Membransystem

Membransystem is a configuration of membranes and ancillary components designed to separate, concentrate or convert components of a mixture. In engineering contexts it refers to artificial membrane assemblies used for selective transport, while in biology it denotes natural membrane structures such as cellular membranes and organelle boundaries. Both uses rely on the property that certain substances permeate the barrier more readily than others.

Membranes act as selective barriers. Transport is driven by pressures, concentration gradients, or electrical potentials. Separation mechanisms include size exclusion (pore-based), diffusion through the membrane matrix, and selective adsorption. The performance is characterized by permeability and selectivity, and by fouling tendency in real process streams.

Artificial membranes are typically classified by pore size and mechanism: porous membranes used in microfiltration and ultrafiltration, tight barrier membranes used in nanofiltration and reverse osmosis, and non-porous membranes used for gas separation and pervaporation. In biomedicine, dialysis membranes separate small solutes from larger ones. In fluid engineering, membrane bioreactors combine filtration with biological treatment.

Materials include polymeric membranes (polysulfone, polyethersulfone, polyvinylidene fluoride), ceramic membranes (alumina, zirconia) and increasingly composite or graphene-based membranes. Common applications are water treatment and wastewater reuse, food and beverage processing, pharmaceutical separations, gas separation, and energy devices such as fuel cells and redox flow systems. Fouling, scaling and energy demand are major design considerations.

Membransystems are related to processes such as osmosis, dialysis, and membrane distillation, and to broader topics in separation technology and systems biology.