Optimization Studies on the Coagulation–Flocculation Process for PWW Treatment Using Cactus oputia Extract: Comparative Studies for Performance Evaluation

The treatment of Paint Waste Water, PWW is an important global issue for the minimization of water pollution especially in a developing country like Nigeria. The coagulation–flocculation process using Cactus Oputia Extract, COE as natural coagulant is reported for PWW treatment in the present study. The important process parameters pH, settling time, coagulant dosage and initial concentration were optimized using design of experiments (DOE). A full factorial composite experimental design and response surface methodology (RSM) were used to obtain the optimum values of the parameters. Also utilized in this study were Artificial Neural Network, ANN and Adaptive Neuro Fuzzy Inference System, ANFIS for performance evaluation. Using the numerical optimization technique of the design expert software, a combination of factors which concurrently fulfil the requirements placed on the response variable were determined. The best effluent removal efficiency was predicted to be 89.78% at the optimum values of the process parameters pH 6, settling time 30 mins, coagulant dosage 3 g and initial concentration 1.2 mg/l in this study.