Optimization of adsorption removal of ethylene glycol from wastewater using granular activated carbon by response surface methodology

Wastewater reuse has been attracted a lot of attention in recent years especially in places with low water availability. The effluents that were considered to be discharged are now could be used as potential sources of reusable water. In this study, variables affecting the removal of ethylene glycol (EG) by adsorption on granular activated carbon (GAC) from the synthetic wastewater solutions were optimized by response surface methodology (RSM) using a central composite design. The investigated factors were temperature, EG concentration, contact time, activated carbon amount and granular size. Adsorption kinetic was also studied and an acceptable correlation between Langmuir model and experimental data was observed. As a result, a modified third degree equation was proposed and used to find the optimized condition. The maximum adsorption was achieved at 27.7 ºC with 0.8 g of 20-30 mesh activated carbons for an EG feed concentration of 135 mg/L at 210 minutes.