Optimization of Adsorption Process of Dissolved Organic Matter in Water by Magnetic Ion Exchange Resins Towards Response Surface Method

Based on the experimental results of independent-factor adsorption of dissolved organic matter (DOM) in water by magnetic ion exchange (MIEX) resin, four parameters, including MIEX resin dosage, solution pH, dissolved organic carbon (DOC) concentration in water, and adsorption time, were selected as response surface experimental factors, and a quadratic polynomial regression equation was established with a Box-Behnken Design model to optimize the process of DOM adsorption in water by MIEX resin. The results show that the higher the dosage of MIEX resin, the higher the organic removal efficiency, solution pH has the greatest effect on DOC removal, while turbidity and temperature have less influence. The optimized process conditions are 8.1 mL/L MIEX resin dosage, pH 5.1, DOC mass concentration 14.55 mg/L, and adsorption time 73 min. The predicted results of DOC removal efficiecy under the optimized process conditions are in good agreement with the experi‐ mental results, and the established quadratic polynomial regression model is highly reliable, which can effectively predict the removal efficiency of DOM in the water source by resin.