On January 20, 2017 Lucas Jagodzinski successfully defended his PhD thesis entitled “Compositional variation and hazards of wood ash in Ireland”.
Examiners and Supervisors
External examiner was Prof Roeland Samson (University of Antwerp, Belgium).
Internal examiner was Dr Fidelma Butler (School of Biological, Earth and Environmental Sciences, UCC).
Supervisors for this PhD project were Prof John O’Halloran (School of Biological, Earth and Environmental Sciences, UCC), Dr Frank van Pelt (Department of Pharmacology and Therapeutics, UCC), and Prof Marcel Jansen (School of Biological, Earth and Environmental Sciences, UCC).
Wood is a biofuel which can contribute substantially to a renewable energy portfolio. However, it can be questioned whether wood can be (part of) a sustainable energy supply. This was the central question asked by Lucas Jagodzinski in his PhD research at University College Cork.
Burning wood generates wood ash, which is currently mostly landfilled rather than returned to the soil. In the process, desirable plant nutrients are removed from forest sites, leading to the impoverishment of soils.
Lucas’ research focussed on the physico-chemical characteristics of wood ash, and he has created a detailed report on the typical composition of wood ash in Ireland. A large percentage of wood burned in Ireland is made up of Sitka spruce (Picea sitchensis). Notwithstanding the relative homogeneity of this biofuel, substantial variation in its composition was found between ashes from different boilers. Compositional variation was also found between bottom and fly ash, and between ashes generated at different times in the same boiler. The observation of such heterogeneity must inform any after-use of wood ash, including the possibility to return wood ash to sites where trees were harvested. Indeed, hazard levels due to accumulation of metals, heavy metals and persistent organic pollutants varied dramatically between different wood ashes.
Lucas’ PhD thesis not only highlights the hazards of composite wood ash, but also pinpoints possible solutions. This includes separation of bottom and fly ash, and further size fractionation of wood ash, to reduce contaminant load without reducing levels of beneficial plant nutrients.
This PhD project was funded by COFORD.