Waste management has undergone many changes since the 1960s. These changes include a key role for political guidance, the development of the waste hierarchy as a strategic basis for waste management planning, a political definition of waste to cover all items and materials to be discarded, the use of advanced and new technologies, an increased interest of commercial companies for business opportunities and an enhanced status in terms of professional and industry status. Behind these changes there are many political, societal and scientific development patterns; such issues as an increased awareness of needs for environmental protection and better management of limited natural resources, rapid global population growth and urbanization, a necessity to support developing countries, an increasing transition towards consumerism societies based on global markets, new material and product innovations, and telecommunication development enabling the availability of information throughout the world.
Already in the 1970´s the most industrialized countries responded politically to these patterns by combining sanitation, environmental protection and mainly commercial and charity based existing recycling and reuse practices into the modern waste management. Particularly through UN processes modern waste management practices have become one of the key areas in targeting sustainability. Today, despite many achievements in waste management, there are still several challenges to be resolved. A major challenge is to integrate modern waste management as an integral aspect of material and energy flows management. Accordingly, there is an obvious need for advanced information management based on a coherent conceptual understanding of the systems we are dealing with. We need improved capability to identify the real ecological and social benefits which we are targeting through our management and engineering solutions. In particular, waste prevention, the top of the waste hierarchy, calls for a transparent identification of key players with their respective interests and operational limitations. The waste industry has an important role to support, facilitate and maybe even drive waste prevention activities.
Challenges to be faced
The global extraction of natural resources such as minerals, metals, biomass and fossil energy carriers, is steadily increasing showing a near exponential growth. As shown in Figure 1 the increase from 1980 to 2007 (i.e. 27 a) was only 62 % (from 38 to 62·109 t). However, in the period from 2007 to 2010 (i.e. only 3 a) the increase accounted for 32 % (from 62 to 81·109 t) even if the time was only one tenth. By 2030 it is expected that the amount of global extraction will be more than doubled (from 62 to 130·109 t) compared to 2007 or range at 2.4 times compared to 1980. Parallel to the distinct increase in global extraction the share of various regions is significantly altering. Figure 2 illustrates that the share of Asia (1980: 36 %; 2007: 45 %; i.e. + 24 %) is increasing while at the same time the percentage of extraction in Europe (1980: 18 %; 2007: 11 %; i.e. – 36 %) and North America (1980: 23 %; 2007: 17 %; i.e. – 24 %) is decreasing.
A recent study from UNEP on the impacts of consumption and production shows that materials are important intermediaries of environmental impact. In developed countries material consumption has to a large extent stabilized. In developing countries, however, especially in rapidly growing economies such as India and China, material demand is rising rapidly. For many materials, scarcity problems are envisaged, which cannot be supplemented by secondary raw material production in the short term. The rapid increases in energy and metal prices are a clear indicator of the fact that the resource and energy supplies are not meeting demand.
It seems that due to rising demand and declining ore grades the energy requirements of the production of metals from ore might increase to a very high level. Further, many proposed sustainable technologies for energy supply and mobility rely for a large part on the use of metals (e.g. applied in batteries, fuel cells and solar cells). The production implications of such novel infrastructure developments may hence be very energy-intensive and may lead to the scarcity of certain materials2 . In a recent report from the EU, 41 minerals and metals have been analyzed for their importance to the economy and their supply risk according which the materials are plotted in Figure 3. The materials can be classified into the following three groups of: 1. Materials showing a relatively low economic importance as well as a relative low supply risk are situated in the left bottom of the chart (indicated by green triangles). Thus, these 14 materials seem not be crucial for the industry. 2. Materials showing a relatively high economic importance but a relative low supply risk are situated in the right bottom of the chart (indicated by blue circles). In spite of the economic relevance their abundance and/or their possibility of substitutability between materials means that these 12 materials are not crucial. 3. 14 Materials showing a relatively high economic importance as well as a relative high supply risk falling within the top right cluster of the chart are critical.
