Mid Sweden University

A previously described model for the evaluation of sustainability in waste management has been expanded and applied to biodegradable and other combustible household waste. The model was applied to a case-study focusing on the special conditions in a municipality in the sparsely populated region of northern Sweden. In this region it is usual that the collection distances are long, the volume of waste is low and treatment facilities are remote. Four scenarios for the management of municipal household waste were compared: incineration, anaerobic digestion, composting and landfilling. A system analysis was performed to ensure that each scenario fulfil all the functions that the waste could provide (heat, electricity, fuel, and soil with a high nutrient content) and a sensitivity analysis was carried out to test the reliability of the results. The results show that the evaluation model can be used to assess the sustainability aspects of different treatment scenarios for combustible household waste. The model also allows for an individual interpretation of the results presented, depending on the choice of priorities. The effects of varying the time horizons and the difference in impact depending on what fuels are ultimately replaced in energy production are discussed.

During the last decade, systems analysis has become a more frequentlyused tool in municipal waste management. Thispaper investigates how one such analysis, carried out in a Swedish county, was perceived by local municipalofficers and politicians as support in the decision-makingprocess. A questionnaire was sent to municipal officers and politicians in local government committees andmunicipal councils. The respondents consideredthe most important aspects in evaluating scenarios to be: possibilities for municipal co-operation to minimizecost and negative environmental influence; soundworking conditions for refuse disposal personnel; low emissionsof greenhouse gases; keeping household economyin mind; and using technologies that are knownand reliable. Aspects of relatively low importance were thenumber of locally generated job opportunities,and minimizing work efforts for the households. The study also showed differences between male and femalerespondents and between politicians and municipalofficers, on how scenarios were valued and on which aspects of the systems analysis were of greatest importancefor this valuation. Respondents, on average,were satisfied with the systems analysis, and its usefulness as a decision-support tool. However, more workshould be carried out to explain and presentthe results of the systems analysis to further improve its usefulness.

Emergy analysis and socio-ecological principles were used for sustainability assessment in a wastewater treatment case study. A constructed model of a microalgae wastewater treatment plant (ALGA), assumed located in Sweden at latitude 60°N, was tested by comparing it to a conventional three-step treatment plant (WWTP), and a mechanical and chemical treatment plant complemented with a constructed wetland (TP+CW). Based on the results from the two assessment methods the ALGA model were considered having a better position for sustainable development, than the other two. In emergy terms the ALGA model had about half the resource use of the other two alternatives, the highest relative use of local free environmental resources, and the best emergy sustainability index (ESI). The violation against the 2nd and 3rd socio-ecological principles were considered equal for the three alternatives. The 4th was estimated to be in favour of the ALGA model, and the 1st principle was calculated to be in favour of the ALGA model with about 8 times lower indicator value. This paper focus on the methods used in the case study. The performance of the methods is compared, including a discussion on how they relate to the concept of sustainability. The two methods were developed from very different starting points, and use different assessment parameters. Regardless of this, the ranking of different options comes out identically, indicating that both methods are equally useful for assessments of sustainability in the studied system.

Dealing with waste is a major issue in our endeavour to create a sustainable society. The purpose of this thesis is to develop a model for assessing sustainable development in waste management systems. The model should provide a valid, reliable, useful and efficient assessment tool for waste management planners. The objective has been to improve methodologies that can support decision-making processes for sustainable waste management. The study is based on a series of case studies in which suitable indicators of sustainability aspects for different types of waste have been developed and incorporated into a model that can be used to assess the potential for sustainable development of waste management systems. Some important methodological conclusions can be drawn

The sustainability of a microalgae wastewater treatment plant model (ALGA), assumed serving a small Swedish town with 10,000 inhabitants at latitude 60°N, was tested by comparing it to a conventional three-step treatment plant (WWTP), and a mechanical and chemical treatment plant (TP) complemented with a constructed wetland (TP + CW). Using two assessment methods—the socio-ecological principles method and emergy analysis—the ALGA model considered to have a better position for sustainable development, than the other two. In emergy terms the ALGA model had about half the resource use of the other two alternatives, and used most local free environmental resources, four times the TP + CW, and 100 times the WWTP. The violations against the second and third socio-ecological principles were considered equal for the three alternatives, the fourth was estimated to be in favor of the ALGA model, and the first principle was calculated to be in favor of the ALGA model with about eight times lower indicator value sum. Recirculation of nutrients back to society or production of economically viable products from the treatment by-products would strongly influence the sustainability. The ALGA model has a potential advantage due to interesting biochemical contents in the microalgae biomass, depending on what species will become dominating.

A model is presented for evaluating waste management systems for their contribution to a sustainable development, including environmental, economic and social aspects. The model was tested in a case-study, where groups of long term unemployed people were offered both education on environmental issues and practical work with the recovery and recycling of building and demolition waste as a form of vocational development. Application of the suggested model revealed the overall effects on sustainability of different methods of waste management. In addition, negative aspects of the systems analysed were identified, which led to discussions about possible improved practices within the waste management systems. Two of the waste management systems investigated (the recycling of steel and re-use of sanitary porcelain) showed a potential contribution to sustainable development in all of the aspects studied. Preparing bricks for re-use showed the largest potential for eco-efficiency, but had negative effects on sustainability from the social perspective of health and the working environment. The possibility of further use of the model and the remaining obstacles to such analyses are discussed. One observation is that the data collection needed to perform this kind of sustainability analysis is resource-demanding, and that it would therefore be better to identify a smaller number of key indicators.