Assessment of Hybrid Subsurface Flow Constructed Wetland Planted with Arundo Donax for the Treatment of Domestic Wastewater at Different Hydraulic Retention Time

Due to water scarcity, storage and reuse of water has become a great challenge all over the world. The conventional methods for the wastewater treatment require large capital investment, operating cost, and need trained personal for supervision and maintenance. Therefore non conventional wastewater treatment methods have gained the popularity worldwide. Use of constructed wetland (CW) technology for wastewater treatment is highly efficient since CW are easy to construct, cost effective and increase the aesthetic value. Wetlands behavior and efficiency concerning wastewater treatment mainly depends upon macrophytes, substrate, hydrology, temperature and hydraulic retention time in the system. Present study deals with the removal of pollutants in two stage hybrid subsurface flow CW at different hydraulic retention times (HRT). The domestic wastewater was supplied to CW and treated using the available perennial macrophyte, Arundo donax. The system was run in replicate along with one control. To assess the removal efficiency of the pollutants, parameters like pH, temperature, dissolved oxygen (DO), total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN) were analyzed at different HRT i.e., 36, 30 and 24 h. The result of the study observed maximum percentage removal of TSS, BOD, COD, and TKN was up to 84.61, 98.37, 61.39 and 91.87% respectively at 30 h of retention time.