IN SITU TREATMENT WITH HYDROGEN PEROXIDE Bruce Leavitt PE PG, Consulting Hydrogeologist Washington, Pennsylvania Prepared in conjunction with West Virginia.
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IN SITU IN SITU TREATMENT TREATMENT WITH WITH
HYDROGEN PEROXIDEHYDROGEN PEROXIDE
Bruce Leavitt PE PG, Consulting Hydrogeologist Washington, Pennsylvania
Prepared in conjunction with West Virginia University under a grant from
the Office of Surface Mining Applied Science Research Program
Hydrogen Peroxide:Hydrogen Peroxide:
Net alkaline mine drainage Rapidly oxidize ferrous iron in mine drainage2 Fe2+ + H2O2 + 4 OH¯ → 2 Fe(OH)3
Is used at some AMD treatment facilities.Freezing point -33 C° (35 % solution)Density 1.132 (35 % solution)
T & T Mine ComplexT & T Mine Complex
Mine Portal Discharge Mine Portal Discharge
H-Flume & Sample PipeH-Flume & Sample Pipe
T & T Water QualityT & T Water Quality
Year pH Acidity Sulfate Al Fe Mn1996 2.80 1324.6 1287.3 50.2 213.7 2.261997 2.82 952.1 1158.7 35.8 197.2 2.211998 2.81 642.8 1115.3 34.3 152.3 1.951999 3.07 670.2 1216.7 36.6 139.5 1.922000 2.95 865.6 1630.2 58.9 177.3 2.682001 3.19 509.4 1743.8 32.1 99.0 2.462009 2.80 453.3 1237.1 25.1 34.4 1.39
Well LocationsWell Locations
Two Inch Well with Two Inch Well with Sampling Well DischargeSampling Well Discharge
Five Inch Well CasingFive Inch Well Casingya gotta love hydrostatic pressureya gotta love hydrostatic pressure
Hydrogen Peroxide StorageHydrogen Peroxide Storage
Variable Peristaltic PumpVariable Peristaltic Pump
Effect of Peroxide AdditionEffect of Peroxide Addition
Bench TestsBench Tests
10 liter continuously stirred Dilute 35% H202 to 11.67%
Monitor pH, ORP, & DO Micro pipette (0.02357 g/dose)Aeration tests with and without peroxideSettling tests
T & T #2 Mine WaterT & T #2 Mine Water
y = 6.578e-0.29x
R² = 0.997
5.8
6
6.2
6.4
6.6
6.8
0 0.1 0.2 0.3 0.4 0.5
pH
grams 35 % H2O2
10 Liter Bench TestpH
T & T #2 Mine WaterT & T #2 Mine Water
y = 521.9x2 + 214.7x - 22.90R² = 0.998
-500
50100150200250300
0 0.1 0.2 0.3 0.4 0.5
ORP
mill
i vol
ts
grams 35 % H2O2
10 Liter Bench TestORP
Settling of Peroxide Treated Mine WaterSettling of Peroxide Treated Mine Water
50 min.
100 min.
24 hours
Travel TimeTravel Time Ruthbelle to main discharge 32 hours at 700 to
750 gpm, Coastal Coal dye test. Coastal well to sampling well: 87 minutes first
arrival, 212 minutes complete reaction.
