The Desalination Process

We plan to purify the groundwater in Dajarra by utilizing basic desalination system. We plan on using solar power as well as hydrophobic membranes in order to separate the pure water from the brackish, salty water. The process we will use is a direct contact hydrophobic membrane desalination system. The most important part of the design are the hydrophobic membranes – they are the filter that separates the pure water from the salt concentrate. A partial pressure difference serves as the driving force that allows water vapour to filter through the pourous holes in the membrane and separate from the salt concentrate. This pressure difference can be generated by heating the water to approximately 60-80°C.

The basic units for the desalination unit include a solar thermal collector/solar hot water heater and the membranes themselves. The solar thermal collector, powered by the sun, will heat the groundwater as it passes through the collector. The water will then pass over the membrane, where the water vapour will filter through and condense on the other side – forming pure, clean water. The salt concentrate – known as brine – has several commercial applications – the simplest of which includes serving as a preservative for certain foods and meats. The direct contact membrane desalination process is a simple process as it has low technical maintenance and compared to other desalination techniques, is very inexpensive.