【摘要】 利用天然膨润土、羟基铁和羟基铁铝柱撑膨润土,进行吸附EDTA络合铜离子(EDTA-Cu)的实验。研究了溶液中EDTA与Cu2+摩尔比、pH值、吸附时间对吸附过程的影响和吸附等温线的变化规律。结果表明,达到吸附平衡的时间为1 h;pH值对天然膨润土的吸附影响甚小,柱撑膨润土的最佳吸附pH在6～8之间;膨润土的分配系数随着溶液中EDTA与Cu2+的摩尔比的增加而减少,当摩尔比>2后,分配系数趋于稳定;柱撑膨润土羟基吸附位的活性是决定吸附性能的关键因素;吸附过程符合Langmu ir和Freund lich等温吸附模型,吸附容量的大小和吸附作用强弱的顺序为:羟基铁铝膨润土>羟基铁膨润土>天然膨润土。更多还原

【Abstract】 The adsorption of copper(Ⅱ) in the presence of EDTA by hydroxyl-Fe,hydroxyl-Fe-Al pillared bentonites,and natural bentonite was studied.The influences of pH,the mole ratio of EDTA and Cu2+(EDTA/Cu),adsorption time and isotherm in adsorption process were considered respectively.Results indicate that the balance of adsorption was achieved in 1 hour.The pH value has little effects on adsorption of the natural bentonite.The optimal range of pH value was 6~8 in adsorption process of the pillared bentonites.With the increase of EDTA/Cu ratio,the partition coefficient(kd) of copper complexes onto bentonites decreased.And in condition of EDTA/Cu ratio >2,value of kd fluctuated little.The adsorption isotherms were agreed with Langmuir or Freundlich mode and their constants were also determined.The activities of adsorption site played an important role in adsorption process.The sequence of the amount adsorbed and adsorption affinity is that: hydroxyl-Fe-Al pillared bentonite>hydroxyl-Fe pillared bentonite>natural bentonite.更多还原