Reactive oxygen species responsible for the enhanced desorption of dodecane in modified Fenton's systems.
The enhanced treatment of sorbed contaminants has been documented in modified Fenton's reactions; contaminants are desorbed and degraded more rapidly than they desorb by fill-and-draw or gas-purge desorption. The reactive species responsible for this process was investigated using dodecane as a model sorbent. Hydroxyl radical, hydroperoxide anion, and superoxide radical anion were generated separately to evaluate their roles in enhanced dodecane desorption. Dodecane desorption from silica sand over 180 minutes was negligible in gas-purge systems and in the hydroxyl radical and hydroperoxide anion systems. In contrast, enhanced desorption of dodecane occurred in superoxide systems, with >80% desorption over 180 minutes. Scavenging of superoxide eliminated the enhanced desorption of dodecane in both superoxide and modified Fenton's systems, confirming that superoxide is the desorbing agent in modified Fenton's reactions. Conditions that promote superoxide generation in Fenton's reactions may enhance their effectiveness for in situ subsurface remediation of sorbed hydrophobic contaminants.
Corbin
Joseph F
JF
Department of Civil and Environmental Engineering, Washington State University, Pullman, Washington 99164-2910, USA.
Teel
Amy L
AL
Allen-King
Richelle M
RM
Watts
Richard J
RJ
D000327:Adsorption; D000473:Alkanes / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D006861:Hydrogen Peroxide / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013481:Superoxides / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
D000473:Alkanes; C045076:Fenton's reagent; D017382:Reactive Oxygen Species; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D013481:Superoxides; C007548:n-dodecane; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron