Papers by Suzelle Barrington
International Journal of Innovation and Sustainable Development, 2018
At 35%, world food production wastage is jeopardising the sustainability of global resources and ... more At 35%, world food production wastage is jeopardising the sustainability of global resources and the future of food security, especially considering that agriculture uses 60% and 37% of the world water and land resources. Ironically, rural populations are most exposed to poverty and hunger when they feed the world. Through a literature review, this paper will demonstrate that supply management, based on consumption, is a solution to food wastage and can in parallel, improve rural wealth, introduce sustainable agricultural practices, resolve major urban pressures and bring about global climate change adaptation. The concepts presented in this paper confront modern world agricultural policies as production management systems are being abolished throughout the world, including Canada.
Air water-vapour pressure deficit is the prime factor controlling plant water uptake in greenhous... more Air water-vapour pressure deficit is the prime factor controlling plant water uptake in greenhouses. In tum, plant water uptake affects several physiological processes such as pollination, plant growth, and fruit yield. In this study, plant water uptake and fruit yield were measured under four different ambient water-vapour pressure deficits (VPD). Four identical greenhouses were used to produce tomatoes under four different regimes of VPD. Greenhouses #1 and #2 were kept under a low and high VPD, respectively, while greenhouse #3 was kept under a low VPD during the day and a high VPD during the night. Greenhouse #4 was kept under a VPD dynamically controlled to maintain plant water uptake at 800 mUplant per day. Plant water uptake and yield were highly correlated to ambient VPD as greenhouses # 1and #2 produced a low and high water uptake rate and yield, respectively. Greenhouse #3 produced an intermediate water uptake and yield, while greenhouse #4 lead to a water uptake and yield...
In this paper, a new numerical method, called Numerical Method of Lines (NMOL), is used to solve ... more In this paper, a new numerical method, called Numerical Method of Lines (NMOL), is used to solve initial-boundary value problems for solute transport in soils. The simulation results are compared with an analytical and a finite element solution of the problem. The results are alike: there are no significant differences. One of the major advantages of the NMOL technique is that the time involved in obtaining numerical solutions of problems is reduced from months to hours. Another significant advantage of the technique is the modest amount of computer programming and the level of mathematical background involved in solving a given initial-boundary problem. The NMOL package is available for the IBM PC or compatible micro-computers and should prove to be very useful to consulting and educational professionals.
Waste Management, 2016
In-Storage-Psychrophilic-Anaerobic-Digestion (ISPAD) is an ambient temperature treatment system f... more In-Storage-Psychrophilic-Anaerobic-Digestion (ISPAD) is an ambient temperature treatment system for wastewaters stored for over 100 days under temperate climates, which produces a nitrogen rich digestate susceptible to ammonia (NH 3) volatilization. Present acidification techniques reducing NH 3 volatilization are not only expensive and with secondary environmental effects, but do not apply to ISPAD relying on batch-to-batch inoculation. The objectives of this study were to identify and validate sequential organic loading (OL) strategies producing imbalances in acidogen and methanogen growth, acidifying ISPAD content one week before emptying to a pH of 6, while also preserving the inoculation potential. This acidification process is challenging as wastewaters often offer a high buffering capacity and ISPAD operational practices foster low microbial populations. A model simulating the ISPAD pH regime was used to optimize 3 different sequential OLs to decrease the ISPAD pH to 6.0. All 3 strategies were compared in terms of biogas production, volatile fatty acid (VFA) concentration, microbial activity, glucose consumption, and pH decrease. Laboratory validation of the model outputs confirmed that a sequential OL of 13 kg glucose/ m 3 of ISPAD content over 4 days could indeed reduce the pH to 6.0. Such OL competes feasibly with present acidification techniques. Nevertheless, more research is required to explain the 3-day lag between the model results and the experimental data.
