Recent Progress on Biosorption of Heavy Metals from Liquids Using Low Cost Biosorbents: Characterization, Biosorption Parameters and Mechanism Studies

TLDR

Biosorption studies worldwide focus on optimizing removal efficiency and understanding mechanisms, with functional groups such as carboxyl, hydroxyl, sulfate, and amino groups and solution pH playing key roles. FTIR, SEM‑EDX, TEM, and titrations are employed to elucidate surface processes in biosorbents. Ion exchange and complexation are the predominant mechanisms for heavy‑metal biosorption.

Abstract

Abstract A significant number of biosorption studies on the removal of heavy metal from aqueous solutions have been conducted worldwide. Nearly all of them have been directed towards optimizing biosorption parameters to obtain the highest removal efficiency while the rest of them are concerned with the biosorption mechanism. Combinations of FTIR, SEM‐EDX, TEM as well as classical methods such as titrations are extremely useful in determining the main processes on the surfaces of biosorbents. Diverse functional groups represented by carboxyl, hydroxyl, sulfate and amino groups play significant roles in the biosorption process. Solution pH normally has a large impact on biosorption performance. In brief, ion exchange and complexation can be pointed out as the most prevalent mechanisms for the biosorption of most heavy metals.