When it comes to eco-friendly products some people confuse the meaning of the terms biodegradable and compostable. What do these terms mean and why is compostability important in waste management?
Products which qualify as biodegradable, need to be decomposed within a relatively short period of time (few months to a year) after disposal. This reduces the accumulation of waste in landfills, which in turn contributes to a healthier environment.
Biodegradability is the ability of organic matter to be broken down by the enzymatic action of microorganisms. When the process is fully completed, the organic matter will be entirely broken down into inorganic matter such as water, carbon dioxide, and or methane (a substance produced in anaerobic decomposition).
Biodegradation is part of a natural cycle, producing substances that are utilized by photosynthesis and entered into the food chain. When plants and animals die, microorganisms present in the environment, feed on them and release water and carbon dioxide through biodegradation, therefore completing the cycle.
Compostability is the capacity of organic material to be transformed into compost through the composting process. This process exploits the biodegradability of the initial organic materials to transform them into a finished product called compost. Compost is therefore the result of disintegration and aerobic biodegradation (occurring in the presence of oxygen): mature compost is similar to fertile soil and its high proportion of organic substances means it can be used as a fertilizer. Therefore, compostability is one step further from biodegradability, where nutrients are released back into the soil, once the components have been completely broken down into simpler form.
Biodegradation is strongly influenced by the chemical nature of the material to be biodegraded and by the environment in which this process takes place. This natural process can be imitated and improved upon in order to deal with organic waste produced by human activities. For this to be effective, the ideal environment in which the biodegradation process can reach maximum efficiency must be identified, and an ‘industrializable’ duration must be established that is compatible with the pace at which organic waste is produced.
The environments in which biodegradation occurs at a consistent pace, and in which it can be managed industrially, are those of composting and anaerobic digestion. In these systems it is therefore possible to process solid organic waste, including man-made substances (such as biodegradable plastic) for which the speed of biodegradation is compatible with these processes. Composting will produce mature compost (which is a fertilizer) while anaerobic digestion (followed by stabilization through composting) will produce biogas (and therefore energy) as well as compost.
Using biodegradable products, such as waste bags, that are also compostable is particularly significant with regards to waste management. The compostable bag allows for the creation of homogenous wet waste (such as food and garden waste which have high water content and decompose at a rapid rate), where both the container and the contents have the same biodegradation properties. At iCOMPOST our compostable bags and other packaging solutions, comply with compostability standards which means that they can play a fundamental role in optimization of the composting process and in the production of high quality compost. This increases the efficiency of separate wet waste collection, because it speeds up the decomposition of waste, it can encourage domestic separation of wet waste, and therefore, increase the quantity of organic waste received, thereby ensuring the quality levels required for the finished compost.
