Chloramphenicol sodiumsuccinate(CAP,C15H15Cl2N2 Na2O8) isabroad-spectrumantibioticexhibiting activity againstbothGram-positiveandGram-negativebacteriaaswellasothergroupsofmicro- organisms onlypartiallyremovedbyconventionalactivatedsludgewastewatertreatmentplants.Thus, CAP anditsmetabolitescanbefoundineffluents. Thepresentworkdealswiththephotocatalyticde- gradation ofCAPusingTiO2 as photocatalyst.Weinvestigatedtheoptimizationofreactioncontacttime and concentrationofTiO2 considering CAPanditsby-productsremovalaswellaseffluent ecotoxicity elimination. ConsideringaCAPrealconcentrationof25mgL1, kineticdegradationcurveswerede- termined at0.1,0.2,0.4,0.8,1.6and3.2gL1 TiO2 after5,10,30,60and120minreactiontime.Treated samples werecheckedforthepresenceofby-productsandresidualtoxicity(V. fischeri, P.subcapitata, L. sativum and D. magna). ResultsevidencedthatthebestcombinationforCAPanditsby-productsremoval could besetat1.6gL1 of TiO2 for 120minwithanaverageresidualtoxicityofapproximately10%,that is thethresholdsetfornegativecontrolsinmosttoxicitytestsforblankandgeneraltoxicitytestac- ceptability.
Chloramphenicol sodium succinate (CAP, C15H15Cl2N2 Na2O8) is a broad-spectrum antibiotic exhibiting activity against both Gram-positive and Gram-negative bacteria as well as other groups of microorganisms only partially removed by conventional activated sludge wastewater treatment plants. Thus, CAP and its metabolites can be found in effluents. The present work deals with the photocatalytic degradation of CAP using TiO2 as photocatalyst. We investigated the optimization of reaction contact time and concentration of TiO2 considering CAP and its by-products removal as well as effluent ecotoxicity elimination. Considering a CAP real concentration of 25 mg L-1, kinetic degradation curves were determined at 0.1, 0.2, 0.4, 0.8, 1.6 and 3.2 g L-1 TiO2 after 5, 10, 30, 60 and 120 min reaction time. Treated samples were checked for the presence of by-products and residual toxicity (V. fischeri, P. subcapitata, L. sativum and D. magna). Results evidenced that the best combination for CAP and its by-products removal could be set at 1.6 g L-1 of TiO2 for 120 min with an average residual toxicity of approximately 10%, that is the threshold set for negative controls in most toxicity tests for blank and general toxicity test acceptability. (C) 2015 Elsevier Inc. All rights reserved.
Photocatalytic degradation of the antibiotic chloramphenicol and effluent toxi-city effects
LOFRANO, GIUSY;
2016-01-01
Abstract
Chloramphenicol sodium succinate (CAP, C15H15Cl2N2 Na2O8) is a broad-spectrum antibiotic exhibiting activity against both Gram-positive and Gram-negative bacteria as well as other groups of microorganisms only partially removed by conventional activated sludge wastewater treatment plants. Thus, CAP and its metabolites can be found in effluents. The present work deals with the photocatalytic degradation of CAP using TiO2 as photocatalyst. We investigated the optimization of reaction contact time and concentration of TiO2 considering CAP and its by-products removal as well as effluent ecotoxicity elimination. Considering a CAP real concentration of 25 mg L-1, kinetic degradation curves were determined at 0.1, 0.2, 0.4, 0.8, 1.6 and 3.2 g L-1 TiO2 after 5, 10, 30, 60 and 120 min reaction time. Treated samples were checked for the presence of by-products and residual toxicity (V. fischeri, P. subcapitata, L. sativum and D. magna). Results evidenced that the best combination for CAP and its by-products removal could be set at 1.6 g L-1 of TiO2 for 120 min with an average residual toxicity of approximately 10%, that is the threshold set for negative controls in most toxicity tests for blank and general toxicity test acceptability. (C) 2015 Elsevier Inc. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
