The Client
A Central Ohio Municipal WWTP, with conventional activated sludge, processes an average flow rate of 5 MGD. The biosolids are processed utilizing typical belt press dewatering equipment.
The Client’s Needs
A wastewater treatment plant in Central Ohio used a primary clarification system which contributes to excessive odors within the belt press dewatering building.
Sludge is stored in a gravity thickener and the belt press is operated approximately 27 hours a week (3 days @ 9 hrs/day).
While H2S is not a significant contributor of the odor, there are other malodorous compounds that create an unpleasant condition for the operations staff.
The Solution
The Hydrex™ Odor Control technology is a very robust redox process that quickly oxidizes sulfides and other malodorous compounds.
In 2 to 3 minutes of adequate mixing, the combination of Hydrex™ 67808 and Hydrex™ 9562 will remove > 90% of hydro-sulfides and the only by-products are elemental sulfur, dissolved oxygen, and water.
Injecting the Hydrex™ chemistries in-line, immediately upstream from the belt press dewatering equipment, allows for a safer and more pleasant work environment.
The Benefits
- Quick solution
- Enhances health & safety of employees
- Non-hazardous option
- Reduction of malodorous odors
- No harmful by-products
Process Description
The Hydrex™ 67808 lean chelated iron (Fe3) complex is dosed into a manifold or pipe, as shown below, where it reacts with hydrogen sulfide and creates elemental sulfur, thus losing an electron, resulting in a rich (Fe2) molecule. When an oxygen source (Hydrex™ 9562) is introduced it regenerates the Hydrex™ 67808 chelated iron molecule and allows it to react with additional hydrogen sulfide. This redox process is created repeatedly until there is no presence of hydrogen sulfide available.
