Optimization of Flocculation Process for a New Myco-Coagulant to Reduce Water Turbidity

Abstract

The flocculation process of a new myco-coagulant, isolated from River Water Fungus (RWF5) was optimized to reduce turbidity from kaolin suspension. The results indicated that turbidity removal of 94% (from 650 NTU to 38 NTU within 5 min settling time) could be achieved by a combination of rapid and slow mixing process. A sequential optimization strategy, based on a statistical experimental design, was used to determine the suitable agitation and mixing time. Four process parameters were optimized by the response surface methodology (RSM), based on the face-centered central composite design (FCCCD). The optimum agitation speed and mixing time were found as 250 rpm and 7 min for rapid mixing stage and 90 rpm and 22 min for slow mixing process, respectively. Analysis of variance (ANOVA) showed a good regression coefficient (R2) of 0.95, which indicated satisfactory fit of the model data with the experimental results. The findings were statistically significant at confidence level of p <0.05.