Wastewater treatment plants receiving inconsistent
influent loads are often challenged with maintaining
an effective biological treatment. Many of the key
microorganisms in wastewater processes are dependent
on organic substrate to grow and divide. When influent
flows are limited, the biodegradable carbon source for the
treatment system may be too low to sustain biomass. Not
having enough organic substrate in the plant will diminish
the biological treatment efficiency. Calculating the food to
microbiology ratio (F:M) is one way to monitor changes in
organic carbon quantity and biomass in a system. Although
optimal F:Ms are variable between different plants, F:Ms
will decrease below stable values when the carbonaceous
food supply is limited.1Augmenting a wastewater process
with an external carbon source can help to balance F:M.
BioLynceus® Candy Carbon® is a high strength organic
carbon product. The following paragraphs detail the use of
CC in a mechanical wastewater treatment plant (MWTP)
struggling with year-round biomass stability.
Figure 1. Resort location where the study MWTP received toxic waste from tourist and distilling activities.
A 0.06 MGD MWTP at a resort in Utah was having issues
maintaining a consistent F:M. During weekends and peak
recreation seasons, winter and summer, the resort hosted
thousands of visitors. The resort had consistently high
flows during these time periods.
1 Mishoe, G.H. (1999). F/M ratio and the operation of an activated sludge
process. Florida Water Resources Journal 3, 20–21.
Consequently, the biomass in the system wasn’t supplied
with a consistent food source to facilitate growth and
metabolism. Oppositely, during the weekdays and off
seasons, fall and spring, the biology in the plant suffered.
The organic carbon inputs were too low to sustain the
organisms that multiplied when visitors were present.
Issues arose during quick transitions between low and
high flows throughout the year. When high flows would
arrive, the plant biomass was dispersed and unable to
utilize the increased organic substrate in the influent. This
resulted in high biological oxygen demand and nutrient
concentrations in the effluent wastewater. The plant
operators struggled with this for years and needed to
secure a viable food supply for the biology when flows
decreased.
The plant was using Old Roy dog food as a daily organic
carbon supplement, but this did not effectively increase
the biology at the facility. Management at the plant
contacted BioLynceus®. A company representative
suggested replacing the dog food with CC. The CC
treatment would provide a concentrated organic carbon
source to sustain the wastewater microbiology when
tourists were not around.
Over the course of 120 days, CC was applied to the aeration
basin. The treatment kept the biomass active regardless
of variable influent loading. An additional benefit for the
plant was that CC promoted long-term denitrification
better than ever before. After the biology in the plant was
sustained all year, the facility manager reported, “I am
extremely pleased with the BioLynceus® product.”
The treatment established a balanced F:M in the system
and improved denitrification.
BioLynceus® Candy Carbon® helps to maintain stable F:M in wastewater systems.