Biosorption of metals – from the basics to high value catalysts production

Abstract

Increasing awareness of environmental pollution with heavy metals and its long-term and xenobiotic effects has instigated growing research and development efforts towards pollution abatement. The application of different biological materials in the removal and recovery of metals from wastewater has been reported in numerous studies.1–5 Usually, the mechanisms of biosorption are defined as being metabolic independent, but some authors2 have defined biosorption as the ability of biological materials to accumulate heavy metals from waste streams by either metabolic mediation or by purely physico-chemical uptake pathways. These different perspectives will be presented. It is important to identify and evaluate extensively the factors that affect the performance of biosorption systems in order to optimize their practical application. The main operational conditions that significantly influence the biosorption of heavy metals are the solution pH, the biomass and the metal concentrations, the temperature, age of the cells, contact time and the competitive presence of other metals in solution. All these points will be discussed, as well as some application perspectives that will be presented.