The current levels of recycling are not able to meet these demands and as long as the total demand for resources is still growing enhanced recycling is only a partial answer to resource scarcity. Contributing to this gap is the fact that increased consumption does not only lead to an increase in waste and/or recoverable resources, but also to a significant increase in the stock of materials in society. These materials are in use in buildings, infrastructure and products and are in many cases not available for recovery for over a period of years or more often decades.
There are, of course, important social and political aspects connected to resource use and resource scarcity. Reserves of fossil fuels and metals are unevenly distributed across the world. The production of many materials is concentrated in a small number of countries, e.g. more than 90% of rare earths and antimony and more than 75% of germanium and tungsten are produced in China and more than 90% of niobium in Brazil and 77% of platinum in South-Africa. Securing reliable and undistorted access to natural resources has become a critical challenge to many resource-dependent countries all over the world.
Access to natural resources will therefore be an important strategic political and economical asset. Climate change, which is often regarded to be our biggest environmental challenge, is just one of the consequences of resource consumption. Our growing energy consumption, dominantly powered with fossil fuels is the main causes for climate change. The ISWA White Paper on Waste and Climate Change has shown that the waste sector has the potential of becoming a net carbon saver through enhanced recycling and energy recovery and the application of proven waste technologies. Waste prevention may have an even bigger positive impact on climate change since it could also help to reduce the production impacts of new consumer goods.
Waste hierarchy and life cycle thinking The waste hierarchy has become a widely accepted guideline for waste management operations throughout the world, although the precise interpretation may vary from one place to another. The waste hierarchy stipulates a priority order in waste prevention and management legislation policy. Figure 4 shows the hierarchy according the directive 2008/98/EC which had to come into force in all EU countries.
Although the waste hierarchy seems to be quite clear in practice several uncertainties exist. On the one hand the term recycling stands for a great variety of processes and methods which significantly differ in terms of environmental and economical benefit. The recycling of mixed plastic, as opposed to material separated plastic, for instance, has a very different environmental and economic impact. Generally speaking recycling operations which lead to materials with the same quality as the original have a better environmental performance than recycling operations which lead to materials with a lower quality. In the end the optimal form of recycling should however be decided based on a Life Cycle Assessment (LCA).
To reveal the overall impact of products and processes on the environment it has become clear that life-cycle thinking has to be applied. Choices in the stages of production and consumption affect the environmental impact of a product as a whole and also the possibilities for later re-use or recycling. The waste hierarchy is useful for decisions in the waste phase, but only through life cycle thinking can a more comprehensive picture of the environmental performance of a product can be achieved. Decisions on the functionality of a product, the materials and resources from which they are made and their design should therefore be based on life cycle thinking. In these circumstances waste prevention and waste management may become resource management.
Resource management means the process and policy of managing materials and energy throughout their life cycle with the aim to maximise the efficiency of material and energy utilisation and minimise loss of material as waste for disposal. As shown in table 1 resource management is the broadest term and covers the complete chain from “cradle to cradle”. It can be seen as evolution of waste management. In contrast to waste management, which exclusively deals with the end-of-life phase, resource management is a holistic approach and covers a variety of actions. Waste is no longer in the foreground but any action or policy that results in material cycle process.
Although the waste hierarchy gives a clear priority order for different waste management methods, waste prevention can be further unraveled into different actions and methods relating to different stages in the chain of production and consumption. Figure 5 depicts the relationship of waste management methods and waste prevention as an aspect of resource management.
As shown in the previous chapter, a variety of methods exist for treating waste and end-of-life products. It is of importance to define the most relevant driving forces that influence the routes of waste and material streams. Legislation plays an important role in the treatment of waste. Waste legislation originates from the desire to prevent sanitary problems and environmental pollution. Modern waste legislation, however, is aimed at turning waste into a resource. Regulations such as landfill bans for untreated waste and incineration bans for recyclable waste are tools to steer waste streams up the waste hierarchy. Today many waste recovery activities are undertaken within the framework of extended producer responsibility which has become one of the most important instruments for enhancing and financing separate collection and recycling of different types of products and materials. Minimum recycling rates, which are usually part of a system of producer responsibility, can give a great push to the development of recycling methods. More recently legislation has been developing more in the direction of environmental product regulation, such as the EU RoHS Directive and the Eco-design Directive.
