新型除氟剂竹炭的优选和改性方法实验研究

Study on Fluoride Removal from Drinking Water by Modified Bamboo Charcoal

采用不同产地的竹炭进行除氟研究,分别进行了直接除氟和改性后除氟的效果比较。在水浴恒温振荡箱,振荡速度100 r/m in,温度30件下,保持固液比0.03,反应1.5 h,处理初始氟浓度10 mg/L的溶液,浙江丽水的机械竹炭的直接除氟效果比其它地方的竹炭都好,其对氟去除率为47.8%。通过该竹炭的直接除氟工艺参数优化结果可知,pH是影响竹炭除氟的关键因素,最佳值为4;随着竹炭量的增大,氟离子的去除率明显上升;氟离子的初始浓度增大,竹炭的单位吸附量也逐渐上升;反应时间为90 m in时,反应逐渐趋于平衡。选用A l2(SO4)3对竹炭进行改性后,浙江丽水的机械竹炭的除氟率有很大的上升;采用MgSO4改性后各类竹炭除氟效果均有所下降。采用Fe2(SO4)3改性后,氟离子的去除率达到91.8%,剩余浓度为0.82 mg/L,达到国家饮用水的标准。

Comparison of defluorination effect by bamboo charcoals with different manufactories was conducted in this study.The results of experiments indicated that effect of mechanical bamboo charcoal of Lishui,Zhejiang on removal rate of F^- in shaking bed for 1h was the best in all the bamboo charcoals,removal rate of F^- achieved 47.8% under conditions of initial F^- concentration 10 mg·L^-1,solid-to-liquid ratio 3：100,pH value 4.0,at 25 ℃ and shaking rate 100 rpm.In the optimizing experiments of directly adsorption of F^- with the mechanical bamboo charcoal,effects of parameters on defluorination were investigated in detail.The results show that pH value was an important factor for the removal of F^-,and the best value is 4.Obvious effect of solid-to-liquid ratio on removal of F^- was found that the removal proportion enchanced with the increase of solid-to-liquid ratio under the adsorption time 1 h.Relationship between initial F^- concentration and adsorptive ability of bamboo charcoals was nearly liner.After modified by Al2（SO4）3,bamboo charcoals were also improved for the removal of F^- obviously.But compared with those modified by Fe2（SO4）3,the removal proportions of bamboo charcoals were not increased obviously except the mechanical bamboo charcoals（A）.After modified by MgSO4,all kinds of bamboo charcoals decreased their abilities of F^- removal.After modified by Fe2（SO4）3,all kinds of bamboo charcoals were increased for the removal of F^- obviously,the mechanical of Lishui,Zhejiang was improved to 91.8% and remained F-concentration of 0.86 mg·L^-1,which satisfied the regulation of local government.