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Ready, AIMS, Fire:Treatment Solutions for Arsenic,
Iron, Manganese, and Sulfide2018 PAAW Annual Conference
Brit MerolaAdEdge Water Technologies
About AdEdge Started company in 2002, target was the emerging arsenic marketplace to the new lower standard of 10 ppb.
Over 450 installations for arsenic removal…more than any company globally
We have sold over 750 systems into 15 countries/45 States/9 Canadian Provinces
Multiple contaminant specialist 20/20 matrix
Design solutions from 0.5 gpm to 12 MGD
AdEdge Treatment Matrix
Systems by Contaminants
Contaminant Number of Systems
(different technologies & media)
Arsenic removal > 450 systems
Iron, Manganese & Sulfide removal > 250 systems
Nitrate removal > 15 systems
Radionuclides > 30 systems
Color, Odor, & TDS > 30 systems
Purpose / Agenda
Arsenic, Iron, Manganese, and Sulfide Contamination
Treatment Options Adsorption
Oxidation/Filtration
Coagulation/Filtration
EPA Max Contaminant Levels
MCL
As = 0.01 mg/L
Secondary MCL
Fe = 0.3 mg/L
Mn = 0.05 mg/L
SO4 = 250 mg/L Sulfide > 0.5 – 1 mg/L causes aesthetic issues
7
• Adsorption (media-based)• Various Adsorbents
• Oxidation/Filtration
• Coagulation/Filtration
• Anion Exchange
• Reverse Osmosis
Primary Arsenic Treatment Options
Technology Considerations
AdsorptionSimple to operateLow Capital/Labor Cost and Ease of UseIdeal for water with low interferences
Oxidation + FiltrationCo-contaminant removal (with naturally occurring high Fe)Moderate Capital/Lowest Opex
Coagulation + FiltrationCo-Contaminant removal (with coagulant addition)Moderate Capital/Opex
Common Methods for As Treatment
Technology Considerations
Oxidation + Filtration Oxidant Addition
Aeration (Oxygen) + FiltrationKineticspH
Cation Exchange (Softening)Water chemistry (hardness)Salt and Brine
Polyphosphate (Sequestering)NOT REMOVALDosing challenges
Common Methods for Fe/Mn Treatment
10
Hydrogen sulfide (H2S) is a gas that is insoluble in water, but the gas remains trapped within the water
Concentrations from 0.5 – 1 ppm – musty, swamp smell
Concentrations greater than 1 ppm smell like rotten eggs and create corrosion issues to plumbing
Health risks include nausea, stomach pain, and laxative effect
Sulfide – Why should it be removed?
Technology Considerations
Oxidation + Filtration Oxidant Addition
Air StrippingSulfide < 2.0 ppmSulfide may still be noticeablepH
Carbon Filtration Quickly exhausted, <0.3 ppm ideal
Common Methods for Sulfide Treatment
Adsorption(Arsenic)
Service Flow In
Adsorption Media
Underbedding / gravel
Head space forbackwash expansion
Backwash In
Backwash out
Service out
Underdrain
Arsenic Treatment: Adsorption
Single or multi-vessel configurationDownflow service Parallel or Lead/LadBed depths 34”-36” typicalHub/laterals and distributor internalsPeriodic backwashing
Arsenic Treatment:Adsorption – Granular Ferric Oxide (GFO)
Iron-based adsorbent media
Bayoxide E33 Granular Ferric Oxide media
Dry, granular product
High capacity commercial media
Reduces As (III) and As (V)
Operates over pH range (5.5 – 8.5)
Non-hazardous waste when spent
NSF 61 Certification
12 years of development and application, & commercial use
Arsenic Treatment:Adsorption Media Life Performance Factors
Incomplete water data for design
High iron or manganese (>0.3, 0.05 mg/L)
Arsenic (III) with no oxidation
High silica >45 mg/L
High phosphate >0.4 mg/L
High pH > 8.3
Presence of sulfides
Arsenic Treatment: Adsorption Backwashing and Disposal
