Recently, food waste issue has been raised by many environmental friendly organizations, there are approximately 3,584 tons food waste produced in Hong Kong every day. Food waste originates from commercial and industry (C&I) sector and domestic sector that about 11% and 28% respectively of the municipal solid waste (MSW) generated in Hong Kong. Food waste leads to many pollution problems, as food waste contains a lot of moisture, during the decomposing process, the food waste will release landfill gas and leachate, it will contaminate environment of nearby area of landfills. Furthermore, every day about 9,000 tons MSW will be disposed to landfills, based on the government information, the landfill of Tseng Kwan O will be saturated on 2015, while the other landfills in Tuen Man and Ta Kwu Ling will be saturated in 2017 and 2019 respectively, and MSW will become a big issue for Hong Kong. Currently, Hong Kong has only one Pilot Composting plant in Kowloon bay to recycle 500 tons food waste daily from C & I sectors. And for households sector, only a few housing estates have on-site composting machines to recycle the food waste, most of the domestic food wastes are disposed to landfills. To encourage the on-site food waste recycling within housing estates, the ECF has launched a funding program “Food waste Recycling Projects in Housing Estates” in 2011. ECF believed that providing subsidy as an incentive would attract more estates to implement on-site food waste composting and reduce the quantity of food waste in household side. The “Food waste Recycling Projects in Housing Estates” has launched for two years, so far not many housing estates implement the on-site food waste composting, this research will study the effectiveness of on-site food waste composting in reducing households’ food waste and whether the incentive mechanism is the best tools to enhance the households’ participation in food waste recycling. / published_or_final_version / Housing Management / Master / Master of Housing Management

The food waste problem has recently been put in the spotlight in Hong Kong and around the world. Food waste is the largest part of the municipal solid waste in Hong Kong, which accounts for more than a third of all solid waste. In 2011, there was approximately 3,600 tonnes of food waste generated everyday, with two-thirds coming from households and one-third from the commercial and industrial sector. The capacities of the three strategic landfills in Hong Kong are going to be exhausted soon. Therefore, new policy strategies are needed to combat the food waste problem. A questionnaire was conducted with residents in the Tuen Mun district of Hong Kong, which focused on finding out their level of awareness of the food waste problem in Hong Kong; general behaviours of handling and generation of food waste; views and attitudes towards recycling food waste and perceived need for a household food waste recycling scheme in Hong Kong. The findings show that the majority of the respondents have a high level of awareness of the food waste problem in Hong Kong. However, the general behaviour of handling and generation of food waste does not seem to be in keeping with a reduction of food waste. There are a number of hindering factors that discourage food waste reduction and food waste recycling, such as the lack of food waste recycling facilities, hygiene and public health issues, and other social issues such as convenience. Nevertheless, the respondents agree that Hong Kong should introduce compulsory food waste recycling facilities for households in order to combat the food waste problem. With the vast amount of domestic food waste generated, the introduction of a household food waste recycling scheme has great potential to reduce food waste in Hong Kong. The obstacles of introducing household food waste recycling can be overcome by government provision of food waste recycling facilities, as well as maintaining a good hygiene standard. Full government provision of such facilities would increase the level of convenience, including financial convenience, and hence people would be more willing to participate in recycling and reducing their food waste. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Food waste issue is not only concerned in Hong Kong, but for the worldwide in recent years. Landfilling is the major method treating large amount of food waste by the government in Hong Kong, and only small amount of food waste would be upcycled by the government’s pilot composting plant and the private food waste upcycling companies. This management system on food waste is not sustainable which would lead to different social and environmental problems. Several plans are conducted by the government on dealing with food waste; the most frequently heard project is the project of Organic Waste Treatment Facilities (OWTFs), which is aimed to build five to six OWTFs between 2014 and2024. Besides the government’s efforts on food waste issue, food backs, researches and upcycling food waste by the private parties are observed. Therefore, develop a sustainable food waste management in Hong Kong especially on upcycling would be the best choice to reduce food waste as well as to solve the landfill exhausting problem. The final aims of this study is to confirm the most suitable sustainable food waste management framework for Hong Kong and to develop a set of recommendations on food waste upcycling for stakeholders involved. This is achieved by reviewing related literature and international best practice; developing an universal sustainable food waste management framework; understanding the current situation in Hong Kong and identifying key issues through literature review and first hand data / information collections. Online survey and interviews are conducted. 174 people completed the online survey and 29 interviews are conducted on upcycling businesses, catering sectors, actual customers of those upcycling products and NGOs. 6 factors are recognized and discussed under the 4 – steps food waste upcycling process framework, which causing the differences in management options and outcomes: 1. Late starting point; 2. Low variety of food wastes management methods; 3. Concerns; 4. Availability of food waste industry and market; 5.Lack of promotions and 6. Lack of education and resources. “Research and Development on Upcycling Food Waste Fund” is suggested for researching and developing new value –added upcycled products, subsidies and incentives are also suggested to maintain the competitiveness of upcycled products and develop an upcycling market in Hong Kong. Internet promotions and interactions are highly recommended on promotion, consultation and education aspects. The recent campaign –Food Wise Hong Kong is a good example for food waste management and it should be kept and further focused on food donation, and finally to promote food waste separation. The proposed food waste management plans and projects are also reviewed, collecting food waste from catering sector would be a better method at the beginning. Quantity-based charging scheme that charge by rubbish bags is suggested, facilities in the current waste station are needed to improve. An amended food waste management framework for current Hong Kong is constructed at last, hoping that can lead to sustainable development. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Biopolymers are polymers produced by certain microorganisms, that are readily degradable in the environment. These biodegradable plastics have the potential to be used as substitutes for conventional petroleum based plastic provided that the production costs can be greatly reduced. The high cost of biopolymer production is due to the cost of substrate which mainly is glucose. / The enzymatic hydrolysis of potato processing wastes was to produce glucose as a least expensive feedstock substrate for the production of biopolymers of polyhydroxybutirate (PHB) from the bacterium Alcaligenes eutrophus was studied. The enzymatic hydrolysis experiments were carried out using $ alpha$-amylase liquefaction enzymes from Aspergillus oryzae and barley-malt, and amyloglucosidase saccharification enzyme from Rhizopus. / The results indicated that the production of glucose from potato starch waste to be used as a substrate to produce biopolymers was both technically and economically feasible. A 10 to 90 ratio of barley-malt to potato starch waste gave the highest conversion of starch to glucose of 194.30 gL$ sp{-1}$ (96.56%), and the lowest liquefaction enzyme cost ($0.054) to hydrolyze one kg of potato starch waste. { it A. eutrophus /} produced PHB of 5.0 gL$ sp-1$ (76.9 % of biomass) using the glucose substrate generated from the potato starch waste.

