A 2 MGD domestic wastewater treatment plant in Pennsylvania was experiencing excessive fats, oil and grease in their aeration tanks causing foam and poor BOD reduction.

Investigation:

In February 2017 they began an augmentation program with BioRemove 4200 to degrade the excessive FOG.  For the first week they added 4 pounds of bacteria per day to the aeration tanks; followed by a maintenance dosage of 1 pound per day.

Specifics related to the application:

By the second week they noticed less grease and foam in the plant.  After 6 weeks the foam was gone and a significant reduction in BOD was also noticed.  The biggest savings was noticed in their digester hauling, due to a more efficient aerobic digester with less grease they were able to haul away more solids, less water for a $35,000 savings for the year!  The cost of the bacteria for the 11 month augmentation program was $4,700 for a net savings of $30,300.

Conclusion:

The WWTP with a daily maintenance dosage of bacteria was able to control the FOG in the aeration tank, eliminating foam and lowering BOD.  The aerobic digester had a better solids handling yield providing a significant cost savings to the township.