WASTEWATER TREATMENT IN A PILOT-SCALE CONSTRUCTED WETLAND

Abstract

A pilot-scale constructed wetland (CW) has been set up in Atakoy Biological Treatment Plant (ABTP), Turkey. Graded-sand and plastic ping-pong balls existed as a soil simulation in the first reactor, treatment was based on floating duckweed (Lemna minor) in the second reactor. Effluent of Biological wastewater treatment plant was continuously pumped into the pilot-scale CW by different flow rates and retention times. The average removal rates in the first reactor were 78 % chemical oxygen demand (COD), 85 % suspended solids (SS), 38 % ammonium nitrogen (NH3-N), 42% total kjeldahl nitrogen (TKN), and 25 % total phosphorus (TP) considering the hydraulic retention time (HRT) of 6.7 days and the flow rate of 5.04 1/day, also 69 % COD, 70 % SS, 21 % NH3-N, 32 % TKN and 29 % TP considering HRT of 3.35 days and flow rate of 10.08 1/day. The average removal rates in the second reactor were 29 % COD, 42 % SS, 82 % NH3-N, 80 % TKN, and 10 % IT considering the HRT of 11.4 days and the flow rate of 5.04 1/day, also 45 % COD, 52 % SS, 68 % NH3-N, 56 % TKN and 13 % TP considering HRT of 5.7 days and flow rate of 10.08 1/day. Results of this research show that the proposed system is successful in terms of removal rates of pollutant parameters when they are compared to those cited in literature. Low operational costs make it a proper alternative especially for the developing countries.