Rozprawy doktorskie na temat „Wood waste as fertilizer”

This paper presents the research results of treatment solution of wood waste of Acacia and Eucalyptus in making of bioorganic fertilizers for the effective utilization of plant biomass resources and minimization of environmental pollution. The conversion cycles of the basic chemical compounds of wood waste in composting process were established by two biological products: Biomix and Compost Maker. Research results have shown that, under the action of microorganisms, all basic chemical compounds were modified (among them cellulose was most powerfully modified) whereas lignin, extractives dissolved in ethanol were less destructed. Within about first 75 days of composting, the conversion of the above mentioned compounds is negligible. With the time of composting from 105 days to 120 days, in total over of 70% of cellulose was conversed into compounds dissolved in water and in 1% NaOH solution. The optimal composting time was about 105 days. In this case, the fertilizer obtained was humified, had dark colour and could be used for planting and soil improvement purposes
Bài báo này trình bày các kết quả nghiên cứu giải pháp xử lý mùn vụn gỗ phế thải của gỗ Keo và Bạch đàn thành phân bón hữu cơ vi sinh, nhằm tận dụng hiệu quả nguồn sinh khối thực vật và giảm thiểu ô nhiễm môi trường. Đã xác lập được một số quy luật biến đổi của các thành phần hóa học cơ bản của mùn vụn gỗ trong quá trình ủ compost bằng hai chế phẩm vi sinh Biomix và Compost Maker, để tạo phân bón hữu cơ vi sinh. Kết quả nghiên cứu đã cho thấy, dưới tác dụng của vi sinh vật, tất cả các thành phần hóa học cơ bản của mùn vụn gỗ đều bị biến đổi, trong đó xenluloza bị biến đổi mạnh nhất, lignin và các chất trích ly bằng etanol ít bị phân hủy hơn. Trong vòng khoảng 75 ngày ủ đầu tiên, sự biến đổi của các thành phần nêu trên là không đáng kể. Với thời gian ủ từ 105 ngày đến 120 ngày, tổng cộng có trên 70% xenluloza bị phân hủy thành các hợp chất dễ tan trong nước và dung dịch NaOH 1%. Thời gian ủ thích hợp là khoảng 105 ngày. Trong trường hợp này, phân bón thu được đã bị mùn hóa, có mầu sẫm và có thể sử dụng cho mục đích trồng trọt và cải tạo đất

A large amount of raw wool, practically unserviceable for textile uses, is generated in Europe from sheep shearing and butchery; this is a byproduct that is either dumped, burned or sent to landfill. Following the European Commission regulations on animal by-product control, unserviceable raw wool is classified as a category 3 special waste materials, and its collection, storage, transport, treatment, use, and disposal is subject to European Union regulations because of a potential risk source to human and animal health. Raw wool has a noticeable chemical potential to conceive and generate a broad category of products, spreading from protein-based scaffold tissues to fertilizers. Considering all these points, raw wool has potential to create a circular economy rather than just wasted as an unserviceable material. In general, raw wool finds its application in insulation panels, composites, carpets, etc., but needs a complete pre-treatment before use. The problems begin with the use of raw wool is that; it cannot be used as a fertilizer without any previous pretreatment such as washing because of the potential risk of infection and its slow degradation process in the soil environment. For these reasons, fertilization with untreated greasy wool is forbidden by the EU legislation, which strictly provides guidelines for raw wool storage, transportation, and disposal. These costs heavily weigh on the profit of sheep farmers. The primary objective of this study is to develop the cost-effective, sustainable process to use raw wool prior to any pretreatment. This study aims at • Converting waste wool into nitrogen fertilizers at a commercial scale for grassland management and cultivation purposes. • Development of potential novel applications of hydrolyzed wool In order to achieve the desired aim of fertilizer, the chemical breakdown of wool needs to be done using sustainable way, i.e., chemical-free process. In general, hydrolysis process is performed using acids, bases, and enzymes. The literature survey on existing hydrolysis processes, their limitations, industrial scale-up viability, sustainability, cost-effectiveness, etc., lead towards the process where chemical transformation is based on a green economically sustainable hydrolysis treatment using only green solvent superheated water. The other the advantage of green hydrolysis is that it sterilizes the wool at high temperature, which indirectly overcomes the problem of pretreatment prior to use and infection problem in the application phase.In order to understand the extent of degradation and industrial viability of the superheated water hydrolysis process with the aim of fertilizer; the development the process implies two steps: the first one at laboratory scale (batch process) and the second at semi-industrial scale (continuous process). A set of experiments on batch scale reactors was performed to monitor process parameters and extent a degree of hydrolysis on raw wool; to establish the ground for designing and construction of semi-industrial scale reactor. The green hydrolysis process optimization was carried out in batch and semi-industrial scale reactors by varying parameters such as temperature, wool density, material to liquor ratio, time, depending on the extent of degradation of the final hydrolyzed product. Controlled treatment with superheated water converts wool keratin into simpler compounds. At the end of the process, it is possible to obtain a hydrolyzed product in either solid or liquid phase depending on the extent of hydrolysis parameters implemented. The presence of amino acids, primary nutrients, and micronutrients in wool hydrolyzates, along with a concentration of heavy metals below the standard limit, confirm the possibility of using wool hydrolyzates as nitrogen based ecologically sound fertilizer. On the way to find the possible application of keratin hydrolyzate other than fertilizer, which overcomes the environmental problem of wool waste and byproducts were found to be a foaming agent for dyeing. The foam-forming the behavior of the keratin hydrolyzate along with its application in dyeing was studied to develop sustainable and green dyeing process. The surface tension, foam stability, blow ratio, bubble size of the keratin hydrolyzate in aqueous solutions with and without dyeing auxiliaries were determined. The dyeing influential parameter such as wet pickup was studied to identify their effect on dye fixation and color strength. The foam dyeing was compared with conventional cold-pad batch and pad-steam processes for cotton and wool, respectively. The combination of green hydrolysis and the biodegradable keratin hydrolyzate resulted in the sustainable green dyeing process.

A large amount of raw wool, practically unserviceable for textile uses, is generated in Europe from sheep shearing and butchery; this is a byproduct that is either dumped, burned or sent to landfill. Following the European Commission regulations on animal by-product control, unserviceable raw wool is classified as a category 3 special waste materials, and its collection, storage, transport, treatment, use, and disposal is subject to European Union regulations because of a potential risk source to human and animal health. Raw wool has a noticeable chemical potential to conceive and generate a broad category of products, spreading from protein-based scaffold tissues to fertilizers. Considering all these points, raw wool has potential to create a circular economy rather than just wasted as an unserviceable material. In general, raw wool finds its application in insulation panels, composites, carpets, etc., but needs a complete pre-treatment before use. The problems begin with the use of raw wool is that; it cannot be used as a fertilizer without any previous pretreatment such as washing because of the potential risk of infection and its slow degradation process in the soil environment. For these reasons, fertilization with untreated greasy wool is forbidden by the EU legislation, which strictly provides guidelines for raw wool storage, transportation, and disposal. These costs heavily weigh on the profit of sheep farmers. The primary objective of this study is to develop the cost-effective, sustainable process to use raw wool prior to any pretreatment. This study aims at • Converting waste wool into nitrogen fertilizers at a commercial scale for grassland management and cultivation purposes. • Development of potential novel applications of hydrolyzed wool In order to achieve the desired aim of fertilizer, the chemical breakdown of wool needs to be done using sustainable way, i.e., chemical-free process. In general, hydrolysis process is performed using acids, bases, and enzymes. The literature survey on existing hydrolysis processes, their limitations, industrial scale-up viability, sustainability, cost-effectiveness, etc., lead towards the process where chemical transformation is based on a green economically sustainable hydrolysis treatment using only green solvent superheated water. The other the advantage of green hydrolysis is that it sterilizes the wool at high temperature, which indirectly overcomes the problem of pretreatment prior to use and infection problem in the application phase.In order to understand the extent of degradation and industrial viability of the superheated water hydrolysis process with the aim of fertilizer; the development the process implies two steps: the first one at laboratory scale (batch process) and the second at semi-industrial scale (continuous process). A set of experiments on batch scale reactors was performed to monitor process parameters and extent a degree of hydrolysis on raw wool; to establish the ground for designing and construction of semi-industrial scale reactor. The green hydrolysis process optimization was carried out in batch and semi-industrial scale reactors by varying parameters such as temperature, wool density, material to liquor ratio, time, depending on the extent of degradation of the final hydrolyzed product. Controlled treatment with superheated water converts wool keratin into simpler compounds. At the end of the process, it is possible to obtain a hydrolyzed product in either solid or liquid phase depending on the extent of hydrolysis parameters implemented. The presence of amino acids, primary nutrients, and micronutrients in wool hydrolyzates, along with a concentration of heavy metals below the standard limit, confirm the possibility of using wool hydrolyzates as nitrogen based ecologically sound fertilizer. On the way to find the possible application of keratin hydrolyzate other than fertilizer, which overcomes the environmental problem of wool waste and byproducts were found to be a foaming agent for dyeing. The foam-forming the behavior of the keratin hydrolyzate along with its application in dyeing was studied to develop sustainable and green dyeing process. The surface tension, foam stability, blow ratio, bubble size of the keratin hydrolyzate in aqueous solutions with and without dyeing auxiliaries were determined. The dyeing influential parameter such as wet pickup was studied to identify their effect on dye fixation and color strength. The foam dyeing was compared with conventional cold-pad batch and pad-steam processes for cotton and wool, respectively. The combination of green hydrolysis and the biodegradable keratin hydrolyzate resulted in the sustainable green dyeing process.

Land application of wood ash is becoming more appealing, as a disposable alternative, to landfilling options. It is estimated that 110,000 tonnes of wood ash is produced annually in Alberta by cogeneration systems, a large percentage produced in Central and Peace River Regions of Alberta. Alkaline (pH-13) properties and nutrient content of wood ash provides an alternative for the acidic and nutrient deficient soils within these regions. The objective of this field study was to determine the effect wood ash applications would have under field conditions on: the chemical and physical properties of soils; barley dry matter production; grain and seed yield of barley and canola; and the nutrient and metal uptake by crop tissue. Ash applications significantly increased dry matter and seed yield, improved crop nutrient quality, increased soil pH and improved soil nutrient availability, while not infringing on any environmental regulations.
xxiii, 142 leaves : ill. ; 28 cm.