Thesis (M.A.)--University of North Carolina at Greensboro, 2007. / Title from PDF title page screen. Advisor: Zhi-Ju Liu; submitted to the Dept. of Geography. Includes bibliographical references (p. 83-89).

CAPES / A problemática da geração de resíduos industriais vem se agravando, principalmente pelo fato de que somente uma pequena parcela desses resíduos é corretamente tratada e devidamente destinada em locais próprios. Um exemplo de resíduo com grande potencial poluidor é a manipueira, efluente líquido gerado em grandes quantidades no processamento de mandioca para a produção de farinha e de fécula. A manipueira contém uma elevada carga orgânica na sua composição, com alto teor de fécula residual, resultante do baixo rendimento do processo de extração. Outro grande problema ambiental é a perda de nutrientes aplicados no solo por meio de fertilizantes, principalmente do nitrogênio, decorrente dos processos de lixiviação pela água das chuvas e volatilização pelo aquecimento do solo, que trazem prejuízos financeiros aos agricultores e danos ambientais pelo excesso de nutrientes levados aos corpos hídricos. Aliando-se essas duas questões, o objetivo desse trabalho foi preparar e caracterizar biofilmes à base de manipueira pura, e também de manipueira com a incorporação dos aditivos poli-(álcool vinílico) e alginato de sódio, avaliando-se assim, a influência desses aditivos nas características finais dos biofilmes. Após esta etapa, avaliou-se qual dos biofilmes produzidos obteve características compatíveis para a imobilização da caulinita intercalada com ureia, visando avaliar esse conjunto como fertilizante de liberação lenta de nitrogênio, que prioriza a liberação gradual do nutriente. A partir da caracterização da manipueira utilizada, determinou-se que a mesma possui um teor de 3% de fécula na sua composição, dessa forma, o resíduo foi utilizado como solução filmogênica para formação dos biofilmes. Esses biofilmes foram caracterizados e apresentaram baixas propriedades de barreira ao vapor de água, entretanto, os biofilmes de manipueira pura e de manipueira com poli-(álcool vinílico) possuem boas propriedades mecânicas e alta estabilidade térmica. Os biofilmes de manipueira com alginato de sódio apresentaram características mecânicas inferiores aos citados acima e com menor estabilidade térmica. A partir das características apresentadas, o biofilme de manipueira pura foi escolhido para ser o meio imobilizante da caulinita intercalada com ureia, onde, além da caracterização realizada como nos demais biofilmes, foi também avaliada a liberação do nitrogênio por meio de ensaios de lixiviação e de aquecimento. Observou-se que nos ensaios de lixiviação a imobilização não foi efetiva, perdendo 73,37% do nitrogênio incorporada já no menor tempo empregado no ensaio, entretanto, no ensaio de aquecimento, o biofilme de manipueira pura apresentou uma alta imobilização até 170 ºC, com uma perda de nitrogênio de somente 14,93%. A análise dos resultados mostra que os biofilmes à base de manipueira são uma alternativa viável de reaproveitamento desse resíduo, apresentando boas características, entretanto, quando o emprego é a imobilização da caulinita intercalada com ureia é necessário um maior estudo buscando meios para reduzir as perdas por lixiviação. / The problem of industrial waste generation has aggravating mainly by the fact that only a small portion of that waste is properly treated and properly designed in suitable places. An example of waste with high pollution potential is manipueira, liquid effluent generated in large quantities in manihot processing for the production of flour and starch. Manipueira contains a large organic load in its composition, with high levels of residual starch, resulting in low yield of the extraction process. Another major environmental problem is the loss of nutrients applied to the soil through fertilizers, especially nitrogen, resulting from leaching processes by rain water and volatilization soil heating, which brings financial damage to farmers and environmental damage by excess nutrients carried to water bodies. Allying these two issues, the objective of this work was to produce biofilms based on pure manipueira, and too manipueira with incorporation of additives poly (vinyl alcohol) and sodium alginate, thus assessing the influence of these additives in the final characteristics of biofilms. After this step, we evaluated which of biofilms produced consistent characteristics obtained for the immobilization of kaolinite intercalated with urea, to evaluate this set as a slow release fertilizer nitrogen, which prioritizes the gradual release of the nutrient. From the characterization of cassava used, it was determined that it has a content of 3% starch in