RESUMO
Circularity assessment and monitoring have become a core research topic in academic societies, as well as a basis for developing economic development measures. Despite the circular economy (CE) being a game-changer for the agro-food sector, little effort has been made to identify its level of circularity. In order to achieve the transition to a CE, stakeholders and industry professionals must be provided with appropriate indicators, tools and methods. Due to the complexity of CE measurement, it is necessary to devise indicators, methods and tools that are tailored to each industry. The objective of this review article is to identify the indicators and tools required for assessing the level of circularity in olive oil mills. This research collected data regarding available CE indicators at the company and product levels, as well as those applicable to the agro-food industry. As a result, a list of indicators appropriate to the needs of olive mills has been developed that could be used to measure the level of implementation of circular practices in this industry. The main conclusion reached is that once indicators are defined, they should be compared or combined with life cycle assessment methodologies to determine their applicability and effectiveness. There is no doubt that olive oil plays a significant economic, environmental and social role throughout the Mediterranean region. Hence, evaluating the CE is essential to demonstrate the effectiveness of current policies.
Assuntos
Azeite de Oliva , Gerenciamento de Resíduos/métodos , Gerenciamento de Resíduos/economiaRESUMO
The loop is a material classically used in the laboratory for the purpose of plate streaking and handling biological materials. However, metal loops techniques might be time consuming, considering the amount of time spent to guarantee its cooling process through each inoculation. Furthermore, plastic loops may also represent environmental issues during its production and discard process and can also represent higher costs for the laboratory. Thus, in situations of limited resources, even the simplest materials can be restricted due to logistical and budgetary issues, especially in developing countries. Inspired by demands like these, facing an occasional shortage of supply of laboratory plastic handles, we hereby present a quality control for sterilization methods and cost-effectiveness studies towards the use of wooden sticks in a Latin American country and we discuss the possibility of the large-scale use of this technique.
A alça calibrada é um material usado classicamente em laboratório para fins de inoculação em placas e manuseio de materiais biológicos. No entanto, as técnicas de alças metálicas podem consumir muito tempo, considerando a quantidade de tempo gasto para garantir seu processo de resfriamento a cada inoculação. Além disso, alças de plástico também podem representar questões ambientais durante o processo de produção e descarte e também podem representar custos mais altos para o laboratório. Assim, em situações de recursos limitados, até os materiais mais simples podem ser restringidos devido a questões logísticas e orçamentárias, especialmente nos países em desenvolvimento. Inspirados por demandas como essas, diante de uma escassez ocasional de suprimentos de alças de plástico de laboratório, apresentamos um controle de qualidade para métodos de esterilização e estudos de custo-efetividade para o uso de varas de madeira em um país latino-americano e discutimos a possibilidade de grande uso em escala dessa técnica.
Assuntos
Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodos , Técnicas Bacteriológicas/economia , Técnicas Bacteriológicas/instrumentação , Técnicas Microbiológicas/economia , Técnicas Microbiológicas/instrumentaçãoRESUMO
Operating rooms generate 42% of a hospital's revenue and 30% of hospital waste. Supply costs are 56% of a total operating room (OR) budget. US academic medical centers use 2 million pounds ($15 million) of recoverable medical supplies annually. Forming a multidisciplinary leadership team, we analyzed sources of waste focusing on our Department of Neurosurgery. We developed an 8-wk pilot project to recycle "blue wrap," the number 5 plastic polypropylene material that is ubiquitously used in ORs across the country to wrap instrument pans and implant trays for sterilization. Blue wrap can be baled and sold to recyclers where the material is pelletized and transformed into plastic products. During the 39 d of the pilot, we collected 1247 pounds of blue wrap (32 lbs collected daily). The cost of the pilot was $14 987 that includes a new baler ($11 200) and 5 transport carts ($3697). The revenue received from baled blue wrap was 8 cents per pound. Cost avoidance yielded $31 680.00 in savings. Implementation of this pilot across our main hospital would yield $5000 in revenue annually and $174 240 in cost avoidance. This project can be replicated at other centers and not only reduces the environmental footprint, but also helps generate additional revenue by recycling a necessary packing material that would otherwise require payment for disposal.
