11 ResinTech ASM-10-HP_20170726

RESINTECH ASM-10-HP
APPLICATION BULLETIN
ARSENIC REMOVAL FROM DRINKING WATER

r•
Contents
Introduction -
1
About Arsenic Selective Medias
2
About ResinTech ASM-10-HP
2
Feed Water Quality Guidelines
4
Feed Water Requirements
5
Sizing a System=
6
Calculating Opera g apac ty
6
Tables and Curves
7
Removal of Other Contaminants
8
Domestic Applications
9
Pre -Treatment Requirements
10
Minimum Installation Requirements
11
Additional Suggestions
11
Suggested System Components
11
Monitoring
12
Regeneration
13
Disposal of Media
13

Introduction
ResinTech ASM-10-HP is a strongly basic hybrid anion exchange
resin specially formulated to selectively remove arsenic. Physically,
ResinTech ASM-10-HP is a robust gel type anion exchange resin.
Certain types of ion exchange resins, including ResinTech SBG1, the
parent resin of ASM-10-HP, are listed by the US Food and Drug
Administration for direct and indirect contact with food and have
been used for treatment of drinking waters for more than 50 years.
ResinTech ASM-10-HP falls into this category and is certified to the
ANSI/NSF 61 * standard for filter medias used in potable water and
carries the WQA Gold Seal of approval. ResinTech ASM-10-HP is
patent pending.
ResinTech ASM-10-HP is extremely selective for arsenic and will
generally reduce arsenic concentrations to below the typical detec-
tion limit of 1 ppb. It has very fast kinetics and low-pressure loss.
i_.7,
00
ResinTech ASM-10-HP is fully regenerable and can be used over
and over again without loss of media or capacity. While treating
water that falls within the potable water TDS and pH guideline,
ResinTech ASM-10-HP does not dissolve, compress, become soft
during use, nor does it slough iron. These attributes allow for eco-
nomical trouble -free installations and long life.
ResinTech ASM-10-HP is available from ResinTech, Inc. and its
authorized distributors. It may be purchased in bulk form, in
ready -to -use disposable cartridges through the Aries Division, or
in pre -filled exchange tanks of various sizes. In this bulletin, you
will learn about arsenic, arsenic selective medias, and how to
design and size an arsenic removal system correctly, using the
ResinTech ASM-10-HP media.
Prevalence of Arsenic in the United States
PuertoRi oiW
Arsenic consentrations in at
least 25% of samples exceed:
-
50 ug/L
10 ug/L
5 ug/L
3 ug/L
-
1 ug/L
OInsufficient
Data
Information based on May 2000 USGS Survey
Map Courtesy of USGS.
M USGS
Reference: May 2000 USGS Ground water Study
hitp://water.usgs.gov/nawga/trace/pubs/geo_v46nl 1/fig2.html 1
'Certification lists are shown on the WQA gold seal website — www.wga.org.

