Adsorption of Pb(II) and Zn(II) in the presence and absence of CO2

Adsorption data on goethite vs. pH of Pb(II) and Zn(II) under different conditions especially in the presence and absence of CO2. Aqueous chemical speciation expected of both vs. pH in the absence of adsorption. The data shows that there is no distinction between adsorption on two goethites of different particle sizes in the presence and in the absence of CO2, for Pb(II) up to a pH of 6.4, and for Zn(II) up to a pH of 7.0. This confirms that dissolved carbonate does not affect the adsorption behavior of these and other heavy metal cations, and thus, that laboratory experiments may be performed in open atmosphere, but modeled in the absence of CO2. The model shows a contribution of a bidentate surface complex with the unhydrolyzed metal(II), and a monodentate complex with the hydroxylated metal(II).本数据集包含不同实验条件下（尤其涵盖有、无CO₂两种场景），针铁矿（goethite）对Pb(II)与Zn(II)的吸附量随pH变化的相关数据，同时包含无吸附条件下两种金属的水相化学形态（aqueous chemical speciation）随pH变化的预测数据。 实验数据显示，在有、无CO₂的条件下，当Pb(II)体系pH≤6.4、Zn(II)体系pH≤7.0时，两种不同粒径的针铁矿对重金属的吸附效果无显著差异。该结果证实，溶解态碳酸盐不会影响此类及其他重金属阳离子的吸附行为，因此相关实验室实验可在开放大气环境中开展，而模型构建时可无需考虑CO₂的存在。该模型表明，未水解的金属(II)可形成双齿表面络合物（bidentate surface complex），羟基化金属(II)则可形成单齿表面络合物（monodentate complex）。