Challenges and Strategies for Degradation of Microplastics in Environment

Microplastics are small pieces of plastic less than 5 mm in length, that occur in the environment as a result of plastic pollution. These are hydrophobic in nature because of persistent covalent bonds and the presence of functional groups that are resistant to attack, therefore difficult to decompose in the natural environment. As microplastics have enormous specific surface area, hence they attract other chemicals, which reduce the decomposition rate of microplastics. Some of these chemicals are toxic and hazardous, so they are transferred to numerous organisms through the food chain, causing harm to them. The size of plastics varies from micro to nano-scale depending upon the types of industrial discharge which also contribute large numbers of microplastics into the environment. Microplastics are analyzed via sampling, preprocessing and identification. Degradation is a successful strategy for elimination of plastic pollution. It results from the synergistic effects of many degradation methods in nature as well as in upcoming engineering applications. A thorough understanding of the processes and mechanisms of microplastic degradation is necessary. There are still many hurdles to solve in the degradation strategies of microplastics and there are no realistic and effective technologies that can be used practically.