Diuron abatement in contaminated soil using Fenton-like process

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• 作者：Fernando Vicente ; ^{fervicen@quim.ucm.es} ; Aurora Santos ^{aursan@quim.ucm.es} ; Elena G. Sag&uuml ; illo ^{egsaguillo@quim.ucm.es} ; Á ; ngel M. Martí ; nez-Villacorta ^{angelmma@pas.ucm.es} ; Juana Marí ; a Rosas ^{jmrosas@quim.ucm.es} ; Arturo Romero ^{aromeros@quim.ucm.es}
• 关键词：Citrate ; Diuron ; Fenton-like ; Soil remediation
• 刊名：Chemical Engineering Journal
• 出版年：2012
• 出版时间：15 February 2012
• 年：2012
• 卷：183
• 期：Complete
• 页码：357-364
• 全文大小：469 K

文摘

The use of catalyzed H₂O₂ propagations (CHP) by the Fenton-like process has been evaluated for the treatment of contaminated soil by diuron ((m>qm>_Diuron)_o = 40 mg kg^?) at natural neutral pH. The interaction of H₂O₂ with the soil in batch system has been previously studied at four different initial H₂O₂ concentration (20,000-40,000-60,000-120,000 mg kg^?) at room temperature in order to evaluate the oxidant decomposition by the natural reductants species (soil organic matter and iron minerals).

The oxidation of diuron using only H₂O₂ at an initial concentration of 60,000 mg kg^? was firstly determined (m>Xm>_Diuron = 55 % ). Another test was developed to study the effect of the addition of citrate (m>Cm>_Citrate = 3000 mg kg^?) as a chelating agent to increase the removal of the contaminant up to 73 % suggesting that the concentration of iron mobilized by citrate from the soil (m>Cm>_Fe ?#xA0;40 mg kg^?) promotes the Fenton's reaction. Finally, a third experiment was assessed using an extra amount of iron salt () in addition to citrate, resulting to an increase in the diuron removal (m>Xm>_Diuron > 80 % ) because citrate makes stable iron chelates with Fe³⁺ and increases the generation of OH in aqueous phase and a higher diuron removal is obtained.

Ecotoxicity measurements in the soil and liquid phases at initial and after the Fenton's treatment by the Microtox^? bioassay demonstrated that low toxicity is obtained in the treated soil and temporal toxicity values in the liquid phase is in direct correlation with the residual H₂O₂. The toxicity values decrease with the H₂O₂ concentration to not toxic values with a final total degradation of the oxidant.