Challenge

The Alpine Cheese Factory, in Holmes County, Ohio, is continually looking for ways to make their operation more profitable. Management saw an opportunity to cut costs in their wastewater treatment plant. With an influent flow rate designed for 25,000 gpd, the facility was often producing and disposing of 500 pounds of waste sludge daily, totaling over 1 million gallons per year.

Solution

Cannibal™ Solids Reduction Process was the cost-cutting solution they were looking for. Developed in conjunction with ATS Engineering, this revolutionary process generates savings in multiple ways:

• No aerobic or anaerobic digestion required.
• No sludge thickening or dewatering required.
• No polymer addition required.
• Sludge hauling costs reduced (only trash, grit, and inerts removed).
• Power costs of biosolids handling eliminated.
• Capacity of existing facilities increased.
• Activated sludge tank volume decreased in new facilities.

The Alpine Cheese Plant Treatment Process:

• Aerobic bacteria first feed on the wastewater material in the Vertical Loop Reactor (VLR).
• The oxidized liquid passes into a clarifier where the solids (sludge) fall to the bottom and the clear effluent is decanted off the top, disinfected, tested and released downstream.
• A portion of the activated sludge is pumped to a sidestream bioreactor where it is converted to a facultative-dominant population (non-aerobic).
• A recycle flow is established which allows for a steady-state interchange of biological solids destruction and re-growth; eventually eliminating the biological waste sludge from the treatment plant.

Results

The results for the Alpine Cheese Factory were remarkable.

• In the first year of operation (1999), the plant was so efficient that no sludge needed to be wasted.
• BOD from the final clarifier averages only 4 mg/L, suspended solids of 12 mg/L, and total nitrogen removal; greatly exceeding state requirements.
• With an increased load rate of 50 % above its design flow (39,000 gpd), the facility has hauled away a mere 50,000 lbs of sludge per year.
• Properly balanced interchange of bacteria with air delivery has kept power costs to approximately 0.29 kW per pound of BOD removed.
• Now treating an average of 40,000 gpd, the plant still uses only 60% of its aerated horsepower and is maintaining an effluent rate of 0.04 lbs TSS/lbs BOD.