Ion exchange demineralization is used to remove dissolved ions contained in water. The actual removal of ions is accomplished by ion exchange on filter material called ion exchange resin. These are polymeric substances in the form of spheres, typically 0.3 – 1.2 mm in diameter, which contain a functional group capable of reversibly exchanging ions. Catex for cation exchange, annex for anion exchange, e.g. for H+ and OH- ions. Ion exchange demineralization plant consists of multiple serially installed pressure vessels containing catex and annex resins in order to remove cations and anions from water. Ion exchange works discontinuously, with alternating phases of ion exchange and regeneration. Regeneration is carried out with dilute solutions of NaOH, HCl or H2SO4. According to the required water quality, the sequence of the process line is selected. In the case of ion exchange technologies, pre-treatment of raw water (clarification, filtration, coagulation filtration) is necessary to remove colloidal substances, organic substances, iron and manganese. On the other hand, ion exchange technologies are not as demanding in terms of pre-treatment as, for example, reverse osmosis.
In particular, our company has been using the full ion-ex column technology with UPflow COunter-current REgeneration (UPCORE) for its undeniable advantages successfully since 1994. Here, the filters are filled with ionex and a small layer of inert, which compresses the ionex and allows the leaching of trapped impurities (dust fraction, suspended solids).
Benefits of UPCORE demineralisation
- Easy construction, ideal for reconstruction of existing objects
- High process flexibility (flow change, discontinuous operation)
- High quality of treated water
- Low chemical consumption in comparison with other IE systems
- Short recovery time (catex 1h, annex 1.5 h)
- Higher VSS toleration in inlet
- Self-purification
- Internal washing is part of recovery (no external tanks)
Resources
| Rapide Strata TM.pdf |
| Rapide Strata HF.pdf |
| Rapide Strata SF.pdf |