摘要
本文采用流动法研究了竞争性Zn^(2+),Ca^(2+),Mg^(2+),Na^+离子对红壤中镉吸持动力学特性的影响.实验结果表明:与Cd^(2+)离子等浓度的竞争性Zn^(2+),Ca^(2+),Mg^(2+)离子的存在,使红壤中镉的吸持量降低,解吸量增加,影响的顺序为:Zn^(2+)≥Ca^(2+)>Mg^(2+)。大量竞争性Na^2+离子的存在,使红壤中镉的吸持量大大降低,解吸量亦降低.用一级反应动力学方程拟合实验数据,结果表明:竞争性Zn^(2+),Na^2+离子对红壤中镉吸持动力学特性影响明显;红壤中镉的吸持为多种化学吸持(高能)与物理吸附(低能)共存,高能吸持的主要贡献来自红壤中游离氧化铁组分对镉的专性化学吸持.
The kinetics of Cd competitive Sorption in red earth were investigated using a constant flow leaching method. The experimental results showed that competitive cations (Zn2+, Ca2+, Mg2 + ) with same concentration ( 6ppm) as that of Cd2+ ion, cause the Sorbed Cd in the Soil decrease and deSorbed Cd increase. The effect of the cations were in the following order. Zn2 + >>Ca2 + >Mg2 + . The Sorbed in the Soil and the deSorbed Cd will be greatly decreased in the presence of competitive Na+ ion (0.05N). First-order equation was used to fit the experimental data. It was shown that the characteristics of the kinetics of Cd Sorption in the Soil were ev'dently affected by competitive Zn2+,Na+, ions, and Cd Sorption in the siol may be coexisted with various chemi-Sorption (high energy) and phySico-Sorption (low energy ). The Specific sorption of Cd by free iron oxide plays a major role in the Cd Sorption of high energy in the Soil.
出处
《环境化学》
CAS
CSCD
北大核心
1990年第2期1-5,共5页
Environmental Chemistry
