Drinking water treatment by stepwise flocculation using polysilicate aluminum magnesium and cationic polyacrylamide

In the current work, polysilicate aluminum magnesium (PSAM) and cationic polyacrylamide (cPAM) were stepwise used for drinking water treatment. The flocculant was characterized by fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. PSAM-cPAM was then applied to flocculate the simulated water sample. The simulated water sample was prepared by kaolin and sodium humate. The efficiency of flocculation treatment was highly dependent on the flocculation conditions. Important parameters, such as the pH value of simulated water sample, temperature, settling time, the total dosage of flocculant, and flocculant types, were optimized to ensure an effective flocculation performance. Under optimized conditions, the removal efficiency (more than 98%) was outstanding in terms of turbidity and color removal. In addition, charge neutralization, bridging effect, and co-precipitation interaction could play crucial roles in the flocculation process. Composite flocculants consisting of PSAM and cPAM were found to be environmentally friendly, highly efficient, and fast settling in drinking water treatment.