Biological Processes
Vapex > Hydroxyl Ion Foggers Solve Odor Problems
Chandler, AZ
Chandler, Ariz., located near Phoenix, is one of the fastest growing communities in the nation. The city's population swelled to more than 240,000 in 2006, from 29,000 in 1980, and is still rising, according to census data. The city's wastewater collection and treatment systems have had to keep pace. The extension of sanitary sewers and lift stations into newly developed areas created hydrogen sulfide odor "hot spots," which resulted in a number of citizen complaints.
"We get phone calls, you bet," said Alvin Robertson, Chandler collection systems superintendent. "And some of them from some pretty important people in the community." Currently, the Chandler Municipal Utility maintains more than 1380 km (857 mi) of sanitary sewers, 18,000 manholes, 70,000 sewer taps, and eight pump stations throughout its 180-km2 (70-mi2) area. Initially, the city used several carbon odor scrubbers and sodium hypochlorite for odor control.
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CB&I > Biosolids Profile - ESD Class A System
London, OH
In 2006, the City of London embarked on a major expansion of its' wastewater plant including a new biosolids processing facility to replace existing conventional digesters. The new digestion system was designed as a two phase, Class A system with CB&I's ATP/ESD process.
The Phase 1, thermophilic ATP Reactor acidifies the incoming feed sludge and provides pathogen reduction in a batch feed process in compliance with the USEPA time-temperature requirements. The Phase 2, mesophilic Egg Shaped Digester (ESD), utilizes the volatile acids, generated in the first phase, to further reduce solids and produce methane, completing the solids reduction process.
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Aqua-Aerobic Systems, Inc. > Buxahatchee WWTP
Calera, AL
The Buxahatchee Wastewater Treatment Plant in Calera, Alabama was built in 1960. It upgraded in 1985 to a 0.75 MGD capacity extended aeration system with integrated clarifier and traveling aeration bridge for nitrification. By 2004, the system could no longer handle the flow capacity brought on by community growth, nor the increased stringent nutrient limits set by the Alabama Department of Environmental Management (ADEM). To resolve the plant's issues an upgrade was in order. The CIty of Calera decided to investigate several other treatment technologies, and required a written process performance guarantee. The only company that met the criteria was Aqua-Aerobic Systems with the AquaSBR® sequencing batch reactor (SBR) and AquaDisk® cloth media filters. Not only was Aqua the most cost-effective choice due to the technologies' small footprint, but the new treatment train could also provide advanced nitrogen and phosphorous removal without the use of alum or other chemicals.
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Vapex Inc. > Hydroxyl Fogging Technology Helps Utility Eliminate Sewage Odors
Hot Springs, AR
Hot Springs, AR, lift station manager Craig Stevens knows when his system has odor problems by the number of phone calls he receives from upset citizens. In the last few years, those complaints have been declining.
Since 2003, Hot Springs has been regularly installing hydroxyl ion fogging technology in its pump station wet wells to oxidize hydrogen sulfide and eliminate H2S odors.
"We've had real good results," said Stevens of the odor control fogging units, developed and marketed under the brand name O-Mega by Vapex, Inc., Orlando, FL. "We put the first two into our main stations, and now we have a total of nine units in operation. We try to budget for 1-2 more every year."
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CB&I > Biosolids Profile - ESD Class B System
Spokane, WA
In 2006, the City of Spokane contracted with Garco Construction and CB&I to construct improvements to its' Riverside Park Water Reclamation Facility. The work involved the replacement of a 30 year old concrete anaerobic digester with new steel Egg Shaped Digesters (ESD) and related systems for mixing, heating and process control.
The City evaluated several factors, resulting in selection of steel ESD, including:
- A need to install more capacity in an extremely limited footprint.
- Steel ESD provided better safety relative to the failed post-tensioned concrete digester.
- The vessel is completely gas tight so it minimizes impact on the surrounding neighbors and environment.
- A faster construction schedule and improved constructability could be realized with steel ESD.