Zr-Fe双组分复合除砷吸附剂的优化制备及性能评价

实验发现,铁氧化物或铁的羟基氧化物对As(V)有较好的吸附性能,而锆氧化物或锆水合氧化物则对As(Ⅲ)有优异的吸附选择性,但其使用的pH通常要在9的条件下。通过简单的共沉淀法制备了Zr-Fe双组分复合吸附剂,在制备过程中通过优化制备条件如:沉淀剂浓度、金属离子总浓度、金属离子配比、反应温度、反应时间及吸附剂价格等因素,最终合成出了对As(V)和As(Ⅲ)都具有良好吸附能力的吸附剂。这种吸附剂在中性条件下对As(V)和As(Ⅲ)的最大吸附量为62 mg/g和118 mg/g。

Optimum preparation of Zr-Fe binary oxide adsorbent and its performance evaluation for removal of arsenic from water

Fe oxides or hydrous oxides are widely used as an adsorbent to remove As(V) due to its low cost and adsorption capability. Zr oxides or hydrous oxides have adsorption selectivity on As(III) at pH higher than 9. A method for preparing Zr-Fe binary oxide adsorbents by urea method for arsenic removal was studied. The effect of urea/metal molar ratio, metal concentration, Zr: Fe molar ratio, reaction temperature and aging time were evaluated in the study. The best preparation conditions were found to be : metal: urea molar ratio is 1 : 8,metal concentration is 0. 2 mol/L, Zr: Fe molar ratio is 4: 6, reaction temperature is 373 K and aging time is 4 h. The maximum adsorption capacities for As(III) and As(V) were 62 mg/g and 118 mg/g respectively at pH = 7 by the Zr-Fe binary oxide adsorbent.