凹凸棒负载Zn-Al-La类水滑石对磷的吸附

Adsorption of phosphorus with attapulgite coated by Zn-Al-La layered double hydroxides(LDHs)

采用共沉淀法合成凹凸棒(ATP)负载Zn-Al-La(LDHs)类水滑石纳米复合材料,通过扫描电镜(SEM)、傅里叶变换红外光谱(IR)、X-射线衍射(XRD)对复合材料的结构和形貌进行表征,发现层片状的水滑石覆盖在棒状的凹凸棒表面,凹凸棒成功负载水滑石形成ATP/Zn-Al-La复合材料.对影响复合材料吸附效果的主要因素(pH、吸附时间、温度、溶液浓度)及吸附过程的动力学进行研究.结果表明:磷酸根的吸附过程符合Langmuir等温吸附模型和准二级动力学模型,在40℃,溶液初始浓度为180mg/L,pH值为2,用时5h,最大吸附容量可达到60.24mg/g.

Nano-composites of attapulgite （ATP） covered with Zn-Al-La layered double hydroxides was synthesized by using coprecipitation method. The structure and morphology of the composite was characterized with scanning electron microscopy （SEM）, Fourier transform infrared （FTIR） spectroscopy, and X-ray diffraction spectroscopy. It was found that ATP was successfully coated by Zn-A1-La layered double hydroxides and formed the ATP/Zn-Al-La composite. The main factors of influence （pH, adsorption time, temperature, solution concentration, and dynamics of adsorption process） on the result of composite adsorption were investigated. The result show that the adsorption process of phosphate was consistent with the Langmuir isothermic model and quasisecond-lever dynamic model. The maximal adsorption capacity could amount to 60. 24 mg/g at 40℃ with initial concentration of 180 mg/L, pH=2 and,after 5 h.