摘要
将提纯的镁型蛭石与羟基铁离子溶液作用,制备低聚合羟基铁-蛭石复合体.用化学分析、电子探针分析、粉晶X射线衍射分析、差热分析等手段对蛭石原样、低聚合羟基铁-蛭石复合体进行表征.在模拟实际土壤酸度(pH=4～7)和温度(20 ℃～40 ℃)条件下,进行低聚合羟基铁-蛭石复合体吸附有害元素铬的实验,探讨复合体的铬吸附能力与pH值、温度、吸附时间、铬初始质量浓度、离子强度间的关系,并与蛭石的铬吸附行为进行对比.研究表明,在实验条件下,低聚合羟基铁-蛭石复合体对铬具有明显的亲和力,低聚合羟基铁-蛭石复合体吸附铬的过程有可能是地表岩石和土壤中重要的地球化学过程,是影响铬在地表,特别是土壤中迁移、富集的重要因素.
Chromate has high affinity to soluble hydroxy-Fe species and Fe-oxyhydroxide precipitates,and vermiculite has remarkable effect on the hydrolysis of Fe（ Ⅲ ） and the growth of the initially precipitated Fe（ Ⅲ ） phases. The adsorption of Cr on Fe oxyhydroxide-vermiculite complex is studied in this paper. Fe oxyhydroxide-vermiculite complexes are prepared by mixing vermiculite with hydroxy-Fe for 1,3 and 6 months,respectively. The prepared complexes are studied by chemical analysis ,electron microprobe analysis ,X-ray diffraction analysis and differential thermal analysis. The results indicate that the complexes prepared are combinations of substrate vermiculite and Fe-oxyhydroxide coating. The amount of Fe-oxyhydroxide coating increases with in- creasing of reaction duration between vermiculite and hydroxy-Fe. The Fe oxyhydroxide-vermiculite complex prepared by reacting vermiculite with hydroxy-Fe for 3 months is chosen for Cr adsorption study. The effects of pH ,ionic strength ,temperature ,initial Cr concentration ,and adsorption duration on the overall adsorption of Cr by Fe oxyhydroxide-vermiculite complex are investigated. Under all experimental conditions, Fe oxyhydroxide-vermiculite complex displays very strong affinity to Chromate ,which is supposed to influence the mobility of Cr in soil and water.
出处
《矿物岩石》
CAS
CSCD
北大核心
2005年第3期131-136,共6页
Mineralogy and Petrology
关键词
低聚合羟基铁-蛭石复合体
铬
吸附
土壤
Fe oxyhydroxide-vermiculite complex
chromate
adsorption
soil
