Pilot-Scale Experimental Study of Micropolluted Raw Water with Zeolite-Sand Biofilter

The operational performance of zeolite-sand double-layer biofilter is studied to treat micropolluted raw water on an experimental scale.The feasibility of the micropolluted raw water treated by the biofilter is examined.The results show that the treated water quality can be obviously improved and the removal rate of turbidity, COD_Mn, UV₂₅₄, NH₃-N and NO₂^--N has reached to 93.5%, 38%, 40%, 95% and 100% respectively.The removal is handled mostly on the top layer of 30 cm in the biofilter.Backwashing process of the biofilter has little influence on the biofilm, which can be recovered within one to two hours after the backwashing.It is feasible to replace an ordinary filter with zeolite-sand double-layer biofilter in the process of micropolluted raw water treatment.