The number of biogas plants in Germany is increasing from 3,711 in 2007 to 8,075 in 2016. In these biogas plants, it occurred more than 50 Mt digestate. Therefore, several investigations are started to use digestate as organic fertiliser mostly for field crop cultivation. Experiment with tomatoes was carried out were digestate was used as a supplement to the growing media in an amount of 5%, 15%, and 25%, compared with a treatment of mineral fertiliser and lupine wholemeal. The tomato yield was highest in the treatment with mineral fertilisation, the yield with 25% digestate was only a little lower. More experiments are necessary for particular regarding the amount and frequency of fertilization with digestate from biogas plants. In Germany and in Vietnam the number of sheep flocks is increasing, high amounts of uncleaned sheep wool are available. Because of the high amount of nutrients - especially nitrogen -, sheep wool pellets could be used as multi-functional fertiliser in vegetable cultivations. Four types of sheep wool pellets have been tested in protected cultivation. Tomatoes were cultivated in a greenhouse using substrate culture with perlite, bark compost, sheep wool slabs, respectively, and sheep wool pellets as fertiliser. Best growth and highest yield for tomatoes were obtained using pine bark and perlite as a substrate, both fertilised with sheep wool pellets. Based on the results of the yield and the analyses of the nutrient content in plants it seems that sheep wool pellets can be used, for the cultivation of vegetables in greenhouses.
Số lượng các nhà máy biogas tại CHLB Đức tăng từ 3.711 năm 2017 lên 8.075 năm 2016. Các nhà máy biogas sản sinh ra hơn 50 triệu tấn chất thải. Vì vậy đã có nhiều nghiên cứu liên quan đến sử dụng nguồn chất thải này làm phân bón hữu cơ cho canh tác nông nghiệp. Thí nghiệm với cà chua sử dụng chất thải biogas làm chất bổ sung dinh dưỡng cho giá thể trồng cây theo các tỷ lệ 5%, 15% và 25% đối chứng với công thức sử dụng phân hóa học và bột nguyên vỏ họ đậu. Năng suất cà chua thu được từ các công thức bổ sung chất thải biogas đều cao hơn đối chứng, chỉ có công thức bổ sung 25% có năng suất thấp hơn. Tuy nhiên vẫn cần có những nghiên cứu tiêp theo về lượng và tần xuất sử dụng bón phân với chất thải từ nhà máy biogas. Ở Đức và ở Việt Nam số lượng đàn cừu đang tăng lên, một lượng lớn lông cừu phế phẩm phát sinh. Với hàm lượng dinh dưỡng cao, đặc biệt là nitơ, viên nén từ lông cừu phế phẩm có thể sử dụng làm phân bón đa chức năng cho trồng trọt. Nghiên cứu đã sử dụng 4 loại viên nén lông cừu làm phân bón trong điều kiện trồng có kiểm soát. Cà chua được trồng trong nhà kính với 3 loại giá thể là perlite, vỏ cây thông đã ủ hoai, thảm lông cừu với phân bón là viên nén từ lông cừu phế phẩm. Năng suất cao nhất và đem lại sinh trưởng tốt nhất cho cây cà chua là công thức sử dụng vỏ cây thông và perlite. Dựa trên kết quả về năng suất và phân tích dinh dưỡng trong cây và sản phẩm, nghiên cứu cho thấy sự phù hợp của viên nén từ lông cừu phế phẩm làm phân bón cho canh tác rau trong nhà kính.

Each year a large number of wooden pallets are manufactured, recycled, and disposed of during the transportation of goods throughout the United States. The production of these pallets consumes a significant amount of wood and a large number of pallets also end up in landfills at the end of their useful life cycle. However, these pallets can be recovered through repair, broken apart into components, ground into mulch, fuel, animal bedding, or used by landfills for day to day operations. The purpose of this research was to investigate the total number of pallets and crates reaching landfills in the United States as well as to gain a better understanding of the overall waste stream. This was done by surveying all licensed Municipal Solid Waste (MSW) and Construction and Demolition (CandD) landfills in the continental United States. A questionnaire was sent to these landfills, and this entire study was intended to build upon previous Virginia Tech landfill surveys conducted in 1995 and 1998 with some changes made after careful review. Overall, it was found the average MSW facility in the United States received 185,077 tons of waste and the average CandD facility received 74,911 tons. This results in a total national estimate of 253 million tons of MSW and 76.9 million tons of CandD waste. Approximately 18.3 million pallets were landfilled and an additional 13.8 million were recovered, repurposed, or reused at MSW facilities. At CandD facilities, approximately 19.2 million pallets were landfilled while 38.3 million were recovered.
Master of Science

Concrete, as primary building material, is widely used in most construction project. For this reason, large amounts of concrete waste were generated from construction and demolition. One way to reuse concrete waste is to use it as backfill material for landfilling and road bases. While the demand for backfill material is decreasing as the basic infrastructure construction gradually completes. Another way to reuse concrete waste is to grind it and use it as aggregate in casting new concrete. However, the reuse as aggregate for casting concrete requires large amount of cement. It is unsustainable because the production of cement causes significant amounts of carbon dioxide emission. How to deal with the concrete waste in a sustainable way is presently an urgent issue. Powder compaction is a new approach to completely recycle concrete waste in an environmentally friendly way. This new method was studied in the Sakai lab of the Institute of Industrial Science, The University of Tokyo. The process consists of crushing and milling concrete waste into a fine powder, filling the powder into moulds and compacting it under high pressure. By this process concrete waste powder can be turned into a solid concrete with mechanical properties so that it has potentials to be used again as a building material. Data from previous studies show that the compacted concrete waste can reach strength for construction but the required compaction pressure is quite high. Wood flour can be added in compaction for improving tensile strength and reducing compaction pressure. Lignin is a wood substance that melts under high temperature, fills gaps and improves bonding between particles. Cellulose from the wood substance functions as fibres which improves tensile strength. Wood waste from production of timber building materials, furniture and other wooden products also forms a larger quantities. Recycling of concrete waste with wooden waste through heating compaction is a potentially sustainable method. This Master thesis presents research on the effect from different production conditions on the bending strength of recycled concrete waste with wood waste through heating compaction. The condition factors studied were compaction duration, compaction pressure, concrete proportion, mixture percentage, temperature and particle size of wood flour. To enhance the water resistance of this recycled product, different water resistance treatments were discussed theoretically. The independence of production condition factors was analysed using a statistic method. Results indicated that within a certain range, an increase in compaction duration, compaction pressure, the percentage of wood waste and temperature improves the bending strength of the recycled products. Using smaller particle size of wood flour cannot improve compaction but contribute to give higher bending strength. The mechanical properties of these recycled products suggest application as non-bearing building material, such as decoration tiles and bricks for partition walls. The application as a structural material is expected in the future as improvement treatments are discovered.

In present day society there is an artificial dichotomy between wastes and resources that is perhaps best summed up by the Western Sydney Waste Board slogan 'there is no such thing as waste � only resources in the wrong place and at the wrong time'. Waste management was originally driven by managing the health consequences of wrong time/place materials. This has changed and the significant driver is now the sustainable utilisation of resources, that is, trying to optimally recover as resources (right time/place) those materials that present as wastes requiring management. However, it is not acceptable to justify a resource recovery option purely on the basis that it is diverting material away from landfill. Preferences are emerging for recovery activities that maximise the resource value of a material according to techno-economic, environmental and socio-political criteria; collectively known as the criteria of sustainability. The people and organisations articulating these preferences include owners/operators of resource recovery centres, proponents of alternative waste management technologies, waste planners and managers at both a state and local government level and environmental NGOs representing community interests, in addition to the generators of waste at a domestic, commercial and industrial, and construction and demolition level. It is therefore important to be able to answer the question of 'what is the optimal or most sustainable resource recovery option for materials presenting as waste to landfill in the Greater Sydney Region?' The point of departure for this thesis is twofold. Firstly, that optimal resource recovery options (also known as alternative waste management technologies) can be identified by understanding the context and system drivers and constraints within the system of waste generation and utilisation, by modelling the system using industrial ecology (specifically Materials Flux Analysis) and by using the technology assessment framework developed by the NSW Alternative Waste Management Technologies and Practices Inquiry to evaluate the available options. Secondly, that should the assessment framework from the NSW Inquiry prove to be unsuitable as a framework for evaluation, then an improved and refined assessment framework can be constructed in order to identify optimal resource recovery options and that this process can be successfully demonstrated using wood waste as a case study. The context of waste as an issue has shifted from local government control (pre-1970s) to state government control through the Department of Environment and Conservation. This transition followed experiments with organisations such as the NSW Waste Boards and Resource NSW, in addition to state targets such as a 60% reduction of waste to landfill by the year 2000. In addition to this backdrop of change from a government administrative perspective, there are also a suite of often conflicting drivers and constraints influencing the process of resource recovery. For example, sustainable development is a public policy driver for the integration of environmental and societal concerns, but can also constrain new innovation if competing 'status quo' utilisation options are not subject to the same scrutiny. Similarly, legislation acts as a constraint to resource recovery options by establishing license conditions, prohibiting some energy recovery options and setting recovery criteria; however legislation also acts as a driver for resource recovery options that generate renewable electricity or act to reduce greenhouse gas emissions. Other drivers and constraints include social, technical and economic issues and concerns in addition to environmental impacts such as emissions to air, land and water. Industrial ecology is a model for viewing system components as part of a dependent and interrelated greater whole. Within the context of Industrial Ecology, waste is a by-product of manufacture available as a beneficial input into other processes. Using Materials Flux Analysis as a tool to build a model of waste generation and utilisation, elements within the system are presented as a series of stocks (sources), technology interventions (transformation flows) and sinks (markets). The stocks or sources of materials for resource recovery are categorised as Municipal Solid (MSW), Commercial and Industrial (C&I) or Construction and Demolition (C&D) wastes. Approximately seven million tonnes of waste is generated in the Greater Sydney Region (nearly two and a half million tonnes of materials recovered for recycling and four and a half million tonnes of materials disposed of to landfill). The purpose of technology intervention is to transform the material into a product that is suited to the end market (sink). Markets are grouped according to reuse (same function and form), direct recycling (same supply chain), indirect recycling (different supply chain) and energy recovery (either as process heat, electricity or co-generation, a combination of the two). Landfill is also a potential sink for materials and in this sense can be thought of as a negative value market. The Alternative Waste Management Technologies and Practices Inquiry provided an assessment framework for resource recovery technologies. Each technology was measured and compared against 16 evaluation criteria, resulting in a score out of one hundred. Material sorting scored the highest (81.5), incineration the lowest (50.8) with most of the biological technologies performing �well� (64.6 � 71.7) and with the landfill technologies performing 'moderately well' (60.4 - 61.4). The positive features of the Inquiry included the overview of alternative resource recovery technologies, waste generation and other issues pertinent to decision making and resource recovery. The negatives of the Inquiry arise from the inadequacies of the assessment framework, which lacked technology options, system boundary definition and requisite evaluation criteria in addition to inconsistencies in scoring approaches. By undertaking a sensitivity analysis on the Inquiry�s results, it is shown that rank order reversal results from the allocation of weightings. The improved and refined assessment framework, constructed to overcome identified inadequacies of the Inquiry�s approach, focussed on clearly identifying the problem to be addressed and the primary decision maker involved in the process; ensuring that appropriate options for evaluation were included; defining the system boundary for the assessment; selecting necessary evaluation criteria; adopting a more sophisticated system for scoring; and using a sensitivity analysis to validate the results of the resource recovery option evaluation. Wood waste was used as a case study for this second assessment methodology. Wood waste refers to the end-of-life products, failed products, offcuts, shavings and sawdust from all timber products. Approximately 350,000 tonnes of wood waste are disposed of to landfill each year. This comprises untreated timber (hard wood and soft wood), engineered timber products (particleboard, medium density fibreboard and plywood) and treated timber (predominately copper chrome arsenic). Eight wood resource recovery options are selected for evaluation within the Greater Sydney Region with a different approach to scoring that has the advantage of 'scaling up' the best performers within each attribute (highest score) while 'scaling down' the worst performers (no score). Under this evaluation, an on-site purpose built energy facility is the most preferred option with particleboard manufacture the least preferred option. A sensitivity analysis of the results reveals that the scores of each technology option are sensitive to the weightings of the decision maker. When the change in rankings is examined, it is identified that two eight wood recovery options undergo a large rank reversal. A critique of the results of the wood evaluation reveals five major flaws. Firstly the evaluation produces non-highest resource value results that are non-intuitive (and arguably misleading), for example the poor performance of reuse and particleboard against energy generation options. Secondly, the recording of a single summary score for each recovery option hides unacceptable performance levels in some criteria. For example, the top scorer of Primary Energy On-site hides the fact that such an option is likely to have no political desirability (likely public opposition to 'incineration' within the Sydney air-shed), calling into question its ability to be implemented as a solution. Thirdly there is a reliance on judgement for the scoring of options and weighting of preferences, calling into doubt the accuracy of scores. Fourthly, the rankings of recovery options by the assessment framework are sensitive to the allocation of weightings. Finally and most importantly, the refined evaluation approach suffers from the 'discrete option syndrome', the scoring of each recovery option in isolation with no ability to look at integrated systems with joint recovery options. This is pinpointed as a fundamental flaw in the process of both the Inquiry and the wood evaluation. This leads to the conclusion that the founding assertions of this thesis were false. That is to say that the assessment framework developed by the NSW Alternative Waste Management Technologies and Practices Inquiry is not suitable for use in evaluating resource recovery options. Furthermore a refined assessment framework based on this approach is also unable to identify optimal resource recovery options as demonstrated using wood waste as a case study. The results of this research points to the overall conclusion that any discrete option evaluation and assessment for resource recovery technologies that results in a single summary score for each option will be fundamentally flawed, providing no value in determining optimal resource recovery solutions for the Greater Sydney Region. A systems approach is suggested as an alternative method for the evaluation of optimal resource recovery, the starting point of which is to ask 'what is the highest resource value of the components in the material stream under consideration and how could a network of infrastructure be designed in order to allow materials to flow to their highest resource value use?' A feature of such an integrated approach is a focus on the materials composition of recovered resources, as opposed to recovery technologies, resulting in a 'fit for purpose' as opposed to a 'forced fit' style of resource recovery. It is recommended that further research and public policy efforts be made in logistics planning across the Greater Sydney Region (as opposed to a regional or local government area) in order to create network opportunities for integrated flows of materials to move toward their highest resource value.

