Hamilton Biosolids Management

In the past, the City of Hamilton dewatered biosolids at the Woodward Avenue WWTP, treating them as Class B material and using them as a nutrient source for land application. However, Maple Reinders and its partners took on the task of designing and constructing a new Biosolids Management Facility. This facility has the capacity to manage up to 60,000 wet tonnes of biosolids annually for a period of 30 years.

The end-product of this facility serves multiple purposes. It can be utilized as a slow-release organic fertilizer or serve as a renewable fuel substitute for coal-burning industrial facilities. To ensure effective operations, the project includes a wet cake storage building and extensive measures for odour control. These measures involve treating the air during the biosolids drying process, employing an odour control scrubber in the building’s air treatment system, and implementing operational procedures specifically designed to control odours.

The drying process itself involves pumping the dewatered biosolids to storage through the existing sludge-pumping system. From there, the biosolids are pumped from either of the two storage silos into a mixer, where they are mixed with recycled dry product to create pellets for drying. These pellets are then fed into a drum dryer, situated between the furnace and the drum, where the evaporation of water from the preformed pellets takes place. The drum rotates while high-speed gas conveys the pellets through the drum until they reach the desired dryness. At this stage, the process air, carrying evaporated moisture and dried particles, is directed through a ceramic-lined duct to a two-stage separation system consisting of a pre-separator and a polyclone. This system effectively separates the solids from the process air stream.

By implementing this project, the City gains the ability to process and market biosolids in an efficient manner. It provides a fixed, known cost over a 30-year period, which has been validated through a predetermined affordability threshold.