Nanofiltration of biogenic amines in acidic conditions: Influence of operation variables and modeling

Biogenic amines are present in some fermented and non-fermented beverages and can cause diseases. This study analyzes the feasibility of separating biogenic amines by nanofiltration in acidic medium. Solutions of chloride salts of three biogenic amines: putrescine, histamine and tyramine were filtered through a nanofiltration membrane with a 1000 Da molecular weight cut-off (MWCO) and a positive electrical charge at pH 3. Increasing the transmembrane pressure or cross flow velocity led to an increase in solute rejection and permeate flow. Moreover, a higher electrical charge or lower concentration of amine cations caused a larger rejection indicating that membrane-solutes repulsion governs the filtration process. Finally, the experimental results were analyzed using the classic Donnan–Steric pore model. Values of 0.83 nm and 5.4 μm were estimated for pore radius and membrane effective ratio thickness-porosity from the filtration of neutral solutes. Membrane volumetric charge density and the proton diffusivity inside the pores were estimated from the experimental results.