对厨房垃圾堆肥从水中吸附铬的X射线吸收近边结构研究
XANES study of Cr sorbed by a kitchen waste compost from water.
作者信息
Wei Yu-Ling, Lee Ya-Chun, Hsieh Hui-Fang
机构信息
Department of Environmental Science, Tunghai University, Box 932, No. 181, Section 3, Taichung City 407, Taiwan.
出版信息
Chemosphere. 2005 Nov;61(7):1051-60. doi: 10.1016/j.chemosphere.2005.03.037.
A kitchen waste compost was used to sorb Cr for various times from water containing either Cr(NO3)3 or CrO3 in different concentrations. Scanning electron microscopy (SEM) results show that the composts have been partially oxidized by Cr(VI) during the sorption experiments. X-ray absorption near edge structure (XANES) simulation suggests that about 54.1-61.0% Cr sorbed on the compost is in form of organic Cr(III) through ionic exchange process with the rest being existent as Cr(NO3)3 in the Cr(III) sorption case; no Cr(OH)3 is observed or expected because the solution pH after sorption experiments is <or= 3.31. However in the Cr(VI) sorption cases, about 18.0-24.9% of the total sorbed Cr is in form of Cr(OH)3 precipitate due to the Cr(VI) chemical reduction by the compost and a contaminant increase in solution pH to >or= 5.94. Moreover, organic Cr(III) represents about 51.7-69.0% of the total sorbed Cr, and the rest (6.1-28.5%) is Cr(VI).
使用厨房垃圾堆肥从含有不同浓度硝酸铬（Cr(NO3)3）或三氧化铬（CrO3）的水中吸附铬不同时间。扫描电子显微镜（SEM）结果表明，在吸附实验过程中，堆肥已被六价铬（Cr(VI)）部分氧化。X射线吸收近边结构（XANES）模拟表明，在三价铬（Cr(III)）吸附情况下，吸附在堆肥上的铬约54.1 - 61.0%以有机三价铬（Cr(III)）形式通过离子交换过程存在，其余以硝酸铬（Cr(NO3)3）形式存在；未观察到或预期不存在氢氧化铬（Cr(OH)3），因为吸附实验后溶液pH值≤3.31。然而，在六价铬（Cr(VI)）吸附情况下，由于堆肥对六价铬（Cr(VI)）的化学还原以及溶液pH值升高至≥5.94，总吸附铬中约18.0 - 24.9%以氢氧化铬（Cr(OH)3）沉淀形式存在。此外，有机三价铬（Cr(III)）占总吸附铬的约51.7 - 69.0%，其余（6.1 - 28.5%）为六价铬（Cr(VI)）。
Zotero 插件