PMC Introduces Closed Circuit Reverse Osmosis (CCRO) technology

Closed-Circuit Reverse Osmosis (CCRO) Technology

Closed-Circuit Reverse Osmosis (CCRO) is a semi-batch reverse osmosis configuration designed to increase water recovery and reduce concentrate volume compared to conventional multi-stage RO—especially where wastewater disposal is expensive or discharge limits are strict.

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What problems does CCRO solve?

Conventional RO runs continuously and typically requires a concentrate stream to maintain stable operation. That can mean:

• Higher concentrate volumes (more water wasted)

• Higher operating cost for disposal / hauling / evaporation

• Higher scaling/fouling risk at high recoveries

CCRO is commonly considered when you need high recovery and stable membrane operation on difficult waters (e.g., variable feed, high silica, reuse applications).

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How CCRO works (simple explanation)

CCRO operates in repeating sequences:

1. Pressurize & produce permeate (RO filtration mode)

2. Recirculate concentrate in a closed loop to push recovery higher in a controlled way

3. Short flush / brine purge to remove concentrated brine and help control scaling

4. Repeat with adjustable cycle settings based on feed water and recovery target

This “recovery over time” approach is why CCRO is often described as semi-batch RO.

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CCRO vs conventional RO (what changes in practice)

Note: performance depends heavily on feedwater chemistry, pretreatment, and how concentrate is handled.

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Key benefits (where CCRO can win)

1) Higher recovery = less brine to dispose
Industry sources commonly cite brine reduction up to ~75% in some comparisons versus traditional RO designs.

2) Potential energy efficiency improvement at high recovery
Peer-reviewed modeling work reports CCRO energy savings up to ~37% versus continuous RO in certain brackish desalination scenarios at high recovery.

3) Operational flexibility
Recovery and cycle settings can be adapted to changing feedwater conditions—useful for industrial reuse and variable sources.

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Where CCRO is used

CCRO can be applied anywhere conventional RO is used, especially when recovery and disposal cost matter:

• Industrial process water and rinse water recovery

• Food & beverage / ingredient water

• Boiler feed pretreatment

• Brackish desalination and irrigation supply

• Municipal tertiary effluent polishing / reuse

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CCRO design notes (what we engineer around)

A high-recovery RO project succeeds or fails on fundamentals:

• Feedwater analysis & scaling indices (silica, hardness, alkalinity, sulfate, etc.)

• Pretreatment selection (media filtration / UF / cartridge, dechlorination strategy)

• Antiscalant & pH control strategy

• Instrumentation + automation (conductivity, flow, pressure, SDI where relevant)

• CIP strategy (designing to minimize frequency, but still making cleaning easy)

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What PMC Engineering can deliver

• CCRO system concepting and feasibility (target recovery vs disposal constraints)

• Full skid design and supply (pumps, membranes/vessels, automation, instrumentation)

• Retrofit studies for existing RO plants

• Commissioning support and operating optimization

CTA: Share your feedwater analysis + required permeate flow + discharge limits, and we’ll propose a CCRO concept and budgetary offer.