Improving the Removal of Anionic Surfactant in Cardboard Industry Wastewater by Coagulation/Flocculation: Process Optimization with Response Surface Methodology

Response surface methodology (RSM) and Box-Behnken design (BBD) were investigated to optimize the coagulation-flocculation process (CF) of cardboard industry effluent using polyaluminum chloride (PAC) and cationic polyacrylamides (c-PAM). The aim is to identify the optimum combination of coagulant dose, pH, and flocculant dosage for the highest removal efficacy of chemical oxygen demand (COD) and anionic surfactant removal. According to the results, COD reduction was principally controlled by PAC and c-PAM, while anionic surfactant was affected by pH and PAC. In addition, COD and anionic surfactant removal models fitted well with the experimental results (R-2 > 0.85). Coagulation/flocculation using optimum conditions of pH, PAC, and c-PAM led to the total removal of anionic surfactant and the reduction of more than 95% of COD.

Automated summary

Response surface methodology (RSM) and Box-Behnken design (BBD) were used to optimize the coagulation-flocculation process (CF) of cardboard industry effluent using polyaluminum chloride (PAC) and cationic polyacrylamides (c-PAM). The aim was to determine the optimal combination of coagulant dose, pH, and flocculant dosage for the highest removal efficacy of chemical oxygen demand (COD) and anionic surfactant removal. The results showed that COD reduction was primarily controlled by PAC and c-PAM, while anionic surfactant removal was influenced by pH and PAC. Additionally, the COD and anionic surfactant removal models fitted well with the experimental results (R-2 > 0.85). Coagulation/flocculation using the optimal conditions of pH, PAC, and c-PAM resulted in complete removal of anionic surfactant and more than 95% reduction in COD.