Saturated biosorbents: shift from waste to new class of materials

The use of biosorbents (adsorbents of natural origin, such as, plant derived material) has been regarded as an alternative to traditional wastewater treatment methods (such as chemical precipitation or ion exchange), as it is environmentally friendly and cost-effective process. Literally hundreds of different biosorbents have been tested in laboratory scale sorption experiments, however, the traditional research of biosorbents (i.e., the use of biosorbents in the treatment of polluted waters) seems to be a dead-end direction, with technological problems that are difficult to overcome, and process has found no application on industrial scale until now. For example, biosorbents are short-lived, as the biomass decomposes in the solution, and as a result, it is fragile to technological operations such as mixing or pumping. There are also problems with regeneration and reuse of biosorbents. It explains why this process has not been implemented in industrial scale so far. In addition, the focus in biosorption studies has always been more on the “removal” (i.e., concentration of pollutants into a biosorbent, however this material will become a waste after the biosorption), but not so much on the “recovery”. Therefore, there is an opportunity, as well as challenge to apply biosorption principles in unconventional manner. A new concept will be proposed, with shift away from adsorption of toxic elements to adsorption of essential elements.