ALEXANDRIA, Va. — The Water Environment Research Foundation (WERF) has selected Hazen and Sawyer to perform research as part of a series of new projects on furthering co-digestion, according to a press release.  

The project, Developing Solutions to Operational Side-Effects Associated by Co-Digestion of High-Strength Organic Wastes (ENER8R13), will help water resource recovery facilities (WRRFs) plan, design, and implement co-digestion programs with clearer expectations, improved process design and more consistent operations, noted the release.

The practice of adding waste organic feedstock directly to anaerobic digesters (co-digestion) is becoming an attractive way for utilities to generate revenue from tipping fees, while boosting biogas production. However, the practice is only used by about 20 percent of WRRFs with anaerobic digesters.

Currently, there is uncertainty on how to avoid digester upset. Co-digestion of organic wastes that contain high energy content, such as fats, oils, greases, carbohydrate and sugar waste, and food waste, with wastewater solids represents an opportunity for WRRFs to increase biogas production using existing digester capacity, stated the release.

This work is designed to enhance existing WERF research on Co-Digestion of Organic Waste Products with Wastewater Solids (OWSO5R07). The project team will develop a compilation of data regarding High-Strength Wastes (HSWs) that have been successfully treated through co-digestion, co-fermentation, or mainstream anaerobic treatment, as well as guidance documents to provide utilities with strategies that can be used to overcome operational side effects associated with co-digestion of HSWs.