Environmental assessment of different management options for individual waste fractions by means of life-cycle assessment modelling

Several alternatives exist for handling of individual waste fractions, including recycling, incineration and landfilling. From an environmental point of view, the latter is commonly considered as the least desirable option. Many studies based on life-cycle assessment (LCA) highlight the environmental benefits offered by incineration and especially by recycling. However, the landfilling option is often approached unjustly in these studies, maybe disregarding the remarkable technological improvements that landfills have undergone in the last decades in many parts of the world.This study, by means of LCA-modelling, aims at comparing the environmental performance of three major management options (landfilling, recycling and incineration or composting) for a number of individual waste fractions. The landfilling option is here approached comprehensively, accounting for all technical and environmental factors involved, including energy generation from landfill gas and storage of biogenic carbon. Leachate and gas emissions associated to each individual waste fraction have been estimated by means of a mathematical modelling. This approach towards landfilling emissions allows for a more precise quantification of the landfill impacts when comparing management options for selected waste fractions.Results from the life-cycle impact assessment (LCIA) show that the environmental performance estimated for landfilling with energy recovery of the fractions “organics” and “recyclable paper” is comparable with composting (for “organics”) and incineration (for “recyclable paper”). This however requires high degree of control over gas and leachate emissions, high gas collection efficiency and extensive gas utilization at the landfill. For the other waste fractions, recycling and incineration are favourable, although specific emissions of a variety of toxic compounds (VOCs, PAHs, NO_x, heavy metals, etc.) may significantly worsen their environmental performance.     

Introduction of a waste incineration tax: Effects on the Swedish waste flows

A tax on waste-to-energy incineration of fossil carbon in municipal solid waste from households was introduced in Sweden on July 1, 2006. The tax has led to higher incineration gate fees. One of the main purposes with the tax is to increase the incentive for recycling of materials, including biological treatment. We investigate whether and to what extent this effect can be expected. A spreadsheet model is developed in order to estimate the net marginal cost of alternative waste treatment methods, i.e., the marginal cost of alternative treatment minus avoided cost of incineration. The value of the households’ time needed for source separation is discussed and included. The model includes the nine largest fractions, totalling 85% (weight), of the household waste currently being sent to waste incineration: food waste, newsprint, paper packaging, soft and hard plastic packaging, diapers, yard waste, other paper waste, and non-combustible waste. Our results indicate that the incineration tax will have the largest effect on biological treatment of kitchen and garden waste, which may increase by 9%. The consequences of an incineration tax depend on: (a) the level of the tax, (b) whether the tax is based on an assumed average Swedish fossil carbon content or on the measured carbon content in each incineration plant, (c) institutional factors such as the cooperation between waste incinerators, and (d) technological factors such as the availability of central sorting of waste or techniques for measurement of fossil carbon in exhaust gases, etc. Information turns out to be a key factor in transferring the governing force of the tax to the households as well improving the households’ attitudes towards material recycling.     

Industry Response to the Challenge of Sustainability: The Case of the Canadian Nonferrous Mining Sector

/ The paper investigates how the Canadian nonferrous sector is tackling the challenge of sustainable development. Although there is no consensus as to what sustainable development means in practice for management in the sector, at least three dimensions must be taken into account: (1) metals are recyclable, the availability of this resource is not a concern for the foreseeable future; (2) the need to minimize environmental impacts of metals exploration, extraction, transformation, consumption, and recycling; and (3) production activities should not be socially or culturally disruptive. The nonferrous mining industry faces several environmental problems. Some of the most significant are acid mine drainage, sulfur emissions, recycling, and metals toxicity. The industry has developed a number of responses to address these specific concerns as well as other more general challenges. Six strategies are described and analyzed: (1) research and development, (2) an effort of consensus building among stakeholders known as the Whitehorse Mining Initiative, (3) international networking, (4) active involvement in the development of environmental management standards, (5) management reorganization and (6) voluntary agreements. The importance of external factors in the shaping of corporate environmental management practices is discussed, in particular the role of government. Progress has been achieved in three areas: (1) managerial practices and organization, (2) reducing the impacts of ongoing operations and (3) minimizing future liabilities, but two significant fields of conflict remain, namely mining in wilderness areas and projects on aboriginal lands.KEY WORDS: Canada; Environmental management; Minerals industry; Nonferrous metals; Sustainable development; Whitehorse Mining Initiative     

