Test Comparison between Coagulation-DAF and Coagulation-Sedimentation Processes for Treatment of Low Temperature and Turbidity Reservoir Water

The pilot treatment effects between coagulation- dissolved air flocculation process( DAF) and coagulation- sedimentation process for the low temperature and turbidity water of Queshan reservoir are compared. The polyaluminium chloride iron( PAFC) coagulant is used. The dosing quantity of PAFC of DAF process is 5 mg / L,17% lower than that in coagulation- sedimentation process. The continuous test shows that for the low temperature and turbidity reservoir water the DAF process is superior to coagulation- sedimentation process. The removal rates of turbidity,particle counts,CODMn,UV254 and DOC by DAF are 7. 7%,12. 8%,3. 9%,5. 1% and 8. 5% respectively higher than those by sedimentation process.