About Arsenic Selective Medias
Arsenate forms covalent bonds with iron and certain other metal
cations at neutral pH, thus forming insoluble salts. For example, iron
and/or aluminum based coagulants can be added to water containing
arsenic and will precipitate arsenic along with the coagulation
process. Precipitated arsenic can then be filtered out of the water by a
variety of filtration methods. Arsenite forms coordinate bonds with
the same metal cations. Coordinate bonds are much weaker than
covalent bonds. Coordinate bonds are also pH sensitive generally
forming more readily at higher pH
Coagulation followed by filtration is widely practiced by large munici-
pal water treatment plants and is one very viable method to remove
arsenic from drinking waters, particularly where coagulation is need-
ed for other reasons (such as suspended solids removal). The draw-
back to coagulation and filtration is that it requires a fairly sophisti-
cated operation and is susceptible to upsets if the process is not care-
fully controlled. Coagulation processes generally require someone be
present full time to operate and adjust the system and frequent mon-
itoring to verify the system is operating efficiently.
The same metal cations can be precipitated with certain chemicals,
and then manufactured into powder or larger particles having a vari-
ety of shapes and sizes. These compounds retain some (or all)
of their ability to precipitate arsenic. When the size of the powder par-
ticles is sufficiently large and the shape sufficiently porous
to allow the passage of water, and exhibit useable capacity for arsenic
removal, they can be classified as arsenic selective medias.
Not all arsenic selective medias are created equal. It is a difficult task
to produce a metal oxide/hydroxide precipitant porous enough to have
fast adsorption rates, sufficiently large enough to have a high fraction
of void spaces for water to flow through, yet hard enough to be
durable and not to compact under pressure. Inevitably, some com-
promises must be made. Medias that have very small particle size
have high-pressure loss and are susceptible to channeling. Medias
that are large and porous may be soft and turn to mush after long peri-
ods of use. Medias that are large and hard tend to have very slow
adsorption and/or low capacity, except for ion exchange resins.
About ResinTech ASM-10-HP
Strong base anion resins have high selectivity for arsenate and mod-
erate selectivity for arsenite. While they have been used for arsenic
removal from water for many years they have one important draw-
back. The selectivity for arsenate is lower than the selectivity for
sulfate. When sulfate is present (almost every potable water supply),
and the system is overrun, the sulfate will displace arsenate from the
resin and arsenate will appear in the effluent at higher concentrations
then in the inlet. This effect is often referred to as "dumping"
or chromatographic peaking. If strong base anion resins used for
arsenic removal are run past the point of exhaustion on sulfate -con-
taining waters, the arsenic level in the outlet can rise above the level
in the inlet.

Arsenate ions exchanged into ResinTech ASM-10-HP first enter the
gel phase of the resin in the same manner as with an ordinary ion
exchange resin. However, once inside the gel phase, the arsenate is
exposed to the immobilized iron and immediately precipitates onto
the iron, thus leaving the resin free to react with more arsenic while
the iron -bound arsenic remains trapped inside. Although the
arsenate and arsenite reactions with iron chemistry are the
same for all iron -based medias, there are several important differ-
ences with ASM-10-HP.
Clean, Dust -Free Media
Can be Regenerated
Easily Adapted to Existing Equipment
Superior Physical Strength
Excellent Flow Characteristics
High Capacity &Low Leakage
Economical
ResinTech ASM-10-HP magnified approximately 15x
• Ion exchange reactions are very fast, much faster than pre-
cipitation reactions. The initial capture of arsenate by
ResinTech ASM-10-HP is by ion exchange, thus the removal
rate of arsenic from the inlet liquid is much faster than ordi-
nary iron based media.
• ResinTech ASM-10-HP is made from spherical particles hav-
ing a very high void fraction (greater than 30%) and therefore
the media has very low pressure loss, typically less than
5 PSI across the resin bed.
• ResinTech ASM-10-HP is very strong and durable, suitable
for hundreds of exhaustion and regeneration cycles and has a
useful life comparable to ordinary strongly basic resins such
as ResinTech SBG1-HP (the parent resin). ResinTech
ASM-10-HP is not susceptible to compaction.
• ResinTech ASM-10-HP retains its original strong base
exchange functionality. It can be used simultaneously to
remove nitrate, uranium, chromate and other objectionable
anions while removing arsenate.
• ASM-1 O-HP is stable over the entire acceptable pH range of
potable water, six (6) to nine (9). No iron sloughage occurs at
pHs above 4.

Feed water Quality Guidelines
(for Potable Water Applications)
Feed water quality (aside from arsenic) should generally be
of potable quality. Please consult your ResinTech technical
salesman or ResinTech technical staff for recommenda-
tions outside the following guidelines:
Potable Guidelines
Operating Range of
ResinTech ASM-10-HP
Conductivity
2000 micromhos/cm Max
4000 micromhos/cm Max
Chloride
500 ppm Max
1000 ppm Max
Sulfate
500 ppm Max
1000 ppm Max
pH
6.0to9.0
4.0to8.0
Turbidity
5 NTU Max
5 NTU Max
Chlorine (free)
0.05 ppm Max
0.05 ppm Max
4

