EnviroMix reduces O&M costs for Williams Monaco WWTP with BioMix Compressed Gas Mixing System

SACWSD Williams Monaco WWTP in Henderson, Colorado 

SACWSD Williams Monaco WWTP in Henderson, Colorado 

In 2015, South Adams County Water and Sanitary District (SACWSD) upgraded the Williams Monaco WWTP located in Henderson, Colorado, to improve treatment and increase capacity. The new plant design replaced the previous Moving Bed Biofilm Reactor (MBBR) secondary process with an 8 MGD Integrated Fixed Film Activated Sludge (IFAS) process in an A2O configuration for biological phosphorous removal as well as nitrogen reduction. The new design incorporated existing anoxic selectors and newly constructed anaerobic and anoxic selectors.

Challenge

Prior to 2015, submersible mechanical mixers were used to mix the anoxic selectors, presenting the WWTP with multiple challenges. The submersible mixers were inefficient regarding energy usage and required significant staff time for maintenance — both of these factors negatively affected O&M expenditures.

Solution  

The BioMix Compressed Gas Mixing System was selected by SACWSD and Burns & McDonnell, the engineering firm on the project, as an integral part of the plant upgrade. The technology was installed in the newly constructed anaerobic and anoxic selectors, and in the existing anoxic selectors.  

BioMix uniformly distributes mixing energy across the basin floor, as opposed to mechanical mixers which mix the tank from a single point. BioMix delivers 50-60% or greater energy savings compared to mechanical mixing.  

Uniformly spaced BioMix nozzles provide effective mixing. 

Utilizing a duty and a standby compressor, the BioMix system allows the WWTP to maximize operational reliability. A BioMix compressor system can be used to mix dozens of tanks, while mechanical mixers require at least one unit per basin. All in-tank components of a BioMix system are maintenance free, non-clogging, and self-cleaning. Systems require minimal maintenance of out-of-tank components (compressors, receivers, and air control valves) in controlled environments. 
The BioMix system provides complete mixing with proven negligible oxygen transfer, making it ideal for anoxic and anaerobic environments.  

Results

Andrew Waddoups, P.E., associate environmental engineer with Burns & McDonnell, offered his review of the technology, stating, "We are very excited about this project and the benefits EnviroMix will provide from the perspective of both energy efficiency and ease of maintenance. The EnviroMix system is a key part of the BNR Upgrades Project." 

Compatible with any tank geometry, BioMix nozzle headers are well-suited for long narrow basins. 

Overall, the BioMix system has provided the Williams Monaco WWTP:  

• Bottom-up mixing in a range of tank configurations 
• Uniformly distributed mixing energy 
• Operator-adjustable optimal mixing intensity 
• Maintenance-free in-basin nozzles