Ion Exchange System Companies
Ion exchange resin suppliers and system builders for softening, demineralization, and targeted contaminant removal.
33 specialist providers · 243 related · 28 countries
Qualified suppliers come to you.
Filter results
Country
Industry
Technology
Not sure where to start?
Showing 1-20 of 276
Buyer's guide
The buyer's guide to ion exchange system
Ion Exchange Resin Selection, Capacity Design, and Regeneration Cycle Optimisation
Ion exchange (IX) resins remove dissolved ionic species from water by exchanging them for ions from the resin matrix. Strong acid cation (SAC) resins (sulphonate functional groups, Na-form for softening, H-form for demineralisation) exchange calcium, magnesium, sodium, and other cations. Strong base anion (SBA) resins (quaternary ammonium functional groups, OH-form) exchange sulphate, chloride, nitrate, bicarbonate, and silica.
Weak acid cation (WAC) and weak base anion (WBA) resins have higher regeneration efficiency (80 to 90 percent vs 30 to 50 percent for strong resins) but operate only within specific pH ranges. Total exchange capacity for a typical SAC resin: 1.8 to 2.0 eq per L of resin; working capacity (useful before breakthrough) typically 50 to 70 percent of total capacity.
Column design parameters: empty bed contact time (EBCT) of 2 to 6 minutes for softening, 4 to 8 minutes for demineralisation; service velocity 5 to 15 m per hr; bed depth minimum 0.75 m (to ensure adequate contact time even at minimum EBCT). Dual-train systems (two columns, one in service, one regenerating) ensure continuous supply.
Regeneration uses: SAC resin with NaCl (softening, 80 to 120 g NaCl per L resin) or H2SO4 (demineralisation, 100 to 150 g H2SO4 per L resin); SBA resin with NaOH (50 to 60 g NaOH per L resin); nitrate-selective resin with NaCl brine (requires high salt doses, generates high-chloride regenerant). Regenerant waste requires neutralisation before sewer discharge (typically to pH 6 to 10).
Speciality resins extend IX beyond basic softening and demineralisation. Chelating resins (iminodiacetic acid) selectively remove heavy metals (Ni2+, Cu2+, Pb2+) from high-TDS brine streams where SAC would saturate on Ca2+. Nitrate-selective resins achieve below 10 mg per L NO3-N in drinking water (EU DWD 2020 limit 50 mg per L as NO3, WHO 50 mg per L).
Arsenic-selective resins (iron-oxide-based or hydrous zirconium oxide) achieve below 10 micrograms per L As. PFAS-selective resins (single-use or regenerable) achieve below 70 ng per L sum PFAS (US EPA health advisory). Borate-selective resins for seawater RO permeate polishing achieve below 0.5 mg per L B (WHO guideline). Each speciality resin has unique regeneration chemistry and waste handling requirements.
Frequently asked questions
What is the difference between water softening and deionisation?
Water softening uses strong acid cation (SAC) resin in sodium (Na) form: calcium and magnesium ions are exchanged for sodium ions, removing hardness while leaving total dissolved solids unchanged (hardness salts replaced by equivalent sodium salts). Product water has near-zero hardness (below 0.5 mg per L CaCO3) but still contains all other dissolved ions. Deionisation (DI) uses SAC resin in H form plus strong base anion (SBA) resin in OH form: all cations are exchanged for H+ and all anions for OH-, producing pure H2O. Product water conductivity is 1 to 5 microS per cm (two-bed DI) to 0.055 microS per cm (mixed-bed). DI is used where total ion removal is required (pharmaceutical, semiconductor, high-pressure boilers). Softening is used where only scale prevention is needed. Cost: softening regenerant (NaCl) costs $0.10 to $0.20 per m3 treated; DI regenerants cost $0.50 to $2.00 per m3 depending on feedwater TDS.
How often does an ion exchange resin need to be regenerated?
Regeneration frequency depends on resin working capacity and treated water volume. For a SAC softener treating 500 mg per L hardness water at 10 m3 per hr with 1,000 L of resin (capacity 1.8 eq per L, working capacity 50 percent = 0.9 eq per L): total working capacity = 900 eq; hardness load = 500 mg per L as CaCO3 divided by 50 mg per mEq = 10 meq per L; throughput before regeneration = 900 eq divided by 10 meq per L = 90 m3. At 10 m3 per hr, regeneration required every 9 hours. For low-hardness water (150 mg per L), throughput extends to 30 hours before regeneration. Ion exchange control systems use inline conductivity meters to detect breakthrough (rising product hardness or TDS) and trigger regeneration automatically, optimising chemical consumption versus treating water beyond capacity.
Can ion exchange remove nitrate from drinking water?
