Affiliation:
1. 1 Department of Hydraulic and Water Resources Engineering, College of Engineering & Technology, Wachemo University, P.O. Box: 667, Hossaina, Ethiopia
Abstract
ABSTRACT
In this study, natural coagulants obtained from banana peel and Moringa stenopetala seed were applied to remove total dissolved solids (TDS) and turbidity from river water. Central composite design (CCD) method was applied for the operating conditions of pH (3–10), coagulant dosage (0.3–1 g/L), stirring speed (30–90 rpm), and settling time (20–60 min). The optimum conditions obtained from the numerical optimization for pH, coagulant dosage, stirring speed, and settling time were 8.52, 1.000 g/L, 33.58 rpm, and 37.92 min, respectively, with a desirability value of 0.883 when banana peel powder was used as a natural coagulant. Under those optimum conditions, the experimental results for banana peel showed 81.32 and 93.09%, removal efficiency for TDS and turbidity, respectively. Similarly, the optimum conditions obtained from numerical optimization for pH, coagulant dosage, stirring speed, and settling time were 9.99, 0.999 g/L, 30.0 rpm, and 39.96 min, respectively, with a desirability value of 0.963. Under these optimum conditions for M. stenopetala seed powder, the experimental results showed 83.64 and 95.13%, removal efficiency for TDS and turbidity, respectively. Overall, M. stenopetala seed powder shows a higher potential for TDS and turbidity removal efficiency than banana peel powder.