertical flow constructed wetland allied with water hyacinth based free floating wetland system. Primary treated sewage is allowed to the wetland. Water quality parameters namely Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) are measured before and after treatment. Two case studies have been in this study. In first study the water is allowed for one day contact time in single constructed wetland. In second case study, the treated water from one wetland is immediately transferred to other wetland. It is evident that, a hybrid constructed wetland gives better result in removing BOD and COD in wastewater. It is observed that there is no significant difference is observed in removing TSS removal. The water is allowed to different type of plants may increase the removal efficiency. The maximum BOD removal is obtained for hybrid wetland is 86% at one day detention time. The COD removal is obtained at one day is 48%.