Key issues in Seawater Desalination
Nowadays, desalination* has become a very affordable solution to cope with fresh water shortage typically in tropical as well as of offshore areas. The desalination core process is based on Reverse Osmosis Membrane technology, but stand alone, it doesn’t provide safe drinking water, nor does it guarantee an efficient plant.
The pretreatment includes all the necessary treatment step ahead of the reverse osmosis plant. It is determining for plant life time and to minimise chemical cleaning and membrane replacement. It has a direct impact on the plant performance. There are as many membrane types as applications. They range from “high rejection” to “ultra low energy” or ” high boron rejection”.
The reverse osmosis process can also be built with one or two passes, depending on the product water requirements and the seawater salinity and temperature. In most cases, 1 pass is sufficient to reach the EU drinking water standards, specially regarding the boron content (1 mg/L). To reach WHO boron guideline (0.5mg/L), a second pass might be necessary (Boron removal process)
The energy recovery device is the key factor that determines the plant electrical costs. It must be chosen carefully based on the local energy costs and environment policies. Post-treatment and/or polishing steps are required to condition the water after the reverse osmosis membrane process to make it suitable to your application.
Brine disposal can be an environmental and economical issue in some areas where the fauna and flora are sensitive to local seawater salinity increase. Brine disposal should be studied and engineered case by case. The art of desalination is to determine and combine available technologies to optimize water production costs and quality. To adapt our Desalination Plants to your local needs, we offer containerized mobile units from Intake to Distribution up to a production capacity of 200 m3/h of desalinated water.
All type of water can be produced from a desalination plant:
- WHO or EU drinking water
- Irrigation water
- Process water : boiler feed water, cooling water
- Demi or Ultrapure water
All type of natural seawater source can be treated
- Shallow Surface seawater
- Deep seawater
- Brackish river water
- Beach well seawater
All essential process steps in desalination plants