Sorbents from waste materials: A circular economic approach

Abstract Contaminants emerging from increasing anthropogenic activities are leading to environmental pollution that has profound effect on the ecosystem and human health. In recent years, new water pollutants have become source of significant concern. Traditional methods for wastewater treatment are inefficient and expensive to tackle such emerging contaminants. Alternative, inexpensive and novel techniques are imperative for wastewater treatment with higher efficiency. Adsorption is the most cost-effective technology for water treatment and hence has been applied widely as a low cost, competent, and eco-friendly method for wastewater treatment. Although water pollution is a big issue, another catastrophic problem on the anthropogenosphere is the management of solid waste. There are several examples where waste resources have been used as precursor for development of sorbent materials having wide range of applications. The resultant sorbents also vary in their structure and properties as some of them are classified as nanomaterials as well. The types of waste used as precursor vary widely such as industrial waste, biomass, polymer waste, and even electronic waste. Although the majority of the applications are focused on primarily on wastewater treatment, some of the reported literature has focused on other environmental hazards such as oil spillage, gas upgradation, and CO2 capture. This is an interesting approach where the end product of one anthropogenic activity is being modified for remediation of another anthropogenic activity. This is a perfect case where the loop further can be closed giving rise to a circular economic approach. This study provides a summary of sorbent materials manufactured from waste materials with their different applications. A novel circular economy framework has been proposed based on the outcome of the literature review. This study is anticipated to be helpful for researchers, policy-makers, governing bodies, and relevant stakeholders.