Key issues in Seawater Desalination
Access to sufficient quantities of water for drinking and domestic uses and also for commercial and industrial processes is critical to health and well being. With growth of world population the availability of the limited quantities of fresh water decreases. From the 71% earth surface water, 97.4% is sea water and 2.6% is fresh water.
With the advances of desalination technologies, sea water has become an interesting water source to cope with fresh water shortage. This process can be applied wherever a reliable source of water is needed.
Seawater is also reach in minerals which have market interest. With the large demand of salt in many geographical areas, producing salt.
The most widely applied and commercially available technologies for sea water desalination can be divided in two types: membrane processes and thermal processes.
Reverse osmosis (RO) and Nanofiltration (NF) are currently the leading sea water desalination solutions. The advances in key equipment (membranes, pumps, energycost recovery device), turned the process energy efficient, resulting in a low investment cost (CAPEX) and low operational cost (OPEX).
Nowadays, desalination* has become a very affordable solution to cope with fresh water shortage typically in tropical as well as of off-shore 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.
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
Also misspelled Desaltation, Desalinization, Desalinisation, Desalisation, Desalization or Desal Plant