Filter-membrane treatment of flowing antibiotic-containing wastewater through peroxydisulfate-coupled photocatalysis to reduce resistance gene and microbial inhibition during biological treatment

Abstract

The direct biological treatment of antibiotics containing wastewater brings about a potential risk of antibiotic resistance genes (ARGs) spread. Although advanced oxidation technologies based on photocatalysis generally appear effective at degrading antibiotics in wastewater, the fate of ARGs in succeeding biological treatment system is still unknown. Herein, a filter-membrane-like carbon cloth-immobilized Fe2O3/g-C3N4 photocatalyst is fabricated through immersion-calcination method. Peroxydisulfate-coupled photocatalysis system is developed to degrade tetracycline (TC, an emerging refractory antibiotic pollutant). The system can produce energetic active species (·OH, SO4·−, h+, O2·− and 1O2), exhibiting a superior performance towards TC degradation in static and continuous flow processes under visible-light irradiation. The pretreatment can eliminate the antibacterial activity of antibiotics wastewater, and the chemical oxygen demand removal is greatly enhanced in subsequent anaerobic or aerobic process. The microbial diversity and richness in activated sludge for pretreated water sample are significantly higher than those for the water sample without pretreatment. Meanwhile, the pretreatment can decrease the relative abundance of potential hosts of ARGs and reduce the emergence as well as dissemination risk of ARGs. This study uncovers the effect of pretreatment of antibiotics containing wastewater using advanced oxidation technologies on the treatment efficacy and antibiotic resistome fate in biological treatment system.