Influence of HRT and temperature on treatment of micro-polluted river water by using integrated horizontal-flow constructed wetland

The micro-polluted river water was treated by using integrated horizontal-flow constructed wetland. The micro-polluted river water was mixed up by effluent from wastewater treatment plant in west of Changchun City and Leijia river water. The experimental study hydraulic retention time (HRT) and temperature on the impact of wetland characteristics. The experimental results show that HRT on the wetland effluent COD, total phosphorus and nitrate nitrogen had significant effects, but it on the ammonia and nitrite was less affected. In this study, HRT is best when the treatment was the best around 1.29d. At this time, COD removal rate was about 50%, TP removal efficiency was 80% to 90%, and nitrate nitrogen removal rate was 70%; Temperature on the impact of wetland effluent COD was significant, but on ammonia nitrogen, nitrate nitrogen, total phosphorus, and nitrite was less affected. When the temperature was less than 10 °C, COD removal efficiency was only about 40%. When temperature rised up, COD removal rate was increased, up to 65%.