Hi and welcome again! In this module we will introduce the hot topic of circular economy and its relation to solid waste management. Dr. Ljiljana Rodic is with us again. She has pioneered university education on this topic in the Netherlands. Ljiljana, welcome again! The floor is yours. Thank you very much Imanol. It is a pleasure to be here again. Nowadays, we often hear or read in the media about circular economy. In this lecture I will introduce this term, explain briefly different meanings in which it is used and discuss potential place of solid waste management in circular economy. How did you hear the term circular economy? You may have heard about the circular economy promotion law, the milestone legislation of the People's Republic of China adopted in 2008 to promote the circular economy as a national strategy for sustainable development. Or you may have come across reports towards a circular economy prepared for the Ellen MacArthur Foundation. But what is it all about? Since the industrial revolution our economies have grown following a linear pattern of use of natural resources consisting basically of take, make, use, discard steps. This was based on a false premise that the resources are infinitely available and accessible at an affordable cost, both in terms of money and in terms of environmental impacts. However, such a pattern simply cannot be sustained by the earth system. On the one hand the sources of materials are finite and on the other hand, there are limits to the ability of Earth's ecosystems to recover from habitat degradation and pollution by various hazardous and other chemicals. But if you look at nature and natural ecosystems, how they use natural resources around them, we see that nature functions in a circular pattern. Starting from plants as producers, including several levels of consumers and when they die decomposers get to work to convert them into soil nutrients, which in turn serve as food for the producers again. Circular economy envisages a similar system, where after make and use stages, materials are recovered and processed into a new cycle of production and use. For materials to be recovered and returned to the next cycle of production, they need to be clearly defined in circular economy. Materials can be defined either as biological materials or technical materials. Biological materials are used to make the so-called consumption products, which get consumed during use, such as a soap or shampoo or wear off during use, such as clothes or shoes. These are designed to be safe for human health and the environment and as such they can safely return to the natural biological cycle. Here, we have an example of biological material: food. Technical materials are used to make service products, such as computer, telephone, washing machine, a car. As they are non-renewable and often hazardous to human health and the environment, these are kept within the industrial technical cycle, where they will be used to make new products, time and again. At that some materials lend themselves perfectly for cascading use. This is usually the case with biological materials, wood and textiles are very good examples. Biological materials can be used in defined cascades where the quality deteriorates from one application to the next, but both, along the way and at the end, the material can be fully returned to the biological cycle with no harm to human health or the environment. In the end, they can be processed, by for example, aerobic composting or anaerobic digestion to recover resources such as organic matter nutrients and energy. Of course, products user stages can be extended through reuse and repair. Also, after this assembly parts can be used for refurbishment and manufacture of the products. Here, you see an example of complete disassembly into the part and their corresponding materials. As you know, recycling is usually downcycling, whereby materials loose their quality in each cycle. However, it is possible for recycling to actually be upcycling, whereby quality improves in each cycle. Here, we have an example of a packaging that is made out of 100% PET bottles, and from the PET material during recycling antimony is removed, which was there originally. So, this material is now better quality than it used to be. It often makes sense to explore possibilities of closing material cycles together with energy and water cycles. For example, closing metal cycles saves a lot of energy, if we close water cycles. It allows recovery of nutrients. Also, for renewable energy it is important to consider materials used for such technologies, as they often contain rare and hazardous materials. For a fully circular economy a lot of innovation will be needed in various disciplines in various fields. For example, in material sciences, well-defined materials are particularly important. Also, for the design, end of use stage need to be taken into consideration: How easy the product is to be repaired, to be refurbished, to be disassembled, to be remanufactured. Also of particular importance are the new business models, where a lot of innovation is needed, so that services are sold and not necessarily the products. This also includes our relationship to ownership. Do we actually need to possess and own a product or are we perfectly happy with the service it provides us? This also means that new relationships or new types of relationships are needed along the supply chain, where trust among partners has a prominent role, because it is about sharing proprietary information about materials and parts. This also means that citizens have a new role and that is that they have to make sure that these materials indeed do return into the next production cycle. And government has also a role because it can provide supportive policies, legislation and incentives to enable support such developments in society. You may have seen in literature that the role of the design is very important for circular economy. It is indeed, because it is the design stage when all the decisions are made about the material, about assembly methods, about the usage. However, solid waste management has an equally important role in circular economy, because it makes the other half of the cycle complete. It makes sure that the materials after usage will indeed return to the next production cycles. Circular economy is currently in the focus of political and public debate and its importance is only going to increase. While it begins with the design of products, everybody has a role to play and everybody can contribute. Not the least, us citizens, as consumers to choose buy and discard the products.However, solid waste management has a very prominent role as it makes sure that the materials actually return into the next production cycle. Should you have any questions or comments, do not hesitate to contact me at the email address given here.
