Presentation on theme: "In Situ Treatment with hydrogen Peroxide"— Presentation transcript:
1In Situ Treatment with hydrogen Peroxide Bruce Leavitt PE PG, Consulting HydrogeologistWashington, PennsylvaniaPrepared in conjunction with West Virginia Universityunder a grant fromthe Office of Surface MiningApplied Science Research Program
2Hydrogen Peroxide: Net alkaline mine drainage Rapidly oxidize ferrous iron in mine drainage2 Fe2+ + H2O2 + 4 OH¯ → 2 Fe(OH)3Is used at some AMD treatment facilities.Freezing point -33 C° (35 % solution)Density (35 % solution)
26Flow 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.
27Estimation of Ruthbelle Water Quality LivengoodT&T DischargeRuthbelle est.Flow43175132pH6.322.802.68Acidity-48268371Dissolved Fe44.834.2830.85Ferrous Fe2.00Dissolved Al0.0223.2930.87Dissolved Mn0.421.411.73Dissolved Ca147.3198.8215.6Dissolved Mg34.0341.744.2Sulfate460.1962.11125.6
28Cost of Treatmentmg/L Ferrous required 6.2 to 6.32 mL/min of 35% H2O2.146.5 mL / 1000 gal.600 gal H2O2 = $3,400$0.22 per 1000 gal treated.$ per mg/L/1000 gal.
29ConclusionsIn 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.
30Conclusions 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 $ 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.
31RecomendationsThe 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.