Qom University of Medical Sciences Journal

Background and Objective
Pollution of surface and ground water to arsenic (As) has been reported from many parts
of the world and in some regions of Iran especially in Kurdistan province. Natural
pollution of water to As is in fact dependent to geological characteristics of a region. To
day, various methods have been recommended for As removal that each of which has
special advantages and drawbacks. Granular ferric hydroxide (GFH) is a relatively new
adsorbent available in market which is principally introduced for As removal.
Methods
This study was an applied survey in which the effects of changing contact time, As
concentration, adsorbent weight, pH as well as the effect of sulfate and chloride ions in
arsenic removal were determined. Moreover, the model of absorption by GFH was
studied and compared with Freundlich and Langmuir models. Raw data were analyzed
by Excel and SPSS softwares.
Results
Results showed that As adsorption by GFH imitate both the Freundlich and Langmuir
equations (with R2 >0.95). Optimum PH was 7.5 and duration of the process about 30
minutes was sufficient for optimum removal of As. It was also found that efficiency of
As removal was high when small amounts of adsorbent were used. Furthermore, sulfate
and chloride ions in concentrations used in this study had no noticeable effect on As
removal and Fe added during process remains in the water more than the standard value
(0.3 mg/l).
Conclusion
According to this study, GFH could be considered as a suitable adsorbent for As
removal from polluted water resources because of its high performance without any
needs to PH adjustment. However, there are few drawbacks such as Fe addition and
relatively high initial cost.