As 2020 continues on, plastic pollution continues to be a major problem for our planet. And the more that single-use products become a necessity for sanitation and safety, the more important it becomes for us to find an end-of-life solution that benefits our planet rather than harms it. Industrial composting may just be that answer. Industrially compostable bioplastics provide the functionality we need from single-use plastics, but are able to be transported to commercial facilities and turned into usable composts and fertilizers in under 180 days. These facilities are able to process large volumes of municipal compostable waste, allowing communities to not only invest in bioplastics, but to reduce the amount of food waste that is transported to landfills.
Two smaller scale methods of composting are on-site composting and vermicomposting. On-site composting is ideal for small organizations looking to use composting to reduce food waste. These types of compost piles are often made up mainly of food waste and yard trimmings. It requires very little time and equipment, however there is a right and wrong way to do it. Food scraps must be properly sorted and handled, and the compost process can take up to 2 years without manual turning of the pile. Vermicomposting involves adding red worms to a compost bin in order to break down the material into high quality compost called castlings. The worms help to speed up the compost process to about 3-4 months without turning. However, there is the added factor of caring for the worms, and ensuring they have the proper living environment and food sources.
On a municipal scale, there are 3 types of industrial composting: aerated windrow, aerated static, and in-vessel. Each has the ability to process large volumes of compostable waste. In aerated windrow compost, the waste is arranged into rows of long piles (4-8 feet high and 14-16 feet long) called “windrows,” which are turned regularly to provide all of the compostables time in the warm center of the pile where increased heat further encourages breakdown. This method is suitable for a wide range of wastes, including yard trimmings, grease, liquids, and animal byproducts. It can stand up to a variety of climates, and the pile can be adjusted or covered to accommodate weather patterns. The most important factor to consider with aerated windrow composting is that there needs to be a system in place to control odor, due to the open-air nature of the system.
Aerated static composting results in usable compost fairly quickly, between 3-6 months. This method works best with a homogeneous mix of organic waste (like yard trimmings and food waste) but isn’t suitable for grease or animal byproducts. In this method, waste is placed into a large pile that is split up with layers of “bulking agents,” like wood chips or shredded newspaper that allow air to pass through and aerate the pile. Air blowers and other ventilation systems can also be used to aerate the pile. Due to the passive nature of the aeration, these types of piles require constant and vigilant temperature monitoring to ensure ideal compost conditions.
Finally, covered in-vessel composting takes up less space than windrows and can accommodate virtually any type of organic waste. The waste is fed into a covered drum, silo, trench, or similar set-up, which allows for complete control over temperature, air flow, and other variables. The material is mechanically turned for aeration, and compost is created in just a few weeks. Due to this high speed of formation however, the compost then needs time to allow the microbial activity to balance and the pile to cool before it is usable. While this method provides the most control over the compost and a fast turnaround, it is the most expensive of the 3 methods due to the technology requirement.
Not only does composting provide a better end-of-life option for bioplastics and other materials, it can divert a huge volume of waste away from landfills, where that waste can be converted into something new and usable for agricultural and other purposes. Up to 50% of the waste that is currently being landfilled could be composted instead. When food waste breaks down in landfills, it does so anaerobically, meaning that it does so without oxygen present. This process releases methane gas, an extremely harmful greenhouse gas. The compost process brings oxygen into the equation, allowing carbon to be sequestered away in the final compost material rather than released into the atmosphere.
Besides providing usable fertilizers and compost, industrial and commercial compost facilities provide twice the number of jobs currently created by the recycling industry, and triple the jobs created by landfilling. There are also a huge range of environmental benefits provided by composting that cannot be matched by either recycling or landfilling. Composting on the municipal level can help communities to reduce their waste volumes and protect the planet. Commercially compostable products and packaging are the first step towards creating a fully circular economy for single-use products, and saving our planet from the plastic noose that is continually tightening around it.
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