Anaerobic Dynamic Membrane Bioreactor Treating Swine Wastewater: Fate of Sulfonamide Antibiotics and Heavy Metals with Their Effect on Filtration Performance

Abstract

Sulfonamide antibiotics (SMs) and heavy metals, simultaneously existing in swine wastewater, threat ecological security and public health. Anaerobic dynamic membrane bioreactor (AnDMBR) technology has shown great potential for excellent and cost-effective treatment of various types of industrial wastewaters. Herein, it was for the first time applied for treating the swine wastewater containing both SMs and heavy metals, with particular efforts devoted to understanding the fate of SMs and heavy metals with their effect on dynamic membrane (DM) fouling. The AnDMBR exhibited effective removal efficiency of COD (91.2%), sulfamethoxazole (SMX) (94.2%), sulfadiazine (SDZ) (51.2%), sulfamethazine (SMZ) (52.8%), Cu2+ (88.5%) and Zn2+ (73.3%). Biodegradation and bioadsorption was found to be the major mechanism for the removal of SMs and heavy metals, respectively, with DM playing considerable roles. Furthermore, EPS adsorption turned out to be another key mechanism for removing SMs and heavy metals, particularly in DM. The exposure to SMs and heavy metals significantly increased the specific resistance of DM, and consequently expedited DM fouling. This was mainly due to the increased content of small particles, EPS content (mainly hydrophobic proteins) and relative abundance of biofouling-related bacteria (i.e., Firmicutes, Chloroflexi and Clostridia), resulting in a denser DM structure with lower porosity

Keywords: Anaerobic dynamic membrane bioreactor, Swine wastewater, Sulfonamide antibiotics, Heavy metals, Membrane fouling