黑土对Cu2＋的吸附作用及其影响因素

Adsorption of Cu^(2+) onto Black Soil and its Influencing Factors

采用批量平衡法研究了东北地区典型黑土对重金属Cu^(2+)的吸附热力学特征,以及离子强度、温度和DOM对黑土吸附Cu^(2+)的影响.结果表明:Freundlich模型能够较好地描述一般条件及其不同影响因素下黑土对Cu^(2+)的热力学吸附过程(R>0.985,P<0.01).离子强度的增加抑制了Cu^(2+)在黑土上的吸附,不同离子强度作用下黑土对Cu^(2+)的吸附能力顺序为:0.001 mol/L>0.01 mol/L>0.1 mol/L.温度的增加促进了Cu^(2+)在黑土上的吸附,不同温度作用下黑土对Cu^(2+)的吸附能力顺序为:35℃>25℃>15℃.浓度范围在0~400 mg/L的DOM能够抑制黑土对Cu^(2+)的吸附,且抑制作用随着DOM浓度的增加而增大.Cu^(2+)在黑土上的吸附量随着p H值的增加而增加,DOM的抑制作用随着p H值的增加而增大.

The batch equilibrium method was employed to study the thermodynamic characteristics of heavy metal Cu2＋ , and the effects of the ionic strength, temperatures and the dissolved organic matter （DOM） on the thermodynamic adsorption of Cu2＋ onto the black soil in Northeast, China. The results showed that the thermodynamic process of Cu2＋ adsorption under the general condition and some influencing factors onto black soil can be well described by Freundlich equation（R 〉 0. 985,P 〈 0. 01 ）. The adsorption of Cu2＋ was inhibited by the increase of ionic strength, and Cu2 ＋ adsorption onto black soil in the presence of different ionic strength followed this order of 0.00 1 mol/L 〉 0. 01 mol/L 〉0. 1 mol/L. But the adsorption of Cu2＋ was enhanced by the increase of temperature, and Cu2＋ adsorption onto black soil under different temperatures followed the order of 35 ℃ 〉 25 ℃〉 15 ℃. And the adsorption of Cu2＋ was inhibited by 0 -400 mg/L of DOM, and its inhibition increased with the increase of DOM concentration. Moreover, the adsorption of Cu2＋increased with the inhibition increased with pH increasing. pH increasing, but it was inhibited by DOM, andthe inhibition increased with pH increasing.