title: Oxidative degradation of pyrene in contaminated soils by δ-MnO2 with or without sunlight irradiation.
abstract: The enhanced oxidative degradation of pyrene in quartz sand and alluvial and red soils by micro-nano size birnessite (δ-MnO(2)) in the presence and absence of sunlight was investigated. The degradation of pyrene by δ-MnO(2) in quartz sand showed very little synergistic effect of sunlight irradiation on δ-MnO(2) oxidizing power. However, pyrene degradation by δ-MnO(2) in alluvial and red soils was greater under solar irradiation than the combination of photooxidation of pyrene and oxidation of pyrene by δ-MnO(2). The oxidative degradation percentages of pyrene by δ-MnO(2) under sunlight irradiation are 94.8, 97.7, and 100% for alluvial soil, red soil, and quartz sand, respectively. Oxidative degradation percentages of pyrene by δ-MnO(2) in alluvial and red soils with irradiation of sunlight almost attained a maximum at 1 h with a 5% (w/w) dose of the amended oxidant. Due to their different total organic carbon (TOC) contents, the sequence of enhanced oxidative degradation of pyrene by δ-MnO(2) in quartz sand and alluvial and red soils was quartz sand>red soil>alluvial soil. Further, this study revealed that δ-MnO(2)-enhanced oxidative degradation of pyrene is very pronounced in contaminated soils in situ even at deep soil layers where irradiation by sunlight is very limited.
authors.affiliation: Chaoyang University of Technology, Wufong Township, Taichung County 41349, Taiwan, ROC.
authors.forename: S W
authors.initials: SW
authors.lastname: Chang Chien
authors.forename: C H
authors.initials: CH
authors.lastname: Chang
authors.forename: S H
authors.initials: SH
authors.lastname: Chen
authors.forename: M C
authors.initials: MC
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Madhava Rao
authors.forename: S
authors.initials: S
authors.lastname: Satya Veni
mesh_terms: D052918:Environmental Restoration and Remediation; D017895:Manganese Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D011721:Pyrenes / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013472:Sunlight; D013997:Time Factors
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; C027424:manganese oxide; C030984:pyrene