Introduction

Resource recovery from waste is one of the primary objectives of waste management systems in developed countries like Sweden. Waste-to-energy technology such as incineration has been implemented in Sweden for managing municipal solid waste for many decades. The first incineration plant for waste was built at Lövsta in Sweden in 1901 (RVF 1999). Incineration of waste is now in advance development stage in the context of technological efficiency. However, advanced waste management systems like incineration have various environmental and socio-economic problems. Due to the development of awareness on environmental pollution and various consequences of climate change, a sustainable waste management system is required and comparatively difficult to achieve for every country. Municipal solid waste (MSW) includes household waste, and wastes from commercial office, business centre and normal industrial waste which is generally managed by local municipal authority. The biological treatment of waste parallel to waste incineration is implemented widely in Sweden, playing a vital role in the countries’ overall waste management strategy. Biological treatment of organic waste (35 % of all organic household waste) is mandatory and a part of Swedish national environmental objectives (SEPA 2007). Treatment of solid waste continues to be a topic on the environmental agenda (Formas 2004) and now has a place also on the political agenda (Finnveden et al. 2007). Today’s consumption-driven society produces an enormous amount of waste. The large volume of waste puts a huge pressure on the waste management sector. Moreover, waste management systems include socio-economic, political, environmental and technological considerations and have many stakeholders. All these points of view are inter-related and dynamic in nature. Therefore, waste management systems create a complex cluster of different aspects, and functions of this complex cluster are also dynamic and interdependent. Global climate change and its various effects on human life drive current society toward a more sustainable society. There is very little analysis data available on the interdependent of the social, economic and environmental demands on waste management systems. This study aims to identify the important drivers of waste management systems in Sweden and tries to understand the development trends in the Swedish context. Taking into consideration of social, economic and environmental aspects, the study will also outline the emerging waste treatment technologies for Sweden. The paper will also attempt to explain interrelationship of different drivers in waste management systems in Sweden.

Materials and methods

The study was done using three research methods: literature study, questionnaire survey and analysis of the case studies of waste management systems in Sweden. A number of waste management research studies were analysed to identify the key development drivers in the waste management sectors in Sweden. Waste management development drivers are analysed within social, economic and environmental parameters. Literature studies include waste management books, research papers, peer reviewed journal publications, reports from business organizations and online resources. The questionnaire survey gathered responses from 39 selected waste management professionals from various sectors including academia, business organizations and local government bodies in Sweden. Questionnaire survey was conducted by email. Three survey questions were sent to the waste management professionals seeking their opinions on the key factors in the current Swedish waste management systems and possible future development. Box 1 shows the sample for the questionnaire survey.

Box 1: Questionnaire for experts’ survey

Question 1: In your opinion, what are the key factors (drivers) for developing waste treatment technologies in Sweden?

Question 2: What are the most challenging factors in sustainable waste management systems in Sweden?

Question 3: Do you recommend any emerging (new or developing) technology for Sweden which can be implemented in future for sustainable waste management systems?

The research also includes review of a case study of exiting waste management systems in Sweden. Potential emerging technologies have been identified through the research based on key criteria’s process type of the technology, handling capacity of the waste category, potential contamination methods, technological development stage and data availability of the technology. Figure 1 shows the selected key criteria used for examining the potential waste treatment technologies in Sweden.

Fig. 1
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Key criteria for analysing emerging technologies

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The study analysed municipal solid waste treatment technology in Sweden. Potential emerging technologies in Sweden, are analysed based on following criteria,

  • Process type (biological, mechanical biological, thermal, thermo-chemical, hybrid, etc.).

  • Waste categories (organic, inorganic, paper, mixed MSW etc.).