In present day society there is an artificial dichotomy between wastes and resources that is perhaps best summed up by the Western Sydney Waste Board slogan 'there is no such thing as waste � only resources in the wrong place and at the wrong time'. Waste management was originally driven by managing the health consequences of wrong time/place materials. This has changed and the significant driver is now the sustainable utilisation of resources, that is, trying to optimally recover as resources (right time/place) those materials that present as wastes requiring management. However, it is not acceptable to justify a resource recovery option purely on the basis that it is diverting material away from landfill. Preferences are emerging for recovery activities that maximise the resource value of a material according to techno-economic, environmental and socio-political criteria; collectively known as the criteria of sustainability. The people and organisations articulating these preferences include owners/operators of resource recovery centres, proponents of alternative waste management technologies, waste planners and managers at both a state and local government level and environmental NGOs representing community interests, in addition to the generators of waste at a domestic, commercial and industrial, and construction and demolition level. It is therefore important to be able to answer the question of 'what is the optimal or most sustainable resource recovery option for materials presenting as waste to landfill in the Greater Sydney Region?' The point of departure for this thesis is twofold. Firstly, that optimal resource recovery options (also known as alternative waste management technologies) can be identified by understanding the context and system drivers and constraints within the system of waste generation and utilisation, by modelling the system using industrial ecology (specifically Materials Flux Analysis) and by using the technology assessment framework developed by the NSW Alternative Waste Management Technologies and Practices Inquiry to evaluate the available options. Secondly, that should the assessment framework from the NSW Inquiry prove to be unsuitable as a framework for evaluation, then an improved and refined assessment framework can be constructed in order to identify optimal resource recovery options and that this process can be successfully demonstrated using wood waste as a case study. The context of waste as an issue has shifted from local government control (pre-1970s) to state government control through the Department of Environment and Conservation. This transition followed experiments with organisations such as the NSW Waste Boards and Resource NSW, in addition to state targets such as a 60% reduction of waste to landfill by the year 2000. In addition to this backdrop of change from a government administrative perspective, there are also a suite of often conflicting drivers and constraints influencing the process of resource recovery. For example, sustainable development is a public policy driver for the integration of environmental and societal concerns, but can also constrain new innovation if competing 'status quo' utilisation options are not subject to the same scrutiny. Similarly, legislation acts as a constraint to resource recovery options by establishing license conditions, prohibiting some energy recovery options and setting recovery criteria; however legislation also acts as a driver for resource recovery options that generate renewable electricity or act to reduce greenhouse gas emissions. Other drivers and constraints include social, technical and economic issues and concerns in addition to environmental impacts such as emissions to air, land and water. Industrial ecology is a model for viewing system components as part of a dependent and interrelated greater whole. Within the context of Industrial Ecology, waste is a by-product of manufacture available as a beneficial input into other processes. Using Materials Flux Analysis as a tool to build a model of waste generation and utilisation, elements within the system are presented as a series of stocks (sources), technology interventions (transformation flows) and sinks (markets). The stocks or sources of materials for resource recovery are categorised as Municipal Solid (MSW), Commercial and Industrial (C&I) or Construction and Demolition (C&D) wastes. Approximately seven million tonnes of waste is generated in the Greater Sydney Region (nearly two and a half million tonnes of materials recovered for recycling and four and a half million tonnes of materials disposed of to landfill). The purpose of technology intervention is to transform the material into a product that is suited to the end market (sink). Markets are grouped according to reuse (same function and form), direct recycling (same supply chain), indirect recycling (different supply chain) and energy recovery (either as process heat, electricity or co-generation, a combination of the two). Landfill is also a potential sink for materials and in this sense can be thought of as a negative value market. The Alternative Waste Management Technologies and Practices Inquiry provided an assessment framework for resource recovery technologies. Each technology was measured and compared against 16 evaluation criteria, resulting in a score out of one hundred. Material sorting scored the highest (81.5), incineration the lowest (50.8) with most of the biological technologies performing �well� (64.6 � 71.7) and with the landfill technologies performing 'moderately well' (60.4 - 61.4). The positive features of the Inquiry included the overview of alternative resource recovery technologies, waste generation and other issues pertinent to decision making and resource recovery. The negatives of the Inquiry arise from the inadequacies of the assessment framework, which lacked technology options, system boundary definition and requisite evaluation criteria in addition to inconsistencies in scoring approaches. By undertaking a sensitivity analysis on the Inquiry�s results, it is shown that rank order reversal results from the allocation of weightings. The improved and refined assessment framework, constructed to overcome identified inadequacies of the Inquiry�s approach, focussed on clearly identifying the problem to be addressed and the primary decision maker involved in the process; ensuring that appropriate options for evaluation were included; defining the system boundary for the assessment; selecting necessary evaluation criteria; adopting a more sophisticated system for scoring; and using a sensitivity analysis to validate the results of the resource recovery option evaluation. Wood waste was used as a case study for this second assessment methodology. Wood waste refers to the end-of-life products, failed products, offcuts, shavings and sawdust from all timber products. Approximately 350,000 tonnes of wood waste are disposed of to landfill each year. This comprises untreated timber (hard wood and soft wood), engineered timber products (particleboard, medium density fibreboard and plywood) and treated timber (predominately copper chrome arsenic). Eight wood resource recovery options are selected for evaluation within the Greater Sydney Region with a different approach to scoring that has the advantage of 'scaling up' the best performers within each attribute (highest score) while 'scaling down' the worst performers (no score). Under this evaluation, an on-site purpose built energy facility is the most preferred option with particleboard manufacture the least preferred option. A sensitivity analysis of the results reveals that the scores of each technology option are sensitive to the weightings of the decision maker. When the change in rankings is examined, it is identified that two eight wood recovery options undergo a large rank reversal. A critique of the results of the wood evaluation reveals five major flaws. Firstly the evaluation produces non-highest resource value results that are non-intuitive (and arguably misleading), for example the poor performance of reuse and particleboard against energy generation options. Secondly, the recording of a single summary score for each recovery option hides unacceptable performance levels in some criteria. For example, the top scorer of Primary Energy On-site hides the fact that such an option is likely to have no political desirability (likely public opposition to 'incineration' within the Sydney air-shed), calling into question its ability to be implemented as a solution. Thirdly there is a reliance on judgement for the scoring of options and weighting of preferences, calling into doubt the accuracy of scores. Fourthly, the rankings of recovery options by the assessment framework are sensitive to the allocation of weightings. Finally and most importantly, the refined evaluation approach suffers from the 'discrete option syndrome', the scoring of each recovery option in isolation with no ability to look at integrated systems with joint recovery options. This is pinpointed as a fundamental flaw in the process of both the Inquiry and the wood evaluation. This leads to the conclusion that the founding assertions of this thesis were false. That is to say that the assessment framework developed by the NSW Alternative Waste Management Technologies and Practices Inquiry is not suitable for use in evaluating resource recovery options. Furthermore a refined assessment framework based on this approach is also unable to identify optimal resource recovery options as demonstrated using wood waste as a case study. The results of this research points to the overall conclusion that any discrete option evaluation and assessment for resource recovery technologies that results in a single summary score for each option will be fundamentally flawed, providing no value in determining optimal resource recovery solutions for the Greater Sydney Region. A systems approach is suggested as an alternative method for the evaluation of optimal resource recovery, the starting point of which is to ask 'what is the highest resource value of the components in the material stream under consideration and how could a network of infrastructure be designed in order to allow materials to flow to their highest resource value use?' A feature of such an integrated approach is a focus on the materials composition of recovered resources, as opposed to recovery technologies, resulting in a 'fit for purpose' as opposed to a 'forced fit' style of resource recovery. It is recommended that further research and public policy efforts be made in logistics planning across the Greater Sydney Region (as opposed to a regional or local government area) in order to create network opportunities for integrated flows of materials to move toward their highest resource value.

