Notice of Retraction: The Optimum Study of Operation Conditions on the Dual-Media Flofilter with GAC and Sand

The water of Queshan reservoir (Jinan, China) which derived from Yellow River was treated by the technology of dual-media flofilter with GAC and sand, and the flocculation conditions, the flotation parameters and the filtration parameters were separatedly optimized. Based on the test result, PAFC was suited for Queshan reservoir water, and the optimum dosage was 2.0 mg A13+/L. HCl was added to adjust the pH of raw water, the influence of removal efficiency on turbidity was small, while the influence of removal efficiency on organic substance was comparatively large, and the influence result indicated: UV254 >; CODMn >; turbidity. The optimal value of dissolved air pressure was 0.30 MPa, and the optimal value of reflux ratio was 20% in the flotation unit. The filtration rate could not exceed 8m/h, and the filtration cycle was 3 days.