城市污泥制备水中重金属吸附剂及其吸附特性研究

本实验利用城市污水厂的脱水污泥,通过化学活化法制备活性炭.研究活化温度、活化时间、固液比和活化剂浓度等因素对制备污泥活性炭的影响,确定氯化锌法制备污泥活性炭的最佳工艺为活化温度550 ℃、活化时间30 min、固液比1∶2、氯化剂浓度45％.将制备的污泥活性炭吸附Cu2＋,Cr6＋,Cd2＋3种重金属离子模拟废水,研究pH值、吸附时间、污泥投加量、温度等因素对吸附过程的影响.实验结果表明,剩余污泥对Cu2＋,Cr6＋,Cd2＋3种重金属离子都具有良好的吸附效果,在优化条件下,3种重金属离子去除率分别达到94％,76％,81％,吸附能力大小顺序为Cu2＋＞Cd2＋＞＋Cr6＋.

Research on adsorption of heavy metal ions by activated carbon produced with sewage sludge

In this paper, urban sewage sludge was used to prepare activated carbon with chemical activation method. The impact of activation temperature, activation time, solid to liquid ratio and chloride concentration and other factors on the activated carbon sludge preparation were studied. The optimum conditions of activated carbon preparation with sludge by zinc chloride were determined： the optimum activation temperature 550℃, the activation time of 30min, solid-liquid ratio of 1：2, chloride concentration of 45%. Then absorption of three heavy metal ions Cu2＋,Cr6＋,Cd2＋ in wastewater by the activated carbon was studied, and the impacts of pH, adsorption time, the sludge dosage, the temperature on the adsorption process were also studied. Experimental results showed that the adsorption effect of the sludge on three heavy metal ions Cu2＋,Cre＋,Cd2＋ was good. Under the optimum conditions, removal rates of three heavy metal reached 92% ,76% and 80%, adsorption capacity in the order Cu2＋〉Cd2＋〉Cr6＋.