Desalination Technologies

Desalination is a well established method of removing salts from water in order to produce process water, ultrapure or potable water. This is accomplished through using membranes (reverse osmosis and nanofiltration) and thermal processes (multi effect distillation, evaporation and crystallisation).

This mainly involves the production of freshwater from saltwater by introducing energy to pump the water through a semi-permeable membrane or a heat source for evaporation. It can also be used to recover valuable products for the manufacturing industry.

The different water qualities can be produced by a selection of systems including membrane or thermal technologies designed to treat industrial or municipal wastewater, seawater, brackish groundwater, surface water or potable water. The alternative solutions include:

  • Membrane processes - reverse osmosis and nanofiltration 
  • Thermal processes - multi effect distillation, evaporation and crystallisation technology

Of the world’s total water supply, only 3% is fresh water. Seawater constitutes the remaining 97%. With Veolia Desalination technologies, seawater is converted to process water for industry and potable water for municipalities. Complete the enquiry form to get more info on our desalination technologies.

Almost one quarter of the world's population lives within less than 25 kilometres of the coast and seawater covers 71% of earth's surface. Desalination therefore presents an effective solution to the challenges of rapid population and economic growth that are leading to water shortages. Veolia Water Technologies has over 100 years of desalination experience dating back to the first thermal desalination units in 1890.

Processes & Technology

  • Reverse osmosis (RO)
  • Multiple effect distillation (MED)
  • Multi-stage flash (MSF)
  • Hybrid systems using thermal and reverse osmosis

Selection of the most appropriate solutions

The development of the technologies over the last ten years has reduced capital, operating costs and especially the energy consumed.

However, the careful selection of the most appropriate solution depends on the source of the feed and the treated water quality required so that the costs and environmental impact of the solution can be minimised.

Approximately 15% of the world’s desalination plant capacity was designed and constructed by Veolia internationally. Veolia - we know water! Contact us to speak to a Veolia expert about your desalination technology needs.

Membrane solutions

Membrane desalination processes are typically applied to treat water with a lower dissolved salt content as they are less energy intensive than equivalent thermal processes. Recent improvements in energy recovery systems have increased performance of membranes and pre-treatment processes. In addition, high efficiency process designs have led to a reduction in energy consumption, while still maintaining a high product water quality.

Reverse Osmosis (RO)

RO involves pushing water under pressure through a membrane that lets through the water but retains the salt and other impurities.

Membrane separation processes are used for:

  • Desalination of seawater
  • Production of process and potable water
  • Polishing and demineralisation of boiler feedwater and pharmaceutical water
  • Rehabilitation and recycling of process and municipal effluent
  • As part of an integrated zero liquid discharge process

Thermal solutions

Thermal desalination processes are best applied to water and process streams with a high dissolved salt content, where the applied pressure required for an equivalent membrane system would be excessive. The use of a low-cost energy source, such as available from co-generation power plants, is advantageous with respect to reducing energy cost, if available. Another option is to use low temperature, high-efficiency vacuum evaporation systems that can be operated on waste heat and a low electrical energy demand.

Various Multiple Effect Distillation Configurations

  • Multiple Effect Distillation (MED)
  • Multiple Effect Distillation with Thermal Vapour Compression (MED-TVC)
  • Multiple Effect Distillation with Mechanical Vapour Compression (MED-MVC)

A Multi Effect Desalination MED unit is an evaporator where sea water is evaporated in one or more ( up to 14 ) evaporation stages at low temperature ( < 70°C ) in order to produce clean distillate water.

MED process is designed to produce distilled water with waste heat from power production or chemical processes, and to produce potable water.

Previous Projects

Veolia Water Technologies, parent company of Veolia South Africa and world leader in water treatment, has reference sites across the globe, most notably in Israel, Australia and Spain.

Veolia South Africa has used this technology for various projects:

Saldanha Iron Ore Terminal - Western Cape

A reverse osmosis desalination plant was designed, built and commissioned for Transnet's iron ore terminal in the port. The plant has a capacity of 2400m³ per day, upgradeable to 3600m³ per day, and process seawater to potable standards so that it can be used for dust suppression. An essential part of the plant's design is the inclusion of an energy recovery system which saves both money and energy consumption.

Cannon Rocks & Boknes Communities - Eastern Cape

A reverse osmosis desalination plant was supplied to these communities to supply 750m³ of treated water per day. The plant will remove dissolved salts, as a result of sea water intrusion in the ground water, from the raw water. Potable water, complying with SANS 241 specifications, is supplied. It was to be commissioned in 2009.

Holiday Resort - Mauritius

Two containerised reverse osmosis water purification plants were supplied to a four star hotel in Mauritius. The plants produce approximately 125m³ drinking water per day, and employ a number of technologies and strategies to ensure the systems are energy efficient and environmentally friendly.

I’m interested in achieving process and / or potable water through desalination technologies

Desalination Technology Enquiry

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