Feedwater Requirements
ResinTech ASM-10-HP is not greatly affected by ordinary ions com-
monly found in drinking water. Ions, such as sodium, bicarbonate,
chloride and sulfate pose no interference unless concentrations are
well above the maximum range for drinking water. In general, the TDS
(total dissolved solids) should be less than 2000 ppm and no single
ion concentration greater than 1000 ppm. Although operation at high-
er concentrations is possible, the ResinTech technical staff should
review any proposed installation outside this guideline.
Substances, such as silica, phosphate, and the oxyanions
either interfere with the adsorption or compete for adsorption sites,
reducing the arsenic removal capacity. Their presence at
any concentration should be noted when requesting sizing and
throughput recommendations.
ResinTech ASM-10-HP has limited capacity for arsenite compared to
arsenate. It is necessary to know not only the total arsenic concentra-
tion, but also the relative fractions of arsenate and arsenite. In cases
where the arsenite fraction is greater than 25% of the total arsenic, it
is advisable to chlorinate or otherwise pre -oxidize to convert any
arsenite to arsenate. For potable waters, the optimum pH range is
below 8.0. The operating capacity decreases more and more rapidly
as pH rises. At pH levels above 8.0 and when silica is present, a sig-
nificant de
Any syster
be reviewe
levels during the service cycle can lead to unstable performance and
can cause desorption of arsenic and other substances, especially at
higher operating pH levels (above 7.5).
Suspended solids will tend to accumulate in the media's void spaces
and on the bed surface over the very long service cycle. High levels of
suspended solids or substances that may precipitate during the load-
ing process, such as iron from well water sources, will require peri-
odic backflushing to maintain void spaces and prevent channeling. For
suspended solids greater than 1 NTU, pre -filtration is recommended.
Periodic backwashing at weekly or bi-weekly intervals is suggested for
installations expected to last more than one month between change
outs or regeneration.
Calcium carbonate scale will blind off the media and could eventually
cement the bed together. Water with a positive Langelier scaling index
above 0.3 should be reviewed by the ResinTech technical staff prior to
finalizing a system design. In some cases, it may be advisable to
reduce pH and/or pre -soften the water to reduce scaling potential.
However, even small variations in pH resulting from erratic chemical
feed rates or changing water flow rates can cause performance degra-
dation and premature leakage.

Sizing a System
Calculating Operating Capacity
Systems using ResinTech ASM-10-HP are generally sized for flow
rate requirements as the throughputs are very large and change -outs
(or regenerations) occur infrequently. Inlet pressure and connection
sizes generally determine maximum flow rate, thus it is the tank size
and not the media volume that is used to determine sizing. The
exception is when ResinTech ASM-10-HP will be replacing some
other media. Here, the original media volume requirements must be
considered and possibly maintained to comply with the mechanical
requirements of the system, even though less ResinTech ASM-10-HP
may be required to meet the throughput requirement of the system.
Suggested Operating Conditions
Flow Rate* 1 to 10 gpm/cu. ft.
Temperature 140OF max.
* Flows as high as 20 gpm/cu. ft. have been tested successfully.
However, pressure loss increases exponentially with increasing
flow and when an inlet supply contains even small amounts of
suspended solids; bed pluggage is likely at the highest possible
flow rates.
The base throughput capacity of ResinTech ASM-10-HP for arsenic
in gallons per cubic foot at unit volume flow rates up to 7 gpm/cu. ft.
is approximately 700,000 gallons per cubic foot. This is based on
waters containing 50 ppb of As+5 at neutral pH with no silica, vana-
dium, phosphate, sulfide or other oxyanions. For other arsenic con-
centrations, the following formula will give the approximate gallon-
age at flow rates below 7 gallons per cubic foot per minute.
Base operating capacity, gallons per cubic foot = 34,000,000/(As ppb)
For example, a water with 35 ppb of As would treat approximately
34,000,000/35 ppb = 971,000 gallons per cu ft between change -outs.
The operating capacity of ResinTech ASM-10-HP decreases with
increasing pH. Below pH of 7.0, silica and pH have a relatively minor
impact on performance. As the pH rises, their presence causes
reduced operating capacities. For operation above pH 7.5, we sug-
gest you consult the ResinTech technical staff for specific capacity
estimates and sensitivity factors that could impact performance.
Phosphate also competes for adsorption sites; however phosphate
often combines with calcium or other cations to form complex anions
or colloidal precipitants. Although phosphate does have an adverse
effect on the throughput of ASM-10-HP, the effect is generally mini-
mal because the colloids and complex anions do not come into direct
contact with the iron hidden inside the resin.
TDS caused by salts, such as sodium bicarbonate, calcium chloride
and magnesium sulfate, has practically no effect on ResinTech ASM-
10-HP throughput until the concentration is greater than 1000 ppm.
Several other anions, if present, will decrease performance. When
Present, the following substances are exchangeable and should be
added to the arsenate concentration for purposes of calculating
throughput (see table on page 7). Also, a pH higher than 7.0 and the
presence silica has negative impacts on capacity.

