MODERN UTILITY GOALS FOR ODOR AND CORROSION CONTROL, INCLUDE:
- H2S Prevention and Control
- Proven Corrosion Control (raise surface pH of corrodible surfaces)
- Added value for plant BNR processes and solids treatment
Several iron, iron catalyst and peroxide treatments have emerged over the years, and all are designed to treat hydrogen sulfide that has already formed in the collection system. These treatments can be classified as:
- Iron Sulfate or Iron Chloride treatment
- Iron Compound added, and wastewater stream later treated with Hydrogen Peroxide
- Iron Catalyst in combination with Hydrogen Peroxide
The purpose of this document is to illustrate the pitfalls, and hidden costs inherent in depending upon iron and hybrid iron, plus peroxide treatments. What may initially appear to be a cost effective treatment strategy will often result in increased costs and can increase corrosion.
Iron and other hybrid treatments often claim that they prevent corrosion by reducing sulfide gas, but only Thioguard can actually result in increased surface pH on pipes and other infrastructure, in addition to reducing hydrogen sulfide gas. Corrosion is a system-wide problem, requiring a system-wide solution. Thioguard Technical Grade Magnesium Hydroxide treatment is a proven, superior alternative, delivering added value throughout your operation.
The following is a quick comparison of Thioguard to three common classes of treatment:
IRON SALTS/IRON COMPOUNDS TREATMENT
When treating with iron salts, what happens to the alkalinity in the wastewater? One pound of iron salts consumes 1.75 lbs. of alkalinity. Every gallon of iron sulfate, upstream of the plant and in biological processes, can result in significant alkalinity replacement costs later on.
Does iron addition prevent corrosion? No, iron compounds are acidic in nature, and will cause or increase corrosion at your plant. In addition, using iron and proprietary catalysts requires eye wash installations and extensive PPE, one more “hidden cost” of using an outdated technology.
HYBRID IRON, CATALYST AND PEROXIDE TREATMENTS –
ANOTHER QUESTIONABLE OPTION
These treatments depend on Iron or a catalyst to achieve hydrogen sulfide complexation, followed by peroxide as a strong oxidant to oxidize the sulfide. Some catalyst treatments warn not to combine their product with hydrogen peroxide – due to the potential for an exothermic reaction. Why introduce this kind of a hazard, when it can be easily avoided?
In general, the iron treatments above do little or nothing to prevent corrosion in long sewer lines, and when used for odor control, they simply cannot compare to the long lasting power of Thioguard to deliver consistent, reliable system-wide performance.
INCREASED ACIDITY = INCREASED CORROSION
INCREASED SURFACE pH = INCREASED STRUCTURAL LONGEVITY
In an acidic environment (pH=2), corrosion is rampant, tearing through 2″ of concrete in as little as 8 years. When effective surface pH=4, similar corrosion levels are pushed out to 50+ years.
COMPARISON TO THIOGUARD CHEMISTRY
In contrast, Thioguard does nothing to lower the pH of the wastewater, produces no reaction products that can lead to additional sulfide production, and produces no sludge to settle out in the system or to be dewatered at the WWTP. The reaction is as follows:
The Magnesium binds the sulfide in a similar manner to iron and it will not be released unless the pH drops to 5.5 which is not normal In wastewater. More importantly, Thioguard is preventative and controls the formation of sulfide by increasing the pH and retarding the Sulfate Reducing Bacteria activity.
CHOOSING THIOGUARD WILL:
- Decrease Maintenance
- Reduce Capital Replacement Costs
- Decrease FOG related SSOs and ARV Malfunction
- Reduce Overall Costs