Removal of Arsenic from Drinking Water using Hybrid Ion Exchangers or HIX : A Prudent approach for Rural Water Utilities

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Removal of Arsenic from Drinking Water using
Hybrid Ion Exchangers or HIX A Prudent approach
for Rural Water Utilities

• Presented
• by
• VEETech, P.C.
• 942 Millbrook Avenue, STE 6
• Aiken, SC

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Effect of Arsenic in Drinking Water

• Sources
• Natural Geochemical contamination through soil
  leaching
• Inorganic arsenic, which occurs as As(III) or
  As(V) in drinking water, presents great threat to
  public health
• Exposure can cause
• Thickening and decoloration of skin
• Nausea and Diarrhea
• Decreased production of blood vessels
• Skin cancer and tumors of the bladder, kidney,
  liver and lung

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Illustration of a typical three-step procedure to
disperse both crystalline and amorphous HFO
nanoparticles inside the spherical polymer beads
to form Hybrid Ion Exchangers or HIX
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Desirable Attributes of Fixed Bed Sorbents (e.g.,
HIX) for Arsenic Removal

• Excellent Mechanical Strength and Attrition
  Resistance
• Selective towards both As(III) and As(V)
• Does not require pre or post treatment (e.g.,
  pH)

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Desirable Attributes (contd)

• Does not alter the electrolytic quality of
  treated water
• Does not generate fines or pressure drops during
  long term column operation
• Efficiency is not affected by the presence of
  high concentrations of silica, phosphate, or
  sulfate in water
• Can treat up to 40,000 bed volumes (BV) of
  water/cycle
• Can be regenerated up to 20 to 30 cycles of
  operation
• Can remove multiple contaminants such as Ra, U,
  and perchlorate along with Arsenic

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Typical Influent / Effluent TDS vs. Bed Volume
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Typical Influent / Effluent pH vs. Bed Volume
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Typical Bench Scale Study Arsenic(III) Effluent
History for a column run
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Typical Bench Scale Study Comparison of Arsenic
and Silica Breakthrough
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Typical Pilot Scale Study Arsenic Effluent
History at City of Rosharon, TX
Inlet As 27ug/l Run length 14 days Flow rate
1.2 gpm Column Dia 3 Column Ht 2
Maximum contaminant level (MCL)
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Typical Pilot Scale Study Arsenic Effluent
History at City of Andrews, TX
Inlet As 25ug/l Run length 35 days Flow rate
0.2 gpm Column Dia 3 Column Ht 2
Arsenic ug/l
Maximum contaminant level (MCL)
Bed Volumes
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Typical Fixed Bed Sorbent (HIX) Based Arsenic
Removal System for Rural Water Utilities
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AVAILABLE TECHNOLOGIES/TREATMENT METHODS

• The Technologies/Sorbents that are available in
  the
• marketplace to remove arsenic from drinking
  water are
• Granular Ferric Oxide (GFH)
• E33 Granular Ferric Oxide (GFO)
• G2 Ferric Oxide Treated Diatomite
• Apyron Aqua-Bind SP60
• Most of the above sorbents lack Mechanical
  Strength
• and require pre/post treatment
• Most of the above media except HIX and G2 are not
• Regenerable. HIX clearly stands out particularly
  for
• simultaneous removal of Arsenic and other
  co-contaminants (U and Ra).

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Typical Installed Cost for Fixed Bed Systems
Population Served Service Flow Rate Installed Cost
100 7 gpm 20 K
300 20 gpm 38 K
500 35 gpm 60 K
1,000 70 gpm 85 K
3,000 200 gpm 200 K
5,000 350 gpm 300 K
10,000 700 gpm 525 K
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Typical Operating Cost for HIX Fixed Bed Systems
Range of Inlet Arsenic Concentration Cost/1000 gal of treated water
15 to 30 ppb 30 to 50 cents
31 to 60 ppb 50 to 75 cents
61 to 100 ppb 75 cents to 1.10
Note For inlet water containing Arsenic and
other co-contaminants like Radium or Uranium, the
operating cost for treatment is expected to
increase in the range of 40 to 60