氟污染对土壤胶体稳定性影响的研究

 通过对土壤黏粒悬浮液中加入氟,研究了氟污染对1种水稻土和2种红壤胶体稳定性的影响.结果表明,氟污染使土壤黏粒的稳定性增强,土壤胶体的临界聚沉浓度增大;土壤中增加氟,对土壤胶体临界聚沉浓度增大的影响程度因土壤类型不同而不同,表现为红壤大于水稻土;氟污染使土壤胶体的临界聚沉浓度增大的机理是土壤胶体对氟的配位吸附放出羟基而使溶液的pH值升高,增大了胶体负电荷间的静电排斥力,土壤胶体趋向稳定.表明氟污染不利于土粒聚沉,且使其他污染物质易从土壤进入水体,进而污染水源.

Studies on the effect of fluorine pollution on the stability of soil colloid

The effect of fluorine pollution on the stability of one paddy soil and two red soils by adding fluorine into the soil colloid was studied. The results indicated that fluorine pollution strengthened the stability of soil colloid and increased the critical flocculation concentration. The effect extent of increasing the critical flocculation concentration is different among various soils, expressing that the effect on red soils is more remarkable than that on the paddy soil. The mechanism of fluorine pollution increasing the critical flocculation concentration of soil colloid is that fluorine adsorption on the soil colloid releases hydroxyls, so that the pH value of the solution is raised; the electrostatic repulsion forces among the negative electric charge of the colloid are increased and the colloid tends to be stable. The study indicated that fluorine pollution is not favarable to the flocculation of soil colloid; and makes other pollutants come easily into water from soils and pollute the water source.