Influence of organic flocculants on the flocculation performance of aerobic sludge

ABSTRACT This study used cationic polymers poly (methacryloyloxyethyl trimethyl ammonium chlorideacrylamide, MPAM) synthesized in laboratory and poly (acryloyloxyethyl trimethyl ammonium chloride-acrylamide) (APAM) commercially available for aerobic sludge flocculation. The relationship between the dosage and the flocculation effect was investigated, and the influence of the polymer structure and cationicity on the flocculation performance was compared. The results revealed that the polymers with 10%–50% cationicity were suitable to flocculate the aerobic sludge. The flocculation efficiency of MPAM was better than APAM, which can attribute to the enhanced inhibitive hydration effect through compressing the double electrode layer by the methyl group in methacryloyloxyethyl trimethyl ammonium chloride (DMC). MPAM with 50% cationicity exhibited superior dewatering efficiency, a low moisture content of 75% and a specific transmittance of 97% at dosage of 90 mg L –1 . Consequently, MPAM, especially the polymer with 50% cationicity, is suggested as a promising and sustainable candidate in aerobic sludge dewatering agent. Furthermore, the possible flocculation mechanism involved in the flocculation process is proposed.