赤泥负载镧新型吸附剂的制备及其除氟性能

Study on preparation of new type adsorbent of lanthanum-loaded red mud and its property on fluoride removal

以盐酸活化的赤泥为载体,氧化镧为活性组分,制备了赤泥负载镧的新型吸附剂.探讨了新型吸附剂制备最佳的条件对除氟效果的影响.结果表明在盐酸浓度为6 mol/L,赤泥负载镧的反应时间为20 h,镧离子浓度为0.25 g/L,焙烧温度为500℃的条件下制备的吸附剂对氟离子具有较强的吸附能力;当吸附时间为60 min,pH值为6.0,氟的初始浓度为40 mg/L,氟与吸附剂的质量比为l:100时,氟去除率可达98%以上.在25℃下,吸附除氟过程符合Langmuir吸附等温式,线性方程为:c_e/q_e=0.015 9c_e+0.049 5,线性相关系数为:R^2=0.992 5,其饱和吸附量为62.89 mg/g.单分子层吸附氟是吸附的主要形式.

A new type of adsorbent of lanthanum - loaded red mud is prepared with activated red mud by hydrochloric acid as a carrier, and lanthanum oxide as an active component. The effects of optimum preparation conditions of the new type adsorbent on fluoride removal efficiency are discussed. The results show that the prepared adsorbent against fluoride ion has very good adsorption efficiency under the condition of hydrochloric acid concentration 6 mol/L, reaction time of lanthanum - loaded red mud 20 h, lanthanum ion concentration 0.25 g/L and calcination temperature 500℃ ; the fluoride removing efficiency is above 98% at an adsorption time of 60 min, from the wastewater with a pH value of 6.0, initial fluoride concentration of 40 mg/L in the waste water, and the dosage ratio of fluoride to the adsorbent of 1 ： 100. The adsorption fluoride removal process of the adsorbent fitted Langmuir isotherm equation, its linear equation is ceqe = 0. 015 9ce ＋ 0. 049 5, its adsorption capacity of fluoride is 62.89 mg/g at 25 ℃, linear correlation coefficient is R^2 = 0. 992 5. The maximum and the main type of adsorbing fluoride is monolayer adsorption.