【摘要】 将提纯的钙蒙脱石与羟基铁离子溶液作用,制备了低聚合羟基铁-蒙脱石复合体。在实际土壤的酸度(pH=4～8)和温度(t=34～50℃)条件下,进行了低聚合羟基铁-蒙脱石复合体吸附P和F的实验,探讨了复合体的P和F吸附能力与pH值、温度、吸附时间、P和F的初始浓度、离子强度间的关系,并与蒙脱石和含水氧化铁的P和F吸附行为进行了对比。研究表明,在实验条件下,低聚合羟基铁-蒙脱石复合体对磷具有明显的亲合力,对氟的亲合力较低,只略高于蒙脱石原样。低聚合羟基铁-蒙脱石复合体对P和F的吸附,特别是对磷的吸附行为对该元素在土壤中的迁移过程有重要影响,成果对土壤学和环境学研究有参考价值。更多还原

【Abstract】 Phosphate and fluoride are ubiquitous in the earths crust as a result of oxidative weathering and dissolution of P and/or F containing minerals, excess use of some fertilizers and from mine drainage, smelter wastes and other industrial wastes. The dissolved inorganic phosphate and fluoride are transported in surface or groundwater and their mobility depends on the mineralogy of the soil and on reactions at mineral surfaces. The adsorption and subsequent release of P and F on soil minerals and sediment particles can elevate the levels of P and F in soil and water and affect their quality. In this paper, the adsorption of phosphate and fluoride on hydroxy Fe montmorillonite complex is studied. The effects of pH, ionic strength, temperature, initial Fe, P and F concentrations and adsorption duration on the overall uptake of P and F by hydroxy Fe montmorillonite complex are investigated. The results show that under all experimental conditions, hydroxy Fe montmorillonite complex studied displays a very strong affinity for P but weak affinity for F. The authors attribute this to the differences in the form of these anions and the particular way they coordinated with mineral surface, although experiments indicate that both P and F are adsorbed through inner sphere complexation.更多还原