镁铝双氢氧化物用于染料废水脱色的研究

以氯化铝、氯化镁、氨水等为原料,合成了镁铝双氢氧化物正电溶胶(MADH).以水溶性染料模拟废水为研究对象,检验了MADH对染料废水的脱色效果,并对其脱色机理进行了探讨. 结果表明,MADH对活性染料、酸性染料和直接染料等阴离子型染料具有明显的脱色效果.在足量MADH存在的条件下,废水脱色率可达99%以上,最佳pH为6～9,最佳反应时间为10 min.温度升高不利于吸附过程的进行,其饱和吸附容量为327～2 113 mg/g.MADH用于实际印染工业废水处理,脱色率和CODCr去除率同样较高.脱色机理为MADH对染料的化学吸附作用.MADH对阳离子型染料的去除效果较差. 

Study on Decolorization of the Wastewater Containing Dyestuffs by Aluminum Magnesium Double Hydroxide

The sol charged positive of magnesium aluminum double hydroxide （MADH） was prepared by using AlCl₃·6H₂O, MgCl₃·6H₂O and NH₃·H₂O as raw materials. The behavior of MADH in decolorization process was studied using simulated wastewater containing different kinds of soluble dyestuffs, and the mechanism of decolorization was discussed. The results showed that the efficiency of decolorization was obviously high for the anionic dyestuff, such as reactive, acidic or direct dye, at the optimum pH range 6～9 and the optimum reactive time 10 min. The decolorization rate reached above 99% if enough dose of MADH was added. The maximum absorbable quantity, i.e. absorbed anionic dyestuff per unit MADH, was 327～2 113 mg/g. Higher temperature was unfavorable for absorption process. In practical treatment of textile effluent by MADH, the decolorization and COD Cr removal were also effective. The mechanism of decolorization was chemical absorption of MADH on dyestuff. Also, the decolorization effect for cationic dyestuffs was not desirable.