A high priority in order to combat climate change is disposal of waste. In low-income countries, a large portion of biomass residues generated in the forestry, agricultural and industrial sectors could be usable, instead of being seen as waste. For instance, it could be converted into biochar, which is proven to have many environmental benefits. In Rwanda, the agricultural sector employs 80% of the population and accounts for 35% of GDP. This sector, together with later refinement of crops and forestry production, cause large amounts of residue that many times is considered as waste. In this report, a literature study was conducted to evaluate possible biochar production from agricultural and wood wastes in Rwanda. Characteristics that determine if a biomass could be suitable for a biochar production were identified as C, H, O, N, S, hemicellulose, cellulose, lignin, ash and moisture content, residue-to-product ratio, and low heating value. These characteristics were assessed for the chosen Rwandan agricultural and wood wastes, by compiling values from published reports. The result shows that there are large volumes of residues that have potential for biochar production instead of being seen as waste in Rwanda. Biochar production from these wastes could enable environmental benefits for Rwanda, although further investigation of each single biomass could be needed in order to see if it is practically, technically and financially possible to do in reality.
För att bekämpa klimatförändringen är avfallshantering en hög prioritet. I låginkomstländer kan en stor andel av biomassarester som genereras i skogsbruk, jordbruks- och industrisektorer vara användbara, istället för att ses som avfall. Till exempel skulle det kunna omvandlas till biokol, som har visats sig ha många miljömässiga fördelar. I Rwanda arbetar 80% av befolkningen inom jordbrukssektorn och den står för 35% av BNP. Denna sektor, tillsammans med förädling av grödor och skogsbruksproduktion, orsakar stora mängder rester som många gånger betraktas som avfall. I denna rapport genomfördes en litteraturstudie för att utvärdera möjlig produktion av biokol från jordbruks- och träavfall i Rwanda. Egenskaper som avgör om en biomassa kan vara lämplig för en biokolsproduktion identifierades som C-, H-, O-, N-, S-, hemicellulosa-, cellulosa-, lignin-, ask- och fukthalt, samt andel avfall som uppstår i förhållande till färdig produkt och värmevärde. Dessa egenskaper utvärderades för det valda jordbruks- och träavfallet genom att sammanställa värden från publicerade rapporter. Resultatet visar att det finns stora volymer rester som har potential för biokolsproduktion istället för att ses som avfall i Rwanda. En biokolsproduktion från dessa avfall skulle kunna ge miljömässiga fördelar för Rwanda, även om ytterligare undersökning av varje enskild biomassa skulle behövas för att se om det är praktiskt, tekniskt och ekonomiskt möjligt att genomföra i verkligheten.

Thesis (M.S.)--West Virginia University, 2009.
Title from document title page. Document formatted into pages; contains xii, 92 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 87-90).

Thesis (M.S.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains viii, 71 p. : col. ill. Includes abstract. Includes bibliographical references (p. 62-63).

Composting is considered as an effective and sustainable food waste treatment technology from the perspectives of volume reduction, stabilization and releasing the pressure on landfills. Community composter is a decentralized composting facility in fed-batch operational mode which is usually being installed in the backyard of institutes, hospitals, housing estate etc. to handle the food wastes generated daily. Albeit numerous operational issues including high initial acidity and oil content, poor decomposition and odor generation are commonly encountered in these facilities, which make it difficult to be accepted by the public. Therefore, the aim of the present study is to develop a composting mix formulation that can provide a solution to all these issues in a fed-batch food waste composting process. The first phase of this study aims at finding out an optimized formulation in a batch-scale food waste composting process through the use of alkaline amendments and microbial inoculum. For the first two experiments, artificial food wastes were prepared by mixing 1.3kg bread, 1kg boiled rice, 1kg cabbage, 0.5kg fully boiled pork and mixed with sawdust to obtain a C/N of 30 and adjusted moisture of the mixtures to 55%. The effect of different concentrations of zeolite compared to lime was studied in the first experiment. Zeolite was amended with food wastes and sawdust mixtures at 2% (ZI-2), 5% (ZI-5), 10% (ZI-10) to compare with lime in 2.25% (L-2.25) w/w (dry weight basis) and composted for 56 days. Results demonstrated that 10% of zeolite was optimal amendment rate compared to lower dosage of zeolite (2% & 5%) with stronger pH buffering capacity and greater decomposition efficiency. Addition of 2.25% of lime buffered the pH efficiently but increased the ammonia loss significantly which eventually reduced total nitrogen (TN) content of final product and posed odor emission problem. Amendment of 10% zeolite provided a higher adsorption affinity on ammonia resulting in 2.05% of TN value of final product which was higher than 1.72% of lime treatment. Furthermore, significantly higher seed germination 150% was achieved of ZI-10 compost compared to 135% of L-2.25 due to low ammonium content of product. The first experiment showed that application of less than 10% zeolite was not sufficient to buffer the acidity; as a result, organic matter decomposition was inhibited. However, the cost and reduction in treatment percentage of food waste in 10% application rate of zeolite is an issue of concern. To tackle this dilemma, food waste was amended with struvite salts at 1:2 molar ratio of MgO and K2HPO4 (Mg:P) with or without zeolite amended at either 5% or 10% amendment (Mg:P, Z5 + Mg:P & Z10 + Mg:P) and a control treatment with food waste only was also included. Results showed that treatment of Z10 + Mg:P was synergistically achieved of pH and EC buffering, and N conservation but not for the case of 5 % zeolite. Treatment of Z10 + Mg:P further reduced the N loss to 18% compared to 25% and 27% of Mg:P and Z5 + Mg:P respectively. However, there was insignificant difference in the final nitrogen content and decomposition rate among all treatments with struvite salts amendment. Comparing to the treatment of Z-10 of the first experiment to Z10 + Mg:P of the second experiment, Z-10 showed superior performance since better decomposition efficiency, shorter time to require to pass the GI (28 Days) and lower cost because of salts exclusion. To develop a multipurpose formulation for the fed-batch operational food waste composter, high lipids problem in food waste cannot be neglected because it is a critical factor to hinder the decomposition efficiency. Inoculation of oil degradative microorganisms was reported as an effective approach to facilitate the lipids. Therefore, the third experiment was to investigate the overall composting performance supplemented with 10% zeolite and microbial consortium. 10% zeolite with bacterial consortium significantly reduced the lipid contents from 7% to 1% compared to control treatments. Furthermore, treatments amended with 10% zeolite was proved to reduce ammonia emission and total volatile fatty acids level in the composting mass, therefore the total odor emission level can be reduced. Zeolite at 10% was found to be a suitable optimum additive for both synthetic and real-food wastes. Therefore, treatment of 10% zeolite with bacterial consortium is selected as an optimized formulation for further study of its application in a fed-batch composter. Following the food waste zeolite composting formulation obtained in Phase I, the aim of Phase II was to develop an ideal composting mix formulation for on-site commercial composters. Although the results have been demonstrated 10% zeolite with bacterial consortium facilitated the composting efficiency in batch composter, those amendments may be over-estimated if applied in a fed batch composter by using real food wastes. With this constraint, the applicability of these additives in commercial fed-batch composter needs to be assessed using locally generated food wastes. Treatments included food waste and sawdust mixtures at 4:1 mixing ratio (wet weight basis) were mixed with 2.25% of lime (L2.25), 10% of zeolite (Z10) and 10% zeolite with bacterial inoculum (Z10+O) and a control of food waste with sawdust mixture only was also included. 35 kg compost mixture was fed into each composter respectively daily for a period of 42 days. Only Z10+O was the most suitable composting mix for fed-batch food waste composting process with continuous sustained high temperature (55-60oC), optimal moisture (55%-60%), alkaline pH and low EC during the experimental period. Bacterial inoculum significantly improved the lipids decomposition from 22.16% (C) to 3.10% (Z10+O) after the composting period. In contrast, lime and zeolite alone treatments could not maintain the optimal pH that led to reduce degradation and longer stabilization period. Only compost taken from Z10+O treatment could be classified as mature compost. The aim of the third study phase was to examine an optimal application rate of food waste compost produced from decentralized food waste composter for plant. A plant growth experiment was conducted in this phase to evaluate the change in soil properties and plant growth of Brassica chinensis and Lycopersicon esculentum. The experiment was conducted in a loamy soil amended with 0%, 2.5%, 5% and 10% food waste compost amendment rate compared to the control soil with chemical fertilizer amendment only. Results indicated that 5% was the optimal application rate of food waste compost for both crops among all treatments which can be evidenced by the highest biomass production and nutrients value of the plant tissues. Plant available nutrients such as NH4+, NO3-, PO43- were proportionally increased with increase in compost application rate. However, 2.5% of the food waste compost did not provide sufficient nutrients for plant growth and 10% showed negative effects due to increased salts content. Plants amended with chemical fertilizer had relatively low biomass production compared to compost amended treatments due to soil compaction and fast leaching of nutrients. It can be concluded that application of 10% zeolite with microbial consortium is an ideal composting mix formulation for on-site commercial composters and 5% is an optimal application rate of food waste compost of Brassica chinensis and Lycopersicon esculentum

This study asks a question of three bodies of material: who were Gillows? As a furniture-making firm, working between 1760 and 1800, Gillows have been recorded within furniture history, within a biography by historian Lindsay Boynton and within their own records, their autobiography. Furniture history is viewed within this thesis as a construction, a history that both includes and excludes. Roland Barthes' exercise in the semiology of fashion. The Fashion System, is used as a means of viewing the taxonomic system of classification that the furniture historians have employed to categorise old English furniture. I assert that this, the furniture system, has sought to use style, age and author to determine the nature of eighteenth-century furniture. A discussion of how Gillows have been viewed by the furniture historians provides an image of the firm as provincial, middle class makers, followers rather than leaders in the field of eighteenth-century furniture design. From this history I move to Boynton's biography of the firm of Gillows^ Gillow Furniture Designs. 1760-1800. It is my contention that Boynton has sought to question the furniture historians' view of the firm, by reasserting their authorship over their work, introducing to us a constructed author: the Firm of Gillow, whilst at the same time trying to locate Gillows' furniture within the furniture systern. Gillows themselves have left behind an archive of their letters and books, presenting what I view as their own autobiography. By asking of this archive a series of questions, it becomes clear that the image of the firm presented to us by the furniture historians and by Lindsay Boynton is unsatisfactory. However Gillows' own story is also incomplete. Thus the differing interpretations of Gillows that these three bodies of material present to us shed light on how the story of one firm has been created and how the agendas of the individual authors have altered the tale, challenging the constructed history of furniture.

