Carbon-based sorbets for heavy metal removal from aqueous solution, discrepancies, and future prospects: a state-of-the-art review

Abstract

Heavy metal contamination is severely affecting human health and environment. These metals are known to exist naturally but the anthropogenic activities have contributed towards increasing their concentrations beyond permissible limits, which in turn have proved to be hazardous for the human health as well as environment. Various industries release the untreated wastewater containing heavy metals into the open streams, thereby creating a contaminated source affecting negatively on consumers. In order to deal with this, several materials have been researched and proposed as adsorbents to remove these contaminants. Amongst them are carbon-based materials, that have shown to be effective, efficient, and environment-friendly option for heavy metal adsorption from aqueous solutions. The present review thoroughly summarizes the recent developments of carbon-based materials, specifically in terms of their application in heavy metal removal from aqueous solutions. Moreover, it elaborates the adsorption mechanism and compares it with other technologies available for metallic removal. Similarly, various parameters affecting the adsorption using carbon-based materials and their recent regenerative strategies are presented. In the end, numerous shortcomings and discrepancies associated with carbon-based materials are given along with their future prospects that need to be addressed in the upcoming research.