Efficient Degradation of an Antibiotic Norfloxacin in Aqueous Solution via a Simulated Solar-Light-Mediated Bi2WO6 Process

A simulated solar-light-mediated bismuth tungstate process (SSL/Bi2WO6) was employed to degrade norfloxacin photocatalytically. The effects of environmental parameters, including catalyst dosage, probe concentration, and solution pH, on the process performance were investigated systematically. Under weak alkaline conditions, an optimal decay performance that can be attributed to the beneficial effect of hydroxyl ions was obtained. The reaction rationale and related constants were determined by the Langmuir-Hinshelwood (LH) model, combined with the experimental results. Our results showed that the adsorption of norfloxacin onto Bi2WO6 benefited the SSL/Bi2WO6 process, and the Bi2WO6 maximum adsorption capacity was 3.20 x 10(-3) mmol/g. In the SSL/Bi2WO6 process, the degradation of norfloxacin was accompanied by the decomposition of germicidal group and benzene ring, as well as gradual generation of inorganic ions of NH4+ and F-. Furthermore, the toxicity of initial norfloxacin solution was efficiently eliminated by this SSL/Bi2WO6 process.