Water Air and Soil Pollution, Dec 1, 1999
Granular activated carbon (GAC), granular activated alumina (GAA) and a ferric chloride solution ... more Granular activated carbon (GAC), granular activated alumina (GAA) and a ferric chloride solution (FCS) were tested for the treatment of leachate contaminated by heavy metals. The leachate was collected following the remedation of soils using weak organic acids and/or their salts, EDTA and DTPA. Only GAC was found to effectively remove heavy metals (Cd, Cu, Cr, Hg, Mn, Pb and Zn as chelates) from the leachate. At optimum pH ranging from 5.4 to 6.9, 97% of Hg was removed while at optimum pH ranging from 6.9 to 7.7, 78 to 96% of Cd, Cu, Mn, Pb and Zn were removed. Some 77% of the Cr was removed at optimum pH of 5.4. Adsorption rate constant and Langmuir adsorption capacity of GAC were found to be 0.01 min −1 and 19 mg metal chelate g −1 of GAC, respectively. Freundlich constants, k and n were found to be 21 mg g −1 and 2.778, respectively. The brown color of the leachate turned colorless after GAC treatment.
Proceedings of the Water Environment Federation, 2014
Applied and Environmental Soil Science, 2012
Swine manure subjected to in-storage psychrophilic anaerobic digestion (ISPAD) undergoes proteins... more Swine manure subjected to in-storage psychrophilic anaerobic digestion (ISPAD) undergoes proteins degradation but limited NH3volatilization, producing an effluent rich in plant-available nitrogen. Accordingly, ISPAD effluent can offer a higher fertilizer value during land application, as compared to manure of similar age stored in an open tank. However, this additional nitrogen can also be lost by volatilization during land application. The objective of this study was therefore to measure NH3volatilization from both ISPAD and open tank swine manures when applied to 5 different soils, namely, washed sand, a Ste Rosalie clay, an Upland sandy loam, a St Bernard loam, and an Ormstown loam. This research was conducted using laboratory wind tunnels simulating land application. The five experimental soils offered similar pH values but different water holding capacity, cation exchange capacity, cation saturation, and organic matter. After 47 h of wind tunnel monitoring, the % of total avail...
2004, Ottawa, Canada August 1 - 4, 2004, 2004
Abstract. A septic tank and seepage bed system was modified in order to develop an effective puri... more Abstract. A septic tank and seepage bed system was modified in order to develop an effective purification system for milk house wastewater while also valorizing its nutrient and water value. This new system was design and is being tested over a two years period. The ...
Journal of Environmental Management, 2014
In-Storage-Psychrophilic-Anaerobic-Digestion (ISPAD) is a wastewater storage tank converted into ... more In-Storage-Psychrophilic-Anaerobic-Digestion (ISPAD) is a wastewater storage tank converted into an anaerobic digestion (AD) system by means of an airtight floating geo-membrane. For process optimization, ISPAD requires modelling with well-established microbial kinetics coefficients. The present objectives were to: obtain kinetics coefficients for the modelling of ISPAD; compare the prediction of the conventional and decomposition fitting approach, an innovative fitting technique used in other fields of science, and; obtain equations to predict the maximum growth rate (m max) of microbial communities as a function of temperature. The method consisted in conducting specific Substrate Activity Tests (SAT) using ISPAD inoculum to monitor the rate of degradation of specific substrates at 8, 18 and 35 C. Microbial kinetics coefficients were obtained by fitting the Monod equations to SAT. The statistical procedure of Least Square Error analysis was used to minimize the Sum of Squared Errors (SSE) between the measured ISPAD experimental data and the Monod equation values. Comparing both fitting methods, the decomposition approach gave higher correlation coefficient (R) for most kinetics values, as compared to the conventional approach. Tested to predict m max with temperature, the Square Root equation better predicted temperature dependency of both acidogens and propionate degrading acetogens, while the Arrhenius equation better predicted that of methanogens and butyrate degrading acetogens. Increasing temperature from 18 to 35 C did not affect butyrate degrading acetogens, likely because of their dominance, as demonstrated by microbial population estimation. The estimated ISPAD kinetics coefficients suggest a robust psychrophilic and mesophilic coexisting microbial community demonstrating acclimation to ambient temperature.
