based in Atlanta, GEORGIA (US) (USA)
Hydrogen Peroxide typically controls odors and corrosion at treatment plant headworks by direct oxidation of hydrogen sulfide (H2S) within the wastewater. In the direct oxidation mode, H2O2 is applied to the wastewater 5-30 minutes prior to the point where the odors are being released, generally as the wastewater line enters the plant boundary.
The efficiency of hydrogen peroxide treatment depends upon the available reaction time, the level of iron in the wastewater (reaction catalyst), wastewater pH and temperature, and the initial and target levels of H2S odor. Under optimal conditions, effective dose ratios are 1.2 - 1.5 parts H2O2 per part dissolved sulfide, and can be reliably estimated through beaker tests.
H2O2 + H2S → S0 + 2H2O
Frequently, control of odors through the primary clarifiers is wanted. In such case, the mechanism of control is both direct oxidation of H2S (as it rises from the solids blanket), and prevention of odor generation (by supplying dissolved oxygen). Control is typically achieved with a booster dose of 1-2 mg/L H2O2 added to the clarifier influent. Higher doses or alternate modes of addition may be required in cases where: 1) hydraulic retention times are > 2-3 hours; 2) solids blanket depths are > 1-2 feet; 3) soluble BOD levels are > 200-300 mg/L; or 4) waste activated sludge is co-settled with the primary solids.
2H2O2 → O2 + 2H2O