Yes. Nitrate-selective anion exchange resins (based on Type II quaternary ammonium with longer alkyl chains, e.g. tributylamine quaternary ammonium) preferentially remove nitrate over sulphate, unlike standard Type I SBA resins which have higher affinity for sulphate than nitrate. Standard SBA resins exhibit the 'nitrate chromatographic peaking' problem: when sulphate-loaded resin regenerates, it temporarily ejects previously captured nitrate at concentrations above the inlet, risking product water nitrate spikes. Nitrate-selective resins avoid this problem and achieve product water below 10 mg per L NO3-N (WHO and EU DWD limit: 50 mg per L as NO3, equivalent to 11.3 mg per L as N). Regenerant waste from nitrate IX contains high-nitrate brine requiring specialist disposal or agricultural land application under permit.
What causes ion exchange resin to degrade?
Resin degradation causes: (1) Oxidative degradation from free chlorine above 0.1 mg per L (particularly for SBA resin, causing loss of quaternary ammonium functional groups; anion resin requires dechlorination to below 0.05 mg per L before IX); (2) Osmotic shock from rapid changes in ionic concentration during regeneration (size of resin beads cycles, causing cracking); (3) Fouling by iron (above 0.3 mg per L) and manganese (above 0.05 mg per L) oxidising on the resin surface and blocking exchange sites; (4) Biological fouling in warm, nutrient-rich water (requires biocide treatment of feedwater or periodic resin sanitisation with NaOCl); (5) Physical attrition from backwash hydraulics (bead breakage at velocities above design). New resin loses 3 to 8 percent of capacity per year under normal operating conditions; expected service life 8 to 15 years.
Illustrative scenario · Semiconductor manufacturing
A composite drawn from typical projects in this category, not a single client engagement. Figures are indicative.
- Challenge
- A semiconductor component manufacturer in Scotland required ultrapure water (UPW) at below 0.1 microS per cm conductivity for rinsing operations. The existing two-bed IX system was consuming 1,200 kg of H2SO4 and 800 kg of NaOH per month and producing regenerant waste that attracted high trade effluent surcharges. Resin was being replaced every 4 years due to chlorine damage from inadequately dechlorinated mains supply.
- Approach
- Retrofitted a dechlorination step (sodium metabisulphite dosing plus activated carbon guard filter) before the existing cation vessel, eliminating chlorine damage to anion resin. Replaced the two-bed IX with an RO pre-treatment stage (removing 97 percent of TDS) followed by a single-pass CEDI unit, reducing IX regenerant consumption by 85 percent. The CEDI unit regenerates electrochemically using applied DC current with no added chemicals.
- Outcome
- Regenerant chemical consumption fell from 2,000 kg per month to 180 kg per month (for residual mixed-bed polishing only). Trade effluent surcharges for brine disposal fell by 22,000 GBP per year. Resin service life extended from 4 to an expected 12-plus years with no chlorine exposure. UPW conductivity consistently below 0.055 microS per cm (pure water theoretical value).
Questions to ask shortlisted providers
5
- 01
What is the TDS and ionic composition of our feed water, and have you modelled the optimum combination of softening, RO, and IX to minimise total lifecycle cost?
For feedwater above 300 to 500 mg per L TDS, RO as a pre-treatment stage before IX or CEDI typically reduces chemical consumption by 80 to 95 percent and extends resin service life dramatically. The economic crossover point between IX-only and RO plus IX depends on feedwater TDS, flow rate, and local chemical and energy costs. A supplier who proposes IX-only without analysing RO integration may be defaulting to the familiar rather than the optimal.
- 02
What chlorine removal and iron removal pretreatment are included in the system design, and how will these be maintained?
Free chlorine above 0.1 mg per L irreversibly damages SBA anion resins, shortening service life from 10 to 15 years to 3 to 5 years. Iron above 0.3 mg per L fouls resin exchange sites. These pretreatment steps (activated carbon, sodium metabisulphite dosing, iron removal filter) must be included in the design and maintained proactively. A supplier who does not explicitly address these in the design is exposing you to avoidable accelerated resin replacement cost.
- 03
What is the regenerant chemical waste volume and composition, and have you confirmed the trade effluent consent limits for discharge from this site?
IX regenerant waste (high-chloride NaCl brine, spent acid, spent caustic) must be discharged within trade effluent consent limits. Sites in high-chloride or low-pH sensitive receiving areas may have restrictive consent limits that make large IX systems impractical without regenerant neutralisation and dilution. CEDI or RO-based alternatives may be preferable specifically to avoid consent-limit constraints.
- 04
For specialty resins (nitrate-selective, PFAS-selective, arsenic-selective): what is the regeneration waste classification, and what are the approved disposal routes for spent regenerant from this application?
Specialty resins used for selective contaminant removal concentrate the target contaminant in the regenerant waste. Nitrate-selective resin regenerant contains high-nitrate brine that may require agricultural land application under Environment Agency permit. PFAS-selective resin spent regenerant, if thermally regenerated, produces high-temperature destruction residues requiring specialist incineration. Disposal routes and costs for specialty resin regenerants must be confirmed before design is finalised.