-100-80-60-40-20020
5.906.006.106.206.306.406.50
0 200 400 600 800 1,000 1,200 1,400
ORPpH
Minutes
Travel Time Injection Well to Sampling Well
pH ORP
Peroxide Dosing Rate Peroxide Dosing Rate
Aeration with pH MonitoringAeration with pH Monitoring
Carbon Dioxide RemovalCarbon Dioxide Removal
5
6
7
8
9
0 10 20 30 40
pH
Minutes
Aeration of Untreated and Peroxide Treated Mine Water
Untreated Treated
Determination of Complete Determination of Complete Oxidation Oxidation In SituIn Situ
Dissolvedy = 0.157x + 0.026
R² = 0.990Dissolved
y = 0.156x + 0.014R² = 0.994
0%
20%
40%
60%
80%
100%
0.00 2.00 4.00 6.00 8.00 10.00
ml / minute 35% H2O2
In Situ Percent Iron Oxidized / Settled
Dissolved Ferrous Settled
ORP at the DischargeORP at the Discharge
0
100
200
300
400
500
600
700
800
0
50
100
150
200
250
300
350
400
07/15/09 08/15/09 09/15/09 10/15/09
ORP
gpm
T&T Discharge
2" Well NoInjection
MiddleWell
NoInjection
Percent Ferrous Iron in the Percent Ferrous Iron in the Mine DischargeMine Discharge
0
5
10
15
20
25
30
35
40
0
50
100
150
200
250
300
350
400
07/15/09 08/15/09 09/15/09 10/15/09
Perc
ent f
erro
us ir
on
gpm
T&T Discharge
2" Well NoInjection
MiddleWell
NoInjection
Dissolved Iron at the DischargeDissolved Iron at the Discharge
0
10
20
30
40
50
60
70
80
0
50
100
150
200
250
300
350
400
07/15/09 08/15/09 09/15/09 10/15/09
Disso
lved
Iron
gpm
T&T Discharge
2" Well NoInjection
MiddleWell
NoInjection
0
200
400
600
800
1000
1200
1400
1600
0
50
100
150
200
250
300
350
400
07/15/09 08/15/09 09/15/09 10/15/09
Diso
lved
Sulfa
te
gpm
T&T Discharge
2" Well NoInjection
MiddleWell
NoInjection
Flow in the Mine EntryFlow in the Mine Entry
Mine Discharge 175 gpm.Calculated flow in the test entry 43 gpm.Calculated flow is 24.6% of total flow.Mined area is about 33% of total mined
area.Flow unlikely in up dip entry.Possibilities: Non-uniform recharge, Sludge
disposal, Flow in up dip entry.
Estimation of Ruthbelle Water Estimation of Ruthbelle Water QualityQuality
Livengood T&T Discharge Ruthbelle est.
Flow 43 175 132
pH 6.32 2.80 2.68
Acidity -48 268 371
Dissolved Fe 44.8 34.28 30.85
Ferrous Fe 43 2.00 0
Dissolved Al 0.02 23.29 30.87
Dissolved Mn 0.42 1.41 1.73
Dissolved Ca 147.3 198.8 215.6
Dissolved Mg 34.03 41.7 44.2
Sulfate 460.1 962.1 1125.6
Cost of TreatmentCost of Treatment
43 gpm @ 33.45 mg/L Ferrous required 6.2 to 6.32 mL/min of 35% H2O2.
146.5 mL / 1000 gal.600 gal H2O2 = $3,400
$0.22 per 1000 gal treated.$0.0066 per mg/L/1000 gal.
ConclusionsConclusions
In Situ oxidation of ferrous iron using hydrogen peroxide has been demonstrated. The reaction is rapid and proportional to dose.
Either pH, ORP, or both may be used to determine the completion of the oxidation process so that over treatment does not occur.
Hydrogen Peroxide addition does not affect the amount of carbon dioxide dissolved in the mine water.
Conclusions Conclusions continuedcontinued
Hydrogen peroxide can be used to determine the volume of flow in an entry.
Injection of hydrogen peroxide into a point of concentrated flow was deemed essential.
The chemical cost of Hydrogen Peroxide treatment has been calculated to be $0.0066 per mg/l ferrous per 1000 gallons.
The estimated capital cost for a single site is $36,000 although this number will vary with site specific conditions.
RecomendationsRecomendations
The potential addition of alkalinity to the sludge disposal water in T&T #3 should be investigated.
In Situ settlement of iron should be achievable in T&T #2 if the location of the injection well is located further in-by the test location.
Pre-aeration may reduce ammonia requirement.
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