What factors affect the flocculation effect of cationic polyacrylamide (CPAM)?

Cationic polyacrylamide (CPAM) is a commonly used flocculant for water treatment. Factors that affect the flocculation effect and can be controlled manually include the type and dosage of CPAM, wastewater pH, stirring time and settling time, and their reasonable setting is critical to the flocculation effect of CPAM.

Does CPAM neutralize negatively charged sludge?

Specifically, the positive charge in CPAM can thoroughly neutralize the negatively charged sludge particle, makes sludge particle destabilize, and generates relatively dense flocs through adsorption and bridging effect (Yuan et al. 2011; Rabiee et al. 2014; Wang et al. 2018, 2019).

Does CPAM affect the flocculation effect?

The single-factor test results showed that the flocculation effect was better when the intrinsic viscosity was larger or the cationic degree of CPAM was higher; the CPAM dosage, wastewater pH and stirring time had significant impacts on the flocculation effect of CPAM and existed optimums.

How does CPAM affect wastewater turbidity?

Figure 7 shows that with increasing CPAM dosage and stirring time, the wastewater turbidity first decreased and then increased under the condition of fixed wastewater pH, and when the CPAM dosage and stirring time were in the range of 5.5 to 6 mg·L −1 and 5 to 7 min, respectively, the wastewater turbidity had a minimum value.

Does tpamd improve sludge dewatering and flocculation effect?

Compared with CPAMD and the commercial flocculants, the sludge dewatering effect (FCMC and SRF) of TPAMD has been evidently improved by 1.4% for FCMC and 1.01 × 10 12 m/kg for SRF at least based on the sludge dewatering and flocculation test. TPAMD had good flocculation effect on water plant sludge.

Is sewage suitable for flocculation treatment with CPAM?

Most sewage containing suspended solids exhibits a colloidal property and negative charge and is very suitable for flocculation treatment with CPAM. UV-initiated polymerization is a new method for preparing organic flocculants, and there have been many studies in this field .