Tank Sizing
Effect of pH and Silica
The following table can be used to select tank sizes for various flow
rates. Many other tank sizes may also be used.
ResinTech suggests using a coarse sand support bed that completely
covers the underdrain. Such a support bed provides a flat surface
for the resin to rest on and helps promote equal distribution, even at
very low flow rates, and helps to reduce pressure losses at the under -
drain entrance.
Capacity Curves
The following charts may be used in a general way to predict through-
put for similar waters.
Please consult the ResinTech technical staff for throughput recom-
mendations. Due to the complexity of throughput calculations and their
dependence on a complete water analysis, no throughput recommen-
dation should be considered a guarantee of performance.
6 6.5 7 7.5 8 8.5 9
Sulfate = 200 ppm as SO4, Arsenic = 50 ppb as As+s,
Nitrate = 2 ppm as NO3, Chloride = 64 ppm as Cl, Bicarbonate = 50 ppm as HCO3
NSF high pH Challenge
(pH 8.5, Si02 20ppm, AS 50 ppb as As+5, Flow= 0.8 BV/min)
10
8
Y
d 6
LO
4
0
a 2
a
0
0 2,000 4,000 6,000 8,000 10,000 12,000 14,000
Bed Volumes Throughput
(35 ppb As+5, 14 ppb V, 20 ppm Si02, pH 8)
10
9
LO 8
y 7
ti 6
d 5
CM
Y 4
d 3
a 2
a
a
1
0
0 10,000 20,000 30,000 40,000 50,000
Bed Volumes Throughput
7

Removal of Other Contaminants by ASM-10-HP
ResinTech ASM-10-HP retains its original Type I strong base ion
exchange resin characteristics. As such, it will exchange with and
remove other contaminants in the manner typical of such products. It
initially functions as a chloride cycle anion exchanger and will remove
sulfates, nitrates and alkalinity (unless buffered), until the chloride
exchange sites have come to equilibrium with the feed water. During
the initial portion of the operating cycle there may be some pH depres-
sion due to the removal of alkalinity. The pH will then rise back to influ-
ent levels and stay there throughout the remainder of the exhaustion
cycle. Sulfates will continue to be removed along with nitrates,
uranium and arsenic. As the resin continues to exhaust, nitrates will
eventually begin to leak. If the resin is used for nitrate removal also,
this is the point where the resin is regenerated or replaced. Otherwise,
nitrate levels will continue increase, possibly to higher levels than in
the inlet depending on the initial nitrate, sulfate and TDS levels. Silica
will be partially reduced for up to several thousand gallons per cubic
foot. Eventually, silica and sulfate removal ceases and these appear in
the effluent equal to influent levels, while the resin continues to remove
arsenic. The foregoing typically occurs during startup, which repre-
sents less than 1% of the volume to reach 10 ppb arsenic leakage.
Certain ions, such as uranium, which forms complex anions that have
very high selectivity for the strong base exchange groups will continue
to be removed for many thousands of bed volumes. Thus ResinTech
ASM-10-HP is a very good media for reducing uranium concentrations
in water, in addition to arsenic.
Nitrate and chromate are removed until the chloride exchange sites are
depleted. Although the useful throughput for these ions may only be
a few hundred bed volumes, regeneration with sodium chloride will
restore the chloride form capacity of the resin and allow continued
operation for removal of these contaminants, in addition to arsenic. In
such dual -use cases, arsenic capacity can be extended indefinitely by
employing Counter -current Regeneration (CCR).
The scope of dual-purpose operation is complex and site specifics and
is not covered in detail in this bulletin. Please contact ResinTech tech-
nical staff for help in designing systems that will remove other con-
taminants in addition to arsenic.
Uranium
Vanadium
Chromium
Nitrate
Sulfide
Silica
(not considered a contaminant of potable
water but removed during the initial portion
of the exhaustion)

