Simultaneous removal of sulfamethoxazole and enhanced denitrification process from simulated municipal wastewater by a novel 3D-BER system

Abstract

In this study, at an electric current intensity at 60mA, more than 90.50 ± 4.76% of Sulfamethoxazole (SMX) was degraded. The strengthening of bacterial metabolisms and the sustainment of electrical stimulation contributed to the rapid removal of SMX and nitrates from simulated wastewater by a novel 3D-BER system. From the literature, very few studies have been performed to investigate the high risk of nitrates and antibiotics SMX found in wastewater treatment. The highest antibiotic SMX and nitrogen removal efficiency was 96.45 ± 2.4% (nitrate-N), 99.5 ± 1.5% (nitrite-N), 88.45 ± 1.4% (ammonia-N), 78.6 ± 1.0% (total nitrogen), and SMX (90.50 ± 4.76%), respectively. These results were significantly higher as compared to control system (p< 0.05). The highest denitrification efficiency was achieved at the pH level of 7.0 ± 0.20 - 7.5 ± 0.31. Lower or higher pH value can effect on an approach of heterotrophic-autotrophic denitrification. Moreover, low current intensity did not show any significant effect on the degradation, however, enhanced the removal rate of nitrate or nitrite as well as antibiotic SMX. Based on the results of HPLC and LC-MS/MS analysis, the intermediate products were proposed after efficient biodegradation of SMX. Finally, these results is expected to provide some new insights towards the high electric currents, changes the bacterial community structure, and the activated sludge which played an important role in the biodegradation of SMX and nitrates removal more efficiently.