研究了钙基膨润土和钠基膨润土对废水中铜离子的吸附特性.结果表明,钠基膨润土和钙基膨润土的吸附行为都依赖于溶液的pH值,初始离子浓度和吸附剂用量.在低pH值时主要是H+与Cu2+竞争吸附位.pH值在3到7时基本的吸附机制是离子交换的过程.在高pH值(＞8.3)时,在膨润土颗粒表面形成氢氧化铜的吸附或沉淀.随初始金属离子浓度的增加去除率降低,而吸附剂的单位吸附量迅速增加.Cu2+浓度为40mg/L时,钠基膨润土和钙基膨润土的去除率分别达98.4%和81.2%.钠基膨润土和钙基膨润土的最大吸附容量分别为26mg/g和12mg/g.%The effects of removal rate and adsorption capacity on different adsorption conditions were investigated. The results show that the adsorptions of both Na - bentonite and Ca - bentonite strongly depend on the pH, initial concentration and adsorbent amount. At lower pH values, the mechanisms that govern the adsorption behavior of bentonites are competition of the metal ions with the H+ . The basic mechanism is an ion exchange process while the pH values range from 3 to 7. At higher pH values ( more than 8.3), formation of copper hydroxyl species may result either participation to the adsorption or precipitation onto the bentonites. Increasing initial metal ion concentration led to the decrease of removal rate and increase of unit adsorption of adsorbent. While Cu2+ initial concentration is 40mg/L, Na - bentonite has the removal rate of 98.4％ for Cu2+ and Ca- bentonite has the removal rate of 81.2％, respectively. The maximum adsorption capacity of Na- bentonite for Cu2+ is 26 mg/g and Ca- bentonite is 12 mg/g.
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