Assuntos
Salas Cirúrgicas , Reciclagem/economia , Reciclagem/métodos , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodos , Centros Médicos Acadêmicos , Humanos , Projetos Piloto , PolipropilenosRESUMO
The abatement of valproic acid sodium salt (VA) via photo-Fenton process was investigated to evaluate the effect of irradiation type. Three different light sources have been used: UVA (black light blue lamps, BLB reactor), UVC (UVC reactor) and simulated sunlight in a Solarbox (SB). Using the highest concentrations of Fe2+ (10mgL-1) and H2O2 (150mgL-1), 100% of VA degradation was observed in BLB and UVC devices, and 89.7% in Solarbox. Regarding mineralization, 67.4% and 76.4% of TOC conversion were achieved in BLB and UVC, respectively. In Solarbox, mineralization was negligible. Treated solutions under UVA or UVC radiation became biodegradable (BOD5/COD≥0.25), which was not observed in Solarbox where BOD5/COD achieved was only 0.20. Regarding to toxicity (Vibrio Fischeri method), all processes have promoted the overall toxicity reduction of VA solution. Transformation products were identified by a LC-ESI-TOF mass spectrometer, and degradation pathways were proposed. Operating costs and the energy needed by mg of VA removed were estimated and compared, for the different installations, showing that UVA can remove around 3 times more VA than SB and 2 times more VA than UVC, under the same conditions.
Assuntos
Peróxido de Hidrogênio , Ferro , Ácido Valproico/química , Ácido Valproico/efeitos da radiação , Biodegradação Ambiental , Custos e Análise de Custo , Resíduos de Drogas/química , Resíduos de Drogas/efeitos da radiação , Resíduos de Drogas/toxicidade , Peróxido de Hidrogênio/economia , Ferro/química , Ferro/economia , Fotólise , Luz Solar , Raios Ultravioleta , Ácido Valproico/toxicidade , Eliminação de Resíduos Líquidos , Gerenciamento de Resíduos/economiaRESUMO
In Macao, about 7200 t yr-1 of bottom ash (BA) is generated and conventionally landfilled with construction waste. Because the properties of BA are similar to those of natural aggregates, it is suitable to be recycled as construction material. However, pre-treatment processes for BA reuse may require more resource input and may generate additional environmental impacts. Life cycle assessment, multi-media transport model analysis, cost-benefit analysis and the analytical hierarchy process were conducted to evaluate the impacts of current and potential BA management scenarios regarding environmental, economic, social and regulatory aspects. The five analysed scenarios are as follows: (0) BA buried with construction and demolition waste (current system); (1) pre-treated BA used to replace 25% of the natural aggregate in asphalt concrete; (2) pre-treated BA used to replace 25% of the natural aggregate in cement concrete; (3) pre-treated BA used to replace 25% of cement in cement concrete; and (4) pre-treated BA sent to China, blended with municipal solid waste for landfill. The results reveal the following ranking of the scenarios: 3 > 2 > 0 > 1 > 4. Scenario 3 shows the best conditions for BA recycling, because the quantity of cement concrete output is the highest and this brings the greatest economic benefits. Our use of integrated analysis provides multi-aspect investigations for BA management systems, particularly in accounting for site-specific characteristics. This approach is suitable for application in other non-western regions.
Assuntos
Cinza de Carvão , Gerenciamento de Resíduos/métodos , Carcinógenos/toxicidade , China , Cinza de Carvão/análise , Cinza de Carvão/química , Cinza de Carvão/toxicidade , Materiais de Construção , Análise Custo-Benefício , Meio Ambiente , Lógica Fuzzy , Humanos , Incineração , Macau , Modelos Teóricos , Opinião Pública , Reciclagem , Eliminação de Resíduos/métodos , Instalações de Eliminação de Resíduos , Gerenciamento de Resíduos/economiaRESUMO
Municipal solid waste disposed in landfill sites decomposes under anaerobic conditions and produces so-called landfill-gas, which contains 30%-40% of carbon dioxide (CO2) and 50%-60% of methane (CH4). Methane has the potential of causing global warming 25 times more than CO2 Therefore, migration of landfill-gas from landfills to the surrounding environment can potentially affect human life and environment. Thus, this research aims to determine municipal solid waste generation in Oman over the years 1971-2030, to quantify annual CH4 emissions inventory that resulted from this waste over the same period of time, and to determine the economic and environmental benefits of capturing the CH4 gas for energy production. It is found that cumulative municipal solid waste landfilled in Oman reaches 3089 Giga gram (Gg) in the year 2030, of which approximately 85 Gg of CH4 emissions are produced in the year 2030. The study also found that capturing CH4 emissions between the years 2016 and 2030 could attract revenues of up to US$333 million and US$291 million from the carbon reduction and electricity generation, simultaneously. It is concluded that CH4 emissions from solid waste in Oman increases enormously with time, and capture of this gas for energy production could provide a sustainable waste management solution in Oman.
