[关键词]
[摘要]
以城市污泥为研究对象,利用电热管式炉对其进行焚烧实验,研究了不同焚烧温度和不同停留时间下Pb、Cd的迁移和转化特性。研究结果表明:随着焚烧温度的升高,焚烧底渣中Pb、Cd残留率下降趋势明显,底渣中Cd的残渣态转化为可还原态及可氧化态,而Pb由可氧化态向残渣态转化,且焚烧底渣中Pb和Cd的残渣态所占的比率均在90%以上,有利于降低焚烧底渣中Pb和Cd的浸出浓度。在焚烧温度900 ℃下,随着焚烧时间的延长,Cd和Pb残留率在20 min时达到最低,底渣中Cd的残渣态向可氧化态转化,Pb的残渣态比率几乎不变,且焚烧底渣中Pb和Cd的残渣态所占的比率均在90%以上。
[Key word]
[Abstract]
Partitioning and transformation of Pb and Cd contained in sewage sludge during incineration process were investigated under different incineration temperature and residence time using a laboratory tubular furnace.The result indicates that the fixation rate of Pb and Cd significantly decreases with the increase of incineration temperature, and the residual fraction of Cd transforms into the reducible and oxidizable fraction, while the oxidizable fraction of Pb transforms into the residual fraction.Moreover, the ratio of residual fraction of Pb and Cd in the incineration bottom slag is above 90%, which is beneficial to reduce the leaching concentration of Pb and Cd in the incineration bottom slag.Additionally, at the incineration temperature of 900 ℃, with the extension of incineration time, the residual ratio of Cd and Pb reaches the minimum at 20 min, and the residual fraction of Cd in the bottom slag converts to the oxidizable fraction, while the ratio of residual fraction of Pb is almost unchanged.And the ratio of the residual fraction of Pb and Cd in the incinerated bottom slag is above 90%.
[中图分类号]
X705
[基金项目]
国家科技支撑计划资助(2012BAA04B01);上海理工大学科技发展项目(16KJFZ094)