Optimization of coagulation-flocculation process for wastewater treatment using selected coagulants

Abstract

Plant-based coagulants represent a new paradigm in wastewater treatment, advancing the transition to a green economy and promoting cleaner production. This research focuses on the coagulation-flocculation process for the treatment of wastewater using indigenous and imported alum combined with the bark of the Brideliaferrugineae (BF) tree as a natural coagulant. Two hundred grams (200 g) of B.F (Iran-Odan) bark was soaked in 2-litres of distilled water for three days, 1:10. The qualitative and quantitative phytochemical parameters of the bark extracts - Alkanoid, Sapon, Tannin, Phloba tannin, Anthraquinone, flavonoid, steroid and Terpenoid, were determined in percentage using Thin-layer chromatography (TLC), High-performance liquid chromatography (HPLC) and UV-Vis spectrophotometry approach. The optimal ratio of BF respectively mixed with imported and indigenous alums. The physicochemical properties of normal and treated wastewater which include pH, EC, Turbidity, Phosphate, Chemical Oxygen Demand (COD), and Biochemical Oxygen Demand (BOD), were also determined. The effectiveness of each dosage of Alum and BF was determined through laboratory analysis. The optimal mixture that produced desirable results as compared with the effluent standard of the Food and Agriculture Organisation (FAO) was determined. The effectiveness of each dosage of Indigeneous Alum - BF mix ranged from 16.56-24.56%. The corresponding value for the Imported Alum - BF mix ranged from 16.41-26.11%. The optimal mix ratio of the coagulation-flocculation process was 50:50 of Alum and BF mix. Both mix effectively treated industrial and domestic wastewater and should be given more attention.