Feedstock mixture design in anaerobic co-digestion to maximise resource recovery potential

Mike Meng is currently working as resource recovery engineer at Queensland Urban Utilities in Australia leading multiple resource recovery initiatives and R&D projects . Mike has obtained a chemical engineering PhD on anaerobic co-digestion from the University of Queensland and has strong interest in applying expertise to water industry applications for achieving circular economy outcomes.

Mike enjoys wastewater and waste education through knowledge sharing, evident by 5 years of teaching for undergraduate courses “Industrial Wastewater & Solid Waste Management” and “Process Control and Synthesis” at the University of Queensland. An immediate past member on the Australian Water Association Young Water Professional Committee, Mike is passionate about driving a positive change in the committee through participation in mentoring and leading student engagement activities. Mike’s goal is to keep developing engineering expertise and leadership in water and organic waste management and assist Water Utilities in transitioning to full spectrum of resource recovery implementation.

Anaerobic co-digestion (AcoD) is an established technology typically applied to water and agricultural industries to redirect organic wastes away from landfill for beneficial reuse. In AcoD, designing co-digestion mixtures to ensure optimal digester performance and effectively manage co-digestion products is important. In the presentation, Mike will share his PhD research outcomes and practical experience around co-digestion mixture design and operation at one of Australia’s largest sewage treatment plants (STPs).
 
 Currently, in the Australian water industry, there is emerging and strong interest in co-digestion at sewage treatment plants (STPs), which redirects commercial trade wastes away from the landfill for beneficial reuse. AcoD is a biochemical engineering approach that simultaneously treats two or more waste streams in a centralized digestion facility for enhanced energy recovery and enables circular economy outcomes.
 
Designing co-digestion mixtures for optimised digester performance was a knowledge gap in research as well as in practical application. This means selecting compatible feedstocks at the right volumes with optimal feeding strategies for digesters needs to be understood and incorporated into specific digester operating scenarios.
 
Co-digestion of complex solid wastes such as fat, oil, grease and food waste with sewage sludge is a step change for many water utilities in Australia and hence requires a series of technical and organizational barriers to be overcome. Developing in-depth understanding of the co-digestion process, its associated downstream impacts, and meeting additional infrastructure requirements for co-digestion are important. In particular, organic waste characterization, co-digestion mixture design, and co-digestion product management are some key areas many water utilities’ waste-to-resources initiatives are currently focusing on. As part of the presentation, Mike will also give an overview of some of the resource recovery initiatives Queensland Urban Utilities are undertaking and how he is using research findings to assist the organisation in the resource recovery space.

You can watch a recording of this event here: