Optimization of coagulation process for municipal wastewater treatment using Response Surface Methodology (RSM)

Abstract

Water is a vital element to maintain healthy life. However, water scarcity is the critical issue to be met by the world today. Outcome using bacteria at treatment plant are time consuming, low efficiency and larger size of treatment plant. Alum can affect human health and environment. This project aims to study the optimization of process parameters of coagulation process for municipal wastewater treatment. The raw sewage was first collected from Indah Water Konsortium (IWK) Perlis. The characterization was carried out using standard method (American Public Health Association, APHA). The wastewater quality parameters of this municipal wastewater were pH 6.8, >1000 NTU of turbidity, 104.6 mg/L of Biological Oxygen Demand (BOD) and 6575 mg/L of Chemical Oxygen Demand (COD). Polyacrylamide (PAM) was used to replace alum as coagulant in coagulation processes using jar text experiment. Its effects on the wastewater quality parameters of treated wastewater were compared with untreated wastewater under standard effluent (Jabatan Alam Sekitar, JAS). Its shows obviously improved and fulfilled to the standard effluent. The optimization of process parameters of coagulation was carried out by using tradisional (One-factor-at-a-time, OFAT) and statistical designed (Response Surface Methodology, RSM) jar test experiment. The actual turbidity removal in optimized coagulation condition using OFAT was 99.987 % that are pH 6, 60 mL and 150 rpm. The predicted turbidity removal in optimized coagulation condition using RSM was 100 % that are pH 5.32, 60.75 mL and 193.22 rpm.