Presentation on theme: "IN SITU TREATMENT WITH HYDROGEN PEROXIDE Bruce Leavitt PE PG, Consulting Hydrogeologist Washington, Pennsylvania Prepared in conjunction with West Virginia."— Presentation transcript:
IN SITU TREATMENT WITH HYDROGEN 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: Net alkaline mine drainage Rapidly oxidize ferrous iron in mine drainage 2 Fe 2+ + H 2 O 2 + 4 OH ¯ 2 Fe(OH) 3 Is used at some AMD treatment facilities. Freezing point -33 C° (35 % solution) Density 1.132 (35 % solution)
Flow 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 Quality LivengoodT&T DischargeRuthbelle est. Flow43175132 pH6.322.802.68 Acidity-48268371 Dissolved Fe44.834.2830.85 Ferrous Fe432.000 Dissolved Al0.0223.2930.87 Dissolved Mn0.421.411.73 Dissolved Ca147.3198.8215.6 Dissolved Mg34.0341.744.2 Sulfate460.1962.11125.6
Cost of Treatment 43 gpm @ 33.45 mg/L Ferrous required 6.2 to 6.32 mL/min of 35% H 2 O 2. 146.5 mL / 1000 gal. 600 gal H 2 O 2 = $3,400 $0.22 per 1000 gal treated. $0.0066 per mg/L/1000 gal.
Conclusions 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 continued 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.
Recomendations 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.