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Comparison of two inorganic-organic composite coagulants in treating reservoir raw water from the Yellow River. |
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Abstract Two inorganic-organic composite coagulants PFC-PDMDAAC and PAC-PDMDAAC with series of Fe(Al)/PDMDAAC mass ratios were prepared for treatment of summer reservoir raw water from the Yellow River. The influence of Fe(Al)/PDMDAAC mass ratios, dosage, pH and dosing order on coagulation effect (turbidity, organic matter and chlorophyll-a removal) was investigated. The coagulation mechanism of the two coagulants was analyzed by the variation of Zeta potential during coagulation processes. The composite coagulants performed better than using them as dual-coagulants. The coagulation effects of both composite coagulants were greatly impacted by the mass ratio of Fe (Al)/PDMDAAC. The best coagulation effects were obtained when Fe (Al)/PDMDAAC mass ratio was 4:1with the dosage of 4mg/L. The composite coagulants could give excellent coagulation effect in the pH range from 5.0to 8.0, which is much wider than the inorganic coagulants. In comparison of PFC-PDMDAAC, PAC-PDMDAAC gave better turbidity and chlorophyll-a removal and worse organic matter removal.
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Received: 18 April 2011
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