NITROGEN REMOVAL FROM DOMESTIC WASTEWATER USING TWO STAGE TIDAL FLOW CONSTRUCTED WETLANDAtul S. Shinde and Milind L. Waikar
In this study two stage tidal flow constructed wetland (TSTFCW), with three different ratios for Hydraulic Retention Time (HRT) 1:1, 1:2 and 1:3 in Phase-I and 1:1, 2:1 and 3:1 in Phase-II, is used to treat domestic wastewater. To enhance the removal efficiency first stage CW was planted with Typha sp. It was demonstrated that the maximum removal efficiencies of BOD5, COD, TSS, NH4-N, NO2-N and TN were 46.09 %, 46.05 %, 77.25 %, 86.40 %, 50.47 % and 82.38 % respectively in Phase-I for 1:3 HRT ratio while maximum removal efficiency of NO3-N was in Phase-II for 3:1 HRT ratio as 65.25 %. This study shows lower removal efficiency for organic matter removal which may be due to less HRT. The results suggest provision of more duration of HRT to achieve increase in efficiency of organic matter removal under same operating conditions.