A novel Coagulant based on Lignin and Tannin for Bentonite Removal from Rawwater

By using FTIR, UV, GC-Mass, X-ray DSC and TG techniques, polymer based on lignin and tannin have been prepared and characterized. All characterization techniques confirm the existence of lignin and tannin. The study concerned with the effectiveness of lignin-tannin polymer as a coagulant/flocculant in treatment of surface water. The tests of two kinds of water were carried out in laboratory. The first one is synthesis water mixed with high and low concentrations of bentonite, simulating thus turbid water. The second one is raw water from the treatment station of Shatt Al-Arab River. The performance of coagulation/flocculation process has been assessed by measuring the supernatant turbidity for different pH, doses and flocculation time of lignin-tannin polymer . The obtained results show that lignin-tannin polymer effectiveness was strongly dependent on pH and the doses of lignin-tannin polymer, on the initial turbidity and on the water quality.