Photocatalytic degradation of Amoxicillin in pharmaceutical wastewater: A potential tool to manage residual antibiotics

The present study investigates the degradation of amoxicillin (AMX) using TiO2 photocatalysis and sono-photocatalysis in aqueous solution under UV-A (365 nm) and sunlight exposure. The photocatalysis, as well as sono-photocatalysis, were coupled with H2O2 as well to assess the improvement in the degradation of AMX. Response surface methodology (RSM) based on three-level and four variable Box-Behnken experiment design was used to analyse and validate the degradation of AMX. Upon comparison of observed values with predicted, the value of the coefficient of regression (R-2) was 0.87 which indicate the good fit of the model. The optimum conditions for maximum degradation (80%) of AMX were AMX - 30mg/l, TiO2 dosage - 450mg/l, H2O2 concentration - 150 mg/l and pH - 7.0 under UV irradiation (672 W/m(2)). Significant improvement in rate kinetics of degradation was observed when photocatalysis was complemented with H2O2 and sonication (40 KHz) under optimized condition, but the maximal removal remained almost unaffected. The method proved efficient towards degradation of AMX in real pharmaceutical wastewater with reduced reaction time for targeted level treatment. It was concluded that photocatalysis is a potential method for degradation of AMX under the set optimized conditions, and it may be adopted in-silo since photocatalysis coupled with sonication becomes energy-prohibitive for degradation of AMX. (C) 2020 Elsevier B.V. All rights reserved.