Efficient removal of acetic acid by a regenerable resin-based spherical activated carbon

Carboxylic acids are the main pollutant of industrial wastewater during the Advanced Oxidation Process (AOPs). In this study, we here study a resin-based spherical activated carbon (RSAC, AF(5)) as an adsorbent and use acetic acid as a model substrate for adsorption investigation. The pH = 3, temperature = 298 K were fixed by batch technique. The pseudo-second-order kinetic model, the intraparticle and external models are fitted well, and it was found that the adsorption of acetic acid onto AF(5) was controlled by liquid film diffusion. Freundlich model indicates the adsorption process is heterogeneous multi-molecular layer adsorption on the surface. AF(5) shows good regenerative ability; the recovery rate of adsorption capacity is similar to 88% after 5 cycles. And COD adsorption removal rate can be maintained 100% for over 35 h in an actual AOPs effluent, and it can be eluted for 100% after 8 h by 0.8wt% NaOH. The characterizations, including XRF, XRD, TG/DSC,FTIR, SEM and N-2 adsorption, show that the excellent adsorption performance is mainly due to the microporous structure and large specific surface area (1,512.88 m(2)/g), the adsorption mechanism mainly including pore filling effect and electrostatic attraction. After five adsorption-recycles, AF(5)'s pore characteristic does not change significantly. This study provided a scientific basis for the wastewater standard discharge process of AOPs coupled adsorption.