|
H2O2 |
Oxygen |
| 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. |
Oxygen may either be produced on-site (as a gas) or delivered/stored (as a pressurized liquid) in either bulk or pressurized containers of 25 - 30,000 lbs. |
| Control Mechanism(s) |
Oxidizes H2S Retards septicity (adds dissolved oxygen) Promotes bio-oxidation of organic odors |
Retards septicity (adds dissolved oxygen)
Oxidizes sulfide (enhanced by metal catalysis)
Promotes bio-oxidation of H2S and organic odors
|
| Chemical Reaction(s) |
Neutral - Acid pH: H2S + H2O2 --> S + 2 H2O
Alkali: S2- + 2 O2 ----> SO42-
Prevention: 2 H2O2 ----> O2 + 2 H2O
|
Neutral - Acid pH: 2 H2S + O2 ----> 2 S + 2 H2O
Alkali: S2- + 2 O2 ----> SO42- |
| Dose Ratios (lbs / lb-H2S) |
|
Neutral - Acid |
Alkali |
Prevention |
| Theoretical |
1.0 |
4.0 |
4.0 |
| Practical |
1.2 - 1.5 |
4.5 - 5.0 |
2 - 8 |
|
|
Neutral - Acid |
Alkali |
| Theoretical |
0.5 |
2.0 |
| Practical |
> 5 |
> 5 |
|
|
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 < 1-2 hours)
Inverted siphons
Holding tanks |
|
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) |
High dissolved oxygen levels are attainable
Relatively low cost |
|
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
|
Efficient dissolution of oxygen into the water requires pressurization
Significant storage and handling issues
|
|
Special Notes |
Hydrogen peroxide is one of the more rapidly growing alternatives due to its cost-effectiveness and environmental compatibility. |
Oxygen injection is affords greater D.O. levels than does air injection, and is particularly effective on high strength wastes. Its use is more common in Europe that the U.S. |
