Stepping towards benign alternatives: sustainable conversion of plastic waste into valuable products

Abstract

The extensive use of plastic and the absence of efficient and sustainable methods for its degradation has raised critical concerns about its disposal and degradation. Furthermore, the escalated use of personal protective equipment (PPE) and masks during the ongoing COVID-19 pandemic has put us under tremendous pressure of generating huge amounts of plastic waste. Traditional plastic waste disintegration protocols, while effective, pose additional inevitable environmental risks. Owing to this, almost all the used plastic is directly discarded into the marine and terrestrial bodies, causing great harm to the flora and fauna. Plastic has even started entering the food chain in the form of micro- and nano-plastics, leading to deleterious effects. Considering the global need for finding sustainable ways to degrade plastic, several approaches have been developed. Herein we highlight and rationally compare the recent reports on the development of benign alternatives for the sustainable disintegration of plastic detritus into value-added products. Here we discuss, in depth, photoreforming of a variety of polymers to liquid fuels under natural conditions; enzyme-based deconstruction of polymeric materials via microorganisms and their engineered mutants into useful virgin monomers at ambient temperature; and pyrocatalytic degradation of polyethylene through efficient synthetic materials into valuable fuels and waxes. By critically analyzing the methods, we also provide our opinion on such sustainable techniques and discuss newer approaches related to bioinspired and biomimetic chemistry principles for the management of plastic waste.