摘要
采用改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pH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;溶液中富里酸浓度升高,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0.1 mol.L-1加大至0.5 mol.L-1,吸附量逐步降低。
In soil, FA （fulvic acid） can control the lead ions＇ biologic validity, which can be influenced by several soil conditions such as FA concentration, pH, temperature and ion strength in FA - lead solution. In this study the modified potentiomet- rictitration was used. We changed the pH, the concentration of FA, the temperature and the ion strength in FA - lead solution and found that this four matters above can all affect the interaction of FA with lead 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 2.5 to 10.0, which could be simulated by the natural logistic equation. The higer concentration 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 solution, we got results as follows ： higher concentration of fulvic acid decreased the amount of cadmium irons 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 solution higher temprature and lower ion strength made the amount of lead ions absorbed by per gram of fulvic acid grow.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2010年第B03期127-131,共5页
Journal of Agro-Environment Science
基金
西南大学青年基金项目(SWNUQ2004009)
关键词
富里酸
铅
电位滴定
吸附
fulvic acid
lead
potentiometrictitration
adsorption