- 05
What is the expected capacity loss per year for the proposed resin under our feedwater conditions, and at what remaining capacity will you recommend resin replacement?
Resin replacement should be triggered by capacity measurement (breakthrough volume declining to a specified fraction of initial capacity, typically 70 to 75 percent) rather than by a fixed time interval. A fixed-interval replacement schedule may replace resin prematurely (wasting expenditure) or too late (allowing product quality exceedances). Ask for the annual capacity testing protocol and the defined replacement trigger.
What drives cost in this category
4
- Feedwater TDS and flow rate
- A 10 m3 per hr IX demineralisation system treating 200 mg per L TDS feedwater requires approximately 15 to 25 kg of acid and caustic per m3 of resin per regeneration cycle. At 500 mg per L TDS, chemical consumption more than doubles. At TDS above 300 mg per L, RO pre-treatment (capital 30,000 to 100,000 GBP for 10 m3 per hr) reduces IX chemical consumption by 85 percent, typically paying back in 2 to 4 years on chemical cost savings alone.
- Resin service life and replacement cost
- Standard SAC and SBA resin costs 500 to 1,500 GBP per m3. A 1,000 L vessel requires 1,000 to 1,500 GBP of resin. Under good operating conditions (dechlorinated feed, iron below 0.1 mg per L), service life is 10 to 15 years. With chlorine damage or iron fouling, service life falls to 3 to 5 years, increasing annualised resin cost by 3 to 5 times. Specialty resins (PFAS-selective, chelating) cost 5,000 to 20,000 GBP per m3, making pretreatment and operating conditions critical for economic performance.
- Regenerant chemical and waste disposal cost
- A 1,000 L IX system (SAC plus SBA) treating 200 mg per L TDS water at 10 m3 per hr requires approximately 500 to 800 kg of acid and caustic per month in regenerants at 1,500 to 3,000 GBP per month in chemical cost. Regenerant brine disposal to sewer adds 2,000 to 8,000 GBP per year in trade effluent surcharges. CEDI eliminates regenerant chemicals entirely but requires 3 to 8 kWh per m3 of electrical energy.
- Water quality target and downstream system requirements
- Softening to below 1 mg per L hardness costs 0.05 to 0.15 GBP per m3. Two-bed demineralisation to below 5 microS per cm conductivity costs 0.20 to 0.80 GBP per m3. Mixed-bed polishing to below 0.1 microS per cm adds 0.30 to 1.00 GBP per m3. CEDI to below 0.1 microS per cm costs 0.15 to 0.50 GBP per m3 in energy (lower than IX at equivalent quality if RO pre-treatment is included). The step change in cost between softening and high-purity demineralisation (5 to 10 times higher per m3) means that UPW quality should only be specified where genuinely required by the process.
Key regulations and standards
4
- Water Supply (Water Quality) Regulations 2016: WRAS Approval for IX Equipment
- Ion exchange equipment used to treat drinking water or water for food production must be approved under WRAS (Water Regulations Advisory Scheme) or listed on the DWI List of Approved Products for use with drinking water. WRAS approval (based on BS EN 14652 and related standards) ensures that resins, vessel materials, and regenerant chemicals do not impart taste, odour, colour, or toxicologically significant compounds into the treated water supply.
- Environment Agency Trade Effluent Consent: Regenerant Discharge Limits
- IX regenerant brine discharge to sewer requires trade effluent consent under WIA 1991 Section 118. Common consent limit parameters affecting IX systems: chloride (typically 1,000 to 5,000 mg per L limit, which high-brine IX regenerant may exceed), pH (6 to 10 range, which acid regenerant violates requiring neutralisation), and conductivity (indirect TDS indicator). Systems producing out-of-consent brine must collect and arrange specialist disposal rather than direct sewer discharge.
- EU Drinking Water Directive (2020/2184) and UK Implementation: Nitrate and Arsenic Limits
- The EU DWD 2020 (retained in UK as the Water Supply (Water Quality) Regulations 2016, amended) sets parametric values for nitrate (50 mg per L as NO3), arsenic (10 micrograms per L), and fluoride (1.5 mg per L). Ion exchange systems used to achieve these limits in drinking water (nitrate-selective, arsenic-selective resins) must comply with DWI product approval requirements and must demonstrate consistent compliance with these limits under a validated monitoring programme.
- COMAH 2015: Chemical Storage for IX Regenerants Above Threshold Quantities
- IX regenerant chemical storage of concentrated H2SO4 (above 30 percent, SG 1.22) and concentrated NaOH (above 32 percent) above COMAH lower-tier threshold quantities (H2SO4: 50 tonnes, NaOH: not COMAH-listed but PIC Directive-notifiable) requires COMAH safety report and emergency planning. Most IX installations hold below these thresholds (typically 5 to 10 tonne IBC or day tank), but larger industrial water treatment plants require COMAH compliance assessment as part of site design.