composition, thus the residue was used as filmogenic solution for the formation of biofilms.These biofilms were described and presented barrier properties to water vapor low, however, the biofilm manipueira and pure manipueira and manipueira with poly (vinyl alcohol) have good mechanical properties and high thermal stability. Biofilms manipueira with sodium alginate showed inferior mechanical characteristics to those cited above and with lower thermal stability. From the characteristics presented, the biofilm pure manipueira was chosen to be the means of immobilizing kaolinite intercalated with urea, which, besides the characterization performed as in other biofilms was also investigated the release of nitrogen through leaching tests and heating. It was observed that the leaching tests was not effective immobilization, losing 73.37% of the nitrogen already incorporated in the shortest time employed in the assay, however, a test of heating, the biofilm pure manipueira showed high immobilization to 170 ° C, with a loss of nitrogen of only 14.93%. The analysis suggests that biofilms based manipueira are a viable reuse of this waste, with good features, however, when employment is immobilization of kaolinite intercalated with urea requires a larger study looking at ways to reduce leaching losses.

No description available.

Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018. / The rate of waste electrical and electronic equipment (WEEE) is growing at an alarming rate, especially in countries where markets are saturated with huge quantities of new electronic goods. Printed circuit boards (PCBs) are a substantial portion of the value contained in waste from WEEE although they are only 6% of the total weight. It is reported that WEEE is currently the fastest growing waste stream in South Africa as the general population’s access to electronic goods in the last decade has increased, especially access to mobile phones. PCBs are found in any piece of electrical or electronic equipment and consist of various metals including precious metals such as gold (Au), silver (Ag) and palladium (Pd). It is reported that gold has the highest economic incentive at 15,200 $ per ton of PCBs. The rapid introduction of new and advanced technology into mobile phones has caused mobile phones to have a relatively short life span, 1 to 2 years to be exact. Mobile phones printed circuit boards (MPPCBs) have more Au content compared to computer circuit boards. They contain 350 g/ton Au whereas computer (PC) PCBs contains 250 g/ton. This research project will recover gold from waste mobile phones PCBs pregnant ammonia thiosulphate leach solution using copper cementation. The cementation process is preferred to all the other technologies of metals extraction from solution due to ultrahigh purity metals that can be obtained and to the less consumption of materials and energy. Electronic parts on the PCBs were manually removed using pliers and screwdrivers. PCBs were then cut to smaller pieces of about 2 x 2 m. The pieces were crushed and milled respectively. Some of the particles were recycled back to the crusher to get finer particles. The particles were separated to particles of sizes between 0 and 1350 μm using a shaker. The comminuted fractions of the PCBs were then used in the leaching step. Batch cementation experiments were performed by bubbling N2 in glass reaction vessel with a working volume of 0.5 L. The reactor was connected to a circulating water bath for temperature control. The recovery percentage of gold at various temperatures, agitation speeds and different amounts of copper powder used, was determined while pH was monitored. The temperature was varied at 30 °C, 40 °C, and 50 °C and the agitation speeds at 300 RPM and 900 RPM. Copper powder was added at 0.5 g/L, 1 g/L, and 1.5 g/L. Gold concentrations were measured by atomic adsorption spectrophotometer (AAS). Scanning electron microscope (SEM) and Energy-dispersive x-ray spectrometry (EDS) analyses of the copper powder after cementation (precipitates) were used to determine the surface morphology and to evaluate the quantitative aspect of the precipitate. It was found that the recovery of gold from ammonia thiosulphate leach solution was greatly affected by agitation speed. At an agitation speed of 900 rpm, 40 °C and 0.5 g of Copper powder, 96% of the gold was recovered from the leach solution. The cementation rate increased as temperature was elevated from 30 to 40 °C, but slightly decreased as the temperature reached 50 °C. The change in experimental conditions affected the gold concentration on the precipitate recovered. This study will provide a possible solution to the WEEE problem and more specifically mobile cell phones, in South Africa.

