Biosorption and me

Biosorption has been defined as the property of certain biomolecules (or types of biomass) to bind and concentrate selected ions or other molecules from aqueous solutions. As opposed to a much more complex phenomenon of bioaccumulation based on active metabolic transport, biosorption by dead biomass (or by some molecules and/or their active groups) is passive and based mainly on the "affinity" between the (bio-)sorbent and sorbate. A personal overview of the field and its origins is given here, focusing on R&D reasoning and know-how that is not normally published in the scientific literature. While biosorption of heavy metals has become a popular environmentally driven research topic, it represents only one particular type of a concentration- removal aspect of the sorption process. The methodology of studying biosorption is based on an interdisciplinary approach to it, whereby the phenomenon can be studied, examined and analyzed from different angles and perspectives-by chemists, (micro-)biologists as well as (process) engineers. A pragmatic science approach directs us towards the ultimate application of the phenomenon when reasonably well understood. Considering the variety of parameters affecting the biosorption performance, we have to avoid the endless empirical and, indeed, alchemistic approach to elucidating and optimizing the phenomenon-and this is where the power of computers becomes most useful. This is all still in the domain of science-or "directed curiosity". When the knowledge of biosorption is adequate, it is time to use it-applications of certain types of biosorption are on the horizon, inviting the "new technology" enterprise ventures and presenting new and quite different challenges. (c) 2007 Elsevier Ltd. All rights reserved.