FOOD WASTE TO ENERGY USING BAE™

The NJ Department of Agriculture received a federal grant to work with a 6 MGD Wastewater Treatment Facility positioned in an area that is home to many Food Processors. The facility planned to build a Food Waste Treatment System that would utilize an inactive Anaerobic Digester at the plant. With Prodex's assistance and by using existing infrastructure, the project negated the need to spend $3- $5 million on constructing an entirely new digester from the ground up.

The project provided an opportunity to create a tangible, working apparatus to demonstrate whether food waste & manure (provided by food processors and farmers) could be used efficiently and effectively to create gas used to power a co- generation unit that supplies electrical power to run the Authority’s sewage-treatment operations.

The bio-solids being treated were supplemented using BAE™. The addition of BAE™ into the digester stabilized the materials being treated and as a result:

• Biogas output increased by 37%

• Facility is now generating $150K/yr. in revenue & growing

• Plant is able to receive and process external materials effortlessly due to increased buffering capacity & throughput

IMPROVED BIOGAS PRODUCTION USING BAE™

Like many wastewater treatment facilities across the country, a 60 MGD facility was looking to increase their digester gas production. The plant installed four co-generation units with a capacity of 800 kW each. The engines are capable of using either methane gas from the digesters or natural gas supplied by public utilities. Power produced by the co-generation system accounts for over 70% of the total power required to operate the entire facility.

The addition of the co-generation system became a strong incentive to produce more digester gas. Following pilot testing on one of the four digesters with BAE™, the plant personnel chose to test BAE™ for the entire digester treatment system. The results were astounding:

• Digester gas production increased by 41%

• Cost avoidance for facility due to additional gas produced equates to $392K/yr.

IMPROVED SOLIDS HANDLING TREATMENT USING BAE™

A 60 MGB plant wanted to improve their costing structure in the solids treatment section due to the increasing costs of chemical treatment, landfill tipping fees and disposal costs. It was anticipated that adding BAE™ to the treated solids coming from the digesters would improve the solids handling treatment by lowering these costs and producing: higher cake solids, a cleaner return stream, and lower final disposal costs.

BAE™ was introduced at the plant’s Gravity Belt Thickeners and resulted in:

• Annual savings of $353K on re-treatment costs due to return stream clean up

• Cake solids increased & less polymer used to dewater

• A reduction of 2.28 tons per day of sludge cake disposal= reduced tipping fees

ACTIVATED SLUDGE TREATMENT USING BAE™ FOR NITROGEN REMOVAL

A 27 MGD plant treating Waste Activated Sludge & Primary Sludge was experiencing high amounts of Nitrogen in the plant effluent. The facility provides service to 15 municipalities with approximately 207,000 residents, covering a total service area of 150 square miles. The plant treats leachate from the local landfill as well as septage and food waste that is hauled to the facility.

The state ordered the plant to do expensive testing (Bio Assay) to monitor and remedy the problem. Prodex® was contacted to help assist in the matter (BAE™ was used earlier when their Aeration Basins were affected with high biological loadings from larger than normal amounts of leachate that had been delivered to the plant, resulting in a quick resolution and a net annual savings of over $360K).

Prodex® worked on optimizing the dosage to accommodate the fluctuating loadings and was able to come up with a standard dosage that brought effluent numbers down from 39 mg/L to 4 mg/L after only 1 year (a 90% reduction).

MAINTENANCE/ EMERGENCY DOSAGE USING BAE™

A well operated and maintained 12 MGD plant stores BAE™ to use when they experience dramatic changes in the plant influent. The facility treats both industrial and residential flows using anaerobic digesters. The loadings that affected the solids in the Aeration Basins would also affect the solids handling section of the facility.

The plant experienced changes in the influent loadings due to a high amount of organic acids and sulfides which can be toxic to the aeration basins. This can lead to a significant amount of the sludge inventory in the foam, compromising process control. Nitrification and denitrification often occur together within the floc, with no findings of free nitrate when examined. This caused the plant’s gray water that is sold to the neighboring electric utility to be affected.

To counter this problem the plant applied BAE™ at a rate of 10 gallons a day during this challenging time period. After feeding the BAE™ in May, the plant had extended periods of superior plant performance.

The use of BAE™ in the aeration basins:

• Created a strong microbiology for quick response & recovery

• Provided stabilization for smooth plant operation

• Cleaned up gray water & enabled facility to meet contractual obligations