What is Organic waste?
Organic waste, also called bio-waste, is the biodegradable part of waste coming from gardens and parks as well as food waste coming from households, restaurants, shops, caterers and food processing industries. Biodegradable means that it is composed of materials that can naturally be consumed and degraded by microbes or other living organisms. Therefore all the leaves, dry flowers and weeds coming from your garden or balcony, and the vegetable skins, leftovers or food that you forget (sadly) in the back of your fridge are considered organic waste. This waste stream typically has a high water content and starts to deteriorate quickly being the main cause of the bad smell of your trash.
Is organic waste valuable?
Organic waste is a very valuable waste stream since it contains nutrients and organic matter. These characteristics give organic waste the potential of being transformed into natural fertilisers, an alternative to chemical fertilisers. For the production of chemical fertilisers, nutrients such as potash and phosphorus are mined from the ground in their raw rock form. The mining itself is an extremely energy intensive and water consuming process. After being extracted these nutrients also need to be processed and transported all over the word. This makes the production of chemical fertilisers a very unsustainable process and increases the value and necessity of using natural fertilisers. In addition, chemical fertilisers are often connected with cases of toxicity due to the build-up of dangerous contaminants in the soil from arsenic, cadmium and uranium, that eventually end up in our plate.
Organic waste also contains components like proteins and fats that can be used in the production of bio-based materials. This is particularly true for high quality and quantity organic waste streams coming from, for example, food production and processing industries. These sources provide the opportunity to collect pure mono-component organic waste that can be use in the production of high-value materials. For instance, egg shells can be used in the production of cosmetics and dietary supplements while vegetable residues can be used in the production of packaging and bio-plastics. Animal by-products and used oils can be used for the production of soaps, detergents and biofuels. In this way, organic waste creates the potential for the production of fossil-free alternatives to fuels, chemicals and materials. Furthermore, a big advantage of using waste as in input is that this all becomes possible without the negative effects usually linked to bio-based products; namely the misallocation of land, resources and crops normally used for food production.
Organic Waste in Amsterdam
Organic waste is currently not separated in Amsterdam (besides the district of Nieuw West) and ends up in the residual waste. Residual waste is brought to the incineration plants where it is then burned losing all its value. Indeed, incineration ashes are then used in construction and, even if some nutrients survive the process, they end up being locked into cement and lost forever.
Circular Organic Waste management
Organic waste management has the potential of being 100% circular since this is what happens naturally in nature. Unfortunately our modern society can mime natural processes making it very difficult to reach this level of efficiency. However, by applying the principles of a circular economy to the management of organic waste it becomes possible to reach high levels of efficiency while minimising losses and using materials in a cascading way. The biomass cascade indicates how to use biomass through always retaining their highest value.