A comparative study of upflow/downflow biological activated carbon technics effect in drinking water advanced treatment

In order to compare upflow and downflow biological activated carbon(BAC) filter´s advanced treatment effect, the changes of COD_Mn and turbiditity during biofilm colonization process was discussed firstly.Investigation was made on influence of filtration velocity and empty bed contact time(EBCT) after successful biofilm colonizing. Result shows that for the same filtration velocity, the removal rate of COD_Mn and turbidity by upflow BAC were 28.2% and 52%, respectively. The removal rate of COD_Mn were 10% higher than downflow BAC´s, but turbidity´s removal effect was 20% lower. After upflow BAC continuous ran 30 days without backwash, effluent´s turbidity and head loss were stable, which prolong backwash cycle effectively. Similar conclusion was obtained when upflow/downflow BAC have same EBCT.