Egirani D E, Baker A R, Andrews J E
School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom.
J Colloid Interface Sci. 2005 Nov 15;291(2):319-25. doi: 10.1016/j.jcis.2005.05.007. Epub 2005 Jul 6.
This study investigates the reactivity and removal kinetics of Cu and Zn onto mixed mineral systems from aqueous solution related to acid mine drainage impacted areas. The sorbents used were kaolinite, Al-montmorillonite, goethite, and their mixtures. The effects of surface charge, proton coefficient, and sorption kinetics were studied at room temperature (23+/-2 degrees C). Using an empirical model, mineral mixing reduced the exchange of protons for sorbing ions and the acidity of the reactive sites, thus impeding Cu and Zn removal by proton exchange. Based on the amount of Cu and Zn sorbed on the mixed mineral suspensions at ionic strength 0.01 to 0.1 M and pH 4, it is suggested that Cu and Zn removal from aqueous solution was by both inner and outer sphere complexation. Mineral mixing reduced the transfer rate of Cu relative to the single mineral suspensions in both slow and fast reaction phases. The behavior of the mixed suspensions in Cu and Zn sorption suggest that different reactive sites were involved at the onset of sorption, becoming similar to those of the single mineral components over time.
本研究调查了与酸性矿山排水影响区域相关的混合矿物体系对水溶液中铜和锌的反应性及去除动力学。所使用的吸附剂为高岭石、铝蒙脱石、针铁矿及其混合物。在室温（23±2℃）下研究了表面电荷、质子系数和吸附动力学的影响。使用经验模型，矿物混合减少了质子与吸附离子的交换以及反应位点的酸度，从而阻碍了通过质子交换去除铜和锌。基于在离子强度0.01至0.1M和pH值为4时混合矿物悬浮液上吸附的铜和锌的量，表明从水溶液中去除铜和锌是通过内层和外层络合作用。在慢速和快速反应阶段，相对于单一矿物悬浮液，矿物混合降低了铜的转移速率。混合悬浮液在铜和锌吸附中的行为表明，在吸附开始时涉及不同的反应位点，随着时间的推移变得与单一矿物成分的反应位点相似。
