黄铁矿对水体中腐殖酸的吸附特性  

Adsorption characteristics of humic acids on pyrite in water

作　　者：方艳芬[1,2] 李新玉[1,2] 周薇[1,2] 王小维[1,2] 蔡宽[1,2] 贾漫珂[1,2] 黄应平[1,2] 

机构地区：[1]三峡地区地质灾害与生态环境湖北省协同创新中心(三峡大学),宜昌443002 [2]三峡库区生态环境教育部工程研究中心(三峡大学),宜昌443002

出　　处：《环境化学》2014年第11期1941-1949,共9页Environmental Chemistry

基　　金：国家自然科学基金(21377067;21207079;21177072);湖北省新世纪人才入选人员优先资助项目(201203);中国科学院生态环境研究中心开放基金(KF2011-07);三峡大学人才科研启动基金(KJ2011B074)资助

摘　　要：选择富里酸(fulvic acid,FA)和胡敏酸(humilic acid,HA)作为吸附对象,通过铁矿物吸附筛选实验,以黄铁矿(pyrite)为吸附剂研究其对水体中两种典型腐殖酸(humic acid)的吸附特性.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X-射线光电子能谱(XPS)、红外光谱(IR)、纳米粒度及电位(Zeta)分析仪和比表面仪(BET)对黄铁矿进行组成及结构表征.考察了腐殖酸溶液p H、离子强度和温度等条件对黄铁矿吸附的影响.结果表明,黄铁矿是层状结构,吸附腐殖酸后,在黄铁矿表面形成了大小均匀的分子簇,且黄铁矿晶粒尺寸减小了约10 nm;黄铁矿对FA、HA的最大吸附量分别为11.8 mg·g-1和13.1 mg·g-1.随着p H增加,黄铁矿对腐殖酸的吸附量均表现为先增大后减小;离子强度(NaCl)对吸附的影响较小;随着温度升高,其吸附量不断增大.两种腐殖酸吸附数据与Langmuir吸附模型拟合良好且其吸附动力学规律均符合二级动力学模型,热力学研究表明,黄铁矿吸附两种腐殖酸均属于自发进行的吸热反应.Fulvic acid（ FA） and humilic acid（ HA） were used as the adsorption substrate in water,and the adsorption of two humic aicds to pyrite chosen from severals iron minerals were studied. Xray diffraction（ XRD）,scanning electron microscope（ SEM）,infrard spectrum（ IR）,nanoparticle size and zeta potential ananlyer,X-ray photo electron spectroscopy（ XPS） and surface area analyzer（ BET） were employed to characterize the pyrite. The effects of adsorption conditions including p H,ionic strength and temperature were investigated. It was found that the pyrite had a layered structure. After the adsorption of humic acids,molecular clusters were formed on its surface,and the size of pyrite crystal was reduced by 10 nm. The maximum adsorption of HA and FA is13. 1 mg·g- 1and 11. 8 mg·g- 1,respectively. The amount of adsorbed humic acids to pyrite first increased and then decreased with increase p H. Ionic strength（ NaCl） had little effect on the adsorption. The adsorption capacity of pyrite increased with the increase of temperature. The adsorption processes of the two humic acids are well described by the Langmuir isotherm model and the pseudo-second-order kinetics model. Thermodynamic results showed that the adsorption was a spontaneous process.

关 键 词：天然铁矿物 腐殖酸 吸附 机理 

分 类 号：P579[天文地球—矿物学] X52[天文地球—地质学]