Application of sand layer in activate-carbon filter for micro-polluted source water treatment processes
活性炭柱中砂垫层在微污染水源水处理工艺中的应用

The experiments were carried out with the settled water of a Jiaxing water work as influent. The pollutants removal efficiency of sand/carbon filter, the possibility of using sand/carbon filter to replace activated carbon filter plus sand filter and the applicability of this short process technology were discussed. The results show that sand/carbon filter can remove turbidity, NH4+-N, CODMn ,Fe and Mn, effectively. Compared with single active carbon filter, sand/carbon filter has advantages on reducing effluent turbidity and lessening effluent particle counts. It shows that the sand layer plays a positive role on the controlling the turbidity and guaranteeing microbial safety. Under the experimental conditions, to increase thickness of carbon layer or reduce filtration velocity to some extent can improve the removal efficiency of CODMn. When filtration velocity is 9~10 m/h and sand/carbon influent CODMn<4.5 mg/L, sand/carbon filter can replace active carbon filter plus sand filter, and can keep the effluent CODMn<3 mg/L.