TY - JOUR
T1 - Oxidation of aquatic pollutants by ferrous-oxalate complexes under dark aerobic conditions
AU - Lee, Jaesang
AU - Kim, Jungwon
AU - Choi, Wonyong
N1 - Funding Information:
This research was supported by Hallym University Research Fund ( HRF-201303-004 ), Basic Science Research Program (NRF-2013R1A1A1007312) and EPB Center (No. 2008-0061892 ) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning.
PY - 2014/6/15
Y1 - 2014/6/15
N2 - This study evaluates the ability of FeII-oxalate complexes for the generation of OH through oxygen reduction and the oxidative degradation of aquatic pollutants under dark aerobic conditions (i.e., with oxygen but without light). The degradation of 4-chlorophenol (4-CP) was rapid in the mixture of Fe2+ and oxalate prepared using ultrapure water, but was absent without either Fe2+ or oxalate. The formation of FeII-oxalate complexes enables two-electron reduction of oxygen to generate H2O2 and subsequent production of OH. The significant inhibition of 4-CP degradation in the presence of H2O2 and OH scavenger confirms such mechanisms. The degradation experiments with varying [Fe2+], [oxalate], and initial pH demonstrated that the degradation rate depends on [FeII(Ox)22-], but the degree of degradation is primarily determined by [FeII(Ox)22-]+[FeII(Ox)0]. Efficient degradation of diverse aquatic pollutants, especially phenolic pollutants, was observed in the FeII-oxalate complexes system, wherein the oxidation efficacy was primarily correlated with the reaction rate constant between pollutant and OH. The effect of various organic ligands (oxalate, citrate, EDTA, malonate, and acetate) on the degradation kinetics of 4-CP was investigated. The highest efficiency of oxalate for the oxidative degradation is attributed to its high capability to enhance the reducing power and low reactivity with OH.
AB - This study evaluates the ability of FeII-oxalate complexes for the generation of OH through oxygen reduction and the oxidative degradation of aquatic pollutants under dark aerobic conditions (i.e., with oxygen but without light). The degradation of 4-chlorophenol (4-CP) was rapid in the mixture of Fe2+ and oxalate prepared using ultrapure water, but was absent without either Fe2+ or oxalate. The formation of FeII-oxalate complexes enables two-electron reduction of oxygen to generate H2O2 and subsequent production of OH. The significant inhibition of 4-CP degradation in the presence of H2O2 and OH scavenger confirms such mechanisms. The degradation experiments with varying [Fe2+], [oxalate], and initial pH demonstrated that the degradation rate depends on [FeII(Ox)22-], but the degree of degradation is primarily determined by [FeII(Ox)22-]+[FeII(Ox)0]. Efficient degradation of diverse aquatic pollutants, especially phenolic pollutants, was observed in the FeII-oxalate complexes system, wherein the oxidation efficacy was primarily correlated with the reaction rate constant between pollutant and OH. The effect of various organic ligands (oxalate, citrate, EDTA, malonate, and acetate) on the degradation kinetics of 4-CP was investigated. The highest efficiency of oxalate for the oxidative degradation is attributed to its high capability to enhance the reducing power and low reactivity with OH.
KW - Dark aerobic reaction
KW - Ferrous-oxalate complexes
KW - OH radicals
KW - Oxidation
KW - Water treatment
UR - http://www.scopus.com/inward/record.url?scp=84899680584&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2014.03.056
DO - 10.1016/j.jhazmat.2014.03.056
M3 - Article
C2 - 24769845
AN - SCOPUS:84899680584
VL - 274
SP - 79
EP - 86
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
ER -