Treatment of 1,2-Dichlorobenzene in Pilot-Scale Constructed Wetlands

Three pilot-scale horizontal subsurface flow CWs of different soil substrates planted with Phragmites australis were installed and operated for field investigations on the removal of 1,2-Dichlorobenzene in simulated wastewater. The optimal HRT was determined at 5 days when the mean removal efficiencies of 1,2-Dichlorobenzene in loam, coarse sand and fine sand CWs were 90%,78% and 77% respectively. The systems carried out for 3 months from summer to autumn and relatively more steady treatment efficiency was observed in loam or coarse sand CWs than that of fine sand CW, which was declining all the time. Spatial concentration dynamics of 1,2-Dichlorobenzene and oxygen were investigated in relation to the distance from the inflow and the depth of the wetland bed, which revealed that oxygen concentration was an important factor for 1,2-Dichlorobenzene removal.