Life cycle assessment of waste paper management: The importance of technology data and system boundaries in assessing recycling and incineration

The significance of technical data, as well as the significance of system boundary choices, when modelling the environmental impact from recycling and incineration of waste paper has been studied by a life cycle assessment focusing on global warming potentials. The consequence of choosing a specific set of data for the reprocessing technology, the virgin paper manufacturing technology and the incineration technology, as well as the importance of the recycling rate was studied. Furthermore, the system was expanded to include forestry and to include fossil fuel energy substitution from saved biomass, in order to study the importance of the system boundary choices. For recycling, the choice of virgin paper manufacturing data is most important, but the results show that also the impacts from the reprocessing technologies fluctuate greatly. For the overall results the choice of the technology data is of importance when comparing recycling including virgin paper substitution with incineration including energy substitution. Combining an environmentally high or low performing recycling technology with an environmentally high or low performing incineration technology can give quite different results. The modelling showed that recycling of paper, from a life cycle point of view, is environmentally equal or better than incineration with energy recovery only when the recycling technology is at a high environmental performance level. However, the modelling also showed that expanding the system to include substitution of fossil fuel energy by production of energy from the saved biomass associated with recycling will give a completely different result. In this case recycling is always more beneficial than incineration, thus increased recycling is desirable. Expanding the system to include forestry was shown to have a minor effect on the results. As assessments are often performed with a set choice of data and a set recycling rate, it is questionable how useful the results from this kind of LCA are for a policy maker. The high significance of the system boundary choices stresses the importance of scientific discussion on how to best address system analysis of recycling, for paper and other recyclable materials.     

Life cycle assessment of waste paper management: The importance of technology data and system boundaries in assessing recycling and incineration

The significance of technical data, as well as the significance of system boundary choices, when modelling the environmental impact from recycling and incineration of waste paper has been studied by a life cycle assessment focusing on global warming potentials. The consequence of choosing a specific set of data for the reprocessing technology, the virgin paper manufacturing technology and the incineration technology, as well as the importance of the recycling rate was studied. Furthermore, the system was expanded to include forestry and to include fossil fuel energy substitution from saved biomass, in order to study the importance of the system boundary choices. For recycling, the choice of virgin paper manufacturing data is most important, but the results show that also the impacts from the reprocessing technologies fluctuate greatly. For the overall results the choice of the technology data is of importance when comparing recycling including virgin paper substitution with incineration including energy substitution. Combining an environmentally high or low performing recycling technology with an environmentally high or low performing incineration technology can give quite different results. The modelling showed that recycling of paper, from a life cycle point of view, is environmentally equal or better than incineration with energy recovery only when the recycling technology is at a high environmental performance level. However, the modelling also showed that expanding the system to include substitution of fossil fuel energy by production of energy from the saved biomass associated with recycling will give a completely different result. In this case recycling is always more beneficial than incineration, thus increased recycling is desirable. Expanding the system to include forestry was shown to have a minor effect on the results. As assessments are often performed with a set choice of data and a set recycling rate, it is questionable how useful the results from this kind of LCA are for a policy maker. The high significance of the system boundary choices stresses the importance of scientific discussion on how to best address system analysis of recycling, for paper and other recyclable materials.     

