Recently, the allowable concentration of arsenic in drinking water has been lowered by the
US Environmental Protection Agency (USEPA) from 50 ug/L to 10 ug/L. To meet this challenge, water utilities may soon be required to
consider existing as well as innovative technologies for effectively removing arsenic. The treatment
technology evaluated as part of this study includes evaluation of a novel adsorbent against
several innovative adsorbent materials for arsenic removal. Novel adsorbent materials designated
herein are materials that have been extensively studied in the past for arsenic removal, which
includes activated alumina (AA) and ion-exchange resins, whereas innovative adsorbents are
those materials that are still in development stages or have been successfully evaluated and tested
for the removal of other types of contaminants (e.g., DOC, phosphate, etc.), but not yet evaluated
for arsenic removal.
Innovative adsorbents evaluated in this bench-scale study include: magnetically
impregnated ion-exchange resins (MIEX), hydrous iron oxide particles (HIOPs), granular ferric
hydroxide (GFH), sulfur-modified iron (SMI), and iron oxide coated microsands (IOC-M). These
adsorbents were first evaluated in synthetic (using Milli-Q, carbon and ion free, water) and later
in natural (surface and ground) waters for arsenic removal. Synthetic water studies were
performed to avoid matrix effects and also to carefully study the effects of various anions and
pH, and to relate this information to natural water systems to elucidate the effects of the water
quality matrix on their performance for arsenic removal. A detailed characterization of these
adsorbent materials in terms of their physico-chemical properties was also performed, which
included determining their dry weight, metal content, particle size distribution, surface area,
crystalline structure, surface charge (i.e., pHPZC) and texture determination. The systematic
approach undertaken, (i.e., adsorbent characterization and evaluation in both synthetic and
natural waters) proved to be an effective scheme in relating adsorbent performances (kinetics,
capacities) to adsorbent characteristics in removing arsenic.
Includes 9 references, tables, figure.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 310 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 13 |
| Published : | 11/01/2002 |
