A team of researchers at UNBC have completed a project opening the door to finding more uses for industrial waste materials.
The work aimed to identify the amounts of ash and biosolids that would best enhance northern B.C. soils for use in reclamation and remediation projects.
"If you can get excited about ash and biosolids, this is a very exciting project," said UNBC forestry professor Hugues Massicotte, who along with environmental science associate professor Mike Rutherford supervised undergraduate student Nichola Gilbert in the trials.
The project used ash sourced from the school's bioenergy plant, local industries and locally sourced biosolids.
Already used as fertilizer, the nitrogen-rich biosolids - stabilized sewage from municipal wastewater treatment plants - were complemented by the nutrient-rich bioenergy ash to grow willow and poplar cuttings for four months.
In some soils, the research showed the pairing could increase plant growth by more than 200 per cent.
Locally, both Canfor Pulp and UNBC's bioenergy plant are producing ash, with other rural and First Nations communities expressing an interest in implementing the technology. Several local companies, such as Red Rock Bioenergy Crops south of Prince George, also produce the material.
The challenge now is to find the happy medium, said Massicotte.
"If there's no toxicity in the ash then surely it's to find the right amount to incorporate back into agricultural and forest soil," he said.
The idea is that further development of this research could find a way to help keep some of these materials, like ash, from going to landfill.
The waste materials contain nutrients such as nitrogen, phosphorus, calcium, magnesium and potassium.
"It almost seems irresponsible to take those nutrients and lock them away in such a form that the biosphere - plants, animals - can't get access to them," said Rutherford. "But it has to be in a way that's responsible."
One of the issues to take into account is the particulars about using ash. The chemical compositions of ash have to be tested to see how they match with the receiving soil and the fine texture means there has to be a way to apply it without it blowing away or blowing into the lungs of the person handling it.
The use of biosolids at an industrial scale is also a contentious issue already, said Massicotte.
"I don't think the public is completely ready to see that yet," he said. "So it needs to be tested so that folks are feeling that we've done our homework."
In 2011, a group of residents blockaded a city delivery of biosolids to a Salmon Valley farm.
"Just like ash, the composition of biosolids is determined and that will dictate whether it can be used in a certain location and also the application rate, too," added Rutherford. "Many people don't realize that in B.C. we have among the most strict environmental regulations in Canada and there are regulations for the use of biosolids and there are regulations for the use of ash in B.C."
