State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China.
State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China; China-EU Institute for Clean and Renewable Energy at Huazhong University of Science and Technology, Wuhan 430074, Hubei, China.
Bioresour Technol. 2016 Oct;218:134-9. doi: 10.1016/j.biortech.2016.06.075. Epub 2016 Jun 21.
This work aimed to investigate effects and reaction mechanisms of CaO/Fe2O3 on emission behaviors of arsenic during sewage sludge pyrolysis. The results showed that 24.8-54.2%, 26.4-60.4% and 27.7-63.1% of arsenic escaped from three samples when pyrolysis process happened at 723, 923 and 1123K respectively. And the sludge which contained higher calcium and iron contents released less arsenic than others. External CaO and Fe2O3 were added into the sewage sludge to study their effects on arsenic emissions during pyrolysis, where both of them inhibited arsenic emission effectively, especially at high temperatures. With the help of thermogravimetry analysis and X-ray fluorescence, inhibitory mechanisms of CaO/Fe2O3 on arsenic emission during sewage sludge pyrolysis were studied. CaO could react with As2O3, As2S3 and NaAsO2 to form nonvolatile substances, such as Ca(AsO2)2; while Fe2O3 could react with NaAsO2 to generate certain substances which was stable below 1123K.
本研究旨在探讨 CaO/Fe2O3 对污水污泥热解过程中砷排放行为的影响及其反应机制。结果表明，在 723、923 和 1123K 热解条件下，三种样品中分别有 24.8-54.2%、26.4-60.4%和 27.7-63.1%的砷逸出。含较高钙和铁含量的污泥释放的砷较少。向污水污泥中添加外源 CaO 和 Fe2O3 以研究它们对热解过程中砷排放的影响，结果表明它们都能有效地抑制砷的排放，尤其是在高温下。通过热重分析和 X 射线荧光分析，研究了 CaO/Fe2O3 抑制污水污泥热解过程中砷排放的机理。CaO 可与 As2O3、As2S3 和 NaAsO2 反应生成不挥发物质，如 Ca(AsO2)2；而 Fe2O3 可与 NaAsO2 反应生成在 1123K 以下稳定的某些物质。
