不同形态氧化铁对黄土性土壤吸附铅的影响

发布时间：2018-04-03 20:33

  本文选题：黄土性土壤　切入点：铁氧化物　出处：《干旱地区农业研究》2017年01期

【摘要】：针对土壤含氧化铁的普遍性以及氧化铁对土壤理化性质的重要影响,探求氧化铁对土壤吸附重金属离子的作用与影响。采用了化学选择性溶提技术,分别去除黄土性母质上发育的古土壤、淋溶褐土和黄褐土中不同形态的氧化铁,采用了等温吸附试验,并以Langmuir和Freundlich方程拟合参数为指标,分析去除不同形态氧化铁前后土壤对Pb~(2+)的吸附特征。结果表明:原土壤对Pb~(2+)的吸附曲线逐渐递增,并无明显阶段特征,且更符合Freundlich方程;而去除不同形态氧化铁后的3类土壤对Pb~(2+)的吸附曲线均为L型,阶段特征显著,更加符合Langmuir方程,且土壤对Pb~(2+)的亲和力(KL)成倍增加;去除络合态铁和无定形氧化铁后,土壤对Pb~(2+)的最大吸附量均有不同程度增加,其中去除无定形氧化铁之后,古土壤对Pb~(2+)的最大吸附量增幅最大,增加了14.71 mg·g-1;去除游离态氧化铁后古土壤、淋溶褐土对Pb~(2+)的吸附量分别下降了5.95、3.10 mg·g-1,黄褐土对Pb~(2+)的吸附量则增加了2.98 mg·g-1。土壤中氧化铁对Pb~(2+)吸附能力与吸附容量的影响不完全依赖于氧化铁的含量,在很大程度上依赖于土壤中氧化铁的形态。对于不同氧化铁形态的土壤采用相应的化学溶提技术,能够获得具有较高吸附性能的粘土矿物环境材料。
[Abstract]:In view of the universality of ferric oxide in soil and the important influence of iron oxide on the physical and chemical properties of soil, the effect of iron oxide on the adsorption of heavy metal ions on soil was explored.Chemical selective extraction technique was used to remove iron oxide from loess parent material, leaching cinnamon soil and yellow cinnamon soil respectively. The isothermal adsorption test was used, and the fitting parameters of Langmuir and Freundlich equations were taken as indexes.The adsorption characteristics of Pb~(2 on soil before and after removal of different forms of iron oxide were analyzed.The results showed that the adsorption curve of Pb~(2 increased gradually, and had no obvious phase characteristics, and was more in line with the Freundlich equation, but the adsorption curves of Pb~(2 for the three kinds of soils with different forms of iron oxide were all L-type, and the phase characteristics were significant.鍙ゅ湡澹ゅ�筆b~(2 )鐨勬渶澶у惛闄勯噺澧炲箙鏈，

本文编号：1706799