Heterogenous photocatalytic degradation kinetics and detoxification of an urban wastewater treatment plant effluent contaminated with pharmaceuticals.
Degradation kinetics and mineralization of an urban wastewater treatment plant effluent contaminated with a mixture of pharmaceutical compounds composed of amoxicillin (10 mg L(-1)), carbamazepine (5 mg L(-1)) and diclofenac (2.5 mg L(-1)) by TiO(2) photocatalysis were investigated. The photocatalytic effect was investigated using both spiked distilled water and actual wastewater solutions. The process efficiency was evaluated through UV absorbance and TOC measurements. A set of bioassays (Daphnia magna, Pseudokirchneriella subcapitata and Lepidium sativum) was performed to evaluate the potential toxicity of the oxidation intermediates. A pseudo-first order kinetic model was found to fit well the experimental data. The mineralization rate (TOC) of the wastewater contaminated with the pharmaceuticals was found to be really slow (t(1/2)=86.6 min) compared to that of the same pharmaceuticals spiked in distilled water (t(1/2)=46.5 min). The results from the toxicity tests of single pharmaceuticals, their mixture and the wastewater matrix spiked with the pharmaceuticals displayed a general accordance between the responses of the freshwater aquatic species (P. subscapitata>D. magna). In general the photocatalytic treatment did not completely reduce the toxicity under the investigated conditions (maximum catalyst loading and irradiation time 0.8 g TiO(2) L(-1) and 120 min respectively).
Rizzo
L
L
University of Salerno, Sanitary and Environmental Engineering Division (SEED), Department of Civil Engineering, 84084 Fisciano (SA) Italy. l.rizzo@unisa.it
Meric
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S
Guida
M
M
Kassinos
D
D
Belgiorno
V
V
D000658:Amoxicillin / Q000032:analysis / Q000633:toxicity; D000818:Animals; D002220:Carbamazepine / Q000032:analysis / Q000633:toxicity; D000460:Chlorophyta / Q000187:drug effects; D002947:Cities; D003621:Daphnia / Q000187:drug effects; D004008:Diclofenac / Q000032:analysis / Q000633:toxicity; D004345:Drug Industry; D007220:Industrial Waste / Q000032:analysis*; D007700:Kinetics; D031220:Lepidium sativum / Q000187:drug effects; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry; D010782:Photolysis; D018675:Toxicity Tests; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity
D007220:Industrial Waste; D004364:Pharmaceutical Preparations; D014874:Water Pollutants, Chemical; D014867:Water; D004008:Diclofenac; D002220:Carbamazepine; D000658:Amoxicillin