Waste Management, 2011
For urban community composting centers, the proper selection and use of bulking agent is a key el... more For urban community composting centers, the proper selection and use of bulking agent is a key element in not only the cost but also the quality of the finished compost. Besides wood chips (WC) widely used as BA, readily usable cereal residue pellets (CRP) can provide biodegradable carbon and sufficient free air space (FAS) to produce stabilizing temperatures. The objective of the present project was to test at a community center, the effectiveness of CRP in composting food waste (FW). Two recipes were used (CRP with and without WC) to measure: FAS; temperature regimes, and; losses in mass, water, carbon and nitrogen. Both recipes were composted during three consecutive years using a 2 m 3 commercial in-vessel composter operated in downtown Montreal (Canada). For all recipes, FAS exceeded 30% for moisture content below 60%, despite yearly variations in FW and BA physical properties. When properly managed by the center operator, both FW and CRP compost mixtures with and without WC developed within 3 days thermophilic temperatures exceeding 50°C. The loss of total mass, water, carbon and nitrogen was quite variable for both recipes, ranging from 36% to 54%, 42% to 55%, 48% to 65%, and 4% to 55%, respectively. The highest loss in dry mass, water and C was obtained with FW and CRP without WC aerated to maintain mesophilic rather than thermophilic conditions. Although variable, lower nitrogen losses were obtained with CRP and WC as BA, compared to CRP alone, as also observed during previous laboratory trials. Therefore and as BA, CRP can be used alone but nitrogen losses will be minimized by adding WC. Compost stabilization depends on operator vigilance in terms of aeration. The measured fresh compost density of 530-600 kg/m 3 indicates that the 2 m 3 in-vessel composter can treat 6.5 tons of FW/year if operated during 7 months.
Waste Management, 2015
Composting wastes permits the reuse of organic matter (OM) as agricultural amendments. The fate o... more Composting wastes permits the reuse of organic matter (OM) as agricultural amendments. The fate of OM during composting and the subsequent degradation of composts in soils largely depend on waste OM quality. The proposed study aimed at developing a model to predict the evolution in organic matter quality during the aerobic degradation of organic waste, based on the quantification of the various OM fractions contained in the wastes. The model was calibrated from data gathered during the monitoring of four organic wastes (two non-treated wastes and their digestates) exposed to respirometric tests. The model was successfully fitted for all four wastes and permitted to predict respiration kinetics, expressed as CO 2 production rates, and the evolution of OM fractions. The calibrated model demonstrated that hydrolysis rates of OM fractions were similar for all four wastes whereas the parameters related to microbial activity (eg. growth and death rates) were specific to each substrate. These later parameters have been estimated by calibration on respirometric data, thus demonstrating that coupling analyses of OM fractions in initial wastes and respirometric tests permit the simulation of the biodegradation of various type of waste. The biodegradation model presented in this paper could thereafter be integrated in a composting model by implementing mass and heat balance equations.
Waste management (New York, N.Y.), 2009
Rather than landfilling, composting the organic fraction of municipal solid wastes recycles the w... more Rather than landfilling, composting the organic fraction of municipal solid wastes recycles the waste as a safe and nutrient enriched soil amendment, reduces emissions of greenhouse gases and generates less leachate. The objective of this project was to investigate the composting effectiveness of three bulking agents, namely chopped wheat (Triticum) straw, chopped mature hay consisting of 80% timothy (milium) and 20% clover (triphullum) and pine (pinus) wood shavings. These bulking agents were each mixed in duplicates at three different ratios with food waste (FW) and composted for 10 days using prototype in-vessel composters to observe their temperature and pH trends. Then, each mixture was matured in vertical barrels for 56 days to measure their mass loss and final nutrient content and to visually evaluate their level of decomposition. Chopped wheat straw (CWS) and chopped hay (CH) were the only two formulas that reached thermophilic temperatures during the 10 days of active compo...
