TY - JOUR
T1 - Degradation of ciprofloxacin antibiotic by Homogeneous Fenton oxidation
T2 - Hybrid AHP-PROMETHEE method, optimization, biodegradability improvement and identification of oxidized by-products
AU - Salari, Marjan
AU - Rakhshandehroo, Gholam Reza
AU - Nikoo, Mohammad Reza
N1 - Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/9
Y1 - 2018/9
N2 - The main purpose of this experimental study was to optimize Homogeneous Fenton oxidation (HFO) and identification of oxidized by-products from degradation of Ciprofloxacin (CIP) using hybrid AHP-PROMETHEE, Response Surface Methodology (RSM) and High Performance Liquid Chromatography coupled with Mass Spectrometry (HPLC-MS). At the first step, an assessment was made for performances of two catalysts (FeSO4·7H2O and FeCl2·4H2O) based on hybrid AHP-PROMETHEE decision making method. Then, RSM was utilized to examine and optimize the influence of different variables including initial CIP concentration, Fe2+ concentration, [H2O2]/[Fe2+] mole ratio and initial pH as independent variables on CIP removal, COD removal, and sludge to iron (SIR) as the response functions in a reaction time of 25 min. Weights of the mentioned responses as well as cost criteria were determined by AHP model based on pairwise comparison and then used as inputs to PROMETHEE method to develop hybrid AHP-PROMETHEE. Based on net flow results of this hybrid model, FeCl2·4H2O was more efficient because of its less environmental stability as well as lower SIR production. Then, optimization of experiments using Central Composite Design (CCD) under RSM was performed with the FeCl2·4H2O catalyst. Biodegradability of wastewater was determined in terms of BOD5/COD ratio, showing that HFO process is able to improve wastewater biodegradability from zero to 0.42. Finally, the main intermediaries of degradation and degradation pathways of CIP were investigated with (HPLC-MS). Major degradation pathways from hydroxylation of both piperazine and quinolonic rings, oxidation and cleavage of the piperazine ring, and defluorination (OH/F substitution) were suggested.
AB - The main purpose of this experimental study was to optimize Homogeneous Fenton oxidation (HFO) and identification of oxidized by-products from degradation of Ciprofloxacin (CIP) using hybrid AHP-PROMETHEE, Response Surface Methodology (RSM) and High Performance Liquid Chromatography coupled with Mass Spectrometry (HPLC-MS). At the first step, an assessment was made for performances of two catalysts (FeSO4·7H2O and FeCl2·4H2O) based on hybrid AHP-PROMETHEE decision making method. Then, RSM was utilized to examine and optimize the influence of different variables including initial CIP concentration, Fe2+ concentration, [H2O2]/[Fe2+] mole ratio and initial pH as independent variables on CIP removal, COD removal, and sludge to iron (SIR) as the response functions in a reaction time of 25 min. Weights of the mentioned responses as well as cost criteria were determined by AHP model based on pairwise comparison and then used as inputs to PROMETHEE method to develop hybrid AHP-PROMETHEE. Based on net flow results of this hybrid model, FeCl2·4H2O was more efficient because of its less environmental stability as well as lower SIR production. Then, optimization of experiments using Central Composite Design (CCD) under RSM was performed with the FeCl2·4H2O catalyst. Biodegradability of wastewater was determined in terms of BOD5/COD ratio, showing that HFO process is able to improve wastewater biodegradability from zero to 0.42. Finally, the main intermediaries of degradation and degradation pathways of CIP were investigated with (HPLC-MS). Major degradation pathways from hydroxylation of both piperazine and quinolonic rings, oxidation and cleavage of the piperazine ring, and defluorination (OH/F substitution) were suggested.
KW - central composite design (CCD)
KW - Ciprofloxacin antibiotic
KW - degradation by-products
KW - homogeneous Fenton oxidation
KW - hybrid AHP-PROMETHEE
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U2 - 10.1016/j.chemosphere.2018.04.086
DO - 10.1016/j.chemosphere.2018.04.086
M3 - Article
C2 - 29738905
AN - SCOPUS:85046702864
SN - 0045-6535
VL - 206
SP - 157
EP - 167
JO - Chemosphere
JF - Chemosphere
ER -