ION EXCHANGER REGENERATION
Ion exchanger regeneration as a service includes the external regeneration of ion exchangers or ion exchanger cartridges / a demineralization cartridge a.o. from applications such as UPW or demineralized water production, semiconductors, circulation of rinsing water, groundwater remediation and selective removal of heavy metals e.g. copper, nickel, chromium (selective exchanger resin) in an industrial plant.
Regenerate and condition ion exchangers (or ion exchanger resin or ion exchanger cartridges)
Ion exchangers in ion exchanger cartridges (e.g. selective exchangers to be regenerated externally or a demineralization cartridge or VE-cartridge) are similar to filters in their effect. The ion exchangers are charged by substances dissolved in the water as long as there is still sufficient capacity. An exchange takes place against the ions present on the ion exchanger (from the delivery form, regeneration or activation) in accordance with the selectivity series. Ions (already bound) that have a lower selectivity compared to the ion exchanger resin and are therefore bound more weakly are displaced by ions with a higher affinity from the head groups of the ion exchanger resin and enter the outlet of the ion exchanger. This exchange process takes place continuously until loading is stopped and the resins are returned to their original state by means of regeneration, i.e. they are regenerated with chemicals in excess. During the regeneration of ion exchangers, the ions previously bound in the process are released from the ion exchanger and the exchanger is returned to its original operational state.
This regeneration process differs depending on the ion exchanger used and the application in which the ion exchanger resin is used (e.g. demineralization cartridge / VE-cartridge or selective exchanger or circulation ion exchanger). Cation exchangers, i.e. sulphonic acid exchangers (SAC) and carboxylic acid exchangers (WAC), are usually regenerated with an acid. Weakly and strongly basic anion exchangers, i.e. teritary amine exchangers (WBA) and quaternary amine exchangers (SBA), are usually regenerated with an alkaline solution. Selective exchangers, so-called IDE exchangers (iminodiacetic acid exchangers), are regenerated with acid like cation exchangers. Special exchangers such as thiourea exchangers or bispicolyanimine exchangers require special treatment.
As part of the regeneration of ion exchangers, the bound substances are eluted from the ion exchanger, e.g. the hardness formers Ca/Mg or the heavy metals Ni, Cr(III)/(VI), Cu, Zn, Pb. The various ion exchangers are then converted into the desired form, known as activation. Cation exchangers are usually converted into the H+, Na+, Ca+, K+ form or protonated ammonium form (NH4), anion exchangers usually into the OH-, Cl- or NH3- form. The process takes place entirely in a WHG safety zone and the eluted substances are treated in the company’s own wastewater treatment plant CP according to the state of the art.
The regeneration of ion exchangers is a service that requires extensive individual steps, depending on the requirements of the resin, the loading and the pre-cleaning process. To ensure success, a considerable amount of equipment is required to supply the necessary media, such as various acids, alkalis, activation chemicals, compressed air, vacuum, sterilized DI-water < 0.1 µS/cm and city water.
Some new resin types require either a special form for their use that differs from the delivery form, such as standard selective exchangers, which regularly have higher capacities and lower slip in the mono-sodium form. Other exchangers, such as strongly basic type I anion exchangers, require pre-cleaning to remove production-related impurities before they can be used.
Ion exchanger regeneration takes place under optimum process conditions
- Regeneration of ion exchanger demineralization cartridge / VE-cartridge or mixed bed resin (< 0.1 µS/cm) or UPW mixed bed resins (< 0.08 µS/cm) from ultrapure water production (e.g. mixed bed polisher ion exchanger after electrodeionization) as closed-pool regeneration.
- Regeneration of heavy metal, chromate or cyanide loaded ion exchangers or selective exchangers or the ion exchanger resins contained therein (selective exchanger resins, cation exchanger resins or anion exchanger resins) e.g. from waterworks, municipal sewage treatment plants, electroplating, groundwater remediation or as final exchangers in an industrial wastewater treatment plant
- Delivery emptied of residual water in cartridges (4L – 2000L) or in containers (e.g. 220 liters PE barrel, big bag), dispatch by forwarding agent or by tour.
- Specific pre-treatment of the resins
- Regeneration using the 2-column principle with separation of anions and cations to avoid cross-contamination or unregenerated interface areas
- Continuous view of the resin bed and any contamination
- Cleaning, separation and regeneration under various technical conditions such as pressure top/bottom, negative pressure top/bottom, swirling compressed air, swirling and rinsing with sterilized DI-water < 0.1 µS/cm or city water.
- Prevention of carry-over in the system by rinsing steps
- Optional proprietary regeneration without external admixture for mixed bed resins (from 400L). Selective resins, anion resins and cation resins are always proprietary regenerations (i.e. no external admixtures)
- Regeneration also of UPW mixed bed resins (e.g. Ultra Pure resins or Polisher resins, which are downstream of reverse osmosis with electrodeionization (EDI) to produce ultrapure water)
- Conversion/conditioning of ion exchangers according to customer requirements in special processes (e.g. cation exchangers in H+, Na+, Ca+, K+ or protonated ammonium form, anion exchangers in OH-, Cl-, NH3- form)
- Removal of production-related impurities (e.g. odour of fish of the ion exchanger ).
- Exchange of upstream filter stages such as activated carbon, surfactant/scavenger resins, gravel/sand filters.
- Special regenerations possible
- Replace ion exchangers with new ion exchangers if regeneration is no longer possible.
We will be happy to send you a quote for ion exchanger regeneration. Contact us without obligation.