A novel method has been developed for anchoring quaternary ammonium/epoxide-forming compounds (QAE) within bituminous and wood based granular activated carbons (GACs). This QAE-anchored GAC was then used to enhance perchlorate removal from perchlorate-spiked natural groundwater. Specifically, for the bituminous based carbon, while processing natural groundwater that had been spiked with 30-35 ppb perchlorate, and passing this water through rapid small scale column tests, the bed volumes (BV) to 2 ppb perchlorate breakthrough increased from 870 BV for pristine GAC up to 21,000 BV for the corresponding GAC that had been pre-anchored with QUAB360 (360 Da). However, the wood based GAC that had been anchored with this QUAB360 achieved only 3000 BV. None of the QAE leached out of these GACs during the column tests. The bituminous GAC that had been pre-anchored with QAE hosted more positive surface charge at pH 7.5 than did the wood based QAE-GAC. Per X-ray photoelectron spectroscopy, the QAE anchored into the GACs increased their N-content by 1-1.3%. By means of multiple analyses, the authors surmised that the active quaternary ammonium sites within the tailored bituminous-based GAC were more exposed and thus more accessible for perchlorate adsorption than those within wood based GAC.
All Science Journal Classification (ASJC) codes
- Materials Science(all)