香蕉茎秆生物炭的制备及其对铜离子的吸附特性  

The preparation of biochar from pre-oxidation of banana stem and its adsorption of Cu^(2+)

作　　者：余伟光 黎吉辉[1] 王敦[1] 梁振益[1] 张玉苍[1] 

机构地区：[1]海南大学材料与化工学院热带岛屿资源先进材料教育部重点实验室,海南海口570228

出　　处：《化工进展》2017年第4期1499-1505,共7页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51263006);海南省国际合作专项(KJHZ2014-02);海南省产学研一体化专项(CXY20150019);海南大学服务地方经济项目(HDSF201311)

摘　　要：香蕉茎秆经过高锰酸钾氧化预处理后于600℃缓慢热解制得生物炭。采用扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、元素分析仪和比表面积及微孔分析仪对生物炭进行表征,批量吸附实验考察其对Cu^(2+)的吸附特性,研究p H、吸附时间、吸附温度和金属离子初始浓度对吸附的影响。从吸附动力学、吸附等温线、吸附热力学判断吸附类型。结果表明:与未处理香蕉茎秆生物炭对比发现,氧化预处理生物炭表面覆盖有MnO_x微粒,且含有更多的含氧官能团,拥有更大的表面积。其对铜离子的去除主要通过表面吸附包括表面MnO_x颗粒和含氧官能团,对Cu^(2+)有很强的吸附能力,实验中最大吸附容量为81.36mg/g,吸附效果明显好于未预处理生物炭,吸附过程符合准二级动力学方程,可以用Langmuir吸附等温线模型来描述,热力学参数ΔH0>0,ΔG0<0,表明该吸附是一个自发的吸热过程。A novel approach was used to prepare engineered biochar from banana stem pretreated with KMnO4 through slow pyrolysis （600℃） . The physicochemical properties ofbiochar were characterized. Batch adsorption experiments were conducted to investigate the effect of pH values, contact time, temperature and initial CuE＋ concentration on the adsorption efficiency and behaviors. The adsorption types were analyzed from the aspects of kinetic, isotherms, and thermodynamic. The results showed that the engineered biochar surface was covered with MnOx ultrafine particles. In comparison to the pristine biochar, the engineered biochar had more surface oxygen-containing functional groups and much larger surface area. The removal of the metals by the engineered biochar was mainly through surface adsorption mechanisms involving both the surface MnOx particles and oxygen-containing groups. The biochar had strong adsorption ability to Cu2＋ with maximum adsorption capacities of 81.36mg/g in experiments, which was significantly higher than that of the pristine biochar. The adsorption process was consistent with the pseudo-second-order model. The process was better described by the Langrnuir isotherm model. AGO was negative and △H^0 was positive, indicating spontaneous and endothermic adsorption.

关 键 词：香蕉茎秆 生物炭 铜离子 吸附 

分 类 号：TQ424.3[化学工程]