Clarification of Pharmaceutical Wastewater with Moringa Oleifera: Optimization Through Response Surface Methodology

Herbal pharmaceutical industrial wastewater contains a high amount of suspended solids and alkaline (pH > 8); therefore it requires approprite coagulant and flocculant compounds for its wastewater treatment. The most widely used flocculant is a synthetic that has certain problems such as non-biodegradability and releases of toxic residual monomers. The use of eco-friendly flocculants as alternative materials for conventional flocculant in water and wastewater treatments is increasing. Numerous factors influence the performance of coagulation-flocculation process, such as coagulant dosage, flocculant dosage, initial potential of hydrogen (pH) and velocity gradient of coagulation-flocculation. The main aim of this research is to evaluate the capability and effectiveness of Moringa oleifera extract for removal of suspended solid in herbal pharmaceutical industry. A coagulation-flocculation test was done by performing jar test at various speeds, according to the variation of the conducted treatment research. In this study, response surface methodology (RSM) approach was used to optimize the concentration of coagulant dosage, flocculant dosage and flocculation velocity gradient (G), and the results were measured as maximum percentage of suspended solid removal. The wastewater used in this research originally came from the inlet of herbal pharmaceutical industry wastewater treatment plant, which was collected over 3 days. The wastewater has a total suspended solids of more than 1250 mg/L, and was alkaline (pH 9–10). The moringa extract was made from the extraction of a fat free moringa powder with a salt solution in a certain ratio. The percentage removal of suspended solid was 93.42–99.54%. The final results of the analysis of response surface showed that the variables of flocculant dosage and the flocculation velocity gradient (G) have a huge impact on the amount of suspended solid removal, compared with the coagulant dosage. The model generated from the response analysis is a quadratic model. The optimum point of the removal suspended solid quadratic model is at 10.6566 mg/L alum dosage, 13.8185 ml/L Moringa oleifera extract dosage, and G velocity of flocculation 84.845 sec-1