Backwash every 45-60 days
Manual valve system OK
Backwash Recycle
Media non-hazardous waste when spent
Accepted by sanitary landfill after TCLP
Richlandtown, PAFlow Rate 100 gpm
Arsenic, Raw 0.028 mg/L
Fe, Raw 0.8 mg/L
Media E33
BW Frequency 1x/month
InstallationDate
Summer 2007
Bakersfield, CAFlow Rate 700 gpm
Arsenic, Raw 0.028 mg/L
Media E33
BW Frequency Every 30 – 90 days
Installation Date Fall 2017
Oxidation Filtration and Coagulation
Filtration
Filtration Treatment Technologies
Oxidation Filtration Naturally occurring Fe + As
(ratio >30:1)
Elevated Fe/Mn/H2S
Coagulation Filtration Coagulant addition
Elevated As + Fe
As + Fe + Mn
As + Mn
Oxidation/Filtration (O/F) – (Fe/Mn/H2S)
Oxidant
Oxidation / Filtration
Media System
Backwash WasteOrH2Zero System
Storage / Distribution
Backwash Supply
Oxidation/Filtration (O/F) – (As/Fe/Mn/H2S)
Oxidant
Oxidation / Filtration
Media System
Backwash WasteOrH2Zero System
Storage / Distribution
Backwash Supply
OxidantpH Adjust
Coagulation/Filtration (C/F) – (As/Fe/Mn/H2S)
Oxidant
Coagulation / Filtration
Media System
Backwash WasteOrH2Zero System
Storage / Distribution
Backwash Supply
OxidantFerric ChloridepH AdjustPolymer
Oxidation/Filtration:Design Basis
GPM = Gallons per Min
Media Surface Area = PI*r2
Oxidation/Filtration Media:Coated Sand
Coated Sand (ADGS+)
Oxidant(s) Chlorine (sodium hypochlorite)
MnO2 Content 3% - 5%
PerformanceFe < 7 mg/LMn < 0.5 mg/L
Loading Rate 3 gpm/sqft – 6 gpm/sqft
Backwash Rate 12 gpm/sqft
Conneaut Lake, PAFlow Rate 250 gpm
Arsenic, Raw 0.028 mg/L
Fe, Raw 0.8 mg/L
Media ADGS+
BW Frequency 2x/week
InstallationDate
Summer 2009
Oxidation/Filtration Media:Solid Phase Manganese Dioxide
20% MnO2 (AD26L)
Oxidant(s) Chlorine (sodium hypochlorite)
MnO2 Content 15% - 20%
PerformanceFe < 7 mg/LMn < 1.2 mg/L
Loading Rate 5 gpm/sqft – 9 gpm/sqft
Backwash Rate 17 gpm/sqft
All Seasons, PAFlow Rate 27 gpm
Iron, Raw 0.7 mg/L
Mn, Raw 0.88 mg/L
Media AD26L
BW Frequency Every 4 days
InstallationDate
Winter 2017
New Windsor, NYFlow Rate 5000 gpm
Fe, Raw 0.12 mg/L
Mn, Raw 1.1 mg/L
Media AD26L
BW Frequency Daily
InstallationDate
Summer 2018
Oxidation/Filtration Media:Solid Phase Manganese Dioxide
80% MnO2 (AD26)
Oxidant(s) Chlorine (sodium hypochlorite)
MnO2 Content > 80%
PerformanceFe < 7 mg/LMn < 2 mg/L
Loading Rate 5 gpm/sqft – 12 gpm/sqft
Backwash Rate 20 gpm/sqft
Hemlock Farms, PAFlow Rate 600 gpm
Iron, Raw 0.35 mg/L
Mn, Raw 0.4 mg/L
Media AD26
BW Frequency 2x/week
InstallationDate
Winter 2015
Honesdale, PAFlow Rate 270 gpm
Sulfides, Raw Present
Mn, Raw 0.2 mg/L
Media AD26
BW Frequency 2x/week
InstallationDate
Summer 2010
Wallenpaupack, PA Flow Rate 45 gpm
Sulfides, Raw 630 ppb
Media AD26
BW Frequency 2x/week
InstallationDate
Spring 2009
9.5 feet
17.5 feet
7.5 feet
13 feet
45% SMALLER
3 gpm/sqft
9 gpm/sqft
Higher MnO2 Filter systemConventional Filter
Why Media Selection is Important
Oxidation/Filtration:Special Considerations
Ammonia (high chlorine demand)
pH (> 8)
Sulfides (oxidant demand)
TOC > 1 mg/L (oxidant demand)
Adverse reactions with TOC and Chlorine to form disinfection by products (THMs, HAA5, etc)
Oxidation/FiltrationSystem Operational Cycles
Service (downflow)◦ 12-32 hours of continuous run time◦ Run length depends on Fe, Mn concentrations
Backwash (upflow 8 min)◦ Removed filtered suspended Fe/Mn solids◦ Backwash until water runs clear
Rinse (downflow 2 min)◦ Flushes out any remaining residual ppt Fe and
Mn in the bed before service
Thank You