Document Type
Article
Publication Date
1-1-2009
Abstract
Activated carbon was tailored with both iron and quaternary ammonium surfactants so as to concurrently remove both arsenate and perchlorate from groundwater. The iron (hydr)oxide preferentially removed the arsenate oxyanion but not perchlorate; while the quaternary ammonium preferentially removed the perchlorate oxyanion, but not the arsenate. The co-sorption of two anionic oxyanions via distinct mechanisms has yielded intriguing phenomena. Rapid small-scale column tests (RSSCTs) with these dually prepared media employed synthetic waters that were concurrently spiked with arsenate and perchlorate; and these trial results showed that the quaternary ammonium surfactants enhanced arsenate removal bed life by 25-50 when compared to activated carbon media that had been preloaded merely with iron (hydr)oxide; and the surfactant also enhanced the diffusion rate of arsenate per the Donnan effect. The authors also employed natural groundwater from Rutland, MA which contained 60 μg/L As and traces of silica, and sulfate; and the authors spiked this with 40 μg/L perchlorate. When processing this water, activated carbon that had been tailored with iron and cationic surfactant could treat 12,500 bed volumes before 10 μg/L arsenic breakthrough, and 4500 bed volumes before 6 μg/L perchlorate breakthrough. Although the quaternary ammonium surfactants exhibited only a slight capacity for removing arsenate, these surfactants did facilitate a more favorably positively charged avenue for the arsenate to diffuse through the media to the iron sorption site (i.e. via the Donnan effect).
Keywords
Activated carbon, Arsenic, Arsenic and perchlorate, Cationic surfactant, Perchlorate, Arsenate removal, Bed volume, Diffusion rate, Donnan effects, Granular activated carbons, Hydrous ferric oxides, Natural groundwater, Oxyanions, Perchlorate removal, Positively charged, Quaternary ammonium, Quaternary ammonium surfactants, Rapid small-scale column tests, Sorption sites, Synthetic waters, Amines, Ammonium compounds, Biophysics, Cationic surfactants, Charcoal, Chemicals removal (water treatment), Dyes, Groundwater, Hydrogeology, Iron oxides, Positive ions, Silica, Sorption, arsenic acid, ferric hydroxide, ground water, quaternary ammonium derivative, silicon dioxide, sulfate, arsenate, diffusion, hydrous mineral, iron oxide, surfactant, water quality, adsorption, article, atomic absorption spectrometry, batch reactor, controlled study, isotherm, priority journal, United States, waste component removal, water contamination, water treatment, Arsenates, Ferric Compounds, Perchloric Acid, Quaternary Ammonium Compounds, Surface-Active Agents, Water Purification, England, Eurasia, Europe, Rutland, United Kingdom, Western Europe
Divisions
fac_eng
Publication Title
Water Research
Volume
43
Issue
12
Additional Information
Jang, Min Cannon, Fred S Parette, Robert B Yoon, Soh-Joung Chen, Weifang eng Research Support, Non-U.S. Gov't England 2009/05/30 09:00 Water Res. 2009 Jul;43(12):3133-43. doi: 10.1016/j.watres.2009.04.021. Epub 2009 Apr 23.