Granular Activated Carbon Anchored With Quaternary Ammonium/Epoxide-forming Compounds To Remove Low Ppb Level Of Perchlorate From Groundwater

A novel method has been developed to remove low ppb level perchlorate from groundwater by anchoring quaternary ammonium/epoxide-forming compounds (QUAB) within granular activated carbons (GACs). The authors evaluated the physical characteristics of four commercial-available GACs and the effect of preparation conditions on perchlorate adsorption capacity of the tailored carbon, and appraised the optimal combination for anchoring QUAB onto GACs. The perchlorate removal capacity of different combination was also compared. Statistical experimental design using Response Surface Methodology was applied to find the optimum preparation conditions for anchoring QUAB onto bituminous based GAC (UC). Pristine and QUAB-anchored GACs were further characterized to study the correlation with perchlorate adsorption capacity and the proposed configuration of QUAB on wood and bituminous based GACs. The effect of competing ions from groundwater on perchlorate removal capacity of QUAB-anchored GACs was also evaluated. It was found that the QUAB-anchored GACs could be regenerated with high concentration of sodium bicarbonate.