TY - JOUR
T1 - Advanced oxidation of the commercial nonionic surfactant octylphenol polyethoxylate Triton™ X-45 by the persulfate/UV-C process
T2 - Effect of operating parameters and kinetic evaluation
AU - Arslan-Alaton, Idil
AU - Olmez-Hanci, Tugba
AU - Genç, Bora
AU - Dursun, Duygu
N1 - Publisher Copyright:
© 2013 Arslan-Alaton, Olmez-Hanci, Genç and Dursun.
PY - 2013/3/20
Y1 - 2013/3/20
N2 - This study explored the potential use of a sulfate radical (SO·-4)-based photochemical oxidation process to treat the commercial nonionic surfactant octylphenol polyethoxylate (OPPE) Triton™ X-45. For this purpose, the effect of initial S2O2-8 (0-5.0 mM) and OPPE (10-100 mg/L) concentrations on OPPE and its organic carbon content (TOC) removal were investigated at an initial reaction pH of 6.5. Results indicated that very fast OPPE degradation (100%) accompanied with high TOC abatement rates (90%) could be achieved for 10 and 20 mg/L aqueous OPPE at elevated S2O2-8 concentrations (≥2.5 mM). S2O2-8/UV-C treatment was still capable of complete OPPE removal up to an initial concentration of 40 mg/L in the presence of 2.5 mM S2O2-8. On the other hand, TOC removal efficiencies dropped down to only 40% under the same reaction conditions. S2O2-8/UV-C oxidation of OPPE was also compared with the relatively well-known and established H2O2/UV-C oxidation process. Treatment results showed that the performance of S2O2-8/UV-C was comparable to that of H2O2/UV-C oxidation for the degradation and mineralization of OPPE. In order to elucidate the relative reactivity and selectivity of SO·-4 and HO·, bimolecular reaction rate coefficients of OPPE with SO·-4 and HO· were determined by employing competition kinetics with aqueous phenol (47 μM) selected as the reference compound. The pseudo-first-order abatement rate coefficient obtained for OPPE during S2O2-8/UV-C oxidation (0.044 min-1) was found to be significantly lower than that calculated for phenol (0.397 min-1). In the case of H2O2/UV-C oxidation however, similar pseudo-first-order abatement rate coefficients were obtained for both OPPE (0.087 min-1) and phenol (0.140 min-1). From the kinetic study, second-order reaction rate coefficients for OPPE with SO·-4 and HO· were determined as 9.8 × 108 M-1 s-1 and 4.1 × 109 M-1 s-1, respectively. The kinetic study also revealed that the selectivity of SO·-4 was found to be significantly higher than that of HO·.
AB - This study explored the potential use of a sulfate radical (SO·-4)-based photochemical oxidation process to treat the commercial nonionic surfactant octylphenol polyethoxylate (OPPE) Triton™ X-45. For this purpose, the effect of initial S2O2-8 (0-5.0 mM) and OPPE (10-100 mg/L) concentrations on OPPE and its organic carbon content (TOC) removal were investigated at an initial reaction pH of 6.5. Results indicated that very fast OPPE degradation (100%) accompanied with high TOC abatement rates (90%) could be achieved for 10 and 20 mg/L aqueous OPPE at elevated S2O2-8 concentrations (≥2.5 mM). S2O2-8/UV-C treatment was still capable of complete OPPE removal up to an initial concentration of 40 mg/L in the presence of 2.5 mM S2O2-8. On the other hand, TOC removal efficiencies dropped down to only 40% under the same reaction conditions. S2O2-8/UV-C oxidation of OPPE was also compared with the relatively well-known and established H2O2/UV-C oxidation process. Treatment results showed that the performance of S2O2-8/UV-C was comparable to that of H2O2/UV-C oxidation for the degradation and mineralization of OPPE. In order to elucidate the relative reactivity and selectivity of SO·-4 and HO·, bimolecular reaction rate coefficients of OPPE with SO·-4 and HO· were determined by employing competition kinetics with aqueous phenol (47 μM) selected as the reference compound. The pseudo-first-order abatement rate coefficient obtained for OPPE during S2O2-8/UV-C oxidation (0.044 min-1) was found to be significantly lower than that calculated for phenol (0.397 min-1). In the case of H2O2/UV-C oxidation however, similar pseudo-first-order abatement rate coefficients were obtained for both OPPE (0.087 min-1) and phenol (0.140 min-1). From the kinetic study, second-order reaction rate coefficients for OPPE with SO·-4 and HO· were determined as 9.8 × 108 M-1 s-1 and 4.1 × 109 M-1 s-1, respectively. The kinetic study also revealed that the selectivity of SO·-4 was found to be significantly higher than that of HO·.
KW - Advanced oxidation processes (AOPs)
KW - Competitive kinetics
KW - Hydrogen peroxide/UV-C process
KW - Hydroxyl radical
KW - Nonionic surfactant
KW - Octylphenol polyethoxylate
KW - Persulfate/UV-C process
KW - Sulfate radical
UR - http://www.scopus.com/inward/record.url?scp=84987618956&partnerID=8YFLogxK
U2 - 10.3389/fchem.2013.00004
DO - 10.3389/fchem.2013.00004
M3 - Article
AN - SCOPUS:84987618956
SN - 2296-2646
VL - 1
JO - Frontiers in Chemistry
JF - Frontiers in Chemistry
M1 - 4
ER -