Euro-trash: searching Europe for a more sustainable approach to waste management

How an economically affordable, environmentally effective and socially acceptable municipal solid waste management system can be developed is currently unclear. Considerable research has been carried out on the practical aspects of municipal waste management (i.e. transport, treatment and disposal) and how citizens feel about source separation, recycling, incineration and landfill but the perspective of the waste manager within the context of long term planning is often ignored. In this study, waste managers from 11 different leading-edge European municipal solid waste programs in nine different countries were interviewed. The economic, social, political, environmental, legal and technical factors of their specific programs were explored and analyzed. The transition of municipal solid waste management to urban resources management was observed and key ‘system drivers’ for more sustainable waste management practices were identified. Programs visited were: Brescia (I), Copenhagen (DK), Hampshire (UK), Helsinki (FI), Lahn-Dill-Kreis (D), Malmö (SE), Pamplona (E), Prato (I), Saarbrücken (D), Vienna (A), and Zürich (CH).     

Assessing environmental impacts of municipal solid waste of Johor by analytical hierarchy process

The views of the public on solid waste bound to be generated in Johor Bahru Malaysia are presented and appraised. This is because of the massive development currently going on to transform the city to an international standing by the year 2025. For this reason, attempts to raise stakeholder awareness on the need to embrace on how best to manage the current problem with reduced impacts to the environment currently and in the future was attempted. Data were collected through contacts and questionnaire survey. Analytical hierarchy process (AHP) technique was used to structure and assess the views and judgments of stakeholders on the environmental impacts of solid waste disposal. SuperDecision software was used to generate and compute results of stakeholder's judgments. The assessment revealed that fauna and flora, habitat depletion and land use among the criteria are most critical environmental impacts. Landfilling, recycling, incineration and composting were evaluated in terms of the environmental impacts. The choice of incineration is perceived to improve environmental visibility, preserves fauna and flora as well as stream ecology, improves environmental air quality and optimizes land use. Similarly, recycling of waste, is perceived to preserves fauna and flora, stream ecology, habitat depletion, improves air quality as well as land use. Composting is perceived to be the best option in terms of preservation of stream ecology, habitat depletion and land use practice. Landfill generates less noise and vibration but found to be responsible for more than 50% of the environmental impacts created by solid waste in this area. Composting and recycling are mostly preferred to landfilling and incineration and the reason why this is so was provided. The study also identified challenges ahead and highlights that benefits attached to some vital disposal options (such as incineration) are yet to be fully implemented.     

Convenience improves composting and recycling rates in high-density residential buildings

Increasing volumes of solid waste, implicated in environmental pollution and health problems, are central to the current environmental crisis. In two randomized field experiments, we demonstrate that convenience dramatically boosts recycling and composting rates in multi-family dwellings and university residences. When compost bins were placed on each floor in a multi-family residence, instead of on the ground floor, composting rates increased by 70%, diverting 27 kilograms of compost from the landfill per unit per year. When recycling stations were placed just meters from suites in student residences, instead of in the basement, recycling increased by 147% (container), and 137% (paper), and composting increased by 139%, diverting 23, 22, and 14 kilograms of containers, paper, and compost, respectively, from the landfill per person per year. Simply making recycling and composting convenient can significantly increase waste diversion, and as such this single intervention has important implications for waste management and environmental policy.     

垃圾填埋气收集利用研究进展

城市生活垃圾填埋过程中伴随产生大量填埋气,造成的环境影响不容忽视,填埋气中的CH4具有很高热值,是可利用的再生能源.对我国垃圾填埋气的特点、常见收集方式、焚烧发电利用现状进行了综述和分析,并探讨了未来的发展方向.     