Assuntos
Dióxido de Carbono/química , Monitoramento Ambiental , Metano/química , Instalações de Eliminação de Resíduos , Gerenciamento de Resíduos/economia , OmãRESUMO
In this study modeled full scale application of thermobarical hydrolysis of less degradable feedstock for biomethanation was assessed in terms of energy balance, greenhouse gas emissions, and economy. Data were provided whether the substitution of maize silage as feedstock for biogas production by pretreated cattle wastes is beneficial in full-scale application or not. A model device for thermobarical treatment has been suggested for and theoretically integrated in a biogas plant. The assessment considered the replacement of maize silage as feedstock with liquid and/or solid cattle waste (feces, litter, and feed residues from animal husbandry of high-performance dairy cattle, dry cows, and heifers). The integration of thermobarical pretreatment is beneficial for raw material with high contents of organic dry matter and ligno-cellulose: Solid cattle waste revealed very short payback times, e.g. 9 months for energy, 3 months for greenhouse gases, and 3 years 3 months for economic amortization, whereas, in contrast, liquid cattle waste did not perform positive replacement effects in this analysis.
Assuntos
Biocombustíveis/análise , Esterco/análise , Gerenciamento de Resíduos/métodos , Poluentes Atmosféricos/análise , Anaerobiose , Criação de Animais Domésticos , Animais , Biocombustíveis/economia , Reatores Biológicos , Bovinos , Monitoramento Ambiental , Feminino , Gases/análise , Efeito Estufa , Temperatura Alta , Hidrólise , Modelos Teóricos , Pressão , Gerenciamento de Resíduos/economiaRESUMO
The ongoing trend in the public sector is to make more sustainable procurements by taking into account the impacts throughout the entire life cycle of the procurement. Despite the trend, the only deciding factor can still be the total costs. This article answers the question of how greenhouse gas (GHG) emissions should be taken into account in municipal solid waste (MSW) management when selecting an incineration plant for source separated mixed MSW. The aim is to guide the decision making of MSW management towards more environmentally friendly procurements. The study was carried out by calculating the global warming potentials (GWPs) and costs of mixed MSW management by using the waste composition from a case area in Finland. Scenarios of landfilling and combustion in three actual waste incineration plants were used to recognise the main processes that affect the results. GWP results show that the combustion of mixed MSW is a better alternative than landfilling the waste. The GHG results from combustion are greatly affected by emissions from the combustion and substituted energy production. The significance of collection and transportation is higher from the costs' perspective than from the point of view of GHG emissions. The main costs, in addition to collection and transportation costs, result from the energy utilization or landfilling of mixed MSW. When tenders are invited for the incineration location of mixed MSW, the main focus should be: What are the annual electricity and heat recovery efficiencies and which are the substituted fuels in the area? In addition, in the case of a fluidized bed combustor it is crucial to know the combusted share of mixed MSW after preparing solid recovered fuel (SRF) and the treatment of rejects. The environmental criteria for the waste incineration plant procurements should be made in order to obtain clear instructions for the procurement units. The results can also be utilized more widely. The substituted fuels in the area and the effect of the plant location on the utilization of the produced energy can already be identified when planning an appropriate site for the waste incineration plant.