Water Air and Soil Pollution, 2001
To compare the soil remediation effectiveness of saltsof weak organic acids with strongchelating ... more To compare the soil remediation effectiveness of saltsof weak organic acids with strongchelating agents, three soils of different textures,all polluted by heavy metals, were washed in a column,at optimum pH, with salts of weak organic acids,namely, citrate, tartarate or oxalate + citrate orchelating agents (EDTA or DTPA). For the clay loam,Cr, Mn, Hg and Pb were removed by citrate andtartarate
Waste Management & Research: The Journal for a Sustainable Circular Economy, 2010
As a result of urbanization and economic prosperity, which has accelerated the generation of muni... more As a result of urbanization and economic prosperity, which has accelerated the generation of municipal solid waste (MSW) along with its organic fraction, the management of MSW is a challenge faced by urban centres worldwide, including the European Union (EU) and Canada. Within a concept of waste recovery, the source separation and on-site treatment of urban organic waste (UOW) can resolve some of the major economic issues faced by urban centres along with the environmental and social issues associated with landfilling. In this context and in a comparison with the traditional landfilling practice, this paper examines on-site UOW composting strategies using a combination of centralized composting facilities, community composting centres and home composting. This study consisted of a feasibility and economic study based on available data and waste management costs. The results indicate that on-site treatment of UOW using practices such as home and community composting can lower managem...
Waste Management & Research: The Journal for a Sustainable Circular Economy, 2006
Landfill gas emissions are one of the largest anthropogenic sources of methane especially because... more Landfill gas emissions are one of the largest anthropogenic sources of methane especially because of food waste (FW). To prevent these emissions growing with world population, future FW best management practices need to be evaluated. The objective of this paper was therefore to predict FW production for 2025 if present management practices are maintained, and then, to compare the impact of scenario 1: encouraging people to stay in rural areas and composting 75% of their FW, and; of scenario 2, where in addition to scenario 1, composting or anaerobically digesting 75% of urban FW (UFW). A relationship was established between per capita gross domestic product (GDP) and the population percentage living in urban areas (%UP), as well as production of municipal solid waste (MSW) and UFW. With estimated GDP and population growth per country,%UP and production of MSW and UFW could be predicted for 2025. A relatively accurate ( R2 > 0.85) correlation was found between GDP and%UP, and betw...
Waste Management, 2014
Compost sustainability requires a better control of its gaseous emissions responsible for several... more Compost sustainability requires a better control of its gaseous emissions responsible for several impacts including odours. Indeed, composting odours have stopped the operation of many platforms and prevented the installation of others. Accordingly, present technologies collecting and treating gases emitted from composting are not satisfactory and alternative solutions must be found. Thus, the aim of this paper was to study the influence of composting process conditions on gaseous emissions. Pig slaughterhouse sludge mixed with wood chips was composted under forced aeration in 300 L laboratory reactors. The process conditions studied were: aeration rate of 1.68, 4.03, 6.22, 9.80 and 13.44 L/h/kg of wet sludge; incorporation ratio of 0.55, 0.83 and 1.1 (kg of wet wood chips/kg of wet sludge), and; bulking agent particles size of <10, 10 < 20 and 20 < 30 mm. Outgoing gases were sampled every 2 days and their composition was analysed using gas chromatography coupled with mass spectrometry (GC-MS). Fiftynine compounds were identified and quantified. Dividing the cumulated mass production over 30 days of composting, by odour threshold, 9 compounds were identified as main potential odour contributors: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone, 1-propanol-2-methyl, dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide and acetophenone. Five gaseous compounds were correlated with both aeration rate and bulking agent to waste ratio: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone and 1-propanol-2-methyl. However, dropping the aeration rate and increasing the bulking agent to waste ratio reduced gaseous odour emissions by a factor of 5-10, when the required threshold dilution factor ranged from 10 5 to 10 6 , to avoid nuisance at peak emission rates. Process influence on emissions of dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide were poorly correlated with both aeration rate and bulking agent to waste ratio as a reaction with hydrogen sulphide was suspected. Acetophenone emissions originated from the wood chips. Olfactory measurements need to be correlated to gaseous emissions for a more accurate odour emission evaluation.
