Evaluating the impact of sulfamethoxazole on hydrogen production during dark anaerobic sludge fermentation

The impact of antibiotics on the environmental protection and sludge treatment fields has been widely studied. The recovery of hydrogen from waste activated sludge (WAS) has become an issue of great interest. Nevertheless, few studies have focused on the impact of antibiotics present in WAS on hydrogen production during dark anaerobic fermentation. To explore the mechanisms, sulfamethoxazole (SMX) was chosen as a representative antibiotic to evaluate how SMX influenced hydrogen production during dark anaerobic fermentation of WAS. The results demonstrated SMX promoted hydrogen production. With increasing additions of SMX from 0 to 500 mg/kg TSS, the cumulative hydrogen production elevated from 8.07 +/- 0.37 to 11.89 +/- 0.19 mL/g VSS. A modified Gompertz model further verified that both the maximum potential of hydrogen production (P-m) and the maximum rate of hydrogen production (R-m) were promoted. SMX did not affected sludge solubilization, but promoted hydrolysis and acidification processes to produce more hydrogen. Moreover, the methanogenesis process was inhibited so that hydrogen consumption was reduced. Microbial community analysis further demonstrated that the introduction of SMX improved the abundance of hydrolysis bacteria and hydrogen-volatile fatty acids (VFAs) producers. SMX synergistically influenced hydrolysis, acidification and acetogenesis to facilitate the hydrogen production. (C) Higher Education Press 2023

Automated summary

This study investigates the impact of antibiotics on hydrogen production during dark anaerobic fermentation of waste activated sludge (WAS). The results demonstrate that sulfamethoxazole (SMX) promotes hydrogen production by enhancing hydrolysis and acidification processes, while inhibiting methanogenesis.