Light-assisted decomposition of dyes over iron-bearing soil clays in the presence of H2O2.
Light-assisted decomposition of dyes over iron-bearing soil clays in the presence of H2O2.
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DOI：
10.1016/j.jhazmat.2009.02.160
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发表时间：
2009-09
影响因子：
13.6
通讯作者：
Zhaohui Wang;Wanhong Ma;Chuncheng Chen;Jincai Zhao
中科院分区：
文献类型：
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作者：
Zhaohui Wang;Wanhong Ma;Chuncheng Chen;Jincai Zhao
选择了中国不同地点的4种土壤粘土，模拟了光辅助类芬顿法对染料污染土壤的化学修复。x射线衍射（XRD）、x射线光电子能谱（XPS）和电子自旋共振（ESR）测量表明，这些土壤粘土中含有氧化铁，如磁铁矿和赤铁矿，其中未扭曲的铁活性位点（ESR谱，g=2.3）占主导地位。在可见光或紫外线照射下，土壤粘土在中性ph下活化h2o2，对罗丹明B （Rhodamine B, RhB）等不可生物降解的阳离子染料非常有效。RhB的光降解速率与粘土中总铁含量和h2o2用量密切相关，表明发生了矿物催化的类芬顿反应。土壤有机质（SOM）对RhB染料的光分解有明显的抑制作用。反应产物是一些低分子量的二羧酸及其衍生物，它们都是易于生物降解的。根据自旋捕获ESR技术的结果，提出了一种可能的机理。
Four types of soil clays from different sites in China have been chosen to simulate chemical remediation of soils contaminated with dyes by light-assisted Fenton-like method. X-Ray diffraction (XRD), X-ray photoelectron spectroscopic (XPS) and electron spin resonance (ESR) measurements indicated that these soil clays contain iron oxides such as magnetite and hematite, where nondistorted iron active sites (ESR spectra, g=2.3) predominate. Upon visible or UV irradiation, the soil clays were very effective for the degradation of nonbiodegradable cationic dyes such as Rhodamine B (RhB) by activating H2O2at neutral pH. The photodegradation rates of RhB were closely related to total Fe content in clays and H2O2dosage, indicating the mineral-catalyzed Fenton-like reactions operated. Soil organic matters (SOM) would remarkably inhibit the photodecomposition of RhB dye. The reaction products were some low-molecular-weight dicarboxylic acids and their derivatives, all of which are easily biodegradable. A possible mechanism was proposed based on the results obtained by spin-trapping ESR technique.