Hydrogen-promoted oxygen reduction Fenton reaction system constructed by Pd/UiO-66(Zr) to efficiently degradate trimethoprim

Abstract

As a representative antibiotic, trimethoprim (TMP), the emerging pollutant has been frequently detected in water bodies, and its potential harm has aroused the attention of society. Although the emerging pollutant could be efficiently degraded by the advanced oxidation process (AOP) represented by the Fenton reaction, both the problem of iron sludge disposal and the safe use of H2O2 have plagued the further promotion of this technology. The H2 (precursor of the active hydrogen [H]) and catalyst Pd/UiO-66(Zr) were introduced into the Fenton reaction in this paper. It was found that the process of reducing Fe(III) and self-generating H2O2 could be facilitated due to the reduction of [H]. Under certain reaction conditions (initial pH 3, trace total iron 25 μM, H2 30 mL·min−1, catalyst 2 g·L−1) and without H2O2, a Fenton-like system was constructed, named MHORF-UiO-66(Zr). While achieving zero iron sludge discharge, 100 % of 20 mg·L−1 TMP was rapidly degraded within 1 h. It was found that the degradation of TMP could be attributed to the attack of singlet oxygen and hydroxyl radical. Furthermore, the performance changes of catalyst before and after six rounds of reactions were studied and it was found that Pd/UiO-66(Zr) had excellent and stable catalytic performance.