Les textiles jouent un rôle important dans notre vie quotidienne. La plupart des fibres textiles et des tissus sont fabriqués à partir de polymères à base de pétrole, des matériaux inflammables et potentiellement dangereux. Afin de conférer le caractère ignifuge aux fibres textiles; entre autres, les composés halogénés sont plus efficaces et largement utilisés pour améliorer le comportement ignifuge des matières textiles. Cependant, en raison de la toxicité des composés halogénés et de l'épuisement progressif des ressources pétrolières, les communautés scientifiques et industrielles sont obligées de trouver des solutions alternatives. Par conséquent, on s’intéresse de plus en plus aux ressources durables, en particulier au développement de systèmes ignifugeants fabriqués à partir de ressources biologiques et respectueux de l’environnement non halogénés. Dans le contexte de l’utilisation de ressources biologiques, une attention particulière a été appelée pour la biomasse. Après la cellulose, la lignine est le deuxième polymère de biomasse le plus abondant et le principal à base d'unités aromatiques. En particulier, la lignine est avantageuse car c’est un coproduit des industries de la pâte à papier et de la fabrication du papier et non une ressource qui nécessite une production spécifique. En fait, sa structure chimique hautement aromatique permet d’améliorer différentes propriétés fonctionnelles telles que la résistance aux UV, l’antioxydant et l’ignifugation des polymères. Récemment, la lignine a fait l’objet d’une grande attention en tant qu’additif retardateur de flamme d'origine biologique en raison de son aptitude élevée à la formation de carbone après la décomposition thermique. Cette capacité de formation de carbone de la lignine en fait un candidat de choix comme source de carbone pour un système intumescent avec un autre additif ignifuge. Lors du chauffage, les matériaux intumescents ignifuges (FR) forment une couche carbonisée cellulaire expansée; agissant comme une barrière physique contre le transfert de chaleur et de masse, qui protège le matériau sous-jacent de l'action du flux de chaleur et de la flamme.Au meilleur de nos connaissances, aucune étude n'a été publiée concernant l'introduction de la lignine en tant que source de carbone dans les structures textiles pour leur conférer des propriétés ignifugeantes. Par conséquent, dans cette étude, la lignine a été introduite dans la structure textile lors de la composition. Cette thèse porte sur le développement de la structure textile ignifuge entièrement biosourcée. Pour atteindre cet objectif, l'approche en plusieurs étapes est adoptée. Dans une première étape, la matrice polymère biosourcée a été sélectionnée pour produire la structure textile et la méthode d’incorporation de la lignine a été étudiée et optimisée. Ensuite, les propriétés ignifuges apportées par la lignine ont été caractérisées et améliorées en ajoutant un additif ignifuge dans les formulations (par exemple, utilisation de sources acides pour développer un système intumescent pouvant améliorer la résistance des textiles au feu). Dans la deuxième phase du projet, la lignine a été combinée à la source d'acide d'origine biologique pour développer une nouvelle génération de structures durables (100% biosourcées) destinées aux marchés du textile. La principale avancée technologique consiste à utiliser et à combiner différents composants biosourcés utilisés dans d'autres industries, telles que l'industrie du plastique, afin de développer des solutions textiles
It has been chosen to study valorization of low-cost industrial lignin as additive in designing the flame retardant (FR) system for polyamide 11 (PA) to develop biobased textile structure. The main focus of this thesis work is to consider lignin as carbon source and introduce in a textile structure in combination with phosphinate salt (FR agent). In the primary study, chemically different industrial lignins were incorporated in PA by extrusion to investigate the charring and fire retardant behaviour of the prepared binary blends. In addition, the introduction of sulphonated lignins significantly reduced the peak of the heat release rate (PHRR) and of the total heat release (THR), and a noticeable increase of the char residue was observed after forced combustion test. In the next approach, lignin was exploited as carbon source in combination with commercially available phosphinate FR (i.e., ZnP and AlP). To achieve this objective, a preliminary study carried out with laboratory grade lignin (LS) combined with ZnP to investigate the thermal stability and fire performance as well as the possible synergy between lignin and ZnP and with the polymer matrix. The results obtained in this study permitted to continue further, the practical implementation of lignin and multifilament production. In the next step, flame retarded blends were developed with direct addition of low-cost industrial lignins (LL and DL) with phosphinate FR. For the systematic understanding, various FR formulations were developed by varying the lignin and FR loading and characterized. Thermal decomposition analysis showed that the presence of lignin decreases the initial decomposition temperature (T5%) due to the decomposition of lignin which starts at a lower temperature region with the evolution of less thermally stable compounds and the maximum decomposition temperature (Tmax) shifts to higher temperature region, at this stage the formation of phenolic, carbonyls, hydrocarbons and CO2 along with phosphinate compounds occurs. Meanwhile, in the condensed phase thermally stable aromatic charred layer is formed because of lignin decomposition and phosphate compounds formation due to the presence of phosphinate metal salt. A higher amount of char residue is obtained when LL combined with ZnP/AlP as compared to the DL and ZnP/AlP blends. It is assumed that, during decomposition of LL, the sulfonate compounds release SO2 and transformed into thermally stable Na2SO4, hence giving rise to the stable char residue. The fire properties were assessed by cone calorimeter tests revealed the combination of lignin and phosphinate FR significantly reduced the PHRR and other fire-related parameters due to the formation of a protective char layer. The presence of lignin not only improve fire retardancy but also reduced the evolution of carbon monoxide (CO). More enhanced fire retardant properties were obtained with LL and ZnP/AlP combination reaches to 10 wt% in ternary blends, which not only promotes char formation but also confer the stability to char in the condensed phase. Furthermore, the most enhanced forced combustion results were obtained with LL and AlP (in particular, PA80-LL10-AlP10). Multifilament yarns were successfully produced for PA-DL-ZnP and PA-LL-ZnP combinations. However, the blends of AlP with lignin were not spinnable because of low compatibility and dispersion level of AlP in the polymer. Optical microscopy and tensile tests were performed to study the physical properties of multifilaments. A double layer (interlock structure) knitted fabrics were developed to evaluate fire behaviour analysis on fabric samples

Main concerns in the building industry includes the development of alternative building materials that reduces the amount of energy spent during manufacturing process and easier to work with. Wood-crete is a composite material developed in this study, made up of wood waste (sawdust), paper, tradical lime and water. Wood-crete is developed to provide an alternative material in construction solving problems associated with the delivery of low-cost housing across all income earners, reducing the amount of energy spent during manufacturing process of construction materials and the ease with which these construction materials are developed and solve issues related to waste management. This thesis presents the processing technologies, factors which affect the performance and properties of wood-crete. Wood-crete properties were found to be closely related to the composition of the constituent elements though compressive strength and modulus of elasticity were low when compared to other building materials like concrete and steel. In a bid to improve the strength of the developed wood-crete, the properties were investigated based on the modification of sawdust by hot water boiling and alkaline treatments which help to modify cellulose fibre surface to reduce the hydrophilic nature of sawdust thereby improving the sawdust-matrix bonding. It was found that the surface modification, processing of cellulosic fibril and the extraction of lignin and hemi-cellulosic compounds with alkali had an effect on the compressive strength of wood-crete, with treating sawdust with 4% NaOH at 140mins of boiling time achieving the highest compressive strength and boiling sawdust from 100mins to 140mins had a gradual increase in compressive strength but reduced at higher boiling time. Furthermore, treating sawdust with NaOH more than 4% weakened the individual wood particles thus leading to poor strength of wood-crete. Additionally, the properties of wood-crete were investigated based on the type of wood sawdust – hardwood (beech and oak) and softwood (pine and cedar). Apart from individual wood density having a significant effect on the density of wood-crete, other factors such as lignin, cellulose, hemicellulose contents including fibre length of individual wood species affect the strength properties of wood-crete. The compressive strength of wood-crete was closely related to the wood species, with highest compressive strength of 3.93MPa recorded for hardwood wood-crete compared to 1.37MPa and 0.26MPa of wood-crete from softwood and mixed wood respectively. Results from thermal conductivity tests on wood-crete also show that wood-crete blocks can be produced with good insulating properties for building construction. Addition of different types of paper fibres to reduce the density of wood-crete and improve the insulating properties of composite developed also had a dominant influence on both strength and thermal conductivity, reflecting its effect on the structure of composite and contribution of self strength of paper fibres. The addition of various percentages of waste paper (de-fibred) had a significant influence on the thermal conductivity of wood-crete with 75% addition of waste paper achieving a thermal conductivity value of 0.046W/mK performed with the TCi thermal conductivity analyser. Thermal conductivity results for wood-crete made from hardwood and softwood sawdust was closely related to the chemical composition of various wood species, with softwood wood-crete having about 20% lower thermal conductivity compared to hardwood wood-crete. The developed wood-crete was able to withstand impact load and considered, like hempcrete, most suitable for wall panelling or other non- and semi-structural applications with good thermal insulating properties. Findings of this study provides an alternative new material for the construction industry and an important background for achieving better strength of wood-crete, choosing what type of sawdust to be used for development of wood-crete and for directing a better use of this potential material with very small embodied energy and carbon negative.

Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2009.
As with any form of intensive agriculture, there are potential environmental impacts associated with the management and housing of livestock on dairy farms. Within the field of dairy farming, particular focus falls to the issue of environmental degradation of water resources, as this form of pollution is currently a major environmental issue around the world. Conventional agricultural practices involving the application of chemical fertilizers to land and crops are causing environmental problems as a result of poor management practices. Dairy wastewater and manures could however be a valuable resource for agricultural producers in the form of an alternate fertilizer for their crops. Waste application as a fertilizer is more environmentally friendly than chemical fertilizers, and could drastically reduce costs for farmers, whilst alleviating storage and management problems often associated with farmyard manures (FYM). The application of organic wastes, notably livestock manures, to land has historically been important for maintaining soil fertility on farms in terms of nutrient status and organic matter levels, as well as helping to reduce soil erosion and improve waterholding capacity. The research sought to investigate the environmental and economical feasibility of using dairy wastewater and manures as an alternative form of fertilizer within agriculture in South Africa.

The waste fines (WF) rejected by paper mill are one of the good resources of lignocellulosic biomass to produce sugars. The potential of hydrolysis yield was around 95% (reducing sugars g/g of digestible fibers). The inhibitory effects of the substrate were studied since the enzyme demand for the hydrolysis was not economically feasible.

