【摘要】 在离子质量浓度25~500 mg.L-1和吸附剂(蛭石)质量浓度10~150 g.L-1范围内分析测试了平衡固液体系中Zn、Cd离子等温吸附量.试验数据表明:平衡离子吸附密度qe(离子吸附量与吸附剂量的比值)唯一由C0/W0(起始点液相离子浓度C0与吸附剂浓度W0的比值)与Ce/W0(平衡液相离子浓度Ce与W0的比值)的差屿来决定,与离子、吸附剂的浓度及吸附反应过程无关.重复测试证实:给定C0/W0时,qe与Ce/W0具有唯一对应的值.指出液/固相离子吸附体系中的强度因子不是离子的浓度而是离子量与吸附剂量的比值,离子吸附反应的方向与速率取决于系统中离子量与吸附剂量的相对水平,离子吸附反应达到平衡的条件是离子与吸附剂化学势之和在液、固相之间的差异为0.更多还原

【Abstract】 Experiments of Zn2+ and Cd2+ adsorption on vermiculite in aqueous solutions were carried out in ion concentration range 25～500 mg/L and adsorbent concentration range 10～150 g/L at a constant temperature of 25 ℃.Results obtained from the tests indicate that the equilibrium adsorption density q_e（the ratio of adsorption quantity to adsorbent quantity） was uniquely determined by the difference between C₀/W₀（the ratio of initial ion concentration C₀ to adsorbent concentration W₀） and C_e/W₀（the ratio of the equilibrium ion concentration in liquid phase C_e to W₀）,independent of ion and adsorbent concentration and process history.Repeated tests have confirmed that given C₀/W₀,q_ecorresponded to a unique C_e/W₀.The argument presented here is that the intensity factor in a liquid/solid ion adsorption system is not the volume-based ion concentration but rather the ratio of ion quantity to adsorbent quantity as it is the relative level of ion quantity to adsorbent quantity that determines both the direction and rate of the ion adsorption.Ion adsorption arrives at equilibrium only when the difference in sum of ion and adsorbent chemical potentials between liquid and solid phases is zero.更多还原