Biosorption of Heavy Metals with Algae: Critical Review of Its Application in Real Effluents

Abstract

Biosorption is a variant of sorption techniques in which the adsorbent is a material of biological origin. It has become an economic and ecological alternative for the treatment of effluents. Among the biomasses employed in biosorption, algae have emerged as a sustainable solution for producing environmentally friendly adsorbents due to their abundance in seawater and freshwater, profitability, reuse and high metal absorption capacities. Although the research on the use of biosorbents is extensive and has grown in recent years, there are not many cases of their use for the treatment of real industrial solutions, which are more challenging due to the complex composition of metals that results in interference or competition over the functional sites of the biomass. This review aims to highlight the current state of research, focusing on the application of algae biosorption to remove copper from effluents. The most studied metals are those with the most significant health connotations, such as Cd, Cu and Pb. Regarding copper, only 2% of the biosorption works using seaweeds have been applied to real effluents, which leaves a relevant gap to advance the technology in the treatment of polluted solutions.