The major inhibitor of WF was the high portion of ash for enzymatic hydrolysis. The CaCO₃ among the ash was the strongest inhibitor with three different inhibiting effects. The first inhibition was related to reduced free enzyme in bulk solution resulted by non-productive enzyme adsorption on CaCO₃. The binding mechanism could be explained by the electrostatic and hydrogen bonding interaction between the enzyme and CaCO₃. The major mechanism of the enzyme – CaCO₃ binding differ with the enzyme – lignin binding which has been reported that the hydrophobic interaction is the major mechanism for the enzyme – lignin binding. The different mechanisms are due to the hydrophobic property: CaCO₃ is hydrophilic and lignin is hydrophobic. The application of a nonionic surfactant, Tween 80, could be a solution to free enzyme in bulk solution via competitive bond on CaCO₃ with a higher affinity than the enzyme. A study of CaCO₃ of particle size and Tween 80 adsorption on CaCO ₃ provided evidence of this Tween 80 effect. The second inhibiting effect of CaCO₃ was pH level shift decreasing enzyme activity by dissolved Ca²⁺. pH adjustment (PAD) was tested with addition of acids to make the pH optimum for enzyme activity. PAD with extra acetic acid resulted in a positive effect but sulfuric acid did not improved hydrolysis yields. The combination application of Tween 80 and PAD yielded more than two times as much sugar release compared to the non-treated waste fines with a 10 FPU enzyme dose. The final inhibitory effect of CaCO₃ was dissolved Ca²⁺ reduced of enzyme activity. This effect was supported by the reduction of hydrolysis yield of Avicel and unbleached kraft pulp (UKP), and documentation of particle size increase due to the aggregation of enzyme in the presence of Ca²⁺.

Some other approaches were studied to improve the hydrolysis yield of paper mill waste fines. These included using combinations of adding nonionic surfactant, high consistency hydrolysis, buffer substitution, and deinking flotation. Each method improved the productivity or reduced the cost of production and may be combined in one process to get synergetic effects.

The reaction kinetics of Iroko and Mahogany were studied using TGA. The pyrolysis process was achieved using six different heating rates of 2,5,8,12,15 and 20˚C. A 15˚C/min heating rate was used for gasification in steam at different temperatures while varying the concentrations of nitrogen and steam in the process. The kinetic parameters, activation energy and pre exponential factor, were obtained by implementing two chosen kinetic models. These models are: Friedman’s Iso-conversional Method, Flynn-Wall-Ozawa Method (FWO). There were substantial differences in the values of the kinetic triplets found from the experiments. Due to the substantial differences in the values, it was not the best way to perform this kind of analysis (which is the traditional way) but instead to use pure regression analysis; but using it for the whole data set (that means for all heating rates) and minimize the difference with experimental data.

Les déchets de bois et de plastiques sont des ressources prometteuses pour la production du gaz de synthèse (syngaz) par la pyro-gazéification grâce à leurs disponibilités et leurs caractéristiques énergétiques. Cependant, le syngaz issu de ces déchets peut contenir des teneurs élevées en chlorure d’hydrogène (HCl) qui est corrosif et toxique et qui doit donc être éliminé. Premièrement, les expériences de pyrolyse des mélanges de bois de peuplier et de plastiques ont mis en évidence l’influence des plastiques sur les produits obtenus. En effet, le HDPE et PS augmentent respectivement le pouvoir calorifique du syngaz et le rendement en huiles, tandis que le PVC augmente le rendement en char et le HCl dans le syngaz. Ensuite, les expériences de pyro-gazéification à l’échelle pilote ont montré que l’ajout de 1 % en masse de PVC dans un déchet de bois augmente la teneur en goudrons et HCl dans le syngaz par un facteur respectivement de 2 et 5,5, tandis que la concentration de chlore dans le char résiduel est 16 fois plus élevée. En parallèle, un model CFD a été développé pour simuler la pyro-gazéification du déchet de bois en couplant les phénomènes d’écoulement de fluides, transfert de masse et de chaleur, et les réactions chimiques. Ce modèle se compose des sous-modèles de séchage, pyrolyse, oxydation et gazéification du char. Les résultats de simulation sont en bon accord avec les données expérimentales obtenues par des expériences dans un gazéifieur à l’échelle pilote. En outre, les analyses de sensibilités du sous-modèle de la gazéification de char ont été réalisées. Finalement, une étude expérimentale a été conduite sur le traitement de HCl dans le syngaz. L’étude se concentre sur la valorisation de deux résidus solides industriels issus de la production de bicarbonate et carbonate de sodium. Leurs réactivités sont comparées avec celles de deux adsorbants commerciaux, NaHCO3 et Ca(OH)2. L’effet de la matrice gazeuse sur la performance des adsorbants est également examiné. Les résidus industriels ont un potentiel intéressant par rapport aux adsorbants commerciaux. Les résultats obtenus montrent des nouvelles approches pour la purification du syngaz généré par la gazéification des déchets de bois et de plastiques
Wood and plastic waste are interesting feedstock for the production of syngas via pyro- gasification, mainly due to their abundant supply and good fuel properties. However, syngas derived from waste may contain significant amounts of hydrogen chloride (HCl), which is corrosive and toxic and must therefore be removed. In this work, co-pyrolysis experiments were first conducted in order to study the influence of mixing different plastics with wood samples on the pyrolysis products. It was found that HDPE and PS significantly increase the heating value and HCl content of the gas product respectively, while PVC increases the yield of char and HCl. Next, pilot-scale experiments were performed, which revealed that adding 1 wt% PVC to wood waste raises the content of tar and HCl in syngas by factors of 2 and 5,5 respectively, and also elevates the chlorine concentration in the char residue 16 time over the value obtained in the absence of PVC. In parallel, a CFD model was developed to simulate the pyro-gasification of wood waste by coupling fluid flow, heat and mass transfer, and chemical reactions. This model consists of drying, pyrolysis, oxidation and char gasification sub-models. The simulation results were in good agreement with experimental data obtained from the pilot-scale experiments. Furthermore, sensibility analyses on the char gasification sub-model were performed. Finally, an experimental study was conducted on the removal of HCl from syngas. The study focused on valorizing two industrial solid wastes generated from the process of sodium carbonate and sodium bicarbonate manufacture. Their HCl adsorption performance were compared to those of the commercial sorbents, NaHCO3 et Ca(OH)2. Moreover, the effect of gas matrix on their performance was studied. The industrial wastes showed potential for treating acid gas as compared to the commercial sorbents used. This opens up new approaches to the purification of syngas generated by the pyro-gasification of wood and plastic waste

Wood wastes are mainly originated from forestry, wood industry and construction and demolition sites activities. Among them, three types of wood waste can be identified: untreated wood waste (raw wood considered as biomass), slightly treated wood wastes (issued from coating or gluing treatments) and highly treated wood wastes (issued from impregnation treatments with CCA and creosote, and considered as hazardous wastes).  According to the regulation, management of wastes in Europe is oriented towards more recycling and less elimination. However, among the French requirements, three main trends can be observed in regards of wood waste recovery: only treated wood wastes can be recovered in combustion units, no extensive technologies are allowed to recover highly treated wood wastes, which must then be eliminated by incineration, and slightly treated wood wastes can be either recovered as particle boards or eliminated.  However, in this context, the amount of wood wastes from construction and demolition sites reach 7 million of tons in France. Among them, 5% correspond to raw wood, and 25% are slightly treated. The high combustion potential of wood wastes is moreover an opportunity to replace conventional fuel used in combustion units.  The four main methods used to treat wood wastes are recycling as particleboards, combustion, incineration and land filling. Due to the various typologies of wood wastes, a conditioning step is needed before recovery. Then, if combustion seems to present advantages because of its neutral carbon impact, life cycle analysis demonstrates that emissions of other pollutants are observed. In addition, it is proved that controlled elimination methods are less impacting than unequipped recovery ones. Recycling is then not always the best practice in regards of the impacts considered in the study.  Competition among the different methods treatment and low prices of wood wastes are specific economical aspects that could influence the development of the field. Moreover, the increasing acceptance of people for recovery and local waste treatment methods, as well as the need for energetically independency are factors that can likely promote wood waste derived fuel. These driving forces are evolving in a very rapid way. Regulation is moving towards implementation of standards to promote the development of slightly treated wood waste derived fuel. Technological and social improvement such as sorting at source, and the development of end of pipe treatment methods are also likely to have positive effects.  An integrated solution to develop wood waste derived fuel would be to implement strong financial incentives in favour of clean technologies for wood wastes recovery methods. This enhancement could then be the mean to answer the double challenge of wood waste treatment and fossil fuel replacement.  Wood wastes are mainly originated from forestry, wood industry and construction and demolition sites activities. Among them, three types of wood waste can be identified: untreated wood waste (raw wood considered as biomass), slightly treated wood wastes (issued from coating or gluing treatments) and highly treated wood wastes (issued from impregnation treatments with CCA and creosote, and considered as hazardous wastes).  According to the regulation, management of wastes in Europe is oriented towards more recycling and less elimination. However, among the French requirements, three main trends can be observed in regards of wood waste recovery: only treated wood wastes can be recovered in combustion units, no extensive technologies are allowed to recover highly treated wood wastes, which must then be eliminated by incineration, and slightly treated wood wastes can be either recovered as particle boards or eliminated.  However, in this context, the amount of wood wastes from construction and demolition sites reach 7 million of tons in France. Among them, 5% correspond to raw wood, and 25% are slightly treated. The high combustion potential of wood wastes is moreover an opportunity to replace conventional fuel used in combustion units.  The four main methods used to treat wood wastes are recycling as particleboards, combustion, incineration and land filling. Due to the various typologies of wood wastes, a conditioning step is needed before recovery. Then, if combustion seems to present advantages because of its neutral carbon impact, life cycle analysis demonstrates that emissions of other pollutants are observed. In addition, it is proved that controlled elimination methods are less impacting than unequipped recovery ones. Recycling is then not always the best practice in regards of the impacts considered in the study.  Competition among the different methods treatment and low prices of wood wastes are specific economical aspects that could influence the development of the field. Moreover, the increasing acceptance of people for recovery and local waste treatment methods, as well as the need for energetically independency are factors that can likely promote wood waste derived fuel. These driving forces are evolving in a very rapid way. Regulation is moving towards implementation of standards to promote the development of slightly treated wood waste derived fuel. Technological and social improvement such as sorting at source, and the development of end of pipe treatment methods are also likely to have positive effects.  An integrated solution to develop wood waste derived fuel would be to implement strong financial incentives in favour of clean technologies for wood wastes recovery methods. This enhancement could then be the mean to answer the double challenge of wood waste treatment and fossil fuel replacement.
Träavfall kommer från skogsbruk, trä‐ och byggbranschen och rivningsplatser. Bland dem kan tre typer av träavfall identifieras: obehandlat träavfall (obehandlat trä betraktas som biomassa), lätt behandlat träavfall (från beläggning eller limning) och högbehandlat träavfall (från impregnering med CCA och kreosot, betraktas som farligt avfall). Enligt avfallsförordningen, är hantering av avfall i Europa inriktad mer mot återvinning och mindre mot eliminering. Bland de franska kraven, kan tre huvudsakliga tendenser iakttas för återvinning av träavfall: endast behandlat avfall kan behandlas i förbränningsanläggningar för energiutvinning, högbehandlat träavfall måste elimineras genom förbränning och lätt behandlat avfall kan antingen återvinnas som spånskivor eller elimineras. I detta sammanhang uppgår mängden träavfall från bygg‐ och rivningsplatser till 7 miljoner ton i Frankrike. Bland dem, motsvarar 5% obehandlat trä, och 25% är lätt behandlat. Den höga förbränningspotentialen för träavfall ger dessutom en möjlighet att ersätta konventionellt bränsle som används i förbränningsanläggningar. De fyra huvudsakliga metoder som används för att behandla träavfall är återvinning i spånskivor, förbränning med energiutvinning, förbränning och deponering. På grund av olika typer av träavfall, krävs ett konditioneringsteg innan återvinning. Även om förbränningen är fördelaktigt på grund av sitt neutrala kol, visar livscykelanalyser utsläpp av andra föroreningar. Dessutom visas att kontrollerade elimineringsmetoder har mindre miljöpåverkar än återvinningsmetoder som ej har rätt utrustning. Återvinning är alltså inte alltid att föredra om man beaktar de effekter som gjorts vid denna undersökningen. Konkurrensen mellan olika behandlingsmetoder och låga priser på träavfall är specifika ekonomiska aspekter som skulle kunna påverka utvecklingen inom området. Dessutom, den ökande acceptansen av människor för återvinning och lokala avfallshanteringsmetoder, liksom behovet av inhemska energikällor är faktorer som sannolikt kan främja bränsle från träavfall. Dessa drivkrafter utvecklas på ett mycket snabbt sätt. Avfallsförordningen är på väg mot införandet av standarder för att främja utvecklingen av lätt behandlat träavfalls bränsle. Tekniska och sociala förbättringar, exempelvis källsortering och utveckling av återvinningsmetoder ger också sannolikt positiva effekter. En integrerad lösning för att utveckla bränsle från träavfall skulle vara att genomföra starka ekonomiska incitament till förmån för ren teknik för återvinning av träavfall. Den här förbättringen kan sedan vara ett medel att anta den dubbla utmaningen av hantering av träavfall och ersättning av fossila bränslen.

