By Carita Parks, Water Environment Research Foundation (WERF)
The Water Environment Research Foundation (WERF) is expanding research efforts into energy production at water resource recovery facilities (WRRFs). Several new projects are on the horizon as this issue continues to increase in popularity among the water quality community.
WERF recently awarded Brown and Caldwell with a contract to lead work on a project entitled Identification of Barriers to Energy Efficiency and Resource Recovery at WRRFs and Solutions to Promote These Practices (ENER7C13). This study will assess the effect of state legislation, public utility commissions, and power companies on energy efficiency and energy recovery; provide case studies that focus on utility attributes related to energy efficiency, energy recovery, energy generation, and materials recovery; and identify the areas or technologies that are of greater interest to researchers for energy efficiency and resource recovery. WERF is collaborating with the New York State Energy Research and Development Authority to co-fund this research.
Another topic of interest within the area of energy production and efficiency is heat recovery from wastewater. Drexel University is moving forward with research on the State of the Science and Issues Related to Heat Recovery from Wastewater (ENER10C13). By focusing on water resource recovery facilities serving the public, this project will examine the extent of heat’s use, the performance of available technologies, and regulatory issues that could impact heat recovery potential. The project is in collaboration with Philadelphia Water and the New York Department of Environmental Protection.
The research team will ultimately provide:
Lastly, Hazen and Sawyer will perform research on a new project called Developing Solutions to Operational Side-Effects Associated by Co-Digestion of High Strength Organic Wastes (ENER8R13). The successful completion of this project will help utilities plan, design, and implement co-digestion programs with clearer expectations, improved process design, and more consistent operations.
The practice of adding waste organic feedstock directly to anaerobic digesters 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 due to the uncertainty on how to proceed without causing digester upset. Co-digestion of high-strength organic wastes (HSWs) that contain high energy content with wastewater solids represents an opportunity for WRRFs to increase biogas production using existing digester capacity.
This work will expand upon existing WERF research on Co-Digestion of Organic Waste Products with Wastewater Solids (OWSO5R07). The project team will develop a compilation of data regarding 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.
Image credit: "Vorklärung - primary settling tank," Sustainable sanitation © 2011, used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by/2.0/