坡缕石酸活化废液石灰中和法制备LDH的吸附性能研究

A STUDY ON ADSORPTION PROPERTIES OF SYNTHETIC Mg/Al LDH EMPLOYING WASTEWATER OF PALYGORSKITE CLAY ACTIVATION AND LIME NEUTRALIZATION

利用坡缕石粘土酸活化废液制备层状双氢氧化物(LDH)可以有效地解决活性白土生产过程产生的废酸液污染。研究了石灰中和坡缕石粘土酸活化废液合成LDH方法,以及制备的LDH材料对CrO42-和PO43-的吸附作用。结果表明:利用坡缕石粘土酸活化废液合成的LDH对PO43-的吸附能力比对CrO42-吸附能力强,对CrO42-、PO43-吸附性能接近于国外商品级LDH的性能,CrO42-、PO43-的吸附等温线符合Freundlich方程,LDH焙烧后对CrO42-、PO43-吸附能力比焙烧前有很大程度提高。

Activated fuller＇ s earth, which is acid-treated bentonite or palygorskite clay, is an important material for decolofization in oil and other chemical industries. Palygorskite clay is the major raw material for the production of fuller＇s earth. A great deal of acidic wastewater that resulted from acid activation of palygorskite clay would severely pollute the environment. On the basis of previous studies of the synthesis and characterization, the properties of adsorbing CrO^2-4 and PO^3-4 of synthetic layer double hydroxide （LDH） employing the acidic wastewater calcined before or after were researched inthis paper. The results indicated that the capabilities of adsorbing CrO^2-4 and PO^3-4 by the synthetic LDH are greater thanthose before calcinations; the capabilities of adsorbing PO^3-4 are greater than those of adsorbing CrO^3-4; the capabilities ofadsorbing CrO^3-4 and PO^3-4 are close to those of merchandise LDH from America. Isothermal curves of adsorption for CrO^2-4 and pO^3-4 on the LDH are in accord with the Freundlich Equation. Parameters of Freundlich Equation adsorption for CrO^2-4 are 1/n 0.53 and 0.28, lgK 0.36 and 1.07 before and after calcination, respectively, and 1/n 0.54 and 0.92, lgK 1.21 and 1.61 for PO^4- before and after calcination, respectively.