Upon discovering that its BOD effluent levels were exceeding permitted discharge parameters by some 300 percent, a central Florida juice processor took action to investigate and remedy its treatment plant upset. The culprit: a new antibacterial cleaner introduced plant-wide last summer, for sanitizing process equipment and production lines.
It was discovered that the sanitizing agent even killed off the beneficial bacteria downstream, in the plants' sequential batch reactor (SBR) pre-treatment system. No domestic discharge enters the plant's on-site treatment system, which consists of a 500,000 gallon main reactor (aeration/ settling tank) and a smaller aeration blower.
The plant's waste stream averages 80,000 gpd, increasing to 120,000 gpd during heaviest production periods. This single-source industrial flow comprises a substantial percentage of the overall volume discharged into the local municipal sewer collection and treatment system (POTW). Close attention is devoted to the plant's BOD/COD levels. Inbound BOD/COD levels from the processing plant commonly exceed 2,500 ppm, with permitted discharge levels of less than 250 ppm BOD and 400 ppm COD. Those levels jumped to 1600 ppm after the upset.
The processor has included bioaugmentation — via regular inoculation of beneficial microbial cultures — as a routine element of its on-site wastewater treatment system. Upon discovery that the SBR's biological activity was dormant, the plant operator conferred with microbiologists at Osprey Biotechnics, the manufacturer and vendor of the bioinoculants. Use of the new sanitizing agent was discontinued in the plant, in favor of previous cleaners approved for the processor's overall HACCP plan.
Next, three 55-gallon quantities of Osprey's Munox® Hungry Bacteria were administered in a single dosage. This reintroduced populations of the microbes which are vital to biological degradation and elimination of BOD/COD (as well as improving settling, reducing sludge, eliminating odor and other benefits). The microbial inoculation immediately helped lower BOD/COD levels, according to the plant operator.
As a stabilized, live vegetative technology, these versatile bacterial strains require no germination period, thus go to work immediately to create more complete metabolism of industrial waste. Conventional bacterial "spores" require time to germinate — and require optimal environmental conditions — before reaching a metabolic state.
Following bioinoculation, the treatment system still didn't yield the effectiveness seen prior to the upset. Effluent BOD/COD was still hovering at or above levels permitted for discharge to the POTW. It was suspected residuals of the culprit sanitizer were still entering and/or present in the system, slowing the Munox® microbes' natural metabolism and growth.
An additional inhibitor to biological treatment was a dramatic pH imbalance, another symptom of the overall plant upset. Normally kept at a pH of near 7, the SBR's pH continued to fall after the plant upset — all the way to the 5.5/5.6 range.
When pH was adjusted back to a level (neutral) 7.0, the microbes still present in the samples returned to
their most robust metabolic state. COD/BOD levels in the samples were reduced an additional 70 percent. Adjustment of the SBR's pH returned the plant to efficient — and compliant — operation. More frequent testing of pH will also be incorporated into normal plant operation procedures.
The Munox® bacteria are patented microbial cultures, specifically formulated for food processors and the degradation of their unique wastes: BOD/COD, TSS, sludge, citrus based oils — and a host of other stubborn organic compounds. Munox® inoculation is also commonly specified in the meat and poultry processing industries for removal of FOG and animal wastes, as well as ammonia removal.
Munox® is an all-natural product which complies with environmental regulations, authorized by EPA and USDA. The wastewater treatment inoculant is comprised of non-pathogenic, naturally occurring microbial strains isolated in the environment for their ability to eliminate a wide range of recalcitrant compounds prevalent in the food processing and agricultural industries. Metabolic by-products of these organisms are simple carbon dioxide and water.
