Removal of Turbidity and COD from a Synthetic Water Sample by Coagulation

The main objective of this research was to study the removal of turbidity and COD (chemical oxygen demand) from a synthetic water sample. The water sample was treated chemically by coagulation. Two inorganic coagulants were used, ferric chloride and the double salt potassium-aluminium sulphate. The optimum coagulant dosage and working pH were examined. The results for ferric chloride as coagulant showed that the maximum removal efficiency (%) of COD was achieved at pH 6 with a dosage of 100 mg·L -1 and the maximum removal efficiency (%) of turbidity at pH 5 with a dosage of 500 mg·L -1 . For double salt, as coagulant, the maximum removal efficiencies (%) of COD and turbidity were achieved at pH 6 with a dosage of 3,500 mg·L -1 . An extensive comparison with results from previous studies was also described in this research.