Impact of cationic polyacrylamide degradation on flocculation in wastewater treatment

Abstract

In wastewater treatment plants, flocculating agents, primarily polymers, are widely employed to cluster sludge particles into larger flocs or aggregates. The flocculation process not only accelerates sedimentation rates of particles but also aids in water release during thickening and dewatering operations This study explores the effects of cationic polyacrylamide (CPAM) degradation on the flocculation process in wastewater treatment. CPAM undergoes noticeable degradation upon contact with specific metal surfaces, resulting in a substantial alteration in its rheological behavior. These modifications have broad implications for sludge flocculation: 1) accelerating polymer/sludge mixing dynamics, and flocculation kinetics, 2) inducing alterations in the resulting floc morphology, ultimately leading to smaller and less filamentous flocs. Notably, degraded CPAM requires a substantially less polymer quantity to achieve complete sludge flocculation, leading to a reduction in the excessive use of flocculating agents in wastewater treatment.