磷、铝与氟交互作用对茶园土壤中氟吸附特征的影响

Effects of Interaction of Phosphate-aluminum-fluoride on Adsorption Characteristics of Fluoride in Tea Garden Soil

通过实验室模拟研究磷、铝与氟的交互作用对茶园土壤氟吸附特征的影响.对照处理下,茶园土壤对氟约25 m in达吸附平衡;在实验浓度范围内,氟的吸附量随氟初始浓度的增加呈上升趋势.有磷酸根存在下,吸附平衡时间缩短,吸附量下降.在不同氟铝比条件下,吸附平衡时间延长,吸附量下降,且随铝比例的增加吸附量下降显著.在低浓度磷酸根和不同氟铝比共存条件下,氟的吸附量呈增大趋势,而高浓度磷酸根和不同氟铝比共存条件下,氟的吸附量有明显减少趋势.茶园土壤对氟的吸附热力学特征均可以用Freundlich方程和Temkin方程描述,部分处理可用Langmuir方程描述.

Effects of interaction of phosphate-aluminum-fluoride on the adsorption characteristics of fluoride in tea garden soil were studied via the imitated test. Adsorption equilibrium of fluoride in the tea garden soil was reached at nearly 25 min and the adsorption amount of fluoride in the soil increased tith the initial concentration of fluoride within test concentration under the control conditions. The equilibrium time was shortened and the adsorption amount decreased in the presence of phosphate. However, the equilibrium time was prolonged and the adsorption amount decreased at different ratios fo fluoride to aluminum. The effect of aluminum onthe adsorption amount of fluoride was more significant with increasing the proportiom of aluminum. Comparing with no phosphate, the adsorption amount of fluoride increased in the co-existence of aluminum and fluoride with different ratios at a low concentration of phosphate, and decreased in the co-existence of aluminum and fluoride with different ratios at a high concentration of phosphate. The two equations of Freundlich and Temkin can be used to describe the thermodynamics characteristics of the adsorption of the soil for fluoride in the tea garden soul whether phosphate and aluminum exist or not, however, the Langmuir equations can only be used to describe the adsorption characteristics of the adsorption of the soil for fluoride for a few cases.