Mechanism of hydroxyl radical generation from biochar suspensions: Implications to diethyl phthalate degradation. (January 2015)

• Record Type: Journal Article
• Authors: Fang, Guodong; Zhu, Changyin; Dionysiou, Dionysios D.; Gao, Juan; Zhou, Dongmei
• Is Part Of: Bioresource technology. Volume 176(2015)
• Page Start: 210
• Page End: 217
• Publication Date: 2015-01
• Subjects: Hydroxyl radical -- Biochar suspensions -- Free radicals in biochar -- Diethyl phthalate degradation; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2014.11.032
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Formation of hydroxyl radical ( OH) from biochar suspensions was confirmed. Electron paramagnetic resonance plus trapping used to verify OH release. Free radicals (FRs) mediate the formation of O2 −, H2 O2 and OH. OH from biochar suspensions degrades diethyl phthalate efficiently. Abstract: This paper investigated hydroxyl radical ( OH) generation from biochar suspensions for diethyl phthalate (DEP) degradation in the presence of oxygen. Electron paramagnetic resonance (EPR) coupled with a salicylic acid trapping method were used to detect free radicals in biochar and verify OH generation from biochar suspensions. Free radicals (FRs) in biochar could induce OH generation, and ≈12 spins of FRs were consumed to produce one trapped [OH] molecule. The proposed mechanism of OH generation was that FRs in biochar transferred electrons to O2 to produce the superoxide radical anion and hydrogen peroxide, which reacted further with FRs to produce OH. Free radical-quenching studies utilizing superoxide dismutase, catalase, and deferoxamine as scavengers were used to testify this mechanism. Furthermore, OH generated from biochar suspensions could degrade DEP efficiently. These findings of this study provide new insights into the physicochemical properties and environmental implications of biochar.