Potential for using paper mill fly-ash as an alternate liming material and mobility and leachability of heavy metals in fly-ash and biochar amended agricultural soil in Western Newfoundland

• Main Author: Maheswaran, Gnanakaran
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2019
• Subjects: Corner Brook; Newfoundland
• Online Access: https://research.library.mun.ca/14411/; https://research.library.mun.ca/14411/1/thesis.pdf

Most agricultural soils in Western Newfoundland are acidic and need lime to raise the soil pH to be productive. Corner Brook Pulp and Paper Ltd produces a substantial amount of fly-ash which is being disposed at a local landfill. This study was conducted to assess the potential for using fly-ash as a liming material for an agricultural soil (pH:5.5) in Western Newfoundland with the addition of biochar for heavy metal stabilization. Heavy metal concentration in the soil and fly-ash were analysed and compared with soil and compost guidelines. Lab scale leaching and pot experiments were conducted to assess the leaching and bioavailability of heavy metals in fly-ash amended soil with different biochar rates. As per quality guidelines, only part of the lime requirement can be substituted by fly-ash. Biochar increased the soil pH and biomass production. Total heavy metal leached from biochar treated soils were low and unlikely to cause groundwater contamination. In general biochar reduces the leachability and the bio availability of heavy metals. Application of biochar could provide a sustainable solution for the heavy metal stabilization of fly-ash treated soil.