Shane Thielges | Shale Plays Media
One of the biggest challenges of cleaning water tainted by oil is the tendency of a small amount of either substance to form a cloud of tiny droplets, called an emulsion, within a large amount of the other. That’s why contaminated bodies of water are unsafe to drink and harmful to animal life even after booms and dredging remove all the visible oil.
Now a team of MIT researchers says they have developed a material that can separate oil and water completely, no matter how small the impure particles may be.
MIT Professor Kripa Varanasi, graduate student Brian Solomon and postdoc M. Nasim Hyder say they have developed a membrane incorporating what they call “hierarchical pore structures” that can be manufactured from small up to industrial sizes:
The membranes combine a very thin layer of nanopores with a thicker layer of micropores to limit the passage of unwanted material while providing strength sufficient to withstand high pressure and throughput. The membranes can be made with contrasting wetting properties so their pores either attract oil and repel water, or vice versa.
The team hopes these membranes will be useful not only in cleanup efforts for oil spills, but in ensuring wastewater used in hydraulic fracturing is as clean as possible before being reintroduced to the water system.
Get the details at MIT: Separating finely mixed oil and water