What high COD means in this stream
A dairy process discharge, rinse and CIP liquor can have similar COD figures yet behave very differently. The split among solids, fat, protein, lactose and other solutes determines what a mechanical barrier can remove. Sample different production states; a composite may hide the episode that fouls a membrane.
Ultrafiltration is often a candidate for particle and macromolecule clarification. Nanofiltration adds selectivity toward smaller species, depending on material, cut-off, charge and chemistry. A technology label cannot predict COD removal percentage without the mixture and membrane.
| Feed datum | Decision it informs |
|---|---|
| Total and soluble COD | Load associated with solids versus dissolved material. |
| Fat and protein | Deposit risk, preclarification and cleaning. |
| Conductivity, calcium and pH | Selectivity, scaling and concentrate destination. |
| Flow and CIP episodes | Equalisation and module compatibility. |
Staged trial with a balance across both outlets
Start with segregation and equalisation where possible. Compare a preclarified sample with the original before testing NF. During a pilot campaign covering production changes, record flux, pressure, temperature, recovery, cleaning frequency and permeate quality. Measure COD, target species and salts in feed, permeate and concentrate; close the mass balance.
Tetra Pak describes the distinct roles of UF, NF and RO in dairy processing. That helps select trials, but a variable wastewater is not the same as a dairy product stream. If reuse specifications require reduction of salts or solutes that NF passes, assess a downstream step or a different treatment route.
- Define permeate destination and required quality first.
- Calculate concentrate volume and destination as well as water recovery.
- Compare cleaning and replacement costs with biological treatment, UF, RO or a combination.
Where Neptuno may fit
Neptuno can evaluate a ceramic-membrane train with RO/UF stages from laboratory data and trials. The chosen NF element needs a specified barrier, geometry, cleaning compatibility and acceptance test; it cannot be inferred from the wastewater's nominal COD.
Common questions
Does ceramic NF remove all soluble COD?
No. Retention depends on composition, membrane and operating conditions; small compounds may pass and must be measured.