Degradation of diclofenac by TiO2 photocatalysis: UV absorbance kinetics and process evaluation through a set of toxicity bioassays |
| |
Authors: | L Rizzo S Meric M Guida V Belgiorno |
| |
Affiliation: | a University of Salerno, Sanitary and Environmental Engineering Division (SEED), Department of Civil Engineering, via Ponte don Melillo,1 - 84084 Fisciano (SA), Italy b University of Naples, Federico II, Department of Biological Sciences, Section of Physiology and Hygiene, Ecotoxicology Research Laboratory (ERL-UNINA), I-80134 Naples, Italy c University of Cyprus, Department of Civil and Environmental Engineering, 75 Kallipoleos, 1678 Nicosia, Cyprus |
| |
Abstract: | In the present study the degradation kinetics and mineralization of diclofenac (DCF) by the TiO2 photocatalysis were investigated in terms of UV absorbance and COD measurements for a wide range of initial DCF concentrations (5-80 mg L−1) and photocatalyst loadings (0.2-1.6 g TiO2 L−1) in a batch reactor system. A set of bioassays (Daphnia magna, Pseudokirchneriella subcapitata and Artemia salina) was performed to evaluate the potential detoxification of DCF. A pseudo-first-order kinetic model was found to fit well most of the experimental data, while at high initial DCF concentrations (40 and 80 mg L−1) and at 1.6 g TiO2 L−1 photocatalyst loading a second-order kinetic model was found to fit the data better. The toxicity of the treated DCF samples on D. magna and P. subcapitata varied during the oxidation, probably due to the formation of some intermediate products more toxic than DCF. Unicellular freshwater algae was found to be very sensitive to the treated samples as well as the results from D. magna test were consistent to those of algae tests. A. salina was not found to be sensitive under the investigated conditions. Finally, UV absorbance analysis were found to be an useful tool for a fast and easy to perform measurement to get preliminary information on the organic intermediates that are formed during oxidation and also on their disappearance rate. |
| |
Keywords: | A salina D magna Mineralization Photocatalysis Pseudo-first and second order kinetics P subcapitata |
本文献已被 ScienceDirect 等数据库收录! |
|