改性硅藻土对重金属离子的吸附规律

Adsorption Law of Heavy Metals on Modified Diatomite

利用CaCO3对硅藻土矿物进行改性.研究结果表明:单组分体系中CaCO3改性的硅藻土对Cu2+,Pb2+,Cd2+和Zn2+的吸附动力学规律均符合伪二阶动力学模型,吸附热力学规律符合Langmuir模型;在混合组分体系中,Pb2+,Cd2+和Zn2+的吸附速率降低,Cu2+的吸附速率增加,对金属离子的吸附动力学规律仍然符合伪二阶动力学模型,但对金属离子的吸附量均明显降低,仅Pb2+的吸附热力学规律符合Langmuir模型.

Rich low-grade diatomite mineral was modified with calcium carbonate so as to improve the adsorption properties of diatomite for heavy metal ions. The results show that in a single component system, the dynamic laws for the adsorption of Cu2＋ , Pb2＋, Cd2＋ and Zn2＋ on the diatomite modified by calcium carbonate obey the pseudo-second-order model and the adsorption thermodynamics laws obey the Langmuir model. In a mixed component system, because of the effect of coexisting components, the adsorption rate of Pb2＋,Cd2＋ and Zn2＋ was decreased respectively and the adsorption rate of Cu2＋ was increased, but the adsorption dynamic laws of four kinds of metal ions still obey the pseudo-second-order model; at the same time, the adsorption capacities of four kinds of metal ions on the modified diatomite were decreased obviously and only the adsorption thermodynamics law of Pb2＋ obeys the Langmuir model.