The removal of perchlorate from groundwater by activated carbon tailored with cationic surfactants.
In rapid small-scale column tests, cationic surfactant-tailored activated carbons (ACs) effectively removed perchlorate to below detection levels for up to 30 times longer than virgin AC. By pre-loading bituminous AC with dicocodimethylammonium chloride, tallowtrimethylammonium chloride, cetyltrimethylammonium chloride, or cetylpyridinium chloride, 75 ppb perchlorate was removed for 27,000-35,000 bed volumes before the effluent perchlorate rose above 1 ppb. These tests employed a natural groundwater that also contained 30 mg/L sulfate, 26 mg/L nitrate (as NO3-), and other ions. By the time of 25 ppb perchlorate breakthrough, 7.3-10.1% of quaternary ammonium sites had perchlorate associated with them. Although some of the surfactants leached out of the tailored carbon beds (0.6-21.2% of the amount loaded), the leached surfactant could be removed to below detectable limits with a virgin AC polishing bed that chased the tailored bed.
Parette
Robert
R
Department of Civil and Environmental Engineering, The Pennsylvania State University, 212 Sackett Building, University Park, PA 16802, USA.
Cannon
Fred S
FS
D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D002412:Cations; D010472:Perchlorates / Q000302:isolation & purification*; D012989:Soil Pollutants / Q000302:isolation & purification*; D013501:Surface-Active Agents / Q000737:chemistry; D014873:Water Pollutants / Q000302:isolation & purification*
D002412:Cations; D010472:Perchlorates; D012989:Soil Pollutants; D013501:Surface-Active Agents; D014873:Water Pollutants; D002244:Carbon; C494474:perchlorate