Zn-Al水滑石及焙烧产物对甲基橙废水的吸附研究

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

关键词:  Zn-Al水滑石  焙烧  甲基橙  吸附 

Key words:  Zn-Al hydrotalcite  calcinations  methyl orange  adsorption

摘要:

采用共沉淀法合成的Zn-Al水滑石,借助FT-IR和XRD方法对水滑石及其焙烧产物进行表征,以水滑石前体及其焙烧产物进行甲基橙吸附实验,测试其吸附性能,探讨了金属离子比例、吸附平衡时间、温度等对甲基橙吸附性能的影响。实验结果表明:合成的水滑石结晶度好,焙烧后CO2-₃层被部分破坏,焙烧态水滑石吸附效果明显高于焙烧前。在焙烧温度为500 ℃、pH值为5、吸附时间为120 min、吸附温度为30 ℃、投加量为0.5 g/L、Zn-Al比为2∶1时的水滑石焙烧产物对甲基橙的去除效果最好,甲基橙最大去除率可达92.3％。 

Abstract:

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 CO2-₃ 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%.