Page 20 - Opportunities in the Treatment of Water and Other Wast Streams

Application:
Why: Membrane distillation could be used for brackish groundwater desalination to generate hydraulic source water
Where: On-site or may be coupled with renewable energy sources at centralized off grid locations.
Membrane distillation systems can use latent heat from produced water, or heat from burning off natural gas in certain areas to reduce energy requirements
Target Contaminants:
Dissolved salts.
Membrane distillation is a thermally driven membrane separation process where constituents are separated as the heated feed solution passes through the membrane as vapor and condenses into the chilled product water. The rate of production depends on the difference in temperature between the feed and product sides of the membrane (Singh and Sirkar, 2011). A source of clean chilled water is required to start the process
Membrane distillation can be used in the same applications as reverse osmosis or nanofiltration when there are sources of economical heat and cooling available. Membrane distillation is can also be used to strip volatile compounds from a source of water, dissolving them into the cool water source or into air.
Benefits:
• Potential for off-grid systems • Modular and mobile systems • Consistent constituent removal
Limitations:
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