作　　者： (王立果）; (钟金魁）; (赵保卫）; (张建宇）; (李柳）; (杨巧珍）; (陈伟仡）;

机构地区： 兰州交通大学环境与市政工程学院,兰州730070

出　　处： 《农业环境科学学报》 2017年第9期1868-1876,共9页

摘　　要： 以核桃壳在600℃热解所得生物炭(WSBC)为吸附剂,通过扫描电子显微镜(SEM)和傅立叶变换红外光谱仪(FTIR)对WSBC进行表征,用批平衡吸附实验研究了WSBC对水体中两种典型污染物Cd(Ⅱ)和芘的吸附特性,考察了吸附时间、Cd(Ⅱ)和芘初始浓度、pH值、WSBC粒径等对吸附的影响,以及Cd(Ⅱ)和芘在WSBC上吸附的交互作用。结果表明:WSBC表面粗糙,孔隙结构明显,富含羟基、羧基、羰基等含氧官能团,具有高度芳香和杂环结构;在25℃时,WSBC对Cd(Ⅱ)和芘的吸附分别在20 h和16h时达到平衡,饱和吸附量分别为23.79、0.17 mg·g-1;pH=5时,WSBC对Cd(Ⅱ)的吸附量最大,而pH在3~11范围内,WSBC对芘的吸附量随着pH的减小而增加。通过对吸附实验数据进行动力学、等温吸附特性分析,发现WSBC对Cd(Ⅱ)和芘的吸附动力学规律均符合准二级动力学方程,等温吸附可以用Langmuir方程很好地描述;Cd(Ⅱ)和芘在WSBC上吸附时存在明显的竞争吸附。 The walnut shell biochar（WSBC）used in this study was made via pyrolysis of walnut shell at 600 °C. Using Scanning Electron Microscopy（SEM） and Fourier Transform Infrared Spectroscopy（FTIR）, the surface structure and functional groups of the WSBC were characterized. The sorption behaviors of Cd（Ⅱ）and pyrene in single and binary systems were investigated. Batch sorption experiments of the kinetics and isotherms for the WSBC were performed under different temperature, contact time, initial concentration of Cd（Ⅱ） and pyrene, and pH of aqueous solutions. The experimental data show that the WSBC contains an aromatic and a heterocyclic and has a coarse surface. Its porous structure is significant, and hydroxyl, carboxyl, carbonyl, and other oxygen-containing functional groups at the surface of the WSBC are abundant. Batch sorption experimental results show that the achieved equilibrium times were 20 h and 16 h for Cd（Ⅱ）and pyrene, respectively, and the saturated adsorption capacities were 23.79 mg·g-1and 0.17 mg·g-1. It was found that the sorption was best described by the pseudo-second-order kinetic model. Two sorption isotherms were tested to fit the monocomponent equilibrium data, with the best description obtained using the Langmuir-type isotherm model. The individual sorption for Cd（Ⅱ）or pyrene was influenced by pH. For Cd（Ⅱ）, the WSBC exhibited the maximal sorption capacity at pH 5. As for pyrene, the adsorption capacity increased with a decrease of pH in the pH range of 3 to 11. The sorption of both Cd（Ⅱ）and pyrene by WSBC depended on WSBC particle size, i.e., WSBC with smaller particle size had a better adsorption capacity for both Cd（Ⅱ）and pyrene. The results also show that the sorption capacity of Cd（Ⅱ）onto WSBC is influenced by the presence of pyrene, and vice versa; thus, there is competition between Cd（Ⅱ）and pyrene for sorption sites.These observations provide a reference for the use of WSBC as an engineered sorbent for environmental appli

关 键 词： 核桃壳生物炭 镉 芘 吸附 交互作用