A Waste to Energy Conversion Ecosystem
The Lulu Island water resource recovery facility (WRRF) operated by Metro Vancouver services wastewater from about 172,000 residents in the western part of Richmond and discharges effluent into the Fraser River. Metro Vancouver uses a process called anaerobic digestion as a secondary form of treatment at Lulu Island to produce renewable biogas for eventual distribution through the Fortis grid system. We work with Metro Vancouver to monitor microbial community structure and function associated with biogas production and to develop new process configurations that improve waste to energy conversion efficiency in support of circular economy development.
Ecosystem Type: Engineered
Location: Richmond BC (49°6.54N, 123°8.86W)
Anaerobic digestion (AD) of wastewater is catalyzed by microbial community metabolism resulting in the conversion of settled particulates (primary sludge) and flocculated bacterial biomass (secondary sludge) into potentially useful products including methane, a major component in biogas, and biosolids, a nutrient-rich material suitable for amending soils. Commercial-scale AD systems can have low biomass conversion to methane and produce significant amounts of biosolids limiting their utility and increasing operating costs. The Lulu Island WRRF treats 26 billion liters of wastewater each year and produces enough energy via methane reclamation to meet all of its own heat requirements. It also produces about 7,800 bulk tonnes of biosolid waste every year. Bench-scale research has demonstrated the potential to substantially increase methane content of biogas by improving organic waste conversion processes and altering electron flow patterns between microbial community members.
Recent advances in high-throughput sequencing technologies are enabling unprecedented access to the genetic repertoire underlying microbial metabolism at the individual, population and community levels of organization in wastewater treatment ecosystems. Initial investigations have identified direct links between physical and chemical parameters including loading rates, substrate types, residence times, temperature, and metal concentrations, and microbial community structure and function. However, effective management and optimization strategies require time-resolved insights into the relationships between operating parameters, performance metrics and microbial community structure and function. In partnership with Metro Vancouver, we are developing these insights by monitoring the waste secondary sludge (WSS) and ADs at the Lulu Island WRRF using high-throughput sequencing approaches supported through NSERC ENGAGE and Collaborative Research and Development (CRD) partnership programs.