水华束丝藻对汞的吸附-解吸特征  

Sorption and Desorption Characteristics of Hg2+ by Aphanizomenon flosaquae

作　　者：孙荣国[1,2] 莫雅斐 金林[1] 李秋华 SUN Rongguo;MO Yafei;JIN Lin;LI Qiuhua(School of Chemistry and Material,Guizhou Normal University,Guiyang 550001,China;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China)

机构地区：[1]贵州师范大学化学与材料科学学院,贵阳550025 [2]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081

出　　处：《地球与环境》2019年第4期552-557,共6页Earth and Environment

基　　金：国家自然科学基金(41563012);中国博士后科学基金(2017M613005);贵州省科技厅联合基金(黔科合LH字[2017]7334);贵州省教育厅青年科技人才成长项目(黔教合KY[2016]135);贵州师范大学博士科研启动基金(2014)

摘　　要：通过室内模拟实验,探究不同丰度的活、死水华束丝藻对Hg^2+的吸附动力学特征和等温吸附模型以及解吸特征.结果表明,水华束丝藻对Hg^2+有较好的吸附效果,能在短时间内吸附大量Hg^2+,120 min左右达到吸附平衡,且活藻对Hg^2+的吸附效果比死藻好;活藻和死藻吸附Hg^2+的动力学过程符合准一级、准二级动力学模型,且准二级动力学模型拟合效果更好;活、死水华束丝藻对Hg^2+的吸附分别符合Langmuir模型、D-R模型,最大吸附量分别为2.07×10^-2 ng/(106 cells)、3.56×10^-2ng/(106 cells);水华束丝藻对Hg^2+的单位吸附量随着藻丰度的增加而减少,吸附总量随着藻丰度的增加而增加.反应初期(0~5 min),活、死水华束丝藻对Hg^2+进行生物吸附,吸附速度快且效率高;随后活藻依靠新陈代谢将Hg^2+转移至细胞内进行生物富集,因而活藻的单位吸附量高于死藻.活藻和死藻对Hg^2+的解吸量随藻丰度的增加而增加,且死藻变化更明显.Laboratory simulation experiments were conducted to investigate kinetics and isotherm patterns of sorption and desorption of Hg^2+by a biosorption agent,Aphanizomenon flosaquae,under different conditions,e.g.live or dead,and abundance.The results showed that algae,Aphanizomenon flosaquae,is a good sorbent for Hg^2+and can uptake a large amount of Hg^2+in a short time,sorption equilibria can be reached in about 120 minutes.The sorption ability of Hg^2+on live algae is much higher than that of dead algae.The sorption kinetics of Hg^2+by algae can be described with either quasi-first-order or quasi-second-order kinetic model.The quasi-secondary kinetic model showed a better fitting result.The sorption isotherms of Hg^2+by live algae and dead algae are consistent with the Langmuir model.The maximum sorption capacity of Hg^2+by live algae and dead algae was 2.07×10^-2 ng/(106 cells)and 3.56×10^-2 ng/(106 cells),respectively.The concentration of Hg^2+on algae decreased while the total uptake amount of Hg^2+on algae increased as the abundance of algae increased.Both live and dead algae sorbed Hg^2+quickly and effectively within 5 min through biosorption,but the sorption amount of live algae was higher than that of dead algae since live algae can transfer Hg^2+into algae cell.The desorption amount of Hg^2+from live and dead algae increased with the increase of algae abundance,and this trend was more significant for dead algae.

关 键 词：水华束丝藻 汞 生物吸附 等温吸附模型 

分 类 号：S154.38[农业科学—土壤学] O647.3[农业科学—农业基础科学]