Mobility of contaminants especially heavy metals and Rare Earth Elements (REE) in subsurface systems is linked to surface interactions with minerals, colloids and porous media. Through batch and column experiments with quartz sand, a representative porous media, my study unveiled surface heterogeneities and preferential adsorption patterns of middle and heavy REE driven by specific binding sites. A developed surface complexation model successfully predicted sorption behavior, emphasizing the competitive binding of middle REE and underscoring the significance of strong sites. Additionally, the study introduced an innovative approach to probe adsorption mechanisms on goethite surfaces, revealing loading-dependent adsorption patterns and providing crucial insights into redox processes on iron-oxides. The influence of organic and inorganic colloids on REE migration in reactive porous media was also studied. The injection of humic acid, goethite, and mixed colloids into quartz sand columns demonstrated their substantial impact on REE transport. These findings provide comprehensive insights into transport behavior of REE in natural systems, which is crucial for understanding pollutant migration in the environment. There is a need to develop predictive capabilities to understand how colloids control the immiscible two-phase flow in complex geological formations.