This research was undertaken to evaluate the feasibility
and cost-effectiveness of granular ferric hydroxide
(GFH) for arsenic removal, in response to the 2002
US Environmental Protection Agency (USEPA) lowering of the arsenic maximum contaminant
level to 10 µg/L in drinking water. The research modeled
the adsorption activation energy, kinetics, and
isotherm thermodynamic parameters. Results show
GFH to be a promising and cost-effective arsenic(V), or
As(V), sorbent. GFH adsorbs As(V) readily and has a
large As(V) adsorption capacity indicated by kinetics
and isotherm models. The adsorption is nonlinear, heterogeneous,
and multilayered. It can also be compromised
by the presence of competitive anions, such as
silica, vanadium, selenium, and phosphate in natural
waters. The interference of silica, for example, may
require a pretreatment step to prolong the life of GFH
as an arsenic sorbent. This could be achieved through
the commonly used unit process of coagulation/flocculation.
The thermodynamics parameters established for
GFH As(V) removal will help water utility managers
compare and find the most suitable arsenic removal
strategy to meet the needs of their utilities. Includes 33 references, tables, figures.
| Edition : | Vol. 99 - No. 11 |
| File Size : | 1
file
, 320 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 11/01/2007 |
