A review on the management of arsenic-laden spent adsorbent: Insights of global practices, process criticality, and sustainable solutions

Abstract

Adsorption is a widely used arsenic remediation technique due to its high efficacy, economic value, ease in operation and maintenance, and other multiple factors. However, the proper management of arsenic-laden spent media is one of the major challenges, which affects the sustainability of this treatment technique in field-scale implementations. This review summarizes the various adsorbents and their regeneration/reuse for the remediation of arsenic from aqueous solution, as well as the several safe management practices, such as landfilling, incineration, stabilization in construction material, etc., for the arsenic-laden spent media. In most of the developing countries disposal of spent media is a major concern, and in many instances, the ecotoxic effects to the environment concerning its direct disposal imposed a critical hindrance on this process. Furthermore, the present study reviewed the physicochemical characteristics of spent media, generation of secondary pollution, ecotoxicological effects, and factors that affect the leaching of arsenic. A brief overview of several methods that determine the leaching from arsenic spent media exhibited that “toxicity characteristic leaching procedure” is widely practiced in spite of some limitations to simulate the landfill conditions. The sustainability assessment framework for spent adsorbent is developed and it was observed that the stabilization/solidification is more environmentally friendly but less cost-effective. The review highlighted the field practices of spent adsorbent management across the globe critically, which streamline the research need in adsorptive removal of arsenic as well as instigate proper selection of techniques for case-specific implementations. • Systematic appraisal on spent-media management is a crucial gap in arsenic research. • Regeneration and contaminant immobilization of spent media are generally practiced. • Difficulties in leachability quantification lie in simulating landfill conditions. • Sustainability of spent-media management methods was analyzed by novel framework. • Solidification/stabilization is promising method of safe handling of spent-media.