Circular Biochar Economy

Insights on going from a linear incineration economy to a circular biochar economy are discussed from the perspective of the Edmonds, WA wastewater treatment plant (WWTP) with reference to the Silicon Valley Clean Water (SVCW) water resource recovery facility (WRRF) and the Morrisville Municipal Authority (MMA) WRRF. A biochar producing facility is being designed for the Edmonds WWTP modeled after the successful resource recovery and renewable energy production process at MMA. MMA has transitioned from disposing of Class B biosolids to recovering resources including dried Class A biosolids, activated biochar, and concentrated nutrients. SVCW has transitioned from sludge incineration to anaerobic digestion, biosolids drying, and pyrolysis to produce biochar. Edmonds solids processing will transition from disposing of ash from sludge incineration to having the flexibility to recover dried Class A biosolids, activated biochar, and concentrated nutrients. Edmonds will be prepared for changing biosolids regulations and markets.