Energy and CO2 from high performance recycled aggregate production

The use of recycled concrete aggregates (RCA) in applications other than road sub-layers is limited by two factors: the high porosity of RCA in comparison with natural aggregates, and the restrictions set forth in standards and building codes. Research efforts aimed at alleviating these restrictions are focused on improving the quality of coarse RCAs by reducing the amount of adhered cement pastes, which is the weakest element in this system and influences the rheological behaviour.This paper presents an analysis of the environmental impacts of the recent mechanical and thermo-mechanical processing techniques which produce high performance RCA by reducing the volume of adhered cement paste. Based on published data, processing scenarios were established. These scenarios permit making rough estimates of energy consumption, CO₂ emissions, fines generation and product quality. Using these data and the available emission factors from several countries, an objective comparison was made between these innovating processes and conventional recycling.The production of fines increases from 40% up to as much as 70% as the volume of adhered cement paste on the RCA is reduced. Fuel fed thermo-mechanical process energy consumption, per tonne of recycled aggregate, varies between 36 and 62 times higher than conventional recycling processes. Mechanical processing, combined with microwave heating, increases energy consumption from 3 to a little more than 4 times conventional recycling. Consequently, CO₂ emissions released by conventional coarse aggregate production go from 1.5 to 4.5 kgCO₂/t, to around 200 kgCO₂/t, for that of fossil fuel fed thermo-mechanical treatments.Mechanical and mechanical/microwave treatments appear to have the greatest environmental potential. Notwithstanding, the further development of markets for fines is crucial for reducing environmental loads.     

Solid waste management in urban areas: Development and application of a decision support system

A decision support system (DSS) developed to assist the planner in decisions concerning the overall management of solid waste at a municipal scale is described. The DSS allows to plan the optimal number of landfills and treatment plants, and to determine the optimal quantities and the characteristics of the refuse that has to be sent to treatment plants, to landfills and to recycling. The application of the DSS is based on the solution of a constrained non-linear optimization problem. Various classes of constraints have been introduced in the problem formulation, taking into account the regulations about the minimum requirements for recycling, incineration process requirements, sanitary landfill conservation, and mass balance. The cost function to be minimized includes recycling, transportation and maintenance costs. The DSS has been tested on the municipality of Genova, Italy, and the results obtained are presented.     

Life cycle assessment of biofibres replacing glass fibres as reinforcement in plastics

This article aims to determine the environmental performance of China reed fibre used as a substitute for glass fibre as reinforcement in plastics and to identify key environmental parameters. A life cycle assessment (LCA) is performed on these two materials for an application to plastic transport pallets. Transport pallets reinforced with China reed fibre prove to be ecologically advantageous if they have a minimal lifetime of 3 years compared with the 5-year lifetime of the conventional pallet. The energy consumption and other environmental impacts are strongly reduced by the use of raw renewable fibres, due to three important factors: (a) the substitution of glass fibre production by the natural fibre production; (b) the indirect reduction in the use of polypropylene linked to the higher proportion of China reed fibre used and (c) the reduced pallet weight, which reduces fuel consumption during transport. Considering the whole life cycle, the polypropylene production process and the transport cause the strongest environmental impacts during the use phase of the life cycle. Since thermoplastic composites are hardly biodegradable, incineration has to be preferred to discharge on landfills at the end of its useful life cycle. The potential advantages of the renewable fibres will be effective only if a purer fibre extraction is obtained to ensure an optimal material stiffness, a topic for further research. China reed biofibres are finally compared with other usages of biomass, biomaterials, in general, can enable a three to ten times more efficient valorisation of biomass than mere heat production or biofuels for transport.     

Future solutions for the treatment and disposal of hazardous wastes in China

The current status of the treatment and disposal of hazardous wastes in China is summarized on the basis of the results of the Declaring and Registration Project initiated nationally in 1995. A principle framework for the sound management of hazardous wastes is proposed, which includes three levels of technical solutions. Large-scale enterprises are encouraged to recycle, to treat, and to dispose of wastes by means of constructing facilities, and to have their extra capacities available to the public for a reasonable fee. Municipal governments, provincial governments, and the Central Government are to plan and construct centralized facilities to recycle, treat, and dispose of wastes. For a solution at the manufacturing level, recycling is identified as the main approach. Centralized facilities at the municipal level will mainly focus on special wastes that are unsuitable to transport and store, such as hospital waste, and for the technical solution at this level, incineration and recycling are identified as the main approaches. For the technical solution at the provincial and national levels, landfill and incineration are identified as the main approaches. Based on this principle and the current available data on hazardous wastes, a preliminary plan for the spatial distribution of cross-provincial centralized treatment and disposal facilities of hazardous wastes is presented. The construction of approximately nine cross-provincial comprehensive facilities is proposed. A priority list for the construction of these planned facilities is also presented.     

