Activated Carbon Adsorption Technique For Clofibric Acid And Sulfamethoxazole Removal From Aqueous Solution

The research on toxic pollutant is mostly focused on POPs and pesticide in the past. However, the research has been paid much more attention to Pharmaceuticals and Personal Care Products (PPCPs) abroad in the latest twenty years. But it didn't cause enough attention so far in China. PPCPs enter into various waters and soil through different pathways. The conventional drinking water process and wastewater treatment process cannot effectively remove this kind of pollutants. In this study activated carbon adsorption technique was selected to investigate its validity on removal of PPCPs due to its stable chemical property, high specific surface and good adsorbability character. The test adopted static and dynamic adsorption method to study activated carbon adsorption performance on clofibric acid and sulfamethoxazole removals. The optimal reaction conditions and adsorption isotherm models were determined, and kinetics and thermodynamic eqution were set up accordingly.The following results through the tests were achieved:the best activated carbons were Taixi 12*40 and TaixiΦ1.5mm, cylinder in selected four types of activated carbon. The optimum adsorption conditions on clofibric acid and sulfamethoxazole are:pH at acid condition, the reaction temperature is 20℃; The adsorbent dosage is 200mg/L of both clofibric acid and sulfamethoxazole when they were adsorbed separately. When the two compounds coexisted, the optimal dosage was 500mg/L. The adsorption equilibrium time was 30min. Both Freundlich and Langmuir adsorption equations can be used to describe the performance very well. For clofibric acid, the Freundlich model was better than Langmuir model, while Langmuir was better for sulfamethoxazole.Both activated carbon adsorption on clofibric acid and sulfamethoxazole were spontaneous exothermic process. The adsorption process was in line with the pseudo-second order reaction kinetic equation model.