研究胶体在饱和多孔介质中的迁移行为在污染物迁移、环境修复等领域具有重要意义.本文通过对比胶体在未酸洗和酸洗过的玻璃珠中的迁移行为来探究多孔介质表面异质性对胶体迁移的影响,并通过扩展DLVO理论来计算每一组中胶体与多孔介质的相互作用能.结果表明,不论在有利环境还是在不利环境下,多孔介质表面的化学杂质均会提高胶体的吸附能力,这主要归因于胶体在初级势阱中的吸附.不利环境下,多孔介质表面的化学杂质能够将不利环境转化为有利环境,而在有利环境下,化学杂质的存在可能提高胶体的单一拦截效率(η_0).此外,研究发现,高pH溶液仍然能使胶体从多孔介质表面解吸下来,并且沥滤作用仍被低估.本研究对化学杂质在胶体迁移过程中所扮演的角色有了进一步的认识,可为胶体迁移行为研究提供实验依据.
Knowledge of colloid transport in saturated porous media is of vital significance in investigating pollutant transport and environment remediation. To discover the influence of surface chemical heterogeneity on behavior of colloid transport in saturated porous media, we compared the behavior in untreated glass bead and acid-washed glass bead. An extended DLV0 approach was employed to calculate the interaction energy for each group. Results showed that chemical heterogeneity can enhance the adsorption ability of colloid especially in the primary minimum under both favorable and unfavorable conditions. Chemical impurities can change unfavorable condition into favorable condition and enhance the single collector contact efficiency ( 7/o ) in favorable condition. A substantial amount of colloid release occurred when background water was displaced by distilled water with high pH value in the experiment. In addition, straining was underestimated. This study improved our understanding on the role of chemical impurities in the process of colloid transport and provided experimental basis for future research.