A North American food processing plant faced regulatory action due to high BOD, TSS and grease (FOG) in their discharge, as well as a highly contaminated lagoon which emitted unpleasant odors. The waste consisted of high levels of protein and vegetable oil. Figure 1 shows the initial condition of the wastewater lagoon.
Figure 1: Lagoon Before Treatment
The recommended solution was bio augmentation and extra aeration to revitalize the lagoon and thus degrade the collected BOD and FOG. BioPlus BA3920 was used to rapidly regrow a population of bacteria.
As time was of the essence, an elevated dosage of 4 pails per day was recommended for the first 5 days, followed by a maintenance dosage of 20 lbs per day thereafter.
pH, ammonia, and phosphate were checked routinely as part of the service program. Plant personnel checked COD and FOG daily.
Result
Within a day or two a large amount of white foam formed as the biomass began to grow rapidly. This is often seen with high F/M, fast growing biomasses. See Figure 2. This indicated the system was coming back to health.
?Figure 2: ?High Growth Rate shown by Foam formation?
Figure 3: Lagoon after 10 days treatment?
Figure 4: Lagoon after 14 days treatment?
By the 10 th day after the first application of BioPlus, most of the foam had disappeared. This was as a result of an older or more stable biomass developing. See Figure 3. In addition, odor was no longer a problem.
By Day 14, the supplemental aeration had been turned off and the pond surface was mostly clear of foam and floating grease. See Figure 4.
At this point, the plant was able to meet their discharge permit and resume normal wastewater discharge.
conclusions
- BioPlus BA3920 accelerated bacterial growth rates and rapidly removed BOD and Grease from a wastewater lagoon.
- Odor emissions were also controlled.
- Customer was able to avoid regulatory fines and shutdown and resume compliant wastewater discharge.