铬在不同粒径土壤中的分布

Studies on the Cr(Ⅵ) Distribution in Different Soil Particle

采用对土壤不同粒径的分选,进而了解Cr6+在土壤中分布的特点。试验结果显示,对两种类型的土壤(水稻土和潮土),分选的5个粒级中,吸附Cr6+的浓度随着粘土、粉粒、沙粒的顺序而增加。粒径0.075～0.005 mm的土壤对Cr6+的吸附贡献率最大。活性氧化铁和活性氧化铝是影响Cr6+吸附的主要因素。活性氧化铁和活性氧化铝含量越高,对Cr6+吸附量越大。土壤中有机质含量与土壤吸附Cr6+的量呈负相关。采用逐步回归法分析表明两种类型的土壤Cr6+吸附量可以用多元线性回归模型表示,Cr6+吸附量与土壤有机质、活性氧化铁、活性氧化铝存在相关性。

This paper used separating different soil particle size method to study two type soil： aquatic soil and paddy soil which were separated five size fractions. Results were summarized as follows： Cr （Ⅵ） concentration in different soil particles was in this order： Clay 〈 Silt 〈Loam. Using adsorption contribution index, metals were found to be associated largely with the fine particle-size fraction （0.075mm-0.005mm）.Fe oxides and Al oxides are the two major factors affecting soil Cr （Ⅵ） adsorption. Based on the findings, using a stepwise regression method, a model was established to illuminate the relationship of Cr （Ⅵ） adsorption with organic matter content and CEC and Fe oxides and Al oxides.