Management of old landfills by utilizing forest and energy industry waste flows

The lack of landfill capacity, forthcoming EU waste disposal and landfill management legislation and the use of non-renewable and energy intensive natural resources for the end-treatment of old landfills increase pressures to develop new landfill management methods. This paper considers a method for the end-management of old landfills in Finland, which is based on the utilization of forest and paper industry waste flows, wastes from paper recycling (de-inking) and wastes from forest industry energy production. Fibre clay wastes from paper mills, de-inking sludges from de-inking of recovered waste paper and incineration ash from forest industry power plants serve to substitute the use of natural clay for the building of landfill structures for closed landfills. Arguably, this method is preferable to existing practices of natural clay use for landfill building, because it (1) substitutes non-renewable natural clay, (2) consumes less energy and generates less CO2 emissions than the use of natural clay, and (3) eliminates considerable amounts of wastes from paper production, paper consumption and from forest industry energy production. Some difficulties in the application of the method are considered and the waste flow utilization is incorporated into a local forest industry recycling network.     

Life cycle inventory of recycling portable nickel–cadmium batteries

In this study, the environmental impact of recycling portable nickel–cadmium (NiCd) batteries in Sweden is evaluated. A life cycle assessment approach was used to identify life cycle activities with significant impact, the influence of different recycling rates and different time boundaries for emissions of landfilled metals. Excluding the user phase of the battery, 65% of the primary energy is used in the manufacture of batteries while 32% is used in the production of raw materials. Metal emissions from batteries to water originate (96–98%) from landfilling and incineration. The transportation distance for the collection of batteries has no significant influence on energy use and emissions. Batteries manufactured with recycled nickel and cadmium instead of virgin metals have 16% lower primary energy use. Recycled cadmium and nickel metal require 46 and 75% less primary energy, respectively, compared with extraction and refining of virgin metal. Considering an infinite time perspective, the potential metal emissions are 300–400 times greater than during the initial 100 years. From an environmental perspective, the optimum recycling rate for NiCd batteries tends to be close to 100%. It may be difficult to introduce effective incitements to increase the battery collection rate. Cadmium should be used in products that are likely to be collected at the end of their life, otherwise collection and subsequent safe storage in concentrated form seems to offer the best solution to avoid dissipative losses.     

A disclosure of social and environmental results/economy resulting from the implementation of reverse logistics and final disposal of the post‐consumption product: The case of computer peripherals industry

This research was conducted with the objective of determining and evidencing the social and environmental/economic results from the implementation of a reverse logistics program providing for the recycling, reuse, and, when necessary, final, environmentally correct disposal of post‐consumption products and product wastes by a multinational manufacturer of computer peripherals with an operation based in the city of São Paulo, Brazil. The reverse logistics process (logisticareversa, or, in this paper, LR) was intended to meet the objectives and principles of the regulatory framework defined in the National Solid Waste Policy (PNRS) in Brazil. A single case study was carried out. The results showed that after the adoption of the solid waste management policy, the study company no longer disposed of 1,413,552 kilograms (kg) of materials classified as mixed iron, polystyrene, cardboard, toner powder, and plastic in landfills. The LR process made a profit in two companies: the company surveyed made, in Brazilian reais (R), R$ 9,188,185.51, and the company contracted to carry out the process made, R$ 411,325.97. This latter profit is called by us the “social profit.” The measurement of the environmental/economic, social, and financial results by internalizing the expenses of the LR program into the costs of production shows that reuse and recycling better meets the needs of society and the company than landfilling these post‐consumption materials. Furthermore, the use of cost accounting allows the verification of other goals not indicated in the current model, such as the generation of employment, income, mitigation of environmental problems, and the profit earned by the company contracted to implement the LR process. We also conclude that cost accounting makes it possible to obtain necessary information for decision makers, who are seeking to neutralize environmental impacts and promote sustainable development, thus harmonizing the economic, social, and environmental aspects, to understand the impacts of the LR process.     

