酸改性膨润土吸附去除镍镉离子的研究

在静态条件下,研究了改性膨润土对重金属离子的吸附性能和吸附机理,着重探讨了改性膨润土去除模拟水样中重金属离子Ni2 ,Cd2 的适宜条件及改性膨润土的再生方法.结果表明,改性膨润土对Ni2 ,Cd2 具有较好的吸附性能;pH值是影响改性膨润土对重金属离子吸附的重要因素,不同的金属离子都有其适宜的pH值范围.吸附的最佳条件是pH值5.0～7.0,废水中Ni2 ,Cd2 含量不大于45 mg/L,搅拌时间约60 min.利用改性膨润土吸附处理Ni2 ,Cd2 含量小于45 mg/L的模拟水样,效果很好,Ni2 ,Cd2 的去除率均可分别达到98.5%以上,出水可达到国家排放标准.

Adsorption of Ni2 + and Cd2+ Ions by Acid-Modified Bentonite

The adsorption capability and mechanism of acid-modified bentonite to heavy metal ions was studied under static state condition, with the proper conditions for the removal of the heavy metal ions such as Ni 2+ and Cd 2+ in a simulated water sample and the methods for the recycle of the acid-modified bentonite to be focused on. The results showed that the acid-modified bentonite had good adsorbing capacity for Ni 2+ and Cd 2+ ions. The adsorbing capacity of the acid-modified bentonite was largely dependent on the pH value of the water sample, while the suitable pH value ranges varied with the types of the metallic ions to be adsorbed. The optimal conditions for the removal of the titled metallic ions were suggested as pH value of 5.0 to 7.0, concentration of Ni 2+ and Cd 2+ in wastewater below 45 mg/L, and mixing time about 60 min. The Ni 2+ and Cd 2+ ions in the wastewater, with a content below 45 mg/L, were removed at a rate above 98.5%, showing good adsorption-removal efficiency, and the discharged water was qualified in terms of the corresponding national discharge standard.