In addition to the traditional R's, an additional R has been added, increasing the total number of R's to a total of four. The original three waste management principles - reduce, reuse, and recycle, with the addition of recovery as a fourth principle. Trash may be cleaned up and recycled by using methods such as reducing, reusing, and recycling. This may result in the recovery of energy or materials from waste. Thermal and biological processes may be utilized to generate a wide range of goods, including electricity, heat, fuel, and compost, among others. All of these benefits may be achieved via the use of research, innovation, and creativity. It is possible to use regenerated or recovered energy and materials for many diverse uses once they have been recycled.
Unless properly managed, waste items that were meant for disposal are no longer considered trash but rather sources of resources for industry and environmental conservation. It is hoped that this would help to strengthen the idea of Circular Economy, which is now getting a great deal of attention.
To achieve this, waste materials may either be disposed of in landfills, where they can biodegrade naturally, or they can be treated using extra processes. Also, the use of thermochemical technology, which encompasses the processes of gasification, pyrolysis, combustion, and liquefaction as well as other methods of energy recovery. It is predicted that as a result of everything going to waste, fewer items would go to waste without gaining any benefits from them. Due to this, along with the three R's (reduce, reuse, and recycle), it is important to give equal consideration to the idea of adding a fourth R. To prevent having a detrimental effect on the environment, we should proceed with care while carrying out this process.
Sources
https://blog.americanchemistry.com/2013/02/reduce-reuse-recycle-and-recover/
https://www.epa.gov/smm/energy-recovery-combustion-municipal-solid-waste-msw