Environmental life cycle assessment of different types of the municipal wastewater pipeline network

With the onset of social life, humans have considered waste disposal as essential, and they have been able to repel it through brick and clay channels. Checking sewage pipes for energy consumption and a longer lifetime than other sewage system components is important. Climate change and exploitation of industrial resources have made environmental impacts, which are important factors in decision making. The purpose of this study was to introduce the most suitable type of sewage pipe considering environmental protection. Therefore, we applied the environmental life cycle assessment (LCA) method, using Sima Pro 8.2.3 software for the one-kilometer length of concrete pipes (300 mm in diameter), Polyvinyl chloride (PVC), and polyethylene (PE) (315 mm in diameter). Also, the BEES method and sensitivity analysis were used to validate the results. The comparison between three types of municipal wastewater pipes indicated that PE pipes are a more environmentally friendly option than PVC, and concrete pipes in pipe recycling, reducing extraction from untapped resources, and inefficient extraction of resources. Electricity, diesel fuel, and sulfate resistance cement consumption for concrete production are the most pollution elements in the LCA of concrete pipes. Usage of PVC granular, sanitary landfill of PVC pipes, and using hydraulic drill in LCA of PVC pipes are the most elements of generating pollution. The usage of PE granules, PE pipes landfilling, hydraulic excavator, and electricity consumption in the LCA of the PE pipes are the greatest polluting parameters.     

The impacts of anthropogenic factors on the environment in Nigeria

Generally speaking, there has been a consensus on the primary drivers of anthropogenic induced environmental degradation. However, little progress has been made in determining the magnitude of the impacts, particularly in developing countries. This creates a lacuna that needs to be filled up. The purpose of this study therefore is to ascertain the degree of anthropogenic induced environmental impacts in Nigeria. To achieve the aim, fossil fuel consumption was used as a surrogate for carbon dioxide emissions while the magnitude of the impacts was determined by regression statistics and the STIRPAT model. The results show that only three variables, namely population, affluence and urbanization, were statistically significant and that the regression model accounts for 60% of the variation in the environmental impacts. However, population and affluence, which have ecological elasticities of 1.699 and 2.709, respectively, are the most important anthropogenic drivers of environmental impacts in Nigeria while urbanization, with an elasticity of -0.570, reduces the effect of the impacts. This implies that modernization brings about a reduction in environmental impacts. The paper therefore makes a significant contribution to knowledge by successfully testing the STIRPAT model in this part of the world and by being the first application of the model at political units below the regional or nation states.     

Botswana's environmental policy on recycling

Recycling operations have become one of the primary strategies for waste management, worldwide. Especially, recycling operations are viewed as among the most effective techniques for reducing the amount of municipal solid waste disposed at landfill sites. Botswana's environmental policy on recycling stipulates, among others, that all waste management authorities should provide information on the classification and quantities of controlled waste targeted for recycling. This paper, therefore, examines the extent to which recycling operations in Botswana have either been conducted in compliance with or in violation of some major environmental requirements as enunciated on statutory guidelines. Compatibility between environmental policies on recycling and actual practice is evaluated focusing on two companies (Dumatau trading and Botswana Tissue) involved in recycling operation. Data from the two companies is complemented by one collected from the Gaborone landfill site. Finally, this study discusses on the role played by various stakeholders in policy formulation and implementation with particular emphasis being placed on a select number of non-governmental organisations (NGO).