School of Environmental Science and Engineering, Shanghai JiaoTong University, Shanghai 200240, China.
J Hazard Mater. 2009 Dec 30;172(2-3):1597-601. doi: 10.1016/j.jhazmat.2009.08.032. Epub 2009 Aug 15.
The effect of pyrolysis process with sewage sludge on the chromium behavior of chromite ore processing residue (COPR) was examined in this study. The behavior of chromium was characterized in term of chromium oxidation test, pH-static leaching tests, column leaching test and sequential extraction test. As a sequence of pyrolysis process, the Cr(VI) in COPR was effectively reduced from 5057 mg kg(-1) for untreated COPR to 8.6 mg kg(-1) for treated COPR at temperature over 600 degrees C, which is far below the New Jersey Department of Environmental Protection regulatory limit of 240 mg kg(-1). As a result, the amount of exchangeable and carbonate-bound Cr fractions, the most mobile for the environment, were largely reduced. At the same time, the amount of the other three Cr fractions which are much less mobile become augmented. pH static test showed that the chromium in the treated COPR at pyrolysis temperature above 400 degrees C was quite stable at pH>7. Column study also indicated that only negligible amount of chromium of the treated COPR at above 600 degrees C can be released by the acid rain.
本研究考察了用污水污泥进行热解处理对铬铁矿加工残渣（COPR）中铬行为的影响。采用铬氧化试验、pH 静态浸出试验、柱浸出试验和连续提取试验对铬的行为进行了表征。随着热解过程的进行，未经处理的 COPR 中 Cr(VI)从 5057mg/kg 有效降低至 600℃以上处理后的 COPR 中 8.6mg/kg，远低于新泽西州环境保护署规定的 240mg/kg 的限值。因此，环境中最具迁移性的可交换态和碳酸盐结合态 Cr 含量大量减少。与此同时，其他三种 Cr 含量较低的形态含量增加。pH 静态试验表明，在热解温度高于 400℃时，处理后的 COPR 中的铬在 pH>7 时非常稳定。柱试验也表明，在 600℃以上高温处理后的 COPR 中，只有极少量的铬可被酸雨释放。
