Comparative Analysis of the Treatment Potential of Cationic Starch and its Polyacrylamide Blend on Tannery and Sewage Effluents

The discharge of tannery and sewage wastewater is loaded with many toxic wastes, especially elevated levels of total dissolved solids (TDS) and suspended solids (SS) poses a significant environmental concern. This study reports the flocculation efficacy of cationic starch (CS) and its polymeric blend with polyacrylamide (CS-PAM) through the standard Jar Test method. Key operational parameters including polymer dosage, contact time and pH were optimized. Maximum solid removal efficiencies of 94% for tannery and 96% for sewage effluents were achieved at optimal dosages of 3.2 × 10–4 g/L and 1.6 × 10–4 g/L, respectively, under acidic (pH 4.0) and neutral (pH 7.0) conditions. X-ray diffraction analysis confirmed the interaction of flocs with the modified polymers. The results indicate that while cationic starch shows the substantial flocculation due to its inherent cationic nature, the CS-PAM copolymer exhibits enhanced performance. These findings highlight the potential of CS-based flocculants as sustainable, biodegradable and cost-effective alternatives to conventional synthetic flocculants for industrial and municipal wastewater treatment.