Study on Adsorption and desorption Characteristics of Heavy Metal Ions from Aqueous Solutions by GAC Adsorbent.

Abstract

Over the past few decades, adsorbents have significantly increased in efficiency and economy when it comes to removing heavy metals and metalloid from water. However, the recovery of heavy metals from the desorbing agents and the recycling of spent adsorbents received less attention. Numerous researchers tried a variety of potential regenerating agents, such as acids, alkalis, and chelating agents, for the regeneration and reuse of adsorbents, with varying degrees of success in some experiments confined to a small number of adsorption–desorption cycles. The recovery of adsorbed (from GAC adsorbents) and desorbed (from regenerating agents) metals was the main focus of only a small number of the published research.

                While managing used adsorbents and recovering heavy metal ions is crucial, the fate of wasted adsorbents prior to disposal has not been extensively studied in research studies. The removal and desorption efficiencies of various adsorbents and regenerating agents, as well as the heavy metal recovery from saturated adsorbents and desorbing solvents utilized in regeneration, are summarized in this paper. The results of this study will assist the scientific community conducting adsorption studies in pursuing the necessary research projects to address practical heavy metal recovery techniques from utilized adsorbents, investigate potential repurposing of desorbing agents, and select an appropriate desorbing/regenerating agent for a given adsorbent.