Evaluation of Cacao Husk Ash Extract as Coagulant Aid in the Removal of Turbidity in Low Alkalinity Aqua Medium

The need to ameliorate some of the inherent limitations in the use of alum in water purification engendered these studies. Synthetic water of varying turbidities (50, 100, 300 NTU) and varying pHs (2, 3, and 4), but low alkalinity were prepared. The results from the different studies showed that water of lower residual turbidity could be got from the use of 50% of optimum alum dose when combined with CHAE as coagulant aid. The depression in the pH of the treated, usually experienced with alum use, could be avoided with the use of CHAE as coagulant aid. Studies on the effect of using CHAE, as coagulant aid, on the kinetics of flocculation showed that the removal rate of the CHAE/alum combination was faster than that of the alum alone and the redistribution and redispersion of the flocs, observed with the use of alum alone was not noticed when the coagulant aid was used. The sludge volume was also greatly reduced with the use of CHAE as coagulant aid.