397Design Manual: Removal of Arsenic from Drinking Water by
Adsorptive Media
EPA 600-R-03-019
This design manual is an in-depth presentation of the steps required to design and operate
a water treatment plant for removal of excess arsenic from drinking water using the
adsorptive media process.
This treatment process is very reliable, simple and cost-effective. Several adsorptive
media products are available in the market-place that have successfully demonstrated
their capability to remove arsenic from drinking water to levels well below the revised MCL,
0.010 mg/L. Other new products continue to be developed.
The adsorptive media products are preferential for the removal of arsenic over other
competing ions. Therefore, unless a water system requires treatment capability for
removal of other suspended or dissolved contaminants, the adsorptive media treatment
method merits evaluation.
The adsorptive media process is implemented with operational options which vary with
the product selected. For water systems that are primarily concerned with financial
feasibility, capital and operating costs, each operational option along with each available
adsorptive media product should be evaluated.
This design manual provides the methods for competently performing each evaluation.
The arsenic removal capacity of some adsorptive media products, such as activated
alumina, are very sensitive to the pH of the water passing thru treatment.
Others, such as iron-based products, are not. Treatment processes incorporating pH
adjustment capability require careful handling and storage of corrosive chemicals (acid
and caustic). Some adsorptive media products, such as activated alumina, are capable of
being chemically regenerated for repetition of treatment cycles using the same corrosive
chemicals as those used for pH adjustment in the treatment process.
Regeneration is not recommended for other adsorptive media products. Whether or not
pH of water being treated is adjusted, the adsorptive media can be replaced in place of
regeneration upon exhaustion of arsenic capacity.
This design manual presents the information necessary to design and operate treatment
systems for any combination of operational options and for any adsorptive media. It also
discusses the capital and operating costs including the many variables which can raise or
lower costs for identical treatment systems.