摘要
采用间歇法(batch method)模拟研究高岭石在柠檬酸、草酸和苹果酸溶液中的长期溶解效应。研究表明:柠檬酸、草酸和苹果酸三种低分子量有机酸能显著促进高岭石的溶解,它们对高岭石的溶解能力都是随其浓度的升高而增强,其溶解能力的顺序为:草酸>柠檬酸>苹果酸;苹果酸导致了高岭石Si的优先释放,而柠檬酸和草酸则导致了Al的优先释放。对于柠檬酸而言,高岭石一般在反应中期趋于同步溶解,且其同步性随其浓度的升高而增强。对于草酸而言,高岭石通常是在反应后期才趋于同步溶解;而对于苹果酸而言,1 mmol L-1时,在整个实验期间,高岭石都是非同步溶解;5 mmol L-1和10mmol L-1时,高岭石是以Al/Si小于1的一定速率比溶解;20 mmol L-1时,高岭石是在反应96 h后才表现为趋于同步溶解。
This study was con ducted to investigate a long-time dissolution effect of citric,oxalic and malic acids solution on kaolinite dissolution usiug the hatch method. The results showed citric oxalic and malic acids enhanced Al and Si release from kaolinite significantly by comparing with the deionised water. The release of Al and Si from kaolinite was increased with the increasing of concentration of citric, oxalic and malic acids. The order of dissolution capability was oxalic acids 〉 citric acids 〉 malic acids; The preferential Si-release of kaolinite was induced by malic acids, while the preferential Al-release of kaolinite was induced by citric and oxalic acids. For the citric acids, dissolution synchronism of kaolinite was at the reaction metaphase, and dissolution synchronism of kaolinite increased with increasing of concentration of citric acids, but for oxalic acids, the dissolution synchronism of kaolinite was at the reaction anaphase. However, for the malic acids, the dissolution of kaolinite was not synchronism when the concentration of malic acids was lmmol L-1 in the whole experiment, while the dissolution of kaolinite was at a cetain speed ratio between Al and Si whose ratio was smaller than 1 in the concentration of 5mmol L-1 and 10 mmol L-1 of malic acids. However, the dissolution of kaolinite was synchronism after 96 hours of reaction in the concentration of 20 mmol L-1 of malic acids.
出处
《土壤通报》
CAS
CSCD
北大核心
2013年第3期635-640,共6页
Chinese Journal of Soil Science
基金
国家自然科学基金(40371067)
中国科学院知识创新工程项目(ISSASIP0208)资助
关键词
高岭石
柠檬酸
草酸
苹果酸
同步性
溶解速率
Kaolinite
Citric acid
Oxalic acids
Malic acids
Synchronism
Dissolution rate
