Fixed Bed Anion Exchange

for Color and Organic Removal

in Potable Waters

Troy L. Lyn, P.E.

October 12, 2015

Describe Ion Exchange

Describe Fixed Bed Anion Exchange

Components of Anion Exchange System

Advantages of Anion Exchange System

Challenges of Anion Exchange System

Existing Fixed Bed Systems

Objectives

Ion exchange is a reversible stoichiometric process in

which unwanted minerals (ion) in water are replaced

with less objectionable ones.

Ion exchange material or resin is a petrochemical

compound shaped into beads or a synthetic zeolite of

crystalline formulation of aluminates and silicates.

The exchange material can be brought back to

original form by regeneration reaction (typically salt or

brine solution).

The two types of ion exchange units are cation (water

softeners) and anion exchange devices.

Water softeners remove cations (positively charged

ions such as calcium and magnesium) and replace

them with sodium.

What is Ion Exchange?

Water treatment Softening

Partial demineralization

Alkalinity reduction

Sulfate removal

Nitrate removal

Fluoride removal

Organic / Color Removal

Purification and decolorization of sugar

Purification and recovery of drugs, vitamins, amino acids, etc.

Purification of DMF, Glyoxal, Caprolactum

Recovery of metals like Thorium, Uranium, Gold Silver, etc.

Catalyst in esterification, condensation, etc.

In water analysis

Purification of brine

Removing hazardous constituents from industrial effluents

Major Applications for Ion Exchange Resins

Utilize vessels like a pressurized filter – Not to be

confused with MIEX – a fluidized bed reactor

Anion exchange devices remove anions

(negatively charged ions such as arsenic and

nitrate) and replace them with chloride.

Used to remove slightly negatively charged

organic material for Color and Total Organic

Carbon (TOC) removal

System Manufacturers

Tonka Water

Hungerford & Terry

US Filter

What is Fixed Bed Anion Exchange?

Tonka Vessel

Thermax A72-MP - Macroporous, Strong Base Type I Styrenic Resin Successfully Piloted in Color/Organic Removal in South Florida

Applications – P&W, Cooper City, Pembroke Pines, Lantana, Davie.

Operational Systems in use at PBC,Pembroke Pines, Lantana, Davie.

NSF Certification

Other Resin Manufacturers Purolite (Lee County to be constructed)

DOW

ResinTech

Research Needed for Resin Comparison of Performance, Longevity, and Fouling.

Anion Exchange Resin for

Color/Organic Removal

AIXInfluent

AIX

Effluent

Regenerate Waste

Anion Exchange Components

Color Removal (>90%)

TOC Reduction (approximately 40 to 50%)

THMs and HAAs Reduction (approximately 40 to 60% when free

chlorine is used)

Low waste quantity (

Chlorine residual restrictions on resin

Increases chlorides in water

Regenerate Waste (Brine) Disposal Wastewater System – Industrial Pretreatment Limits or

Reclaimed Water Limits

Deep Well Injection

Typically used post treatment (lime softening

and filtration) to prevent fouling or plugging of

resin

Potential odors with new resin

Anion Exchange Limitations

The FICE 2005 Engineering Excellence Grand Award Project replaced and old treatment process that used aeration, chlorination, and filtration for iron removal. Project was constructed in 2004 for the 4 mgd facility at a cost of $4.0 M.

Town of Lantana WTP Process Improvements

Mathews Consulting/Globaltech

Anion exchange (3 vessels) for color and DBP precursor removal

Cation exchange for softening2 vessels – partial softening and blending

Sand filter replacement for iron removal

Converted from chlorine gas to sodium hypochlorite

Addition of ammonia for chloramine residual disinfection

Emergency generator upgrades

The 4 mgd anion exchange system was added at the end of the Town’s existing lime softening plant for color removal. Project was constructed in 2008 at a cost of $1.9 M.

Town of Davie Color Removal System

Globaltech – Design Build Project

Anion exchange for color and DBP precursor removal

Reduced raw water color ranging from 40 to 60 CU to less than 2 CU

Regenerate waste disposal via wastewater plant that shares plant site

WTP 8 currently uses lime softening with 10 mgd of anion exchange (7 vessels) as well as ozonation. The existing ozonation system is to be replaced with 14 to 20 mgd of anion exchange.

PBCWUD WTP 8 Anion Exchange System

Globaltech (Under Design)

10 vessels (14 mgd) to 14 vessels (20 mgd)

Four new 75 HP transfer pumps with VFDs

New 60-ton brine maker

Conversion of 1.25 MG Crom Tank toa 0.88 MG Regenerate Waste Storage Tank

New plant site wastewater lift station

Location Year Plant Capacity

(MGD)

Seminole County (Markham WTP) 2014 6.9

Arcadia 2013 3.0

Chuluota – Aqua America 2010 1.1

Pembroke Pines (Phase 2) 2009 7.6

Davie 2008 4.0

Palm Beach County WTP 8 2008 10.0

Lantana 2004 4.0

Pembroke Pines (Phase 1) 2000 6.0

List of Florida Anion Exchange / Organic Removal

Municipal Systems in Operation - Greater Than 1 MGD

Tonka Water Systems with Thermax Resin

Questions?