Loose-rejection membrane separation between UF and RO, used for hardness reduction and partial demineralisation before an RO stage.
- Active
- Available
Ion Exchange IX / IER
Exchanger-based demineralisation and softening, sized by resin volume, bed area, service flow and regenerant demand.
Overview
Exchanger-based demineralisation and softening, sized by resin volume, bed area, service flow and regenerant demand.
How it works
Separation mechanism and feed window. Prefers low-turbidity feed with controlled organic load, since fouling of the resin bed is difficult to reverse.
What the process produces. A demineralised or softened stream with a controlled ionic composition and a defined breakthrough point.
Energy. Low pressure, but regeneration consumes significant chemical and water.
Process sequence
Where this technology normally sits in a treatment train. The steps either side of it are documented in the Library as separate entries.
- Pretreatment
- Ion exchange (IX)
- Primary separation (RO)
Typical applications
- Softening and alkalinity control ahead of RO
- Demineralisation of low-TDS feed for high-purity product
- Polishing after RO or NF where very low conductivity is required
Main equipment
- Ion exchange vessel and resin bed
- Regeneration skid
- Service and regeneration pumps
- Resin transfer and separation equipment
Key design parameters
The parameters an engineer actually sets, and why each one drives the design. EngiMetric does not assume any of them.
| Parameter | Why it matters |
|---|---|
| Service flow rate | Together with resin volume, sets empty-bed contact time. |
| Resin volume | Sets throughput to breakthrough. |
| Bed depth | Sets bed area for the chosen service flow. |
| Ion loading | Drives regenerant mass and volume per cycle. |
Advantages
- Removes dissolved ions that membrane barriers may not fully reject.
- Well understood and controllable on a single service/regeneration cycle.
- Selective — divalent removal can precede RO cheaply.
Limitations
- Regeneration produces a brine of its own.
- Organic fouling of resin is largely irreversible.
- Run-to-waste during regeneration is a real availability and cost factor.
Engineering considerations
- EngiMetric computes stoichiometric regenerant demand from ion loading; it does not model resin kinetics or leakage curves.
- Breakthrough is a time/volume outcome, not a concentration guarantee.
Status and EngiMetric support
Industry maturity and commercial status describe the technology itself. EngiMetric support and quantitative modeling describe what this platform does with it — and those two are read from the engineering registry at build time, so they cannot drift from the code.
- Engineering maturity
- Mature How established the technology is in the industry. Not an EngiMetric claim.
- Commercial status
- Established Where the technology sits in the market. Not an EngiMetric claim.
- EngiMetric support
- Active Derived from the execution registry: ix is registered as supported.
- Design engine
- Planned Whether the Plant Designer can carry this as a configured process step.
- Quantitative modeling
- Available Derived: 2 of 2 registered capabilities run a deterministic engine.
What EngiMetric computes
These capabilities are registered in the EngiMetric execution registry. Each one runs a deterministic engine, so every result is reproducible from the inputs you supply.
- IX resin bed sizing calculateIxBedSizing
- IX regeneration demand calculateIxRegeneration
Related tools
Every tool below exists and is live. EngiMetric does not duplicate a formula here — the calculation lives in the tool, and this page links to it.
- Ion Exchange (IX / IER) Bed Sizing Resin volume and bed area from service flow and EBCT, plus stoichiometric regenerant demand.
- Water Analysis & Treatment Selection Ion loading and hardness that decide the resin volume and the regenerant dose.
- Water Tank Storage Calculator Storage volume the treated stream needs ahead of the next stage.
Sources and references
- Exchange capacity — Resin datasheet; supplied by the engineer.
EngiMetric does not publish a bibliography of external literature for catalogued technologies. Where a figure is required, it is entered by the engineer from a datasheet or a published reference, and it is labelled as an input.