Transforming Biosolids to Value for Municipalities

Many wastewater treatment utilities around the world manage their biosolid residuals using an incineration process that results in a significant mass of ash. Urban Water TMU is studying the composition of this ash in the context of resource recovery. With cooperation from three Ontario municipalities, our researchers analyzed composite ash samples from municipal biosolid incinerators and identified a broad suite of elements, including common and precious metals. Using market prices and ash production estimates, the value of each metal per tonne of ash was calculated, revealing a promising opportunity to offset costs. These results were presented at both the Water and Environment Association of Ontario Annual Conference and the Central Canadian Symposium on Water Quality Research. With support from our municipal partners, this work led to an invited proposal to the Environmental Research and Education Foundation.