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.