Wastewater sludge recycling: An efficient catalyst for photo-Fenton degradation of antibiotics and effluent disinfection

Abstract

An environmentally friendly strategy for recycling sewage sludge is proposed based on the thermal generation of a magnetic material for use as a catalyst in the photo-Fenton process. The main elements present in the catalyst were silicon, aluminum, oxygen, carbon, phosphorus, and iron, and the specific area was 35.53 m2 g−1. X-ray photoelectron spectroscopy and scanning electron microscopy analyses showed that there was no apparent alteration of the catalyst surface after the photo-Fenton process. Photo-Fenton experiments performed under UV irradiation revealed complete degradation of trimethoprim (TMP) and sulfamethoxazole (SMZ) in purified water after 180 min, with the catalytic activity maintained for at least 4 cycles. A comparison was made of the degradation of pollutants in sewage treatment plant effluents under artificial UV and solar irradiation. Under solar irradiation, at pH 3.5, total degradation of TMP and SMZ was achieved, together with TOC removal of up to 21%, showing SLC-600 as a potential low-cost catalyst to be used in photo-Fenton process.