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.

Regeneration of ion exchanger resins Hosing
Regeneration of ion exchanger resins Post-treatment of ion exchanger regenerates
Regeneration of ion exchanger cartridges to be regenerated externally
Regeneration of ion exchanger resins mixed bed system

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.

So-called mixed bed resins (e.g. from a demineralization cartridge / demineralization cartridge) with a mixture of cation and anion resins are first separated from each other in a separation column for mixed bed resin regeneration when the demineralization cartridge is exhausted, then transferred (regenerated) to the H+ or OH- form in separate containers and finally homogenized again in the initial mixing ratio as mixed bed resin. If no proprietary regeneration or closed-pool has been agreed, this results in a mixture of different resins and customer applications. Regeneration should take place as soon as the outlet conductivity rises for the first time, otherwise the demineralization cartridge will be overrun.

In principle, any ion exchanger or ion exchanger cartridge can be regenerated, including UPW mixed bed resins, e.g. for semiconductor production with rinsing, e.g. up to < 0.08 µS/cm. However, depending on the loading, an extremely strong bond between the head group and the adsorbate can make it almost impossible to remove the bound substance. In this case, it is an actual single-use application due to the preliminary process.

As part of the commissioning phase, the technical parameters of the respective process are first validated for general suitability for regeneration (e.g. loading process, any interfering loads such as mineral oils, precipitation, blockages). After ordering the regeneration of ion exchangers, a phone call or a delivery bill is sufficient to place the individual order, depending on the agreement. The loaded ion exchanger, i.e. ion exchanger cartridge or demineralization cartridge, is disconnected from the system and drained of residual water (e.g. using compressed air < 0.5 bar). Instead of the removed cartridge, the 2nd cartridge therefore switches to the first position and an optional additional cartridge takes the place of the 2nd cartridge. The ion exchanger cartridge that has been emptied of residual water is now sent to the central regeneration station for ion exchangers in 92348 Berg either via one of our tours or by a forwarding agent. Regeneration usually takes place within 14 days, in the case of urgent regenerations within 1-2 working days by arrangement. Depending on the agreement, the ion exchanger cartridge is then delivered again on the next tour or sent by a forwarding agent or the customer’s own forwarding agent is informed that it is ready for dispatch. If the ion exchanger can no longer be regenerated due to age, loading, contamination or similar, the ion exchanger will be replaced (resin replacement) after consultation.
Polisher mixed bed resins or Ultra Pure Water (UPW) mixed bed exchangers are ion exchangers that are used for the fine purification of demineralized water in ultrapure water production, e.g. after electrodeionization. These are generally higher quality resins that have a higher capacity and better binding behavior towards residual contamination in demineralized water.

As a rule, this is a closed-pool or proprietary regeneration of the ion exchanger mixed bed resins, as no mixing with other customers is desired here. On the one hand, this would reduce the quality of the resins, and on the other hand, this is the only way to monitor the resin quality over the service life of the ion exchangers over the years.

So-called non-regenerable disposable mixed-bed resins are also frequently used to ensure consistent quality. However, these resins, which are labeled as non-regenerable, can also be regenerated in a special process and retain their consistent quality.

Regeneration of ion exchanger resins Mixed bed resin semiconductors

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.