Domestic Applications
Point -of -Entry (POE) vs. Point -of -Use (POU)
POE treatment is more expensive than POU and less efficient because
some of the water it treats is not used for human consumption or
contact i.e. toilets.
Consider the following factors:
1. What is the local municipality doing about arsenic
levels in the water?
2. What do they recommend?
3. Who drinks water and from which taps?
4 Is the water used for showering or bathing?
5. How high a concentration of arsenic is in the water?
Arsenic is adsorbed through the skin. Early animal tests showed
approximately 6% adsorption in monkeys. Recent research with
human subjects demonstrated that showering in water containing 100
ppb of arsenic resulted in significantly elevated arsenic levels in urine
for several days following.
If the arsenic concentration is only less than 10 ppb, it should not
matter as this has been defined as acceptable or safe by the EPA. At
levels greater than 10 ppb the added cost of whole house treatment
might be a worthwhile investment and offer "peace of mind". There is
no right or wrong answer, only different level of risk.
w

Pretreatment Requirements
Pretreatment requirements for ResinTech ASM-10-HP are generally
minimal, as the media is quite sturdy and resistant to fouling.
However, as with any media that has a very long exhaustion cycle,
ResinTech ASM-10-HP can be overcome by high levels of suspended
solids or other foulants and can become biologically fouled with algae
and mold.
We recommend prefiltration ahead of the ResinTech ASM-10-HP
media whenever the raw water turbidity is greater than 5 NTU.
Whenever arsenite is more than 25% of the total arsenic or 5 ppb or
greater, the feed water should be chlorinated to convert arsenite
(As+3) to arsenate (As+5).
r than 0.05 ppm, the feed water should
ting the resin. d
Er than 0.5 ppm, or manganese greater than
nants should be removed ahead of the resin b

Installation Requirements
The use of a two tank "round robin" system where the first tank is the
working bed and the second tank is the polishing or guard bed is rec-
ommended to minimize the possibility of premature arsenic leakage.
When arsenic breakthrough of the first bed occurs, the media is
removed and replaced or regenerated, then put back online as the pol-
ishing bed. The old polishing bed is placed first and becomes the new
working bed. Monitoring is performed in between the worker and pol-
ishing beds. This configuration provides the maximum possible pro-
tection against arsenic break through.
Where a worker/polisher bed configuration cannot be provided, it is
suggested that the capacity be Berated and testing schedules
increased so that change outs are performed well in advance of break-
through and increasing leakage levels are detected before substantial
leakages occur. All systems, especially single bed systems should
include a water meter to permit accurate monitoring of usage along
with frequent monitoring.
Suggested System Components
Treatment of Water by ASM-10-HP
Control Control
Head Head
Raw Water Totalizing Meter Treated Water
Inlet T Outlet
Sample
Valve
Bac
kwash
Sample
Sample
Valve
Valve
Backwash
Naste
Waste
Worker Polisher
Tank Tank
Point of Entry water treatment system
Additional Suggestions
1. Install sample valves at the effluent of every tank for monitoring.
2. Include isolation and bypass valves for each tank so that the tank
can be valved out for service or replacement, when necessary.
3. Include both backwash and rinse valving, even if the media will not
be regenerated.
4.Systems that use prechlorination should include carbon
prefiltration to remove excess chlorine ahead of the ResinTech
ASM-10-HP bed.
5. Systems where the feed water contains other objectionable con-
taminants, such as suspended solids, turbidity, high organic color,
iron, manganese etc., should include pretreatment systems for
those contaminants ahead of the ResinTech ASM-10-HP media.
6. Design the system to accommodate the highest pH level of the raw
water to ensure against premature arsenic leakage.
Hydra -AS (HY-111-AS)
Point of Use water treatment system
11

