Zn/Cr水滑石吸附-可见光催化水中有机污染物  

Adsorption-visible light photocatalytic degradation of organic pollutants by Zn/Cr layered double hydroxides

作　　者：顾剑杰[1] 王炎锋[1] 蒋茹[1] 朱华跃[1] 

机构地区：[1]台州学院环境工程系,浙江椒江318000

出　　处：《工业用水与废水》2014年第2期9-13,22,共6页Industrial Water & Wastewater

基　　金：国家自然科学基金青年项目(21007044)

摘　　要：通过共沉淀法合成可循环使用的阴离子粘土材料锌铬水滑石(Zn/Cr LDHs),并借助X射线衍射(XRD),N2吸附-脱附曲线,扫描电子显微镜(SEM)和紫外-可见光漫反射光谱(DRS)等对其进行表征分析。以刚果红为模型污染物,研究了Zn/Cr LDHs去除有机污染物的吸附-可见光光催化活性。通过等温吸附试验,得到Langmuir等温线,其饱和吸附量为426.29 mg/g。Zn/Cr LDHs在氙灯模拟太阳光照射下,每次试验180 min,第5次后脱色率仍高达96.35%,具有良好的可循环使用性。刚果红吸附等温线符合Langmuir模型,吸附过程符合拟二级动力学模型,内扩散为主要控速步骤,吸附过程是自发的放热过程,低温有利于吸附的进行。Reusable ZrdCr layered double hydroxides （ZN/Cr LDHs） were synthesized by a coprecipitation method and characterized by powder X-ray diffraction（XRD）, N2 adsorption-desorption isotherms, scanning elec- tronic microscopy（SEM） and UV-vis diffuse reflectance spectra （DRS）. The adsorption- visible light photo- catalytic activity of ZN/Cr LDHs towards organic pollutants was studied with congo red（CR） as the goal pollu- tant. The results of isothermal adsorption test showed that, the adsorption of CR by ZN/Cr LDHs followed the langmuir isotherm model, and the saturated adsorption capacity was approximately 426.29 mg/L With the ZN/Cr LDHs that had been used for 5 times, the decolorization rate of wastewater was still about 96.35% after a 180- rain irradiation under xenon lamp used as simulated solar light, which indicated that ZN/Cr LDHs had excellent reusability. The adsorption isotherm of CR followed Langmuir model, the adsorption process fitted pseudo-sec- ond-order kinetic equation, and the intraparticle diffusion was the rate-controlling step. Lower temperature was favorable to adsorption due to the spontaneous and exothermic nature of adsomtion process.

关 键 词：水滑石 吸附 可见光催化 有机染料废水 脱色 

分 类 号：X703.1[环境科学与工程—环境工程]