为资源化利用城市污水厂污泥,采用ZnCl2活化法制备污泥基活性炭,以碘吸附值和亚甲基蓝吸附值为评价指标,对制备条件进行优化,采用比表面积分析仪、元素分析仪、X线光电子能谱等测试分析手段对制得污泥基活性炭的物理化学性质进行研究,并将其用于城市生活污水处理。研究结果表明:采用ZnCl2活化法制备污泥基活性炭过程的主要影响因素是热解温度,其次是热解时间,活化剂浓度和浸渍比的影响较小。最佳制备条件为热解温度600℃,热解时间50 min,活化剂质量分数40%,浸渍比(g/mL)1:2.5。制得的污泥基活性炭以中孔为主,比表面积相对较小。活性炭中的Al,Fe和Si含量较一般商品活性炭的高。活性炭表面存在大量含氧和含氮官能团,且表面呈酸性。活性炭中重金属元素浸出量低于国家规定的最高允许浓度,且对生活污水有较好的处理效果。
For efficient resource utilization of sewage sludge, the sludge-based activated carbon was prepared by ZnCl2 activation method. Based on iodine and methylene blue adsorptivity, the preparation conditions were optimized. The properties of the sludge-based activated carbon were thoroughly studied by test analysis tools such as specific surface area analyzer and element analyzer, X-ray photoelectron spectroscope. And the sludge-based activated carbon was applied in the treatment of urban sewage. The results show that during the preparation process, the main influential factor is pyrolysis temperature, and then is pyrolysis time, the effects of activator concentration and impregnation ratio being relatively less. The optimum preparation conditions are 600℃, 50 min, 40%, 1:2.5 for the pyrolysis temperature, pyrolysis time, activator mass fraction and impregnation ratio, respectively. The sludge-based activated carbon is mainly mesoporous and has relatively small specific surface area. The contents of A1, Fe and Si in the sludge-based activated carbon are higher than those in commercial activated carbon. Large amount of oxygen-containing and nitrogen-containing functional groups exist on the surface of the sludge-based activated carbon and the surface is acidic. The concentrations of heavy metals leached from the sludge-based activated carbon are lower than the maximum allowable value regulated by China and the treatment effect of the sludge-based activated carbon for urban sewage is remarkable.