  • Contamination medium (air, water, soil or multiple)

  • Development stage of the technology (laboratory scale, pilot scale, large pilot scale, mature and advanced)

  • Data availability and reliability (very limited, limited or available)

Finally, selected potential emerging waste treatment technologies were analysed based on SWOT (SWOT: strength, weakness, opportunity and cost) analysis and the technologies evaluated by a qualitative evaluation method based on waste handling capacity, development stage and waste management problem solving capacity.

Previous studies

Several studies were analysed to understand waste management systems in Sweden including (Sundberg et al. 1994; Hartlén 1996; Björklund et al. 1999; Björklund 2000; Eriksson et al. 2002; Avfall Sverige 2008; Dahlén and Lagerkvist 2010). Global waste management development trends were analysed based on the reference studies of (Larsen and Børrild 1991; Sakai et al. 1996; Bhide and Shekdar 1998; Contreras et al. 2006; Tanaka 2007; UN-HABITAT 2008; Khetriwal et al. 2009; Miliute and Plepys 2009; UN-HABITAT 2010; Bernstad and la Cour Jansen 2011). Key findings from these studies are:

  • Development of waste management systems is dependent on social, political, economic and environmental issues.

  • Development of waste management systems is also dependent on geographical location, social practices and behaviour changes.

  • Waste treatment technologies are developed and applied to manage waste problems depending on local waste management facilities.

  • Waste management development drivers are inter-connected and dynamic in nature; therefore, the actual influence of an individual driver may not be seen in dynamic waste management development trends. For example regulations can influence the development of certain waste treatment technologies.

Waste management scenario in Sweden

Sweden is one of the European Union (EU) member countries; therefore, waste management systems in Sweden are influenced by socio-economic and political decisions made and applied other EU countries. The EU commission acts as the leading driver for waste management regulations and systems within EU countries. In addition, Sweden is also prominent in adopting and applying environmental rules and regulations in the waste management sector. From the early 1960s, landfill was widely used to dispose of waste in Sweden (Miliute and Plepys 2009). This later led to several environmental problems due to lack of advanced pollution control facilities and efficient waste management systems. As a result, an environmental protection act was espoused in the late 1960s. Later in 1970s, resource value of waste was acknowledged and recycling of cans was introduced in the 1980s and a new production design of beverage containers (SJV 2005) was gaining importance at that time. In the mid-1990s Sweden introduced better waste management systems following the EU packaging directive (94/62/EC) (EU Directive 1994) and later in 2000 extended producer responsibility was introduced. These regulations and innovative packaging systems have increased the recycling rate of beverage cans. Some of these recyclable cans have economic value for example, by returning the PET bottle, one can get money back. Therefore, this economic value of waste bottles is favourable to the collection systems. Incineration is the foremost waste treatment technology in Sweden. Air emissions primarily SOx, NOx and dioxin were the leading polluters in the twentieth century in Sweden. Due to the development of public environmental awareness in global climate change which also leads to the urgency of developing EU waste incineration directive (2000/76/EC) for standard emissions into the atmosphere, seeking for an efficient and sustainable waste management systems is important. Later, the landfill directive (2001:512) was introduced banning certain categories of waste from landfill. Those wastes are managed by other waste treatment technologies such as biological treatment, combustible waste by Incineration and so on. Avfall Sverige is the waste management organization which works as a part of local authority and mainly responsible for sustainable waste management systems in Sweden. According to the Avfall Sverige, Swedish waste management goal is to maximize environmental and social benefits by prioritizing a waste hierarchy. The most important treatment methods applied for waste are: material recycling, biological treatment, waste-to-energy and landfill (Avfall Sverige 2010). In 2009, household waste volumes (4,731,660 tons, or 511.2 kg per person) decreased by close to 5 % compared to the year before. 98.6 % of the household waste is recycled, only 1.4 % goes to landfill. The waste quantity that goes to landfill has decreased by 50 % compared to 2008 (Avfall Sverige 2010).

