土壤富里酸对铅的吸附作用与影响因素的研究.pdf

农业环境科学学报2010,29(增刊):127-131
Journal of Agro-environment Science
土壤富里酸对铅的吸附作用与影响
因素的研究
瞿莹雪',魏世强2
(1.西南大学地理科学学院,重庆400715;2.西南大学资源与环境学院,重庆400715)
摘要:采用政进的连续电位滴定法,研究了土壤富里酸对重金属铅吸附量的主要影响因素。通过调节富里酸溶液的
pH值、富里酸浓度、温度和离子强度,得到吸附量的变化情况,结果表明:溶液p从10.0滴定至2.5,富里酸对铅的吸
附量降低,pH对吸附量的影响可用自然对数方程进行拟合,通过各处理中自然对数方程的比较得出,富里酸浓度越
小、金属离子浓度越大,方程的斜率越大,说明吸附量的大小同时与二者密切相关;溶液中寓里酸浓度升高,相应的吸
附量降低,但吸附率升高;温度升高,吸附量增加;离子强度在设定的范围内,从0.1mol?工加大至0.5mol?L',吸
附量逐步降低。
关键词:富里酸;铅;电位滴定;吸附
中图分类号:XS3文献标识码;A文章编号:1672-2043(2010)增?-0127-05
Influencing Factors and Lead Adsorption by Soil Fulvic Acid
ZHAI Ying-xue", WEI Shi-qiang
I. chool of Geoaphca Se uthwest Univei Chon 40071 hina cool of Resources and Enviror
ment, Southwest University, Chongging 400715, China)
Abstract In soil, F A(fulvic acid can control the lead ions biologic validity, which can be influenced by several soil cond
tions such as FA concentration, PH, temperature and ion strength in Fa-lead solution. In this study the modified potentiomet-
ricti at on was use e age he H he ocean of EA, the meaure and the on strength in Fa-lead solution
and found that this our matters above an all affect the interaction of EA with ead ions. By titrating the Fa-lead solution, the
conclusion could be drawn as follows: the amount of lead ions absorbed by per gram of fulvic acid grew with the increasing of
PH from 5 to 10.0, which could e simula ed by the natural log stic equation. The higer oncentration of FA and the lower
concentration of lead ions, the lower slope of the equation was, which proved that the amount of lead ions absorbed by per gram
of fulvic acid could be affecved by fulvic acid and lead ions concentration simultaneously. Through changing the concentration
of fulvic acid in the solu ion we got results as follows higher conentration of ulic acid decreased the amount of cadmium i-
rons absorbed by per gram fulvic acid and the percentage of lead ions absorbed by FA decreased with the declining of PH and
the concentration of fulvic acid in the luton hi er empar and lower on strength made the amount of lead ions absorbed
)y per gram of fulvic acid grow
Keywords fulvic acid: lead potentiometric ration adsorption
土壤铅污染是我国较为严重的土壤环境问题之
跟其他重金属相同,铅可以在动植物内蓄积,也是
备受关注的一种重金属。从20世纪70年代以来,土
收稿日期:2009-08-27
基金项目:西南大学青年基金项目( SWNUQ2000
壤铅污染的报道就层出不穷。由于铅可以通过食物
作者简介:探耄雪(197~ー)女?河北景县人,项士,讲师现从事环境科链进入人体,危害人体健康,如何对土壤铅污染进行
学、环境工程、生态学等领域的科学研究工作。
E-mai]:zhaiying@swu.edu.cn
防治一直是环境科学研究者的重要研究课题。
通讯作者:魏世强
土壤腐殖质是土壤的重要组分,人们对土壤腐殖
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