Control of Effluent Organic Matter, Cytotoxicity, and Disinfection Byproducts in Wastewater with Biological Anion Exchange Resins: Enhanced Performance through Skeleton Design

Effluent organic matter (EfOM) in wastewater threatens ecosystems and drinking water safety via the urban water cycle. Biofiltration using adsorbents with dual adsorption-biodegradation functions, such as biological anion exchange resins (BAERs), offers a promising solution. Compared to biological activated carbon (BAC), BAERs' adjustable skeletons enable targeted EfOM removal. This study designed two BAERs with polystyrene (PS-AER) and magnetic polyacrylic (MPA-AER) skeletons and compared them with conventional polyacrylic BAER (PA-AER) and BACs. During 12 000-bed-volume field applications, BAERs demonstrated 1.7-2.6 and 1.6-2.6 times higher dissolved organic carbon (DOC) and UV₂₅₄ removal rates than BACs. This efficacy stemmed from the high concentration of negatively charged components, which BAERs effectively attract. Furthermore, skeleton modifications improved DOC removal by 15.3-17.2% and UV₂₅₄ removal by 7.3-18.2% for PS-AER and MPA-AER, compared to PA-AER. The MPA-AER's open pore structure enhanced diffusion of high molecular weight components, while PS-AER's enhanced hydrophobicity improved aromatic component removal. These structural changes also influenced the biological effects of BAERs. Notably, the enhanced performance of PS-AER and MPA-AER reduced wastewater cytotoxicity and controlled the production of disinfection byproducts. Overall, this study confirms the potential of BAERs in wastewater treatment and highlights strategies for performance enhancement through skeleton modification.