TY - JOUR
T1 - Degradation of sulfamethazine by cerium mediated photoelectrochemical oxidation with hydroxyl radical oxidation effect
AU - Liu, Yi Hung
AU - Peng, Xiao Qi
AU - Chou, Wei Lung
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/10/1
Y1 - 2020/10/1
N2 - A cerium (Ce) mediated photoelectrochemical oxidation (MPEO)/H2O2 system, integrating UV photocatalysis and hydroxyl radical (⋅OH) oxidation, was developed to improve the degradation of sulfamethazine (SMT). SMT is an emerging contaminant with medical toxicity in environmental matrices. In the study of electrolytic production of Ce(IV), the Ce(III)/Ce(IV) redox reaction was found to have good reversibility at high HNO3 concentrations above 0.5 M, due to more cerium ions being trapped by NO3- ions near the anode. In addition, optimum current density of 8 mA cm−2 and reaction temperature of 313 K, for Ce(IV) production, are determined by considering specific energy consumption (SEC) and Ce(IV) percent yield. The MPEO/H2O2 system demonstrates favorable SMT removal efficiencies of 76% and 98%, at treatment times of 60 and 120 min, respectively. This system outperforms the mediated electrochemical oxidation (MEO) and MPEO systems, for SMT degradation. In addition, the kinetics of SMT degradation, using the MPEO/H2O2 system, was found to follow a proposed pseudo-first order model, rather than a pseudo-second order model, and exhibit a higher rate constant than those of the MEO and MPEO systems. Moreover, the concentration of ⋅OH during SMT treatment can be estimated by measuring the concentrations of 4-Hydroxybenzoic acid (4-HBA) and 3,4-Dihydroxybenzoic acid (3,4-DHBA), over time. Our findings reveal that introducing UV irradiation and H2O2 into the MEO system can induce a higher production of ⋅OH in addition to the Ce(IV) ions, thus leading to improved SMT removal efficiency.
AB - A cerium (Ce) mediated photoelectrochemical oxidation (MPEO)/H2O2 system, integrating UV photocatalysis and hydroxyl radical (⋅OH) oxidation, was developed to improve the degradation of sulfamethazine (SMT). SMT is an emerging contaminant with medical toxicity in environmental matrices. In the study of electrolytic production of Ce(IV), the Ce(III)/Ce(IV) redox reaction was found to have good reversibility at high HNO3 concentrations above 0.5 M, due to more cerium ions being trapped by NO3- ions near the anode. In addition, optimum current density of 8 mA cm−2 and reaction temperature of 313 K, for Ce(IV) production, are determined by considering specific energy consumption (SEC) and Ce(IV) percent yield. The MPEO/H2O2 system demonstrates favorable SMT removal efficiencies of 76% and 98%, at treatment times of 60 and 120 min, respectively. This system outperforms the mediated electrochemical oxidation (MEO) and MPEO systems, for SMT degradation. In addition, the kinetics of SMT degradation, using the MPEO/H2O2 system, was found to follow a proposed pseudo-first order model, rather than a pseudo-second order model, and exhibit a higher rate constant than those of the MEO and MPEO systems. Moreover, the concentration of ⋅OH during SMT treatment can be estimated by measuring the concentrations of 4-Hydroxybenzoic acid (4-HBA) and 3,4-Dihydroxybenzoic acid (3,4-DHBA), over time. Our findings reveal that introducing UV irradiation and H2O2 into the MEO system can induce a higher production of ⋅OH in addition to the Ce(IV) ions, thus leading to improved SMT removal efficiency.
KW - Cerium
KW - Degradation
KW - Hydroxyl radical
KW - Mediated photoelectrochemical oxidation
KW - Sulfamethazine
UR - http://www.scopus.com/inward/record.url?scp=85084501666&partnerID=8YFLogxK
U2 - 10.1016/j.seppur.2020.116929
DO - 10.1016/j.seppur.2020.116929
M3 - 期刊論文
AN - SCOPUS:85084501666
SN - 1383-5866
VL - 248
JO - Separation and Purification Technology
JF - Separation and Purification Technology
M1 - 116929
ER -