Journal of Soil Contamination, 2000
A study was conducted to assess the retention form of arsenic in soil and to evaluate the use of ... more A study was conducted to assess the retention form of arsenic in soil and to evaluate the use of phosphate for releasing it from the soil. In this study, a loam soil was artificially polluted with arsenate at pH 5.5, which is one of the pH values at which maximum arsenic adsorption occurred. The soil was kept for 2.5 months
Korean Journal of Chemical Engineering, 2009
Citric acid production using Aspergillus niger NRRL 567 grown on peat moss has been optimized in ... more Citric acid production using Aspergillus niger NRRL 567 grown on peat moss has been optimized in a column bioreactor using a statistically based method. A 2 3 full factorial design with eight fermentation conditions was applied to evaluate significance on citric acid production and their interactions between variables, where the three independent variables evaluated were aeration rate, bed depth and temperature. Aeration rate and fermentation temperature were identified to be significant variables. Citric acid production markedly increases with aeration rate and fermentation temperature; however, the bed depth of solid substrate showed an insignificant effect on citric acid production. The optimum fermentation condition for citric acid production in a column bioreactor consisted of aeration rate of 0.84 vvm, bed depth of 22 cm and fermentation temperature of 32 o C. Under a given condition, a maximum citric acid production of 120.6 g/l was predicted and matched well with the experimental value of 123.9 g/kg.
Journal of Food Engineering, 2013
Rheological behavior of date syrup is an important factor affecting the efficiency of sugar produ... more Rheological behavior of date syrup is an important factor affecting the efficiency of sugar production and refining processes such as boiling, crystallization, separation and pumping. A rotational viscometer was used to characterize the flow behavior of date syrup solution at four different temperatures (20°C, 40°C, 60°C and 80°C) and four concentrations (17, 24, 31 and 39°Brix). The samples were subjected to a programmed shear rate increasing from 10 to 100 s À1 in 2 min, held constant at 100 s À1 for 10 min and linearly decreasing to 10 during 2 min. The power law model was fitted to shear stress vs. shear rate data to obtain the consistency coefficient (m) and the flow behavior index (n). Both m and n were sensitive to changes in temperature and concentration. The apparent viscosity increases with increasing concentration of date syrup and a decrease in temperature.
Journal of Environmental Science and Health, Part A- Toxic/Hazardous Substances & Environmental Engineering, 2004
The project examined the effect of Pb and Cd on Cu adsorption using sand liners containing 0, 5, ... more The project examined the effect of Pb and Cd on Cu adsorption using sand liners containing 0, 5, and 10% sodium bentonite and exposed to metal solutions at three pH levels (3.7, 5.5, and 7.5). Aliquots of 2 g of liner material were exposed in duplicate, for 14 days, to solutions containing Cu alone or Cu with either Pb or Cd. Selective sequential extraction (SSE) was used to quantity the Cu adsorbed by each liner particle adsorption site (exchangeable, carbonate and hydroxide, oxides and residual). The results indicated that two main factors affected liner material behavior in adsorbing Cu, besides Cd and Pb competition: pH either above or below 6.5; liner cation exchange capacity (CEC) greater or equal and greater than the solution cation equivalence. In general, the liner carbonate and hydroxide fractions precipitated the greatest amount of Cu, under all environmental conditions while the exchangeable, oxide and residual adsorbed more or less the same amount. Lead, and to a lesser extent Cd, significantly increase the mobility of Cu, by competing especially for the exchangeable sites. While Cd also competed against Cu for oxide adsorption, Pb competes for calcium and hydroxide precipitation. Lead, and to a lesser extent Cd, competed especially for the exchangeable site where the adsorption is more dynamic, and less for the more permanent adsorption sites, involving precipitation, and electrostatic bonding.
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Papers by Suzelle Barrington