 

The Swedwood Company is a supplier to IKEA of wood furniture. They have grown larger concurrently with IKEA and at present they have 47 production units spread over twelve countries of which most are located in Eastern Europe.

One of the factories is Zbaszynek which is located in Poland. They manufacture so called board-on-frame furniture. A board-on-frame is basically made out of particle board frames which are filled with special design paper that enfolds air. The frames are then covered with their skin; thinner particle boards, so called High Density Fibre (HDF) boards, and then edge banded with plastic stripes and painted and lacquered into desired design.

This production generates not only furniture, last financial year Zbaszynek generated about 61 000 tons wood waste too. It can be compared to their total production of furniture which reached 439 000 tons during the same period of time. This generation of wood waste has caused a problem for Swedwood in general. A project called IKEA Goes Renewable (IGR) has started within IKEA with the aim to reduce the electric- and heat energy consumption and increase the use of renewable energy sources. But to be able to reduce the heat energy at a board-on-frame factory, such as Zbaszynek, there has to be an economic incentive to do so. But the wood waste is contaminated in comparison with waste from pure wood (free from adhesives, plastics etc.) so purchasers have been hard to find. And since the wood waste is used to generate the heat at the factories, the economic value has become relative low. Zbaszynek earn 1.4 €/MWh for their wood waste at present (energy value of 5.1 MWh/ton), while for example recycled contaminated wood chippings (RT-chippings) are worth about 7.3 €/MWh in Sweden (energy value of 4.4-5.1 MWh/ton). RT-chippings in Sweden are even allowed to contain more contaminations to receive that price, as long as it is not pressure creosoted. 1.4 €/MWh can also be compared to the economic value of coal which is about 13.7 €/MWh, and for district heating to households in Sweden was the average price about 68 €/MWh during 2007 (Energimarknadsinspektionen, 2007).Therefore, the main task of this thesis has been to investigate if there are any possible solutions to increase the economic value of the wood waste in Zbaszynek. There are more board-on-frame factories within Swedwood with the same problem, but Zbaszynek has been the pilot factory during this research.

The first thing which should be considered in Zbaszynek is to keep the amount of waste as low as possible. The main task should be to reduce the amounts of wood waste; in the end it is a furniture factory and not a waste producer, which should be concerned before taking any further action. It is assumed though that this has already been thought through in Zbaszynek and further investigation of the waste has taken place.The wood waste has been sent to the Eurofins laboratory in Sweden for an analysis and the test results were then compared to wood waste of pure wood. The comparison indicates the nitrogen content being the main difference between Zbaszynek's wood waste and pure wood. Nitrogen compounds, often referred to as NO_x can cause severe damage to the environment and foremost lead to increased eutrophication (= Eutrofizacja (Polish) / Övergödning (Swedish)) when it is emitted to the air. Apart from the nitrogen contamination, other significant differences have not been found. The energy content of the wood waste has even revealed it would suit well as bio-fuel, on the condition that proper equipment to reduce the NO_x emissions is present. It has been calculated that the energy content, of the generated wood waste in Zbaszynek during Financial Year 2008, reached 310 GWh. Which can be compared to the electricity consumption of 78 GWh as was bought during the same time of period.

Four main possibilities have been investigated in this report and they are:

• - Selling the waste to cement producers as alternative fuel

• - Make new products and use for furniture production again

• - Make briquettes or pellets and sell as fuel

• - Start up a Combined Heat and Power plant and produce electricity

All these alternatives have their advantages and disadvantages but they all seem to be realistic solutions, on a few conditions.

Les développements récents de la législation associée aux impacts environnementaux des déchets plastiques d’origine post-consommation ont mené à des efforts sur le développement de techniques viables de recyclage. Ainsi, le but de cette recherche était de produire des composites bois-plastique (WPC : wood plastic composites) à partir de la fraction légère des déchets plastiques municipaux (post-consommation) et de résidus de transformation du bois (sciure). Afin d’améliorer la compatibilité et l’adhésion entre le polyéthylène (PE) et le polypropylène (PP), un copolymère d’éthylène-octène (EOC: ethylene-octene copolymer) a été utilisé pour développer la compatibilité entre les phases polymères tout en agissant comme modificateur d’impact. L’ajout de PE et PP maléatés (MAPE: maleated polyethylene; MAPP maleated polypropylene) a permis de fournir une meilleure compatibilité entre la matrice polymère et la farine de bois. Les effets combinés de tous les composants ont mené à la production de composites présentant des propriétés morphologiques (dispersion et adhésion) et mécaniques (traction, torsion, flexion et impact) intéressantes après l’optimisation de l’ensemble des additifs (mélanges d’agents couplants). Dans un second temps, des composites structuraux à trois couches ont été produits à partir des matériaux composites mentionnés plus haut afin d’étudier l’effet des paramètres de design sur les performances en flexion et à l’impact. Les paramètres étudiés incluent la teneur en bois, l’épaisseur des couches individuelles de composite, ainsi que la séquence et la configuration d’empilement des différentes couches (structures symétriques et asymétriques). Enfin, la théorie classique des poutres a été utilisée avec succès pour prédire le module en flexion et ce, avec un maximum de 10% de déviation pour ces structures complexes.
Recent legislations associated with environmental impacts of post-consumer plastic wastes have driven substantial attention toward developing viable recycling techniques. Therefore the aim of this research was to produce wood plastic composites (WPC) from the light fraction of municipal plastic wastes (post-consumer) and wood processing residues (sawdust). In order to improve compatibility and adhesion between polyethylene (PE) and polypropylene (PP), an ethylene-octene copolymer (EOC) was used to compatibilize the polymer phases and also to act as an impact modifier. Addition of maleated polyethylene (MAPE) and maleated polypropylene (MAPP) provided improved compatibility between the polymer matrix and the wood flour. The combined effect of all the components was found to produce composites with interesting morphological (dispersion and adhesion) and mechanical properties (tension, torsion, flexion and impact) after optimization of the additive package (blend of coupling agents). In the second phase, three-layered structural composites were produced from the aforementioned composites to investigate the effects of design parameters on their flexural and impact performance. The studied parameters include wood content, thickness of individual composite layers, as well as stacking sequence and configuration (symmetric and asymmetric structures). In addition, the classical beam theory was successfully used to predict the flexural modulus within 10% of deviation for these complex structures.

Thesis (Ph. D.)--West Virginia University, 2010.
Title from document title page. Document formatted into pages; contains viii, 98 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references.

Urban forest waste utilization has been identified as an essential component of the sustainable urban forest management system. To compile baseline data on generation and utilization of urban forest waste (UFW) in Virginia, 91 urbanized municipalities and 828 International Society of Arboriculture Certified Arborists operating privately in Virginia were invited to participate in a web-based survey. Results indicate that nearly three quarters (74%) of all respondents reported that their local operation generates UFW. For private arborists this included logs, brush, and chips generated by arboricultural practices, and for municipalities this included similar material generated by an in-house tree crew and similar material collected curbside from residents. Two-thirds (67%) of respondents could not estimate the amount of UFW generated by their local operations, but nearly half (47%) could report on its fate. The mean total amount generated was 315 tons/year/employee, or 945 tons/year for a typical tree crew. On average, both municipalities and private operations reported disposing less than 25% of their UFW at a solid waste facility. The majority of logs were utilized to produce firewood or lumber, while the majority of chips and brush were utilized to produce mulch or compost. Municipal operations utilized significantly more chips in-house compared to private arboricultural operations (p = 0.041). Regardless of operation type or UFW type, UFW is rarely left on-site, which indicates that UFW is being handled and transported in the majority of situations. If UFW is being mobilized, then perhaps there might be additional opportunities to divert materials into utilization streams rather than disposal streams. When characterizing the respondents' perceptions of urban forest waste utilization, two-thirds of respondents (65%) either agreed or strongly agreed that UFW utilization is a major issue for the urban forestry industry currently. An even higher percentage (76%) agreed or strongly agreed that UFW utilization will be a major issue for the urban forestry industry in the future. Results also indicate that the primary incentives to utilization were the avoidance of disposal fees and shipping costs. Municipal employees cited a lack of equipment as the primary barrier to greater waste utilization and frequently identified educational seminars or conferences as a technical assistance need. In contrast, private-sector arborists cited a lack of local processors as their primary barrier and frequently identified local facilities for receiving, sorting, and stockpiling UFW as a technical assistance need. These varying perceptions should be taken into account when developing future educational or technical programs aimed at increasing utilization in Virginia.
Master of Science

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, June 2015.
Cataloged from PDF version of thesis. "June 2015."
Includes bibliographical references (pages 38-42).
Management of organic municipal solid waste presents numerous challenges in India. Anaerobic digestion is one technology that can be used to address this problem, by transforming organic waste into methane via microbial activity. This process generates energy (in the form of methane) and a residual byproduct that can be used as fertilizer. Bottling and transportation of methane, however, presents numerous challenges. A novel anaerobic process is in development which would circumvent many of these challenges by instead producing a liquid biofuel. The purpose of this study is to determine if the residual byproduct from the novel process could still be used as fertilizer. A growth test failed to demonstrate the efficacy of the anaerobic residuals as a fertilizer, most likely because the residual byproduct was not dosed correctly. A follow-up growth test was able to show that the residual byproduct is not toxic to plant growth and if dosed in a lower concentration, could have potential as a fertilizer. The carbon to nitrogen ratio of the anaerobic residuals was favorable for plant growth. Further tests are needed to validate the use of the anaerobic residuals as fertilizer.
by Julie Karceski.
M. Eng.

