The Price River Water Improvement District is a provider of drinking water and sewer and wastewater treatment services to residents and businesses in Wellington, Utah. In 2022, the district upgraded the WWTP to meet new nutrient removal standards of 1.0 mg/L total phosphorous.
Anaerobic selector basin with BioMix nozzle header firing
0٫40
hp/1,000 FT3 mixing efficiency,
60
% energy reduction
Challenge
As part of the upgrade, the solids contact basins were converted to anaerobic selector basins, and an efficient mixing system was needed to replace the existing diffused aeration system. Price River also needed to replace the diffused air mixing system in the anaerobic influent channel.
Solution
EnviroMix’s BioMix Compressed Gas Mixing System was chosen for both applications based on its ability to:
- Significantly reduce maintenance versus mechanical mixing.
- Optimize anaerobic conditions for VFA formation and impart negligible oxygen.
- Utilize the plant’s existing compressor system, making it more cost effective than other technologies.
In the anaerobic basins and anaerobic influent channel, BioMix delivers a 60% reduction in energy consumption versus alternative mechanical or diffused air mixing technologies.
The Price River staff has thoroughly enjoyed the low-maintenance aspect of the BioMix system. All in-tank components are maintenance free, non-clogging, and self-cleaning. The system is controlled by EnviroMix’s Zombie Valve Module (ZVM). The ZVM utilizes four air control valves and a zombie controller to allow operator adjustment of firing duration and frequency. Electrical requirements are limited to the power needed to operate the compressor and valve modules.
Existing compressor and receiver tank system that serves the BioMix system
Based on his nearly 30 years of industry experience, Superintendent Blaine Shipley stated, “I like the fact that there are no mechanical or electrical parts underwater. That's part of the reason I wanted to go this route versus some other kind of mechanical mixing. And I like the fact that it's pretty much all stainless steel. So, there's not much opportunity for corrosion.”
Results
As part of the BioMix Compressed Gas Mixing System acceptance validation, rigorous field performance testing was done in the anaerobic selector basins to verify the system does not impart measurable oxygen. Dissolved oxygen (DO) and oxidation-reduction potential (ORP) measurements were collected at four locations and three depths in each basin, once at the beginning and once at the end of the testing period. The results verified that the BioMix system did not impart measurable oxygen nor negatively impact anaerobic process conditions.