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Portage la Prairie, Canada

Olatuyi S.O.,University of Winnipeg | Kumaragamage D.,University of Winnipeg | Akinremi O.O.,University of Manitoba | Grieger L.,Prairie Agricultural Machinery Institute
Journal of Environmental Quality | Year: 2014

Accumulation of metals is a concern with continuous application of swine slurry to agricultural soils. Solid-liquid separation is a promising approach for reducing phosphorus and total metal loadings with swine manure application to farmlands. However, very little work has been performed on the partitioning of different metal fractions in swine slurry to separated solids and liquids. This study examined the distribution of various metal fractions in raw manures (RM), their separated liquids (SL), and separated solids (SS). The three separation techniques used were centrifuge without flocculant (CNF), centrifuge with flocculant (CFL), and rotary press with flocculant (RFL). Concentrations of Cd, Cu, Zn, Ni, and Se in manure and separates were determined by a modified Sposito's sequential chemical fractionation scheme to extract water-soluble, exchangeable, organically bound, carbonateprecipitated, and residual fractions. The greatest concentrations of metals were recovered in the residual fraction, with the organically bound and carbonate-precipitated concentrations much greater than water-soluble and exchangeable fractions. Separation index (Et) (i.e., percentage partitioned to SS) ranged from 13 to 66%, 9 to 87%, 16 to 93%, and 23 to 96% for watersoluble, exchangeable, organically bound, and carbonateprecipitated fractions, respectively. The Et values in general, were significantly (P < 0.05) greater for flocculant-based separation techniques than for CNF. For organically bound and carbonateprecipitated fractions, the greatest Et was obtained with the RFL for most metals. Our results suggest that applying the SL from RFL separation would minimize metal loading to farmlands compared with SL from CNF and CFL techniques. However, further validation is required using more sources of manure and different flocculants. © American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Kumaragamage D.,University of Winnipeg | Akinremi O.O.,University of Manitoba | Grieger L.,Prairie Agricultural Machinery Institute
Journal of Environmental Quality | Year: 2013

Solid-liquid separation is a manure management option whereby P-rich solid is separated from N-rich liquid, allowing the separated liquid to be used as a fertilizer without oversupplying P. Little information is available on how the different P fractions in manures are partitioned to solid and liquid during separation. We examined the distribution of various P fractions in liquid and solid separates of swine manure, separated using different techniques, to gain information useful for making choices regarding the optimum use of manure separates. Samples of raw manure (RM) and their separated solid (SS) and liquid (SL) were obtained using three different separation techniques: (i) centrifugation without flocculant (CNF), (ii) centrifugation with a flocculant (CFL), and (iii) rotary press with a flocculant (RFL). These were subsequently analyzed for P using a modified Hedley fractionation scheme. Only a small proportion of RM, ranging from 5 to 12%, was recovered in SS, an advantage if SS is to be transported off-site. Concentrations of molybdatereactive P and total P in all P fractions were less in SL than in the corresponding RM on a fresh-weight basis. The separation index (percentage partitioned to SS) for total labile P (water-extractable + NaHCO3-extractable P) was 63, 81, and 75% for CNF, CFL, and RFL, respectively. The proportion of total P in labile form was significantly lower in SL than in RM. Therefore, using SL as a fertilizer instead of RM may help to avoid excessive buildup of soil test P with manure applications. © American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Sadek M.A.,University of Manitoba | Guzman L.,University of Manitoba | Chen Y.,University of Manitoba | Lague C.,University of Ottawa | Landry H.,Prairie Agricultural Machinery Institute
Agricultural Engineering International: CIGR Journal | Year: 2014