Assuntos
Poluentes Atmosféricos/análise , Tomada de Decisões , Gases/análise , Efeito Estufa , Resíduos Sólidos/economia , Gerenciamento de Resíduos/métodos , Finlândia , Meios de Transporte , Gerenciamento de Resíduos/economiaRESUMO
BACKGROUND: The provision of health care has significant direct environmental effects such as energy and water use and waste production, and indirect effects, including manufacturing and transport of drugs and equipment. Recycling of hospital waste is one strategy to reduce waste disposed of as landfill, preserve resources, reduce greenhouse gas emissions, and potentially remain fiscally responsible. We began an intensive care unit recycling program, because a significant proportion of ICU waste was known to be recyclable. OBJECTIVES: To determine the weight and proportion of ICU waste recycled, the proportion of incorrect waste disposal (including infectious waste contamination), the opportunity for further recycling and the financial effects of the recycling program. METHODS: We weighed all waste and recyclables from an 11-bed ICU in an Australian metropolitan hospital for 7 non-consecutive days. As part of routine care, ICU waste was separated into general, infectious and recycling streams. Recycling streams were paper and cardboard, three plastics streams (polypropylene, mixed plastics and polyvinylchloride [PVC]) and commingled waste (steel, aluminium and some plastics). ICU waste from the waste and recycling bins was sorted into those five recycling streams, general waste and infectious waste. After sorting, the waste was weighed and examined. Recycling was classified as achieved (actual), potential and total. Potential recycling was defined as being acceptable to hospital protocol and local recycling programs. Direct and indirect financial costs, excluding labour, were examined. RESULTS: During the 7-day period, the total ICU waste was 505 kg: general waste, 222 kg (44%); infectious waste, 138 kg (27%); potentially recyclable waste, 145 kg (28%). Of the potentially recyclable waste, 70 kg (49%) was actually recycled (14% of the total ICU waste). In the infectious waste bins, 82% was truly infectious. There was no infectious contamination of the recycling streams. The PVC waste was 37% contaminated (primarily by other plastics), but there was less than 1% contamination of other recycling streams. The estimated cost of the recycling program was about an additional $1000/year. CONCLUSION: In our 11-bed ICU, we recycled 14% of the total waste produced over 7-days, which was nearly half of the potentially recyclable waste. There was no infectious contamination of recyclables and minimal contamination with other waste streams, except for the PVC plastic. The estimated annual cost of the recycling program was $1000, reflecting the greater cost of disposal of some recyclables (paper and cardboard v most plastic types).
Assuntos
Unidades de Terapia Intensiva , Reciclagem/economia , Gerenciamento de Resíduos/economia , Austrália , Custos e Análise de Custo , Humanos , Auditoria Médica , ResíduosRESUMO
Using a novel approach that links geospatial land resource information with individual farm-scale simulation, we conducted a regional assessment of nitrogen (N) and phosphorous (P) losses to water and greenhouse gas (GHG) emissions to air from the predominant mix of pastoral industries in Southland, New Zealand. An evaluation of the cost-effectiveness of several nutrient loss mitigation strategies applied at the farm-scale, set primarily for reducing N and P losses and grouped by capital cost and potential ease of adoption, followed an initial baseline assessment. Grouped nutrient loss mitigation strategies were applied on an additive basis on the assumption of full adoption, and were broadly identified as 'improved nutrient management' (M1), 'improved animal productivity' (M2), and 'restricted grazing' (M3). Estimated annual nitrate-N leaching losses occurring under representative baseline sheep and beef (cattle) farms, and representative baseline dairy farms for the region were 10 ± 2 and 32 ± 6 kg N/ha (mean ± standard deviation), respectively. Both sheep and beef and dairy farms were responsive to N leaching loss mitigation strategies in M1, at a low cost per kg N-loss mitigated. Only dairy farms were responsive to N leaching loss abatement from adopting M2, at no additional cost per kg N-loss mitigated. Dairy farms were also responsive to N leaching loss abatement from adopting M3, but this reduction came at a greater cost per kg N-loss mitigated. Only dairy farms were responsive to P-loss mitigation strategies, in particular by adopting M1. Only dairy farms were responsive to GHG abatement; greater abatement was achieved by the most intensified dairy farm system simulated. Overall, M1 provided for high levels of regional scale N- and P-loss abatement at a low cost per farm without affecting overall farm production, M2 provided additional N-loss abatement but only marginal P-loss abatement, whereas M3 provided the greatest N-loss abatement, but delivered no additional P abatement, and came at a large financial cost to farmers, sheep and beef farmers in particular. The modelling approach provides a farm-scale framework that can be extended to other regions to accommodate different farm production systems and performances, capturing the interactions between farm types, land use capabilities and production levels, as these influence nutrient losses and GHG emissions, and the effectiveness of mitigation strategies.
