New System Combats Sludge Buildup

A municipality near Detroit, Mich., was experiencing problems with its wastewater treatment system. The system had accumulated a substantial volume of sludge (up to 36 inches deep) that reduced the functional capacity of the lagoons. In addition, extremely unpleasant odors had begun to emanate from the lagoons, which resulted in a series of complaints from residents and surrounding communities

The municipality used a new system developed by B.B. Environmental Inc. and Micro-Bac International Inc. to help them solve these problems and restore the proper functioning of the lagoon system.

The treatment system, termed "Symbiotic Facultative Biological Degradation" (SFBD) technology, was developed to degrade sludge in situ and eliminate the associated unpleasant odors.

The first step for BB was to conduct a brief investigation to assess the status of the system and to identify the most sensible and cost-effective means of restoring proper functioning of the system.

The system consists of four lagoons operating primarily in series with the option of operating in partial parallel mode. Each lagoon has approximate surface dimensions of 600 feet x 300 feet and an average depth of 10 feet. They have an approximate capacity of 10,000,000 US gallons.

Each lagoon was equipped with a series of air diffusers located in parallel rows approximately 30 feet apart along the base of the lagoon. The aeration/diffusion had been neglected over recent years and was in need of repair as it was functioning at only partial capacity (surface turbulence from the diffusers was visible only in certain areas, not throughout the lagoons).

Lagoon #1 had a sludge accumulation of 12-18 inches and Lagoon #2 had a sludge accumulation of 30-36 inches across the base of the lagoon. Substantial unpleasant odors were emanating from the lagoons.

Lagoons #3 and #4 had an insignificant accumulation of sludge and were not considered to be in need of attention.

Wastewater officials made it clear to BB that they wanted a solution that would not disturb the aeration/diffusion system since this system would be relied upon for another six months (throughout the winter) until fair weather would permit replacement. The seasonal window of land application would not permit the disposal of the large amount of sludge in the two lagoons within the allowable timeframe without the added expense of costly premium haulage charges and overtime.

SFBD technology uses proprietary blends of facultatively anaerobic digesters which in turn produce waste-degrading biochemicals to eliminate organic wastes in situ. These digesters literally consume organic sludge and convert it primarily to harmless carbon dioxide and water. This technology is designed to convert indigenous microbial populations in lagoons and other waste streams into extremely active biological communities that degrade organic wastes at maximum achievable rates.

A series of eight weekly applications of liquid products to the surface of the lagoons was performed to provide sufficient sludge elimination to re-establish correct airflow to maintain lagoon efficiency. Each of the eight individual treatments was performed using a utility farm tractor equipped with a 1000-gallon tank, a low-pressure pump, and a discharge hose with an adjustable pitch spray nozzle at the discharge end. The discharge hose was secured to a swinging boom that could extend out past the slope of the lagoon berms and allow for the spray to reach most of the surface of the lagoon. The spray rate was set such that the applicator would travel twice around a lagoon during each treatment.

Within three days of the initial product application all unpleasant odors were eliminated. There have been no re-occurrences of the odors to date.

Sludge depth measurements performed prior to the start of the third application revealed that the original 30-36 inches of sludge in lagoon #2 had been reduced to approximately 12-16 inches throughout the entire base within only two weeks.

Upon final application, both lagoon #1 and #2 had less than 12 inches of any type of build-up across the base.

The aeration/diffusers, although still in need of repair, were easily passing air through the water in the lagoons. Significant surface turbulence was evident throughout each of the lagoons.

Final total cost of the project was estimated at approximately 1.5 cents per lon of sludge eliminated.

The SFBD technology has received widespread acceptance and has become a solution for both township and metroplex municipalities. The technology is currently being retrofitted for municipalities throughout the Northeast and has been contracted by the Anamax corporation. SFBD technology is a result of the collaboration between BB and Micro-Bac International, Inc. Micro-Bac is a pioneer in developing natural biological solutions for a variety of industrial and environmental problems.