Dechlorination of hexachlorobenzene using ultrafine Ca-Fe composite oxides

被引：42

作者：

Ma, XD ^{[1
]}

Zheng, MH ^{[1
]}

Liu, WB ^{[1
]}

Qian, Y ^{[1
]}

Zhang, B ^{[1
]}

Liu, WX ^{[1
]}

机构：

[1] Chinese Acad Sci, State Key Lab Environm Chem & Ecotoxicol, Res Ctr Ecoenvironm Sci, Beijing 100085, Peoples R China

来源：

JOURNAL OF HAZARDOUS MATERIALS | 2005年 / 127卷 / 1-3期

基金：

中国国家自然科学基金;

关键词：

dechlorination; Ca-Fe composite oxides; HCB; co-precipitation;

D O I：

10.1016/j.jhazmat.2005.06.034

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Ca-Fe composite oxides with different Ca/Fe atomic ratios were synthesized by co-precipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy with elemental X-ray analysis (SEM-EDX) and inductively coupled plasma optical emission spectrometer (ICP-OES). Their dechlorination activities were evaluated using hexachlorobenzene (HCB) as a model compound. The results indicate that the dechlorination activity is related to the composition of metal oxides. Different compositions lead to the formation of different phases of Ca-Fe composite oxides. When Ca/Fe atomic ratio was 3.4, the dechlorination activity reached 97%, which was the highest in the dechlorination of HCB at 300 degrees C for 0.5 h. This may be related to the formation of Ca2Fe2O5 phase and small agglomerate size of oxide crystal of about 1 mu m. The effect of reaction time on HCB dechlorination and the pathway of dechlorination were investigated using the Ca-Fe composite oxide with the highest activity. It was found that hydrodechlorination took place in the destruction of HCB, the dechlorination efficiency is almost 100% after 2 h reaction. After reaction, quantitative measurement of chloride ion and qualitative analysis of CaCO3 indicate besides hydrodechlorination, other degradation routes may be present. The mechanism of synergic dechlorination using Ca-Fe composite oxides was discussed. (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：156 / 162

页数：7

共 31 条

[21] Catalytic hydrodechlorination of chlorinated ethylenes in organic solvents at room temperature and atmospheric pressure [J].