Suspended air flotation helps farm overcome treatment challenges
Problem:Chicken producer Fieldale Farms in Baldwin, Georgia faced an expansion that overwhelmed its wastewater treatment system. Designed for 800 gpm, it was operating at 900 gpm. Space constraints made adding a new dissolved air flotation unit impractical.
Solution: The company selected a suspended air flotation system from Heron Innovators. The conversion involved disconnecting air compressors, turning off pumps, removing lamella plates and installing SAF generators and clear mixers while using existing tanks. The systems increased capacity from 900 to 1,500 gpm per tank.
Result: TSS levels dropped from 150 to 70 ppm using 50% less polymer. The system proved easier to operate and maintain, handling shocks such as a 300-gallon peracetic acid spill, with minimal disruption. 916-408-6601; www.suspendedair.com
Clarifier enables plant to efficiently treat wet weather influent
Problem:The Fourth Creek Wastewater Treatment Plant, owned by the Knoxville Utilities Board, was built as an activated sludge facility with blending to handle peak flows. The board wanted to eliminate blending and provide full biological treatment for all flows. The utility also wanted greater treatment flexibility in a relatively short process time while maintaining a compact footprint.
Solution: The upgrade used plant grounds where there had been unused tankage. The phased approach converted a dual-train 9.5 mgd ACTIFLO system to the BIOACTIFLO system from Veolia Water Technologies, a high rate clarifier that includes a biological solids contact tank that can be incorporated to improve soluble BOD removal. A small stream of return activated sludge is borrowed from the secondary system and combined with the peak excess flows within the solids contact tank. A targeted MLSS concentration is maintained in the contact tank to facilitate rapid uptake of soluble BOD via contact stabilization. Clarification follows, producing high TSS and BOD removal.
Result: The system has proven reliable for handling peak flows. The clarification process and the ability to remove soluble and insoluble BOD in a short detention time met regulatory standards and is easy to operate. It was tested in 2018 and 2019 when the area received record rainfall and widespread flooding. The utility treated over 4 billion gallons of water during the event; the BIOACTIFLO process helped the plant handle the load and remain in compliance. 919-677-8310; www.veoliawatertech.com
Improving digester performance with nonobstructing heater
Problem: A Midwestern municipal sewerage district faced issues with its acid-phase steam injector units, including frequent plugging with foreign materials, high labor and parts costs, and disruptions to the digestion process.
Solution: District staff turned to Hydro-Thermal, a manufacturer of direct steam injection heaters, for an unrestricted flow solution called the Non-Obstructive Heater. It allows larger solids to pass through without causing blockages. The replacement units fit the original footprint with minimal piping modifications.
Result: The solution significantly reduced plugging and emergency work disruptions while optimizing the acid digestion process. This reduced labor and maintenance costs. 800-952-0121; www.hydro-thermal.com
