Enhanced anaerobic degradation of amide pharmaceuticals by dosing ferroferric oxide or anthraquinone-2, 6-disulfonate

Amide pharmaceuticals cannot be removed easily in conventional wastewater treatment processes, and the dosage of redox mediators may enhance their removals under anaerobic conditions. Anaerobic batch experiments were carried out for the removals of amide pharmaceuticals with the dosage of ferroferric oxide or anthraquinone-2,6-disulfonate. Factors of redox mediators, organic carbon and steps of anaerobic treatment on the removals of amide pharmaceuticals were evaluated. For primidone, carbamazepine and crotamiton, their removals were poor during anaerobic treatment, and the addition of redox mediators enhanced their removals. For sulfamethoxazole, it was effectively removed by anaerobic treatment (above 90%) and the dosage of redox mediator accelerated its removal. The cooperation of carbon source and redox mediators accelerated the removals of amide pharmaceuticals, but the types of organic carbon had little influence on the anaerobic degradation of amide pharmaceuticals. Furthermore, the hydrolysis/acidification step contributed significantly to the removal of amide pharmaceuticals during anaerobic treatment. For the control of amide pharmaceuticals in wastewater, the incorporation of anaerobic process into the wastewater treatment stream is a valuable strategy, especially with the dosage of redox mediators.