Tensile strength is an important property of hemp fibre, because it determines the mechanical strength of fibre-based products such as biocomposites. Commercial discrete element software, Particle Flow Code in Three Dimensions (PFC3D), was used to develop a numerical model which simulates tensile tests of hemp fibre. The model can predict the tensile properties (such as strength and elongation) of a hemp fibre. In the model, a virtual hemp fibre was defined as a string of spherical balls, held together by cylindrical bonds implemented in PFC3D. To calibrate the model, tensile data was collected for both unretted and retted hemp fibres using a commercial Instron testing system. The average fibre diameter was 0.34 mm for the unretted fibre and 0.30 mm for the retted fibre. The average tensile strength measured was 358 MPa for the unretted fibre and 343 MPa for the retted fibre. The corresponding average elongations for the two types of fibres were 0.88 and 0.80 mm, for an original fibre length of 25 mm. The bond modulus, the most sensitive microproperty of the model was calibrated. The calibrated value was 1.02×1010 Pa for unretted fibre and 1.05×1010 Pa for retted fibre. Using the calibrated bond modulus, elongations of fibre were simulated using the model. The simulation results showed that the elongation increased linearly with the increasing fibre length; whereas the elongation was not affected by the fibre diameter.

Parvin S.,University of Manitoba | Chen Y.,University of Manitoba | Chen Y.,University of Ottawa | Lague C.,University of Ottawa | And 3 more authors.
AES-ATEMA International Conference Series - Advances and Trends in Engineering Materials and their Applications | Year: 2015

Demand of hemp fibre is rising for industrial uses in various fields, such as biocomposites. However, most existing fibre decortication (mechanically processing hemp for fibre) equipment is ineffective to obtain fibre with high purity, i.e. the fibre product contains a significant amount of hemp straw (also referred as to core or hurds). The main goal of this study was to investigate potential methods for post-decortication cleaning of hemp fibre to improve the fibre purity. Three cleaning methods were investigated: pneumatic, carding, and floatation methods. Prior to the use of these methods for fibre cleaning, the relevant fundamental behaviours of fibre and core particles were experimentally studied. Results of aerodynamic experiments showed that core particles had significantly higher terminal velocities than fibre particles. The terminal velocity ranges were 1.28 - 3.52 m/s for core particles and 0.56 - 1.36 m/s for fibre particles, demonstrating that fibre and core particles could be separated by means of air flow. However, the pneumatic method failed to do so due to the problem of fibre and core entanglement. Results of floatation experiment showed that fibre particles sunk and core particles floated in water, which is desired for separation of fibre and core. The floatation method improved the fibre purity up to 90% when used to clean a decorticated hemp material with an original fibre purity of 55%. Carding improved the fibre purity of the same hemp material up to 70%. Both floatation and carding methods caused some losses in fibre yield. © 2015, Advanced Engineering Solutions [AES.COM], Ottawa, Canada. All rights are reserved.

Khan M.M.R.,University of Manitoba | Chen Y.,University of Manitoba | Lague C.,University of Ottawa | Landry H.,Prairie Agricultural Machinery Institute | And 2 more authors.
Biosystems Engineering | Year: 2010

Compressive behaviour of hemp (Cannabis Sativ L.) stems is important for the design of hemp handling and processing machines. Experiments were carried out to measure the compressive properties of stems from two hemp varieties: Alyssa (grown for fibre only) and Petera (grown for both fibre and seed), produced in Manitoba, Canada. The physical properties of the hemp specimens were measured. For each variety, an air-dried hemp stem was divided into three height sections along the stem: upper, middle and lower. For each section, the hemp stem was further cut into 25.4 mm long specimens. Individual specimens were compressed in the axial and lateral directions using a universal testing machine. The load-displacement curves were recorded, and compressive properties were derived from the load-displacement curves. The outer diameter of the hollow hemp specimens varied from 6 to 17 mm; the linear density varied from 10 to 37 g m-1. Diameter and linear density were greater for Petera than Alyssa, and at the lower height section than the higher section for both varieties. The compression tests showed that the maximum compressive load varied from 58 to 1425 N, and the energy requirement varied from 23 to 1809 mJ, depending on the variety, height section and diameter of stem, and compression direction. In general, the maximum compressive load and the energy requirement were greater in the lower section and for larger diameters; higher loads and energy were observed for Petera than for Alyssa and for the axial compression direction than for the lateral direction. © 2010 IAgrE.

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