焙烧态镁铝水滑石对诺氟沙星的吸附行为研究

Preparation of Calcined Mg-Al Hydrotalcite and Adsorption of Norfloxacin

采用共沉淀法合成镁铝水滑石(LDH),用X-射线衍射(XRD)、扫描电镜(SEM)等表征了产物,研究了400℃焙烧后LDH(LDO)的结构、成分及吸附率的变化,通过静态吸附实验考察了LDO对诺氟沙星的吸附性能。结果表明,在固液比1∶500、pH=5.0、吸附温度25℃、离子强度0.1 mol/L的条件下吸附1 h对诺氟沙星(20 mg/L)的吸附率达91.25%。吸附过程符合Langmuir等温线方程,理论平衡吸附量达到32.05 mg/g,推断焙烧态镁铝水滑石对诺氟沙星的吸附是以表面吸附为主的自发反应。

Mg-Alhydrotalcite（LDH） was synthesized by coprecipitation method and calcined at 400℃, then it became LDO. The changes in the structure, composition and rate of absorption after roasting were discussed by the X-ray diffraction（XRD）, scanning electron microscopy（SEM）. Static adsorption experiments were carried out to study adsorption of norfloxacin on LDO, and results showed that the adsorption rate of norfloxacin（20 mg/L） was 91.25% in solid-liquid ratio 1∶500, pH=4.0, adsorption temperature was 25 degrees centigrade, the ionic strength of KNO3 0.1 mol/L. Thermodynamic and kinetic experiments showed that the adsorption process corresponded with Langmuir isotherm equation and quasi two level dynamics equation under the optimized condition. Equilibrium adsorption amount of 32.05 mg/g, it was close to the actual saturation adsorption capacity of 28.62 mg/g, and it was concluded that the adsorption is a spontaneous reaction by surface adsorption.