The general and main goal of this work is the development of know-how for one of the most innovative technologies aimed toward wastewater treatment: biosorption is considered in the literature as an effective technology for the removal of heavy metals due to human activities (mining, metallurgy, electronic and galvanic industries, oil and petroleum, etc.). The key factors in the process development of this technology are as follows: use of economical raw biomass obtained as a byproduct of existing chemical or biotechnological processes; development of suitable systems for biomass immobilization and for regeneration, to allow further use of biomass. The present work summarizes some results obtained in this field, in particular, about the biosorption process in a membrane reactor. A mathematical model has been proposed to describe the process. Both experimental and simulated results showed the technical feasibility of the process in the wastewater treatment, even if some disagreement between experimental and simulated data has been highlighted.