Optimization of Opuntia Dose as Bio-flocculant for Oil Refinery Wastewater Using Response Surface Methodology

Oil refinery wastewater is one of the most polluted types of wastewater with a large variety of organic and mineral pollutants, which need treatment before discharge to the receiving environment. The coagulation–flocculation process was used to treat oil refinery wastewater with ferric chloride (FeCl3-40%) as a coagulant and cactus juice was used as a flocculant to reduce turbidity and chemical oxygen demand (COD).