Assuntos
Agricultura , Dióxido de Carbono/análise , Conservação dos Recursos Naturais/economia , Efeito Estufa/prevenção & controle , Nitrogênio/análise , Fósforo/análise , Gerenciamento de Resíduos , Água/química , Agricultura/economia , Agricultura/métodos , Animais , Bovinos , Conservação dos Recursos Naturais/métodos , Análise Custo-Benefício , Nova Zelândia , Nitratos/análise , Ovinos , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodosAssuntos
Política de Saúde , Gerenciamento de Resíduos , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Congressos como Assunto , Poluição Ambiental/efeitos adversos , União Europeia , Feminino , Prioridades em Saúde , Humanos , Itália , Masculino , Neoplasias/etiologia , Neoplasias/prevenção & controle , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Saúde Pública , Opinião Pública , Transtornos Respiratórios/etiologia , Transtornos Respiratórios/prevenção & controle , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/legislação & jurisprudênciaRESUMO
Waste oil management systems include processes such as generation, collection, recycling, and disposal and result in various environmental, economic, social, and regulatory impacts which complicate waste management analysis. In this paper, the waste oil management system in Finland is analysed using the systems thinking approach to identify the main system components and to describe the interactions between them. The results of analysing the Finnish system increase the understanding of the main factors affecting the performance of waste oil management. The outcome of this analysis can be adapted for the examination of similar systems. The waste oil management system analysis shows an increase in the performance: the waste oil collection rate within the official collection system has increased more than 30% during the last 6 years. The environmental performance of the treatment and recovery system have increased, taking into account the increase of the material recovery rate, more than 70% during the last 6 years.
Assuntos
Poluição por Petróleo/prevenção & controle , Eliminação de Resíduos/métodos , Gerenciamento de Resíduos/métodos , Conservação dos Recursos Naturais , Finlândia , Poluição por Petróleo/análise , Reciclagem , Eliminação de Resíduos/economia , Gerenciamento de Resíduos/economiaRESUMO
Waste management activities can release greenhouse gases (GHGs) to the atmosphere, intensifying global climate change. Mitigation of the associated GHG emissions is vital and should be considered within integrated municipal solid waste (MSW) management planning. In this study, a fuzzy possibilistic integer programming (FPIM) model has been developed for waste management facility expansion and waste flow allocation planning with consideration of GHG emission trading in an MSW management system. It can address the interrelationships between MSW management planning and GHG emission control. The scenario of total system GHG emission control is analyzed for reflecting the feature that GHG emission credits may be tradable. An interactive solution algorithm is used to solve the FPIM model based on the uncertainty-averse preferences of decision makers in terms of p-necessity level, which represents the certainty degree of the imprecise objective. The FPIM model has been applied to a hypothetical MSW planning problem, where optimal decision schemes for facility expansion and waste flow allocation have been achieved with consideration of GHG emission control. The results indicate that GHG emission credit trading can decrease total system cost through re-allocation of GHG emission credits within the entire MSW management system. This will be helpful for decision makers to effectively determine the allowable GHG emission permits in practices.
Assuntos
Monitoramento Ambiental/métodos , Gases/análise , Efeito Estufa/prevenção & controle , Resíduos Sólidos , Gerenciamento de Resíduos/métodos , Monitoramento Ambiental/economia , Efeito Estufa/economia , Modelos Econômicos , Incerteza , Gerenciamento de Resíduos/economiaRESUMO
Open dumps employed for disposal of municipal solid waste (MSW) are generally referred to as landfills and have been traditionally used as the ultimate disposal method in India. The deposition of MSW in open dumps eventually leads to uncontrolled emission of landfill gas (LFG). This article reviews the MSW disposal practices and LFG emissions from landfills in India during the period 1994 to 2011. The worldwide trend of feasibility of LFG to energy recovery projects and recent studies in India indicate a changed perception of landfills as a source of energy. However, facilitating the implementation of LFG to energy involves a number of challenges in terms of technology, developing a standardized framework and availability of financial incentives. The legislative framework for promotion of LFG to energy projects in India has been reviewed and a comprehensive strategy and action plan for gainful LFG recovery is suggested. It is concluded that the market for LFG to energy projects is not mature in India. There are no on-ground case studies to demonstrate the feasibility of LFG to energy applications. Future research therefore should aim at LFG emission modeling studies at regional level and based on the results, pilot studies may be conducted for the potential sites in the country to establish LFG to energy recovery potential from these landfills.
