|
H2O2 |
Potassium Permanganate |
| 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. |
Potassium permanganate (KMnO4) is a granular product available in a 25 or 50 kg pales, 4000 lb bins, and bulk deliveries of up to 40,000. A larger "nugget" product is available for solids blankets (clarifiers) and other slow-release applications. |
| Control Mechanism(s) |
Oxidizes H2S Retards septicity (adds dissolved oxygen) Promotes bio-oxidation of organic odors |
Oxidizes 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: 3 H2S + 2 KMnO4 ----> 3 S + 2 MnO2
Alkali: 3 S2- + 8 KMnO4 ----> 3 SO42- + 8 MnO2 |
| 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 |
|
|
Neutral - Acid pH |
Alkali |
| Theoretical |
3.1 |
12.4 |
| Practical |
4 - 5 |
12 - 15 |
|
|
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 |
Terminus of collection lines
Septage and leachate
Solids processing
Ponds and lagoons
Recycle streams
|
|
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) |
Fast reaction
Effective for organic odors
|
|
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
|
Relatively high cost
Labor intensive feed systems
Messy to handle
Provides no residual H2S control
Solids production is > 3 lbs/lb-Sulfide
Oxidizer classification may restrict feed sites
|
|
Special Notes |
Hydrogen peroxide is one of the more rapidly growing alternatives due to its cost-effectiveness and environmental compatibility. |
KMnO4 finds its widest use in solids processing where its fast reaction with organic odors is valued. |