Economics is also an important driving force in influencing the direction of waste and material streams. It is clear that a recycling process will proceed without intervention if it is economically feasible. For instance, the recovery of noble metals from end-of-life catalytic converters is highly profitable and, thus, there is no need for legislation. On the other hand, even if legislation dictates recycling quotas, waste can be directed to illegal routes if no economically viable procedures for recycling and recovery are available. For instance, it has been reported that up to 75 % of end-of-life vehicles are illegally exported from the EU countries and, thus, circumventing the stringent European waste legislations to recover materials within the EU. Environmental and ethical attitudes can significantly influence waste treatment. More and more consumers and producers are aware of their influence on the supply chain. Fair trade products exhibit an increasing demand even if their price is significantly higher than conventional products. Consumers and producers are becoming more and more aware of the circumstances in which their consumables are being produced. Products made in factories which do not apply minimum standards regarding safety and health, child labour, or minimum wages are no longer acceptable.
However, the drive is still to be more aware of the quality of consumables (product quality as well as social and RESOURCE MANAGEMENT WASTE PREVENTION WASTE MANAGEMENT Extraction Manufacturing Transport Distribution Purchasing Use Re-use Separate Collection Recycling Other treatment and recovery Reduction at source Sustainable consumption Avoided waste flows Diverted waste flows Waste Minimization Preparing for Re-use PRODUCTION CONSUMPTION END OF LIFE environmental quality), rather than the quantity. More sustainable consumption patterns would also entail consuming less and using more second hand products.
Our economy is becoming more and more a global economy. Regional markets are steadily losing their importance and global markets are influencing the world’s economy. Modern developed countries such as Japan, Canada and Europe have the most stringent regulations for waste. The workshop of the world, however, is located in China, India and South East Asia. Thus, the stringent regulation of waste in the developed countries only affects a relatively small share of the total production volume. A high degree of reuse and recycling in the more developed parts of the world therefore primarily affects (imported) end-consumer products, but not the significant portions of waste arising during the production processes in other parts of the world. Furthermore, for economical reasons, a significant amount of discarded products (basically electrical and electronic waste and end near of life vehicles) are shipped to less developed countries for the purpose of re-use. In these countries these products will sooner rather than later, become waste. Because the more advanced treatment and recycling methods for these devices are lacking in the countries concerned, the end-of-life products will in many cases be discarded on unregulated dumps or perhaps be processed with poor technology. This leads to a loss of potentially recoverable valuable resources, to severe health problems for the workers involved and to environmental pollution. Lastly, there is a great demand for resources in the producing countries. The consuming countries therefore ship increasing proportions of their waste to the producing countries for recovery. However, due to a lack of technically and economically sound recovery solutions considerable portions of this waste receive a sub-optimal treatment which also leads to a loss of potentially recoverable resources.
From Waste Management to Resource Management
Moving towards Recycling Ideally we should have a situation where all metal and mineral resources are fully recycled and where all other materials are fully biodegradable. In that case landfill and incineration of waste will be avoided. However, this scenario does not say anything about the amount of resources we are using and the proportion of resources that has to be recycled (i.e. waste per capita). Principally processes of waste management can be classified into the categories: landfill (disposal), incineration (thermal recovery) and recycling (including composting/digestion). When plotting the data of individual countries in a Venn/triangle diagram (Figure ) the position of different countries in terms of waste management becomes apparent. In most cases the initial position is the right corner which means that 100 % of waste ends up in landfill or dumps. The final goal is to reach the left hand corner, where 100 % of the waste is recycled and incineration as well as landfill is completely avoided. As an intermediate target incineration can be found in the top corner. Commonly the evolution in waste management follows the direction indicated by the pink arrow, moving away from the landfill corner towards the edge between incineration and recycling (i.e. landfill: 0 %). However, in order to reach the left corner (100% recycling) it would be necessary to follow the green arrow, meaning that incineration has to be substituted by recycling.