Assuntos
Gases , Eliminação de Resíduos/métodos , Energia Renovável , Gerenciamento de Resíduos/métodos , Carbono , Países em Desenvolvimento , Índia , Metano , Projetos Piloto , Energia Renovável/economia , Energia Renovável/legislação & jurisprudência , Pesquisa , Gerenciamento de Resíduos/economiaRESUMO
The authors conducted a survey based on conjoint choice experiments in Milan, Italy, about mortality risk reductions delivered by hypothetical private behaviors and public programs, and used it to estimate the value of a prevented fatality (VPF) when the cause of death is cancer. Their estimate of the VPF is 4.2 million Euros. The VPF is about C1 million larger when the risk reduction is delivered by a public program, but further analyses reveal that it is so only when the respondent believes that public programs are effective at reducing this particular type of mortality risk This estimate of the VPF is higher than generic European Union-wide figures recommended by the European Commission Directorate-General for Environment (DG Environment) for environmental policy analyses, and is comparable to other VPFs that are appropriate for Italy, hazardous waste regulations, and enforcement-based cleanup programs. The authors use their VPF to compute the benefits of addressing leaking landfills, illegal disposal of hazardous wastes, and poor hazardous waste management practices in the provinces of Naples and Caserta in southern Italy. The authors also examine the importance of the discount rates, since the mortality benefits of remediation begin in 20 yr and are assumed to continue over 30 yr.
Assuntos
Resíduos Perigosos/efeitos adversos , Neoplasias/mortalidade , Neoplasias/prevenção & controle , Gerenciamento de Resíduos/economia , Algoritmos , Custos e Análise de Custo , Resíduos Perigosos/economia , Inquéritos Epidemiológicos , Humanos , Itália/epidemiologia , Saúde Pública , Comportamento de Redução do Risco , Inquéritos e QuestionáriosRESUMO
This paper deals with a system of integration of Radio Frequency Identification (RFID) and communication technologies for solid waste bin and truck monitoring system. RFID, GPS, GPRS and GIS along with camera technologies have been integrated and developed the bin and truck intelligent monitoring system. A new kind of integrated theoretical framework, hardware architecture and interface algorithm has been introduced between the technologies for the successful implementation of the proposed system. In this system, bin and truck database have been developed such a way that the information of bin and truck ID, date and time of waste collection, bin status, amount of waste and bin and truck GPS coordinates etc. are complied and stored for monitoring and management activities. The results showed that the real-time image processing, histogram analysis, waste estimation and other bin information have been displayed in the GUI of the monitoring system. The real-time test and experimental results showed that the performance of the developed system was stable and satisfied the monitoring system with high practicability and validity.
Assuntos
Algoritmos , Sistemas Computacionais/economia , Modelos Teóricos , Dispositivo de Identificação por Radiofrequência/métodos , Eliminação de Resíduos/métodos , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodos , Sistemas de Informação Geográfica/economia , MalásiaRESUMO
The amount of greenhouse gases (GHG) emitted due to waste management in the cities of developing countries is predicted to rise considerably in the near future; however, these countries have a series of problems in accounting and reporting these gases. Some of these problems are related to the status quo of waste management in the developing world and some to the lack of a coherent framework for accounting and reporting of greenhouse gases from waste at municipal level. This review summarizes and compares GHG emissions from individual waste management processes which make up a municipal waste management system, with an emphasis on developing countries and, in particular, Africa. It should be seen as a first step towards developing a more holistic GHG accounting model for municipalities. The comparison between these emissions from developed and developing countries at process level, reveals that there is agreement on the magnitude of the emissions expected from each process (generation of waste, collection and transport, disposal and recycling). The highest GHG savings are achieved through recycling, and these savings would be even higher in developing countries which rely on coal for energy production (e.g. South Africa, India and China) and where non-motorized collection and transport is used. The highest emissions are due to the methane released by dumpsites and landfills, and these emissions are predicted to increase significantly, unless more of the methane is captured and either flared or used for energy generation. The clean development mechanism (CDM) projects implemented in the developing world have made some progress in this field; however, African countries lag behind.
