摘要
[目的 ]探讨汞 (Hg)、镉 (Cd)和铅 (Pb)离子在海带颗粒上的静态吸附平衡和填充柱动态吸附特性。 [方法 ]市售干海带经磨碎、筛分 ,选取 3 0～ 60目的颗粒 ,经 1%HNO3 和 1mol/LCaCl2 浸洗。用静态平衡法测定二价Hg、Cd和Pb离子在海带上的富集平衡。将动态数学模型模拟的海带颗粒填充柱流出液浓度响应曲线与实验测定值进行比较 ,得出填充柱颗粒间弥散系数和颗粒内扩散系数。 [结果 ]这 3种重金属在海带颗粒上单组分的富集量与水相浓度的依赖关系可用Langmuir方程描述 ,回归得到的 3种重金属单组分饱和富集量为 0 .2 47、0 .173和 1.2 2 0mmol/g ,颗粒内扩散系数为 1.61× 10 -7、1.0 4× 10 -7和 9.89× 10 -7cm2 /s。 [结论 ]经较高浓度钙离子预处理的海带颗粒对这 3种重金属有很强的富集能力 ,回归得到的Hg、Cd、Pb离子在海带颗粒内的扩散系数远较理论估算的主体电解质溶液中的扩散系数为小 。
Objective The static adsorption equilibria of mercury(Hg),cadmium(Cd) and lead(Pb) on kelp and adsorption dynamic characteristics of packed column were studied. Dried kelp with 30～60 mesh was leached with 1% HNO 3 and 1 M CaCl 2.The uptake amounts of Hg,Cd and Pb in kelp were determined by using static method.By fitting the calculated eluted curve to the determined one,the intraparticle diffusivities and dispersion coefficients were obtained. The uptake behaviors can be described by Langmuir equation and the correlated uptake ammounts of Hg,Cd and Pb are 0.247,0.173 and 1.22 mmol/g respectively.Regressed intraparticle diffusivities are 1.61×10 -7?1.04×10 -7和9.89×10 -7cm 2/s. [Conclusion] Kelp pretreated by Ca ion has larger capability of accumulation of Hg,Cd and Pb.The obtained intraparticle diffusivities are obviously smaller than those estimated in bulk electrolyte solution.This implies that the complicated pore structure of kelp obstacles intraparticle diffusion.
出处
《环境与职业医学》
CAS
北大核心
2005年第1期24-27,共4页
Journal of Environmental and Occupational Medicine