Results and discussion

Key drivers in waste management systems in Sweden

Waste management systems are dependent on socio-economic issues such as population growth and Gross Domestic Product (GDP) (EEA 2008; Mazzanti and Zoboli 2008). Both GDP and population number have relationship with consumption and the generation of waste. Collection of waste or management of waste is influenced by some other drivers like local practice and recycling. Miliute and Plepys (2009) identified two types (market driven and policy driven) of drivers for household waste recycling systems. Waste was seen as valueless with ‘no economic value’ (Ludwing et al. 2003) before oil crisis in 1970s; however, the view has been changed after the great global energy crisis. Now, waste has been treated as resources and source of energy. Another holistic study on waste management development drivers has been done by Wilson (2007). Six waste management development drivers are categorized by Wilson in his study; those are (1) public health, (2) environmental protection, (3) resource value of waste closing the loop, (4) institutional development, (5) responsible issues and (6) public awareness over the time. The study includes environmental issues with the social drivers. Waste treatment development drivers are categorized in three different broad sectors in this study such as social, economic and environmental. A summary of waste management development drivers is presented below in three sustainability categories such as social, economic and environmental.

Social drivers

Social indicators identified as potential drivers for technological development of the waste sector in Sweden, are population, the volume of waste generation, people behaviour, local waste management practices and the process of urbanization. Population and the volume of waste generation are vital for designing waste management systems. In recent studies, human behaviour and behavioural change have been identified as key drivers in waste management systems. Socio-political drivers such as local and international rules and regulations are also important in the development of waste treatment technology. Regulations have been acting as a supporting tool for promoting, developing or restricting a system. Landfill was conventional waste management systems in Sweden until mid-1990s. However, later regulations were imposed to restrict the disposal of certain waste such as food waste and combustible waste into landfill in Sweden.

Economic drivers

A number of research studies show the relation of economic growth and waste management systems (EEA 2008; Mazzanti and Zoboli 2008). After shifting the perception of ‘no economic value’ of waste into the perception of waste as a resource; waste-to-energy technologies has been developed due to economic drivers. Economic benefits from waste management systems and resource recover from waste encourage technological development, incineration, anaerobic digestion for instance. Waste management systems require a huge amount of investment and labour to run the systems effectively. Therefore, economic benefits is always an issue while designing waste treatment technologies. Landfill tax and waste management treatment cost are also as key economic drivers for Sweden. On one hand, landfill tax has been restricted certain waste streams such as combustible waste and food waste dispose to landfill site in Sweden; energy has been recovered by incineration and anaerobic digestion treatment technologies from those diverted waste streams on the other hand.

Environmental drivers

Environmental drivers such as climate change and environmental awareness have been appeared after the 1990s when sustainability became an important factor for global sustainable development. Now in most of the development and urbanization processes socio-economic and environmental sustainability are the key criteria. Pollution from incineration of waste has been controlled and improved in Sweden due to the influences of environmental drivers. Local climate condition in Sweden is considered as important criteria for the development of incineration because of its facility for recovering energy and heat. As a ‘end of pipe’ solution, landfill and incineration without energy recovery facilities were predominantly applied in early the 1960s. Later in the global oil crisis of the 1970s and environmental awareness in the 1990s commercialization of the waste treatment technology has been started in Sweden. Development and implementation of anaerobic digestion of organic food in Sweden has reduced environmental pollution and recovered bio-fertilizer compared to landfill. Due to climate change and environmental pollution restriction on landfill in Sweden is becoming a reality. In 2009, Sweden only landfill 5 % of the total waste volume (CEWEP 2011). Some of the drivers are mutually inclusive to more than one category. For instant, waste characteristics (organic, combustible or recyclable) is one of the important factors for selecting waste treatment technology which can be considered as the socio-economic driver. Economical and technological efficiency and rules and regulations are also mutually inclusive with more that one driver. However, a simplified diagram of key waste treatment development drivers is presented in Fig. 2 and the diagram shows different drivers and their relationship in waste management systems.

