Investigation of biologically active zeolite: role of colonization in the removal of 14C-labelled sulfamethoxazole in wastewater

Up-to-date approaches to remove micropollutants in wastewater treatment are based on adsorbing materials like activated carbon. These fossil-based materials can also provide a surface for microbial colonization, which could further improve the removal of MPs. As zeolite filters have shown interesting performance in the removal of MPs in previous works, this study aimed to investigate the effect of microbial colonization on such filters on the elimination of 14C-labelled sulfamethoxazole (SMX), an antibiotic from the class of sulfonamides. Lab scale removal tests were set in 100 mL reactors and monitored for 150 days at room temperature. Taxa known to be linked to organic pollutant degradation (Caulobacterales, Rhizobiales, Burkholderiales) were found among the microbial community attached to the zeolite. Bacterial colonization of zeolite filters improved the removal of 14C-sulfamethoxazole by 35 % compared to the control. An analysis of the microbial community dynamics over time revealed the increased abundance of the Vicinamibacterales taxon after 50 days of contact with SMX. This order abundance, linked to degradation of sulfonamides, went from 0 to 17 %; and Shannon diversity ranged from 1.51 to 1.99. Data showed that zeolite filters as adsorbing material in wastewater treatment plants can improve MPs removal by supporting bacterial colonization, making it an interesting support that could synergize with biological activated carbon.