Adsorption research of Zn-Al hydrotalcite and calcined product to methyl orange waste water

Zn-Al hydrotalcite compound was prepared by coprecipitation. Both hydrotalcite and calcined product was characterized by Fourier transform infrared spectra(FT-IR)and X-ray diffraction (XRD). The adsorption experiment of methyl orange solution was conducted for hydrotalcite compound and calcined product, in which the adsorption capacity was tested. The effects of ion ratio, equilibrium time and temperature on the adsorption capacity to methyl orange were studied. The results indicated that the crystallinity of hydrotalcite compound was good and the CO₃^2- layer of calcined product had partly been destroyed. The calcined Zn-Al hydrotalcite showed more effective adsorption capacity for methyl orange than Zn-Al hydrotalcite. Under the optimum conditions of calcined temperature of 500 ℃, pH value of 5, adsorption time and temperature of 120 min, 30 ℃, respectively, concentration of the calcined product of 0.5 g/L and ratio of Zn-Al of 2:1, calcined product was more effective than hydrotalcite to remove methyl orange, and the removal rate of methyl orange could reach 92.3%.