Using Combined Ultrasound and Zeolite-GAC Filtration Lab-Scale Process for Pre-Treating Micropolluted Water

Conventional water processes cannot high effectively removed NH₄-N, COD_Mn, and other pollutants of micro-polluted raw water. Therefore, this study was aimed to examine the combined process of ultrasound(US) and zeolite GAC filter used for pre-treatment of micro-polluted source water. Its factors affecting process efficiency were investigated. Under the Zeolite-GAC Filter conditions of 30min HRT( hydraulic retention time), air-water ratio 0.5 : 1, ultrasound working 30min (8min running, 2min pause) ultrasonic effect of could be maintained for 24 hours, under constant frequency of 20 kHz and water temperature 10~15°C, the removal rate of NH₄-N , COD_Mn, colourity and turbidity were about 96.5%, 54.24%, 91% and 88% respectively, better than that of without US process. The results showed that the combined stuffing filter could quickly remove NH₄-N and turbidity, but it could not high efficiently remove COD_Mn colourity and turbidity. Adding US to the system enhanced the removal efficiency of the process for CODMn, NH4-N, turbidity and UV254. The mechanism of biological activity enhancement by ultrasonic would be investigated in future. The novel method should be of value to improve the design and to optimize the operation.