仿生态Zn/Ti/Fe复合金属氧化物对水中NO_3-N的吸附  

Adsorption of biomorphic Zn/Ti/Fe complex metal oxide for NO_3-N in water

作　　者：钱大鹏 程爱华[1] Qian Dapeng;Cheng Aihua(School of Geology and Environment,Xi'an University of Science and Technology,Xi'an 710054)

机构地区：[1]西安科技大学地质与环境学院,西安710054

出　　处：《化工新型材料》2019年第5期208-212,共5页New Chemical Materials

基　　金：国家自然科学基金(51278418)

摘　　要：以棉花为模板,类水滑石为前驱体,制备仿生态Zn/Ti/Fe复合金属氧化物(LDO)并用于水中NO_3-N的去除;考察了吸附时间、投加量、pH和初始浓度等因素对NO_3-N去除效果的影响,分析了吸附行为和机理。利用扫描电镜对样品的形貌进行表征分析。结果表明:棉花模板自身的纤维形态遗留到了LDO上。在25℃下,反应时间为120min,LDO投加量为0.67g/L,NO_3-N浓度50mg/L,pH=7,LDO达到吸附平衡,平衡吸附量为66.57mg/g,NO_3-N去除率为88.76%,出水浓度符合我国《生活饮用水卫生标准》(GB 5749—2006)。LDO对NO_3-N的吸附有较宽的pH范围。LDO吸附NO_3-N的过程符合准二级动力学模型,属于化学吸附。吸附等温线符合Langmuir吸附等温方程,表现为单分子层吸附。再生实验结果表明:LDO在紫外光照射下,再生性能好,可重复使用3次以上。Using cotton as the template and hydrotalcite as precursor,biomimetic Zn/Ti/Fe complex metal oxide(LDO)was prepared to the removal of NO3-N in water.The adsorption characteristics of NO3-N from aqueous solution by LDO and its influencing factors,such as the solution contact time,dosage,pH and initial concentration were analyzed.The adsorption behavior and mechanism were also discussed.The morphologies of samples were characterized by SEM.The results indicated that LDO had the cotton fiber’s own fiber morphology.The removal rate of NO3-N was up to 88.76% when reaction time was 120 min,the dosage of LDO was 0.67 g/L,pH value was 7.0,temperature was25℃and the concentration of NO3-N was 50 mg/L.The equilibrium adsorption capacity was 66.57 mg/g.Effluent concentration achieved Chinese"drinking water health standards"(GB 5749-2006).LDO adsorption of NO3-N had a suitable pH range.The kinetic adsorption process was fitted by pseudo-second-order kinetic model,and the adsorption was mainly chemical adsorption.Langmuir equation could simulate the material process of isothermal adsorption of NO3-N.The fitting results indicated that the adsorption of NO3-N was monolayer adsorption.Regeneration experiments showed that LDO had better regeneration under ultraviolet light,and could be reused more than three times.

关 键 词：金属氧化物 NO3-N 吸附 棉花 热力学 

分 类 号：X703[环境科学与工程—环境工程]