高铁酸钾辅助土壤吸附Cu2+的性能及影响因素

研究了汾河边砂壤土(A土)和细砂土(B土)在不同影响因素下对Cu2+的吸附特性,对比2种原土和加入高铁酸钾后对水相中Cu2+的吸附动力学和热力学参数。结果表明,B土有机质含量比A土高,其对Cu2+的吸附量大于A土。高铁酸钾的加入对土壤吸附Cu2+有显著效果,最佳吸附条件为A土和B土加入K2FeO4的Fe/Cu质量比分别为20:1和5:1,pH=8~10,T=35 ℃,此时A土、B土、加入K2FeO4的A土、加入K2FeO4的B土的最大吸附量分别为0.36、0.41、0.41和0.46 mg/g。A土和B土对Cu2+的吸附过程满足Freundlich方程,吸附能力大小为:加入K2FeO4的B土 >加入K2FeO4的A土 >B土 >A土。吸附热力学表明,该吸附是自发吸热过程,吸附动力学满足准二级动力学模型,表明土壤A和B对Cu2+吸附是以多层吸附为主,同时存在物理和化学吸附过程。

Properties and influencing factors of soil adsorption of Cu2+ with potassium ferrate assisted

In the loam (A) and fine sand soil (B) on the shore of the Fenhe River,Cu2+adsorption properties and factors that influence absorption were studied.We compared the adsorption kinetics and thermodynamic parameters of Cu2+ in aqueous solution in the two kinds of original soil,as well as in these soils following the addition of potassium ferrate.The results indicated that the organic matter content in B soil was higher than that in A soil.Thus,the adsorption capacity of Cu2+ B soil was greater than that of A soil.The addition of potassium ferrate had a significant effect on the soil adsorption of Cu2+.The best conditions occurred when the Fe/Cu mass ratios of soil A and soil B were 20:1 and 5:1,respectively (pH form 8 to 10,T=35 ℃).The maximum adsorption of soil A,soil B,soil A (+ K2FeO4),and soil B (+ K2FeO4) were 0.36,0.41,0.41 and 0.46 mg/g,respectively.The process of Cu2+ adsorption by soil A and soil B satisfied the Freundlich equation;the size order of the adsorption capacity was:soil B (+ K2FeO4)>soil A (+ K2FeO4)>soil B>soil A.Adsorption thermodynamics indicated that adsorption was a spontaneous and endothermic process,and adsorption kinetics could be best described by a pseudo second-order kinetic model,indicating that the adsorption of Cu2+ by soil A and soil B was dominated by multilayer adsorption,and the physical and chemical adsorption processes existed simultaneously.