From non-renewable waste to activated carbon: A smart move towards sustainable development and environmental protection in a circular economy

Abstract

Waste generation is unavoidable as the population grows and globalisation/modernisation occurs. Ineffective garbage management and treatment raise major environmental concerns. This study provides a comprehensive and unique compilation of available knowledge on the potential use of various non-renewable waste materials to produce activated carbon (AC). One document brings together and evaluates the potential for converting hazardous and non-hazardous waste – from industrial and municipal to recyclable and medical waste – into a valuable resource with wide-ranging applications. The appropriately selected conversion method is key to converting waste into a valuable activated carbon product. It must consider both the applicable legal regulations and the key technological parameters that determine the quality and suitability of the final product for a specific application. The numerous carbonisation and activation methods employed to convert waste to AC include hydrothermal, ionothermal, pyrolysis and microwave-assisted methods. AC’s elemental composition and functional groups are analysed using elemental analysis, XPS and FTIR. Crystal structure and phase identification are performed via XRD, SEM and TEM. Surface area and porosity are determined using the BET and BJH methods, along with the iodine index. Following the thermal conversion of various waste materials into AC, it is widely used in multiple disciplines, including energy and the environment. AC is used as an adsorbent to effectively remove harmful elements from water, including pharmaceutical contamination, dyes and heavy metals. AC has excellent electrochemical characteristics and is highly efficient in CO₂ capture. AC also extracts valuable products such as hydrocarbons, methane and uranium.