UBCO researchers find a new use for waste

Waste materials from the pulp and paper industry have long been seen as possible fillers for building products like cement, but for years these materials have ended up in the landfill. Now, researchers at UBC Okanagan are developing guidelines to use this waste for road construction in an environmentally friendly manner.

The researchers were particularly interested in wood-based pulp mill fly ash (PFA), which is a non-hazardous commercial waste product.

The North American pulp and paper industry generates more than one million tons of ash annually by burning wood in power boiler units for energy production. When it is sent to a landfill, the producer takes on the cost of about $25 to $50 per ton.

“Anytime we can redirect waste to a sustainable alternative, we are heading in the right direction,” said Dr. Sumi Siddiqua, associate professor at UBC Okanagan’s School of Engineering.

Despite the benefits, the construction industry is concerned that toxins used in pulp and paper mills may leach out of the reused material.

“Our findings indicate because the cementation bonds developed through the use of the untreated PFA are so strong, little to no release of chemicals is apparent. Therefore, it can be considered as a safe raw material for environmental applications,” said Postdoctoral Researcher Dr. Chinchu Cherian said.

While Dr. Cherian explains that further research is required to establish guidelines for PFA modifications to ensure its consistency, she is confident their research is on the right track.

“Overall, our research affirms the use of recycled wood ash from pulp mills for construction activities such as making sustainable roads and cost-neutral buildings can derive enormous environmental and economic benefits,” she says.