A critical review on the influence of energy, environmental and economic factors on various processes used to handle and recycle plastic wastes: Development of a comprehensive index

Abstract

The conventional methods of waste disposal, namely landfill and recycling, are associated with environmental and economic inefficiencies. The associated policies and regulations are also found to be inadequate in relation to the current situation. The situation of plastic handling-related policies in India was reviewed in this regard. Alternative techniques such as liquefaction, biological treatment, pyrolysis and incorporation of plastics in road laying have received increased attention in recent years. This paper reviews the fundamentals of each process and offers a clear picture of plastic generation and disposal. The present review also focuses on the benefits and drawbacks of different disposal methods by comparing the methods over several economic, environmental and energy parameters. A comprehensive Energy, Economy and Environmental index (EEE index) has been developed in this study to compare the different methods and reconcile the various parameters based on which the comparison was performed. Incorporation of plastic waste in concrete structures and road pavements were found to be the best methods of plastic waste disposal, with an EEE index score of 42.85%. These two methods were followed by pyrolysis and liquefaction of waste plastic with scores of 23.08% each. Landfill, with an EEE index of −7.14%, was found to be the least holistic method of waste disposal and needs to be minimized wherever possible.