HNEI researchers investigated the performance and durability of novel carbon based biofilm supports to support active methanogenic microbial communities. Using DNA based community analysis the project verified wood derived biochar to host biofilms possessing well-balanced methanogenic microbial communities that realized high digestion rates under anaerobic conditions. HNEI researchers then investigated the performance and durability of a hybrid high rate anaerobic-aerobic digestion (HRAAD) system operated at demonstration scale in an existing wastewater treatment facility. The HRAAD system consisted of an anaerobic reactor packed with a range of materials including biochar and a second aerobic reactor, serving as a trickling filter, packed with highly porous polystyrene media. The project verified that the HRAAD system was capable of achieving an effluent equivalent with EPA discharge requirements and with energy savings of over 50% in comparison with traditional activated sludge treatment.
Point Person: M. Cooney 
- Labscale evaluation of immobilization media , Final Report to DOE, August 21, 2014
- Anaerobic Digestion of Primary Sewage Effluent: Significant Energy Savings over Traditional Activated Sludge Treatment  (Task 3.4 Report 1 Field testing and evaluation of anaerobic digestors, September 2014 )
- 2015, Michael John Cooney, Ken Lewis, Kevin Harris, Qian Zhang, Tao Yan, Start up performance of biochar packed bed anaerobic digesters , Journal of Water Process Engineering, Available online 8 January 2015, ISSN 2214-7144, http://dx.doi.org/10.1016/j.jwpe.2014.12.004 .
- 2014, Ryan J. Lopez, Scott R. Higgins, Eulyn Pagaling, Tao Yan, Michael J. Cooney, High rate anaerobic digestion of wastewater separated from grease trap waste , Renewable Energy, Volume 62, February 2014, Pages 234-242, ISSN 0960-1481, http://dx.doi.org/10.1016/j.renene.2013.06.047 .