天然铝土矿物除氟剂吸附性能研究

文章研究以天然铝土矿物为原料制备的除氟剂的吸附性能及其影响因素,静态吸附实验以及对吸附动力学、热力学的理论分析表明:除氟剂的吸附容量在pH值低于6.0时保持稳定,而高于6.0时随pH值升高而降低,故其最优pH值应为6.0左右;在初始F-质量浓度介于5 ～100 mg/L之间的研究范围内,吸附容量随F-初始浓度呈线性增长;随除氟剂投加量的增大,被吸附的F-量增加,但单位吸附剂的吸附量减少;在反应的前30 min 吸附速度比较快,随着时间的延长,吸附速度放慢,故吸附时间应控制在15～30 min之间较为适宜;铝土矿除氟剂对氟离子的吸附作用符合拟二级反应方程,吸附等温线符合Freundlich等温吸附模型.

Research on characteristics of fluoride adsorbent prepared from natural bauxite

The adsorption characteristics and influencing parameters of the fluoride adsorbent prepared from natural bauxite were investigated. Results show that the adsorption capacity kept constant at pH below 6.0 and increased at pH above 6.0. Therefore, the optimum pH range for adsorbent preparation was around 6.0. In the optimum condition of pH, the adsorption capacity was proved to be linear to the initial F- concentration ranging between 5 mg/L and 100 mg/L. With the increase of adsorbent addition, the F- adsorbed increased, while the adsorption capacity decreased. Within the initial 30 min, the rate of adsorption was high and reduced in the following reaction. Therefore, the adsorption time should be kept in 15～30 min. The adsorption process was found to follow pseudo-second-order rate kinetics as well as the Freundlich isotherm.