Framework for evaluating sorbent usage rate of various sorption column configurations with and without bypass blending

This study evaluated the system performance in terms of sorbent usage rate (SUR) of single column, two-column parallel, and lead-lag configurations, both with and without bypass blending, based on two normalized parameters describing the breakthrough profile (mass transfer zone length to lag ratio, or MTZ:Lag) and treatment objective (C/Co). The pore surface diffusion model was used to simulate a range of single compound scenarios to develop a framework for comparing configurations. From this analysis, regions on a MTZ:Lag versus C/Co plot could be identified in which particular configurations yielded the lowest system SUR. At low MTZ:Lag ratios, bypass blending (single column or lead-lag operation) offered significant improvements because of the ability to bypass untreated flow and reduce sorbent bed mass. However, at low target C/Co values, bypass offered little improvement. Lead-lag without bypass performed best at high MTZ:Lag ratios by passing the mass transfer zone through two columns in series. At high MTZ:Lag ratios and high target C/Co values, two-column parallel configurations yielded significant benefits by blending high and low concentration effluents and improving sorbent utilization.