Membranes

Reverse Osmosis (RO) PlantsClean water, molecule by molecule.

An RO plant pushes water through a semi-permeable membrane under pressure, leaving dissolved salts and impurities behind. You get low-salt water for drinking, boilers and processes.

Request a proposalHow it works
  1. 01Pre-filtration
  2. 02Antiscalant dosing
  3. 03Cartridge filter
  4. 04High-pressure pump
  5. 05RO membranes
  6. 06Storage

What it is

In plain words.

In natural osmosis, water moves through a membrane towards the more concentrated side. Reverse osmosis applies enough pressure to push it the other way. Water molecules pass through the membrane; most dissolved salts, organic matter, bacteria and viruses do not. Common salts are rejected at a nominal 85 to 98 percent. The clean water, called permeate, goes to storage, and the concentrated reject goes to drain or further treatment.

RO goes beyond what ordinary filters can do, without adding chemicals to the product water. It is only as good as its pre-treatment, which protects the membranes from silt, scale and chlorine. We design the full train, from filters and dosing to membranes and controls, then install, commission and maintain it. With regular cleaning and timely filter and membrane changes, an RO system can serve 7 to 10 years.

How it works

Stage by stage.

  1. Pre-filtration

    Sand and carbon filters, or UF, remove silt, turbidity and chlorine that would damage the membranes.

  2. Antiscalant dosing

    A chemical is dosed to stop salts scaling on the membrane surface as they concentrate.

  3. Cartridge filter

    Fine cartridges catch any remaining particles just before the high-pressure pump.

  4. High-pressure pump

    The pump raises pressure above the osmotic pressure, so water is forced through the membrane.

  5. RO membranes

    Water passes through as permeate. Dissolved salts and impurities leave in the reject stream.

  6. Storage

    Permeate is stored for use, with a check valve preventing backflow from the tank.

Options

Built to suit the site.

  • Brackish water RO

    For borewell and surface water with high dissolved solids, producing drinking or process water.

  • Recycle RO

    Treats effluent or sewage after biological treatment and UF, so water returns to the process.

  • RO with mixed bed

    RO followed by a mixed bed polisher, for boiler feed or pharma water that needs very high purity.

Where it's used

Industries and sites.

  • Drinking water
  • Pharmaceuticals
  • Boiler feed
  • Food & beverage
  • Hotels & hospitals
  • Effluent recycling
  • Packaged water

See how we work with each industry →

What we deliver

One team, from survey to service.

  • 01

    Design

    Survey, water or effluent analysis, process design and sizing for your site.

  • 02

    Build

    Supply, fabrication, civil and mechanical works, installation and commissioning.

  • 03

    Automate

    PLC, SCADA and remote monitoring, so the plant can be seen and controlled from anywhere.

  • 04

    Maintain

    Operation, preventive maintenance and AMC under Zeal-Care, with written reports.

Questions

Asked before every project.

What affects how well an RO plant works?

Feed pressure, water temperature, the amount and type of dissolved solids, and the quality of pre-treatment. Cold water passes more slowly, and poor pre-treatment fouls membranes quickly.

What happens to the reject water?

The concentrated stream goes to drain or, in industry, to further treatment and recovery. In a zero liquid discharge plant, it goes to evaporators so that no liquid leaves the site.

How do I keep the membranes healthy?

Keep pre-treatment working, dose antiscalant, change cartridges on time and clean the membranes when output or quality drops. We can do all of this under an AMC.

Membranes

Often built together.

Tell us about your site.

Share your flow, location and timeline. An engineer will review your requirement and call you back within one working day.

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