Sea Water Desalination and Efficient and Cost-Effective Treatment of Sludge

With the worldwide population growth and the resultant increase in demand for fresh water for municipalities, agriculture and industry, there is a corresponding increase in the challenges for the need to assure global water demand with innovative technologies. This is because, whereas demand for fresh water is rising, there is a corresponding decline in its availability, and not only climate change but also environmental contamination are further exacerbating the worldwide water crisis. The trend is therefore increasingly moving in the direction of recovering drinking water from salt water. GEA is supporting this development with powerful decanters which enable procedures for sea water desalination to be designed with economic as well as ecological efficiency.

Header Blue Sea

The three most important processes in sea water desalination are:

  • RO       – Reverse Osmosis (membrane process)
  • MED    – Multi-effect distillation
  • MSF     – Multi-stage flash

Evaporators are used in the MED- and MSF-processes. These operate under vacuum in order to achieve the best performance rate. In all cases, the vacuum is created using multi-stage steam jet vacuum pumps. Together with the corresponding condensers, these vacuum pumps are an integral part of the evaporation plant and are therefore becoming an increasing focus of attention. 

Reverse osmosis is one of the most common methods for the desalination of sea water. In order to remove the insoluble substances in sea water, a flotation or ultrafiltration unit is generally installed upstream of the processing installations. This results in sedimented sludge and back-flush water, which have to be disposed of as a result of organic contamination. 

Volume-reduced sludge lower disposal and transportation costs

The use of GEA decanters enables transportation and disposal costs to be efficiently reduced, as these machines reliably separate the sludge into solids and reusable water. Thanks to their high dewatering capacity, they are able to concentrate the solids up to 25 percent dry matter; this results in a considerable reduction in volume and correspondingly lower disposal costs.

Maximum reliability thanks to robust design

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In order to permanently avoid corrosion even in conditions of extremely high chloride ion content in sea water, we only use high-quality materials for designing our decanters. All components which come into contact with product are therefore generally made from duplex/super duplex steel, and feature maximum reliability.

  • Decanter for concentrating sediment and filtration back-flush water
  • Reduction in the consumption of water
  • Volume-reduced solids with high dry matter content
  • Lower transportation and disposal costs
  • Robust design due to use of corrosion-resistant materials