Fig. 2
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Drivers in sustainable waste treatment technology development in Sweden

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Table 1 shows the key milestones in municipal solid waste management in Sweden. The Table shows the development of waste regulations and other important factors for waste generation and reduction in Sweden.

Table 1 Key milestones in waste generation and management in Sweden (1900–2009)
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Potential emerging waste treatment technologies in Sweden

The term ‘emerging’ technology used in this section refers to developing technology or a technology which will be developed in near future. An emerging technology may be cutting edge technology but not necessarily a new technology; it might be retrofitting of old technology. In this study emerging technologies are considered those technologies which have not been commercialized in Sweden yet. Therefore, traditional waste treatment technologies like incineration, landfill and composting have not been considered in the emerging technology list in Table 2). Every technology is required to be environmentally sustainable in current global climatic condition. Research and development of waste treatment technology has been conducted for more sustainable and efficient technologies. Even for very primitive technology such as landfill, sanitary landfill with less environmental impact and more resource recovery efficiency have been developed. Thermal waste treatment technologies have now been considered as the most efficient waste treatment options due to heat and energy recovery facilities. However, for long term sustainability, thermal waste treatments such as incineration have many limitations in the context of resource preservation and reuse. Biological treatment technologies are also important and have been widely implemented due to the fact that they generate least environmental pollution. However; only organic waste can be managed by biological treatment like anaerobic digestion. Individual technologies which can manage specific waste fraction are getting priority because of efficient waste management and resources recovery options. Therefore, individual technologies are required for the treatment of individual waste fraction like paper, glass, plastics, cans, organic waste, woods metals, e-waste and many other types of waste streams. Table 2 shows the key features of the emerging technologies for Sweden. Emerging technologies are analysed based on the development stage of the technology and waste management problem solving capacity. A qualitative analysis of the emerging technology has also been done and presented in Table 3. Based on SWOT analysis, technologies have been analysed in the context of potential strength, weakness, opportunity and threats. Different technologies have variety of waste streams handling capacity; however, most of the thermal waste treatment technologies can treat all type of waste fractions. Biodegradable waste fractions are handled by biological waste treatment technology. Therefore, some technologies require higher sorting efficiency for better performance and others can manage in lower sorting systems. Dry composting and anaerobic digestion have been identified as potential emerging technologies for Sweden to manage organic waste. Dry composting is mainly used to reduce the volume and weight and preparing organic or kitchen waste for the extended energy recovery from the biological processes. Pyrolysis-gasification of waste has been identified as a potential emerging waste-to-energy technology in Sweden. Plasma-arc and plasma-gasification have also been identified and analysed as potential emerging technologies in the waste sector.

Table 2 The key features of emerging waste management technologies
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Table 3 SWOT analysis of the emerging waste treatment technologies
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Conclusion

Waste management systems are involved with different multi-disciplinary factors; therefore, trends in the development of waste treatment technologies have been led by various social, economic and environmental drivers in Sweden. Identifying development drivers is important to understand, plan for design new system in the waste management sector. Society is very dynamic in nature; understanding the inter-relationship of different drivers are important for predicting and understanding the emerging waste treatment technologies. Dry composting, pyrolysis-gasification, plasma arc and anaerobic digestion have been identified as potential emerging waste treatment technologies in Sweden. However, the development of waste technologies also involves other externalities like shifting personal and social viewpoints on waste such as ‘waste’ to ‘resource’. Currently, a number of studies have been conducted by different researchers on the ‘zero waste’ (Zaman and Lehmann 2011) concept. Therefore, waste avoidance and reduction technology is considered to be the prime challenge rather than the development of new waste treatment technology.

Extended producer responsibility as well as consumer accountability are gaining importance since both are the key drivers for the development of sustainable waste management systems. Therefore, further studies could be done to explore possibilities of consumer accountability in consumption and generation of waste and in product stewardship and sustainable development.