Assuntos
Gases/análise , Efeito Estufa , Gerenciamento de Resíduos/métodos , África , Cidades , Países em Desenvolvimento , Metano/análise , Gerenciamento de Resíduos/economiaRESUMO
The grave concern over climate change and new economic incentives such as the clean development mechanism (CDM) have given more weight to the potential of projects for reducing greenhouse gas (GHG) emissions. In the Adjara solid waste management project, even though the need for reductions in GHG emissions is acknowledged, it is not one of the key factors for selecting the most appropriate treatment method. This study addresses the benefit of various solid waste treatment methods that could be used in the Adjara project in terms of reducing GHG emissions. Seven different options for solid waste treatment are examined: open dumping as the baseline case, four options for landfill technology (no provision of landfill gas capture, landfill gas capture with open flare system, with enclosed flare system and with electricity generation), composting and anaerobic digestion with electricity production. CDM methodologies were used to quantify the amount of reductions for the scenarios. The study concludes sanitary landfill with capture and burning of landfill gas by an enclosed flare system could satisfy the requirements, including GHG reduction potential. The findings were tested for uncertainty and sensitivity by varying the data on composition and amount of waste and were found to be robust.
Assuntos
Efeito Estufa , Eliminação de Resíduos/métodos , Gerenciamento de Resíduos/métodos , Mudança Climática , Conservação dos Recursos Naturais , República da Geórgia , Eliminação de Resíduos/economia , Gerenciamento de Resíduos/economiaRESUMO
As circumstances of operating and maintenance activities for landfilling and composting in Tehran metropolis differ from those of cities in developed countries, it was concluded to have an environmental impact comparison between the current solid waste management (MSW) strategies: (1) landfill, and (2) composting plus landfill. Life cycle assessment (LCA) was used to compare these scenarios for MSW in Tehran, Iran. The Eco-Indicator 99 is applied as an impact assessment method considering surplus energy, climate change, acidification, respiratory effect, carcinogenesis, ecotoxicity and ozone layer depletion points of aspects. One ton of municipal solid waste of Tehran was selected as the functional unit. According to the comparisons, the composting plus landfill scenario causes less damage to human health in comparison to landfill scenario. However, its damages to both mineral and fossil resources as well as ecosystem quality are higher than the landfill scenario. Thus, the composting plus landfill scenario had a higher environmental impact than landfill scenario. However, an integrated waste management will ultimately be the most efficient approach in terms of both environmental and economic benefits. In this paper, a cost evaluation shows that the unit cost per ton of waste for the scenarios is 15.28 and 26.40 US$, respectively. Results show landfill scenario as the preferable option both in environmental and economic aspects for Tehran in the current situation.
Assuntos
Gerenciamento de Resíduos/métodos , Resíduos/análise , Poluentes Atmosféricos/análise , Conservação dos Recursos Naturais , Monitoramento Ambiental , Irã (Geográfico) , Meios de Transporte/estatística & dados numéricos , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/estatística & dados numéricos , Resíduos/estatística & dados numéricos , Poluentes Químicos da Água/análiseRESUMO
Effects of powdered activated carbon (PAC) dosing on the overall performance of membrane bioreactors (MBR) were investigated in two bench-scale submerged MBRs. Positive impacts of PAC dosing on membrane fouling and the removal of 17beta-estradiol (E2) and 17alpha-ethyinylestradiol (EE2) were demonstrated over a six-month stable operational period. PAC dosing in the MBR increased the removal rates of E2 and EE2 by 3.4% and 15.8%, respectively. The average soluble extracellular polymeric substances (EPS) and colloidal total organic carbon (TOC) concentrations in the PAC-MBR sludge was 60.1% and 61.8% lower than the control MBR sludge, respectively. Lower soluble EPS and colloidal TOC concentrations in the PAC-MBR sludge resulted in a slower rate of trans-membrane pressure (TMP) increase during MBRs operation, which could prolong the lifespan of membranes. Cost assessment showed that PAC dosing could reduce the operating cost for membrane cleaning and/or membrane replacement by about 25%. The operating cost for PAC dosing could be offset by the benefit from its reducing the cost for membrane maintenance.