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H2O2 |
Air |
| Description |
Hydrogen peroxide (H2O2) is a liquid product supplied as a 35% or 50% solution. It is available in containers of 50 or 300 gallons, or in bulk shipments of 500 - 20,000 gallons. Solid peroxide products (sodium percarbonate and calcium peroxide) are also available. |
Air is injected into the water using either a diffuser, venturi, or spraying apparatus.
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| Control Mechanism(s) |
Oxidizes H2S Retards septicity (adds dissolved oxygen) Promotes bio-oxidation of organic odors |
Retards septicity (adds dissolved oxygen)
Aids in stripping odors from the water
Promotes bio-oxidation of H2S and organic odors
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| Chemical Reaction(s) |
Neutral - Acid pH: H2S + H2O2 --> S + 2 H2O
Alkali: S2- + 2 O2 ----> SO42-
Prevention: 2 H2O2 ----> O2 + 2 H2O
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None applicable |
| Dose Ratios (lbs per lb-H2S) |
|
Neutral - Acid |
Alkali |
Prevention |
| Theoretical |
1.0 |
4.0 |
4.0 |
| Practical |
1.2 - 1.5 |
4.5 - 5.0 |
2 - 8 |
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| Theoretical: None applicable |
| Practical: None applicable |
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Applications |
Gravity mains (< 3-4 hours retention)Force mains (< 1-2 hours retention)
Terminus of long retention force mainsTreatment plant headworksSolids processingSeptage and leachate
Odor scrubbersPonds and lagoons |
Biological treatment processes (aerobic suspended floc)
Pressurized force mains (with retention time < 1 hour)
Wetwells
Holding tanks
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Advantages |
High selectivity toward H2SAdds dissolved oxygen to retard downstream septicity
Produces no harmful by-productsExtensive history of useIn-line nitrification and BOD reduction possible
Simple feed systemsRelative low feed rates (small storage tanks) |
Low operating cost
Easily implemented
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Disadvantages |
High dosages are needed for control > 2 hoursOrganic odors require bio-mediated oxidation
Reaction may take several minutes (without catalysis)Oxidizer classification may restrict dosing sites
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May air bind pumps and piping
Volatilizes odors into the atmosphere
Dissolution is inefficient, and oxygen solubility limited
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Special Notes |
Hydrogen peroxide is one of the more rapidly growing alternatives due to its cost-effectiveness and environmental compatibility. |
Air injection is most appropriate for preventing the formation of odors in open tanks and basins. Due to the limited solubility of oxygen in water, it is rarely appropriate for preventing septicity in conveyance pipes.
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