384Design 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.