State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science & Engineering, Tongli University, Shanghai 200092, China.
J Environ Sci (China). 2010;22(7):1110-5. doi: 10.1016/s1001-0742(09)60225-4.
To investigate the feasibility of detoxifying chromium slag by sewage sludge, synthetic chromium slag containing 3% of Cr(VI) was mixed with sewage sludge followed by thermal treatment in nitrogen gas for stabilizing chromium. The effects of slag to sludge ratio (0.5, 1 and 2) and temperature (200, 300, 500, 700 and 900 degrees C) on treatment efficiency were investigated. During the mixing process before thermal treatment, 59.8%-99.7% of Cr(VI) was reduced, but Cr could be easily leached from the reduction product. Increasing heating temperature and decreasing slag to sludge ratio strengthened the reduction and stabilization of Cr(VI). When the slag to sludge ratio was 0.5 and thermal treatment temperature was 300 degrees C, the total leached Cr and Cr(VI) declined to 0.55 mg/L and 0.17 mg/L respectively, and 45.5% of Cr in the thermally treated residue existed as residual fraction. A two-stage mechanism was proposed for the reduction and stabilization of Cr.
为了研究利用污水污泥解毒铬渣的可行性，将含有 3%Cr(VI)的合成铬渣与污水污泥混合，然后在氮气中进行热处理以稳定铬。考察了渣泥比（0.5、1 和 2）和温度（200、300、500、700 和 900℃）对处理效果的影响。在热处理前的混合过程中，59.8%-99.7%的 Cr(VI)被还原，但 Cr 很容易从还原产物中浸出。提高加热温度和降低渣泥比可以增强 Cr(VI)的还原和稳定。当渣泥比为 0.5 且热处理温度为 300℃时，总浸出 Cr 和 Cr(VI)分别降至 0.55mg/L 和 0.17mg/L，热处理残渣中 45.5%的 Cr 以残余物形式存在。提出了 Cr 的还原和稳定的两阶段机理。