Food waste is one of an organic waste and contains the value of recycling and reusing. EPA shows that there are almost the amount of 4500 tons food wastes which is about 36~64% in households in Taiwan everyday. Therefore, if food wastes could be reused again, not only greatly reducing the amount of waste, decreasing the problem of odor from progressing food wastes, but also increasing the using year of landfills and incinerators. Furthermore, it can develop fully the value of multiple reusing in recycling. The study is forced on questionnaires for the residents of the city of Kaohsiung and Taichung, to know the present of recycling of food waste and its difficulty in executing a strategy. Conferring the willingness to pay and the willingness to accept of food waste recovery and if the price is different or not by Contingent Valuation Method (CVM), and moreover evaluating the potential benefit. The results of the study are as following: there are conspicuous difference in ¡§if doing something about recovery¡¨ ¡§the way of recovery¡¨ and ¡§if see any inspectors examine the classification of refuse¡¨. The most difficulties of recovery food waste in both cities are ¡§its odor and breed mosquito and fly easily¡¨ and ¡§not knowing clearly what materials should be recovered or not¡¨. About the price of the willingness to pay and the willingness to accept, the major answer shows ¡§No, I would not.¡¨ from this questionnaires. On the other hand, answers of ¡§Yes, I would like.¡¨ all hope that the pay less is better and the compensation more is better. The price of the willingness to pay of Kaohsiung residents is NT$ 41.8 dollars, and Taichung residents is NT$ 45.3 dollars. Otherwise, the higher environmental conscious the Kaohsiung residents have, the higher willing to pay. At the same time, the difficulty of recovery food waste is low comparatively. In addition, ¡§occupation¡¨ ¡§family revenue per month¡¨ ¡§cooking per week¡¨ have effect on the price of the willingness to pay and the willingness to accept. In the result of regression, some of variable parameters could affect the price of the willingness to pay. It maybe provides society for reference according the benefit in the estimating of regression. Therefore, the study hopes to provide the decision-maker more clear environmental and economical information through evaluate and analyze the willingness of pay of food waste. Furthermore, it maybe help the government to make a future policy in order to practice the food waste recovery indeed and carry out the target of reducing the amount of waste and resources recovering for a sustainable resources of food waste.

This thesis examines the technological economics of glass recycling in Britain. Attention was focused on recovery schemes operated within Scotland, comparisons being made with schemes in the rest of Britain and in Europe. An examination was made of general recycling problems and of glass recycling problems in particular. The various systems for glass recycling were reviewed and were put in the context of the waste management system as a whole. A survey was undertaken of Local Authorities operating glass recycling schemes. The aim was to provide a comprehensive data set to enable a consistent assessment of glass recovery schemes to be taken. This emphasised the importance of taking a standard approach to assessing the viability of recovery schemes. This needs to be done in terms of both private and social costs and benefits to provide a full economic assessment of the system. A general computer model has been developed to allow local authorities to check the viability of their on-going operations. As they operate under different conditions this model was split into separate assessment of a Bottle Bank scheme and a trade collection scheme. In addition, an investment appraisal model was developed to cover both situations. These allow managers to assess the viability of their schemes and can be used to highlight key costs. An International review was undertaken to see what lessons may be learned and what actions may be taken by the local authorities, industry, the general public, and by central government.