Optimum use of coagulants for the removal of particulates and organics from Aliakmon River water

The commercial coagulants Al-2(SO4)(3), PACl and FeClSO4 were investigated to identify the parameters affecting the coagulation process of the Aliakmon river water and to determine the optimum operational conditions. The evaluation of the coagulation was based on the removal of both suspended solids and organic matter. All coagulants were efficient in removing about 60% of DNOM at pH 5.5 at the maximum tested dosage of 15 mg Fe or Al/L. Regarding particle removal, FeClSO4 could reduce particle count, by sedimentation, below 800 particles/mL and marginally below 500 particles/ml- by sand filtration. PACl appears to be the most efficient coagulant in the removal of suspended matter by sand filtration resulting in less than 300 particles/mL, even at the lowest dosage tested in this work, 2.5 mg Al/L.