Waste reduction is a key challenge for the sustainable development of the food industry, so reducing it is a pressing issue for most businesses in the industry. Waste recycling and utilization is a strategic goal for each company, which involves the involvement of innovative technologies based on the evaluation of decisions in reducing the cost of finished products, minimizing raw material losses, increasing the yield of finished products.

[Truncated abstract] Standard AOAC methods of chemical analysis have been used to characterize and evaluate the industrial byproducts; partly burnt chicken litter ash (CLA), totally burnt chicken litter ash (CLAT), wood ash (WA) and iron smelting slag for use as a combined liming agent and phosphate fertilizer. Rock phosphate has this function and was included for comparison purposes. All the byproducts had pH values above 9 and a liming capacity above 90% of pure lime, as a result, these materials will be effective as liming agents. Total P concentrations for CLA, CLAT, slag, and WA were 3.6%, 4.75%, 0.26%, and 0.44% respectively indicating that they could be used as P fertilizers when applied at the high rates required for liming soils. ... The RE values for all the materials relative to monocalcium phosphate (100%) for the first harvest are as follows, 50% for dicalcium phosphate, 31% for rock phosphate, 7% for partly burnt chicken litter ash, 7% for totally burnt chicken litter ash and 1% for wood ash and slag. The RE values for the second harvest were 100% for monocalcium phosphate, 80% for dicalcium phosphate, 40% for rock phosphate, 10% for partly burnt chicken litter ash, 8% for totally burnt chicken litter ash and 2% for wood ash and slag. Data for subsequent harvests are not reported due to the death of many plants. Clearly chicken litter ash has appreciable value as a phosphate fertilizer whereas wood ash and slag are ineffective. Explanations for these differences in effectiveness are discussed in the text. An evaluation of the liming effect of the byproducts indicates that they may be used as a soil amendment on acid soils and are nearly as effective as standard lime (CaCO3). Byproducts are also sources of other plant nutrients so they may be regarded as a form of compound fertilizer and liming agent.

Studien som är ett forskningsprojekt men också en produktutvecklingsprocess utgår från de två forskningsfrågorna: Hur kan man genom design hantera befintligt spillmaterial? Hur kan man genom design förebygga och minska avfall?  Eftersom våra resurser på planeten börjar bli knappa måste vi bli bättre på att ta hand om de resurser vi har. Den här studien handlar om spillmaterial och utgår från befintligt sådant från möbelföretaget Blå station. Detta ska representera och visualisera problematiken med att bra spillmaterial energiåtervinns eller deponeras istället för att användas som material i nya produkter. Studien börjar med en teorigenomgång inom hållbar utveckling och cirkulär ekonomi samt hållbar och cirkulär design. Expertintervjuer har gjorts med två designers samt några designexperiment som syftat till att ta fram möjliga designförslag för spillmaterialet vilket resulterade i tre olika designförslag samt några generella principer för hur man kan hantera spillmaterial samt minska mängden avfall när man tar fram produkter.
This study is a research project as well as a product development process and is based on the two research questions: How can design handle existing left-over materials? How can design prevent and reduce waste?  As our resources on the planet are becoming scarce, we need to better handle the ones we have. This study is about left-over materials and is based on such from the furniture company Blå station. This will represent and visualize the problems we have with good left-over materials is burned or thrown away instead of being used as material in new products. The study starts with a theory review in sustainable development and circular economy together with sustainable and circular design. Expert interviews with two designers were done and some design experiment with the intention to produce some possible design proposals for the left-over material and it resulted in three different proposals and some general principles for how to handle left over materials and also reduce waste in new products.

Highly oxygenated compounds in bio-oil produce negative properties that have hampered fuel development. Copyrolysis with plastics has increased hydrogen content in past research. Py-GC/MS analyses for two wood types (pine and oak) and three plastic types (polystyrene, polypropylene and high density polyethylene) established temperature, heating rate and residence time to produce a typical bio-oil. Analysis of various plastics to wood ratios by Py-GC/MS showed that a 50:50 wt/wt ratio produced the highest level of low molecular weight compounds best for fuel viscosity. Copyrolysis was performed on a laboratory-scale reactor at these temperature and wood-to-plastic ratios. Copyrolysis lowered bio-oil oxygen content and increased carbon content. Lower water content, acid value and viscosity also resulted, improving bio-oil suitability for fuels. Cross reactions between wood and plastics formed no new chemical species during copyrolysis. These results indicate that copyrolysis of waste plastics with woody biomass has potential for improving bio-oil properties for fuels production.

Chromated copper arsenate (CCA) has been the most commonly used wood preservative in the UK; up until its partial ban in 2004. The preservative prolongs the service life of wood by 20-50 years by making it resistant to biological attack. As such, in-service CCA treated wood is expected to be a major component of the UK wood waste stream in the future. Concerns over the impact of the chemical constituents of this treatment on both the environment and human health have prompted the introduction of legislation to ensure that such waste is disposed of safely in Hazardous Waste Landfills. Despite this, studies have shown that this waste can still enter into the landscape mulch market due to inadequate detection methods and increasing societal pressures to recycle. A series of laboratory and field-based simulations were used to quantify leaching of copper, chromium and arsenic from CCA-treated wood waste mulch and evaluate the factors involved in promoting leaching. The distribution and behaviour of the metals in the soil column and leachate were also assessed. The samples generated in the study were analysed for a range of physico-chemical measurements, elemental and speciation concentrations. Results show that arsenic, chromium and copper leaches from CCA waste wood; at times to levels exceeding regulatory thresholds by two to three orders of magnitude. Furthermore, the more toxic and mobile species of arsenic (As III) and chromium (Cr VI) were detected in both soil and leachate samples. A mass balance was produced which demonstrated that CCA wood tends to leach on initial exposure to a leachant and also during weathering of the wood. When in contact with soil, metal(loid) transport is reduced due to complexation reactions. With higher water application or where the adsorption capacity of the soil is exceeded, the metal(loid)s are transported through the soil column as leachate. Overall, there was a loss of metal(loid)s from the system that could be due to loss of water, volatilisation of arsenic and plant uptake. Due to the toxicity and concentration levels of the leached elements identified in the current study, it is apparent that adverse environmental and human health impacts may result from direct and indirect exposure to the environmental media.

This thesis is concerned with the management of wood waste generated after demolition of a typical 33 year old coke quenching tower from an integrated steelworks. Wood in the coke quenching tower was treated with traditional waterborne preservative, Copper-Chromium-Arsenic (CCA). Due to the growing environmental concern, changes were introduced in the legislation governing the disposal of waste. Hence, the aim of the thesis was to perform a waste management study by investigating CCA treated wood waste and to develop a waste disposal technique. During the characterisation of the wood waste, elemental analysis was performed to confirm CCA concentration remaining in the treated wood waste. Concentration of CCA elements ranged from 300mg/kg to 10,000mg/kg. The concentration reduced with increase in the years of service life of the treated wood. Leaching tests according to British Standards were performed for different durations from 1 hour to 1 month to determine the leaching behaviour exhibited by the wood. Standard and customised sampling procedures were carried out for leaching tests to study and simulate the loss of CCA from the treated wood during a quenching process. These tests provided a leaching pattern that the loss of CCA follows a trend of As > Cu > Cr which was in agreement with the final concentrations of the quenching tower wood, such that chromium was most resistant to leaching and arsenic was most susceptible to leach. Correlations and linear equations were established between the arsenic-chromium and arsenic-copper leach concentrations. Equations were developed to help in predicting the ratio of leach ability of the CCA elements with respect to each other. It was also found that the wood from the tower contained a substantial amount of iron which was further investigated. The growth ring analysis showed that iron was mainly deposited on the wood surface. The prime sources of iron were identified to be kish, an air borne particulate matter found in steelworks environment as well as coke and coke ash. Leaching studies performed to determine the leachability of iron showed that there was a potential for iron to restrict the mobility of CCA elements in soil. A novel three-step chemical extraction method was developed after analysing the sequential analysis performed with different chemical reagents and leaching behaviour of the CCA wood waste. Step one used sodium hydroxide (NaOH) to break down the wood structure by lignin depolymerisation. The use of NaOH provided alkaline conditions and facilitated the process of lignin depolymerisation mainly to release arsenic as water soluble compounds. This was followed by ammonium chloride (NH4Cl) for release of copper, due to the high affinity of ammonium group to form complexes with copper. Hydrogen peroxide (H2O2) was used as a strong oxidising agent and primarily to release the chromium by forming chromium complexes which are readily soluble in water. The effect of the pH, temperature, concentration and order of the reagent to be used were studied. Therefore, CCA wood was subjected to the three-step process, where the order was designed as NaOH followed by NH4Cl and then H2O2 for 1 hour at 100oC with 1 M, 2 M and 2 M concentration respectively. 98 %, 89 % and 96 % for arsenic, chromium and copper respectively was the extraction percentage achieved by the three step process. The three elements were obtained in a water solution and a dry wood residue. The process showed the potential in an alkaline extraction method with high extraction levels in three hours. The process also provided wood residue with possible uses in paper and pulp industry. In order to complete the treatment method the CCA elements present in water solution obtained after the three-step extraction process were required to be precipitated. The CCA elements present in water soluble state were precipitated by using an electrocoagulation process. Various parameters were analysed including type of electrodes, a suitable pH range, current, and concentration of the solution to optimise the whole process. The pH of the solution played a vital role in the precipitation of the elements. The pH value was adjusted to 4 in order to achieve the maximum removal potential. The mild steel electrodes were selected over the aluminium. The iron ions released from the mild steel electrodes formed insoluble complexes with the CCA elements in the solution as compared to the soluble aluminium ions. The final process was optimised to 15 minutes of duration using mild steel electrodes and 0.8 A current at room temperature. The solution used for the electrocoagulation was diluted to the factor of 1:5. The full process precipitated about 99 % of CCA elements from water which was filtered and analysed. Overall, the thesis provided in-depth characterisation of the CCA treated wood waste arising from a steelworks environment. The leaching behaviour and the presence of iron were studied to provide a better understanding for the disposal of such wastes. A chemical extraction method followed by the electrocoagulation for the disposal of CCA treated wood waste provided a foundation for a scaled up treatment method and final disposal of such wastes.