GREEN TECH
IN JANUARY OF 2014 , the governor of California in the United States declared a state of emergency : The Sierra snowpack , a key measurement of water shortage in the state , was at levels the region had not experienced since the 1950s ; in fact , 2014 was the state ’ s third driest year in over 100 years .
As California ’ s drought moves into its third year , the resulting complications are proving to be devastating . In an attempt to preserve resources , local water departments are rationing water and the government has implemented mandatory consumer reductions , but it ’ s not enough — and the Pacific Ocean may be the solution .
Seawater desalination isn ’ t a novel idea : The Middle East began working to make the Mediterranean potable water some 60 years ago , and California briefly opened a plant in Santa Barbara County in the 1990s during the state ’ s last major drought .
With 15 plant locations in consideration along California ’ s coast , the implementation of desalination is almost inevitable . In fact , officials are gearing up to open one of the world ’ s largest desalination plants in San Diego County for about USD $ 1 billion later this year . The result is expected to be water for 300,000 people in the area .
Various technologies are used for seawater desalination :
THERMAL TECHNOLOGY Thermal desalination uses energy to evaporate water and then condense it , thus removing salt in the process . 1 . High-powered vacuums bring cold , deep sea water into the plant .
2 . The seawater is sprayed into a temperature-controlled space repeatedly to vaporize and then condense it at repeatedly low temperature levels .
MEMBRANE TECHNOLOGY In membrane desalination , the separation of water and salt occurs due to a phase change . 1 . A hydrophobic membrane creates a barrier for the liquid phase and allows the vapor to pass through the membrane ’ s pores .
2 . A temperature change occurs when high-pressured salt water is forced through tight rolls of thin , plastic membranes .
3 . The salt separates from the water in a process called thermodynamics .
8 August 2015