污泥基吸附剂对邻苯二甲酸二甲酯吸附和解吸附性能研究

以城市污水处理厂产生的剩余污泥为原料,采用活化剂氯化锌改性制备污泥基吸附剂,对其物理与化学特性进行表征,考察其对邻苯二甲酸二甲酯(DMP)的吸附和解吸附性能。研究表明,活化改性后的污泥基吸附剂表面具有清晰的孔结构(以微孔为主),且含有较高的含碳量(37.60%)和酸性官能团(0.680 mmol/L);污泥基吸附剂对DMP的最佳吸附条件为:pH值为6,吸附时间为2 h,吸附剂投加量为4 g/L,此时DMP去除率可达80%以上;Freundlich模型对吸附平衡数据有很好的拟合结果,吸附动力学过程符合准二级动力学模型;采用1 mol/L的NaOH作为再生液进行解吸附,污泥基吸附剂经过重复使用7次后,对DMP去除率仍然在80%以上。

Study on adsorption and desorption characteristics of dimethyl phthalate by sludge-based adsorbent

With excess sludge from urban sewage treatment plant as raw material,sludge-based adsorbent was prepared through znic chloride modification,and its physical and chemical property were characterized;besides,its adsorption and desoption performance for dimethyl phthalate(DMP)were studied.The study results showed that,through the activation,the modified sludge-based adsorbent had clear pore structure(mainly micropores)on its surface,and contained high concentration of carbon(37.6%)and large amount of acidic functional groups(0.680 mmol/L).The optimal condition for sludge-based adsorbent adsorbing DMP was as follows:the pH value was 6,the adsorption time was 2 h,the adsorbent dosage was 4 g/L,then,the removal rate of DMP could reach above 80%.Freundlich model has a good fitting result for adsorption equilibrium data,and the adsorption kinetic process accords with quasi-second order kinetic model.1 mol/L NaOH was used as the regenerated liquid for desorption,after repeated use of sludge-based adsorbent for 7 times,the removal rate of DMP was still above 80%.