Degradation of Enrofloxacin by photocatalytic system based on BC-BiOI/PMS

Abstract

In this paper, biochar-supported bismuth iodide-oxidized composite catalyst(BC-BiOI) was prepared by hydrothermal method, and persulfate(PMS) was introduced into the system to couple photocatalysis and PMS advanced oxidation technology. The degradation effect of Enrofloxacin(ENR) by the light /BC-BiOI/PMS composite system was investigated, and the effect of reaction conditions on the removal of ENR was examined. The mechanism of ENR degradation in light/BC-BIOI/PMS system was studied. The best degradation effect of typical antibiotic ENR was determined by light /BC-BiOI/PMS system. Under the conditions of BC-BiOI dosage of 0.2 g/L, PMS dosage of 1.0 g/L, pH of 7, the degradation rate of ENR could reach 76%. The interaction among pH, BC-BiOI dosage and PMS dosage was analyzed by response surface methodology. The results indicated that the order of the effect of various factors on ENR degradation was initial pH>PMS dosage>BC-BiOI dosage. According to free radical quenching experiments and electron paramagnetic resonance (EPR), the main active oxidation species in the system were ·OH, SO4·-, and 1O2, which jointly oxidized and degraded ENR. In the reusability test, BC-BiOI photocatalysis composite material could still remain more than 65% removal rate of ENR after four cycles.

Keywords

• photocatalysis
• biochar
• bismuth iodide
• persulfate
• enrofloxacin