Evaluation of a number of coagulants and coagulation aids in removing water turbidity

Abstract

The physical efficiency of a number of coagulants alum, ferrous sulfate and ferric chloride in addition to coagulation organic aids like poly ethylene glycol (PEG), polyacrylamide (PAM) and non-organic like Bentonite in removing turbidity of raw water in its high and low turbidity 850 NTU, 52 NTU respectively was studied. The optimal dose was determined for each of them that give less turbidity and higher removal percentage. The results declared that alum was the best removal for both high and low turbidity which reach 99.59% and 97.54% respectively. Ferrous sulfate, Ferric chloride, and calcium oxide were the best for removing turbidity of high turbid raw water 98.26, 98.66 and 92.18% respectively. For coagulation aids, the best of them was (PAM) for both raw water turbidity, while (PEG) record good removal percentage for low turbidity that reach 89.81%. Bentonite give lowest removal percentage for low turbidity 31.92%, on contrast with high turbidity 74%. used of Bentonite with alum improved the removal to 88.92%.