Monitoring
Monitoring is an extremely important part of the arsenic removal
process. Arsenic is tasteless, colorless and odorless. Although there
is no indirect method to verify the media is working properly and that
arsenic levels are being reduced, there are a number of direct test
methods, including test strips and water analysis, which can provide
system validation. Arsenic test kits are available for purchase from
ResinTech and its authorized dealers and distributors.
For worker/polisher bed systems we suggest frequent monitoring `
(15% intervals based on capacity projections) in between the two
tanks and the final effluent.
For single tank systems we suggest more frequent monitoring (5% to
10% intervals based on capacity projections) such that the risingiLo
break through levels will be observed in time to prevent effluent levels
from exceeding desired limits. /
Keeping a log sheet with the date, arsenic test result and gallon
throughput readings, noting when change outs occur can be a useful
tool to track performance, establish trends and plan change -outs or
determine if there is a problem with the system operation. F4!�NCoX
12

Regeneration
Regeneration with Sodium Hydroxide
Virtually complete regeneration of arsenic laden ResinTech ASM-10-
HP may be accomplished using dilute sodium hydroxide. This proce-
dure is beyond the scope of what might be expected for a residential
installation. It is solely intended for large commercial, industrial
and/or municipal installations or for portable exchange regeneration
plants where there are permanent industrial waste treatment systems
and trained operators to deal with arsenic laden waste waters gener-
ated by the regeneration process.
A detailed regeneration procedure should be prepared for each
system. The following generalized regeneration may be used as a
starting point.
1. Backwash with soft water for at least 20 minutes at a flow
rate of approximately. 4 to 6 gpm/sq. ft. so that the bed expands
40 to 60 %.
2. Apply 30 gallons of 5% sodium hydroxide solution, made with soft
water, over a minimum 60-minute period.
3. Follow with a slow rinse using soft water at the same flow rate for
30 minutes.
4. Fast rinse to pH less than 13 and conductivity less than 5000
micromho using soft water (flow rate about the same as the serv-
ice flow rate).
5. Regenerate with 15 Ibs of salt diluted with 30 gals of soft water
over a 45 to 60 minute period.
6. Rinse with soft water to pH below 9. If necessary, neutralize the
resin bed by adding small amounts of sulfuric or hydrochloric acid
while air mixing until the pH of the slurry remains less than 7 for
30 minutes.
7. Rinse with tap water until the effluent conductivity is similar to the
tap water (usually less than 500 micromho). Check arsenic con-
centration prior to returning to service.
Note that local waste regulations may not permit the discharge of
spent regenerant solutions containing arsenic and/or sodium hydrox-
ide and/or sodium chloride. It may be necessary to haul the waste
regenerants to an acceptable disposal site. In all cases, check with
local authorities and follow their directions.
Warning
Sodium hydroxide (sometimes called lye) is a very potent chemical
that can cause severe burns. Proper safety gear is essential when
working with sodium hydroxide solutions. Be sure to read and follow
all safety instructions included with the MSDS that accompanies
each shipment of sodium hydroxide.
Disposal of Media
Although ASM-10-HP passes the current EPA TCLP leachables test.
This test may not reasonably reflect actual landfill conditions that in
certain cases such as the presence of acid wastes that conceivably
might cause arsenic to be released. ResinTech recommends compli-
ance with all federal and local laws governing disposal.
In regenerable operation, disposal would consist of regeneration and
re -use of the ASM-10-HP media, precipitation and solidification of
arsenic followed by re -use or disposal of solid arsenic salts as
hazardous waste.
13

ResinTech Inc., an acknowledged leader in ion exchange, manufactures a
broad range of ion exchange resins for water and wastewater treatment,
including deionization, softening, metals removal, product purification,
resource recovery, and pollution control. In addition to its ion exchange
resins, ResinTech supplies activated carbon and inorganic selective
exchangers. ResinTech has developed an application technology resource
group that includes state-of-the-art laboratories and a group of scientists
dedicated to expanding the frontiers of application technology. This group
is put to use whenever product or process recommendations are request-
ed, assuring customers get the most cost-effective approach to achieving
their process goals.
Y
SIIN� EEEC H``
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' For More Information Call 856.768*9600
•
1 RESINTECH PLAZA 0 160 COOPER ROAD • WEST BERLIN, NJ USA 08091-9243
PHONE:[phone] • FAX:[phone]
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