Removal of Phosphate from Aqueous Solution by using Natural Coagulant: Optimization Response Surface Methodology (RSM)

Abstract

Abstract This study aims to remove phosphate from synthetic solution using the coagulation-flocculation process by the natural coagulants (Rice Husk (RH), Moringa Oliveira Seed pods (MOSP)) and optimize coagulant conditions using response surface methodology (RSM). The effects of operating conditions like initial concentration (40-80ppm), coagulant dosing (2-3 g/L), and pH of (2-6) were implemented. The coagulation-flocculation was improved utilizing Box–Behnken Design (BBD) under RSM. Quadratic model produced by BBD, with a value of R2 equal to 0.9894 and 0.9808 for RH and MOSC, respectively. The results of RSM show that the optimum operating conditions for the RH coagulant were an initial phosphate concentration of 60ppm, dosing 2g/l, and an initial pH of 4. Which are the same conditions for another coagulant (MOSP) with a difference of dosing 2.5g/l. The main results showed that the coagulants used in this work have a high ability to treat phosphates efficiently instead of using chemicals at a natural pH. The current study shows that it is possible to use RH and MOSP as new natural coagulants that are cost-effective in treating industrial wastewater.