Fly-ash from a pulp and paper mill: A potential liming material for agricultural soils in Western Newfoundland.

Most agricultural soils in Western Newfoundland are acidic and need lime to raise soil pH to be productive. Corner Brook Pulp and Paper Ltd produces a substantial amount of fly-ash, disposed of at a local landfill. This study was conducted to assess the potential for using fly-ash as a liming material for agricultural soil (pH 5.5) in Western Newfoundland. Heavy metal concentration in the soil and fly-ash were analysed and compared with soil and compost guidelines. As per quality guidelines, only part of the lime requirement can be substituted by fly-ash. The percentage may vary depending on initial soil pH and the desired pH for the crop to be grown. The total lime requirement can be met when fly-ash is applied combined with other soil amendments low in trace element concentration.

Experimental validation of CFD simulations of bioaerosol movement in a mechanically ventilated airspace

A CFD (computational fluid dynamics) model was developed to simulate the movement of bioaerosols in mechanically-ventilated chambers and the results were validated with experiments. Liquid aerosols containing Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) were artificially generated in the chambers. Bioaerosol concentration was monitored with an optical particle counter until steady-state conditions were achieved (aerosols containing viruses are referred to as bioaerosols in this paper). Four treatments with two ventilation rates and two bioaerosol generation rates were tested. The standard k-ɛ turbulence model and a discrete phase model with unsteady tracking was used in an ANSYS Fluent CFD model to simulate the airflow and bioaerosol movement until steady-state was reached. A mesh refinement test was performed to select an optimal mesh size for simulations. The CFD simulations showed good agreement with the measured bioaerosol concentrations at steady-state with differences of 2% to 8%, normalized mean square error of 0.01 to 0.19, and fractional bias of 0.02 to 0.08. Simulations and validation during the transient phase could not be verified because of limited measurement locations.

A simplified logistics model for integrating BIMAT and IBSAL to estimate harvest costs, energy input and emissions

The Agriculture and Agri-Food’s Biomass Inventory Mapping and Analysis Tool (BIMAT) provides internet-based GIS functionality to query and visualize biomass inventory data in Canada. The Integrated Biomass Supply Analysis and Logistics (IBSAL) model is a modularized simulation of biomass supply chain. In this study, IBSAL modules are assembled to simulate harvesting of straw, stover, and switchgrass yields. The operations in this study started from combining for grain crop residues and ended in stacking bales on the field side. The equation C=aR^b Y^c was fitted to the simulated data to estimate constants a, b, and c for cost in $/dry tonne, energy input in MJ/dry tonne, and carbon emissions in kg CO2/dry tonne. Variable R is the fraction of above ground biomass removed during harvest and Y is the yield defined as biomass above ground (dry tonne/ha). These functions are supplied to the BIMAT portal and developed specific values for costs, energy input, and emissions on the map. The farm gate cost cost for the stacked bales ranged from $20 per dry tonne for high yielding regions of southwest Edmonton and Ontario to $27 per dry tonne for the eastern Ottawa region, and $31 per dry tonne for low yielding regions of central Saskatchewan. The costs are validated with published custom rates. It is recommended that the next step is to integrate IBSAL and BIMAT codes so the logistics values are generated and shown automatically on the map.

A review of particulate matter emissions and impacts on human health: A focus on Canadian agricultural and rural emission sources

Particulate matter (PM) has been documented in an increasing number of research studies as having a known or suspected negative impact on human health. The World Health Organization (WHO) estimates that 3.1 million deaths were caused by ambient fine particulate matter (PM2.5) in 2010. While many Canadian studies focus on health impacts from PM2.5, there is a gap with respect to rural sourced PM2.5 and health impacts in these areas. This paper reviews the impact PM2.5 has on Canadians’ health, investigates where PM2.5 data is being gathered, and outlines the sources of PM2.5 reported. Secondary inorganic aerosols that are formed in and around animal production facilities due to the higher prevalence of ammonia gas is of particular interest. The conclusion drawn is that the reporting and gathering of rural sourced PM2.5 data is lacking, leading to a gap in the data used to determine the impacts on Canadian human health.