Dairy whey separation with UF, NF and reverse osmosis
Protein separation, lactose processing and stream concentration require different cut-offs and balances. Neptuno develops the membrane stage around the product to be recovered and the process conditions.
- UF
- Protein concentration
- NF
- Solute selection
- RO
- Water removal
Selecting MF, UF, NF or RO
Recovery objectives must be defined for both permeate and concentrate. In conventional UF, proteins can be concentrated while a substantial proportion of lactose and minerals passes into the permeate.
NF enables finer separation and assessment of the behaviour of specific solutes and ions. RO removes water from a compatible feed to increase its concentration.
| Aspect | Project criterion |
|---|---|
| Microfiltration | Clarification, particle separation or specific fractions according to the cut-off. |
| Ultrafiltration | Concentration and fractionation of macromolecules, including proteins. |
| Nanofiltration | Selectivity for small compounds and certain ions; retention established by testing. |
| Reverse osmosis | Concentration through water removal, accounting for osmotic pressure and fouling. |
When to choose a ceramic plant
Ceramics are particularly relevant when temperature, composition or cleaning intensity constrain membrane material selection. Tubular or multichannel elements are integrated into a cross-flow circuit with hygienic design suited to the application.
The ceramic NF range reaches a nominal MWCO of 200 Da. This figure guides selection; molecular shape, membrane interactions and feed composition determine actual retention. Lactose and salt separation is confirmed under the project conditions.
| Aspect | Project criterion |
|---|---|
| Temperature | Compatibility of the membrane, gaskets and housing, and product stability. |
| Cleaning | Sequences and products compatible with the membrane and hygienic requirements. |
| Selectivity | Protein, lactose and mineral content of each stream. |
Concentration, stability and operation
As the feed concentrates, viscosity, osmotic pressure and filtration behaviour change. The design balances permeate production, final concentration and cycle duration.
For food-grade streams, layout and materials are defined around hygiene and product preservation requirements. When treating dairy effluent, the balance focuses on recovered water quality and management of the remaining load.
| Aspect | Project criterion |
|---|---|
| Feed | Proteins, lactose, solids, fat, salts and available pretreatment. |
| Target product | Concentration, composition and commercial use or management route. |
| Permeate | Required quality, intended reuse and additional treatment. |
Data for an initial assessment
- Stream origin and whether the duty is food processing or effluent treatment.
- Flow rate and solids, protein, lactose and fat composition.
- Temperature, pH, salinity and process variability.
- Target concentration and composition of each fraction.
- Hygienic requirements, cleaning and available equipment.