Reconciliation of expressions for the modified retardation factor and incorporation of non-linear contaminant sorption to the stationary phase

摘要

The retardation factor describes the average velocity of a sorbing contaminant in groundwater relative to the average velocity of groundwater. The modified retardation factor(R' or R*) describes the average velocity of a sorbing contaminant relative to groundwater in the presence of a carrier that binds the contaminant and facilitates its transport. Dissolved organic matter and particulate colloids are examples of potential facilitating carriers. The modified retardation factor R' concerns the case when sorption of the carrier itself to the stationary phase is negliggible, Whereas R* accounts for significant sorption of a facilitating carrier to the stationary phase, and So represents a magnitude less than R, but greater than R'.