Preparation and characterization of coagulation/flocculation behavior of a novel inorganic–organic hybrid polymer for reactive and disperse dyes removal

• A novel synthesized inorganic–organic hybrid polymer was prepared.
• The one-way ANOVA test & Tukey comparisons are applied for significant test on pH.
• Optimal pH ranges various with types of dye to be treated.
• Mw & intrinsic viscosity are crucial in affecting flocculation performance.

A novel synthesized polyaluminum chloride–poly(3-acrylamido-isopropanol chloride) (PACl–PAMIPCl) an inorganic–organic hybrid polymer was prepared with poly(3-acrylamido-isopropanol chloride) (PAMIPCl) and polyaluminum chloride (PACl) through physical blending. Ammonium persulfate ((NH4)2S2O8) and sodium bisulfite (NaHSO3) were used to initiate the redox polymerization of PAMIPCl at 50 °C by varying the molar ratio of epichlorohydrin (EPI) to acrylamide (AM). PAMIPCl of high viscosity was prepared when EPI to AM molar ratio attains 6%:94%. PACl–PAMIPCl hybrid polymers were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscope (TEM), conductivity and viscosity. Effects of solution molecular weight/intrinsic–viscosity, dosage and pH of PACl–PAMIPCl hybrid polymers have been studied. One-way ANOVA shows that pH has a significant effect (p < 0.05) in flocculating both Reactive Cibacron Blue F3GA (RCB) and Disperse Terasil Yellow W-4G (DTY) dyes. The flocculation performance was evaluated with simulated dyes among PACl–PAMIPCl 2, PAMIPCl.c and PACl. PACl–PAMIPCl 2 with higher viscosity shows the best flocculation performance in treating both simulated dyes. It shows reduction of 92% for chemical oxygen demand (COD) and 95% for color at pH 7.5 using 50 mg/L of dosage for RCB dye. It gives reduction of 93% for COD and 96% for color at pH 3 using 20 mg/L of dosage for DTY dye.