Better way to desalinate water discovered

Feb 09, 2006

Chemical engineer Kamalesh Sirkar, PhD, a distinguished professor at New Jersey Institute of Technology and an expert in membrane separation technology, is leading a team of researchers to develop a breakthrough method to desalinate water. Sirkar, who holds more than 20 patents in the field of membrane separation, said that using his technology, engineers will be able to recover water from brines with the highest salt concentrations. The Bureau of Reclamation in the Department of Interior is funding the project.

"Our process will work especially well with brines holding salt concentrations above 5.5 percent," Sirkar said. Currently, 5.5 percent is the highest percentage of salt in brine that can be treated using reverse osmosis.

"We especially like our new process because we can fuel it with low grade, inexpensive waste heat," Sirkar said. "Cheap heat costs less, but can heat brine efficiently."

The science behind Sirkar's membrane distillation process is simple. The inexpensive fuel heats the water forcing it to evaporate from the salt solution. The cleansed vapor then travels through nano-sized pore in the membrane to wind up condensed in the cold water on the membrane's other side.

"The basic principles of membrane separation have been known for a long time," said Sirkar. "Intestines in animals and humans are semi-permeable membranes. Early experiments to study the process of separation were performed by chemists using samples of animal membranes."

Today, membrane separation processes depend on the design of the membrane and the membrane module. The size of the pores is often key to determining which molecular components in either a liquid or gas form will pass through the membrane. Typically molecules flow from a region of high to low concentration. Pressure or concentration differences on both sides of the membrane cause the actual separation to occur. As pore size decreases, the membrane's efficiency and selectivity increases. Membrane separation processes are used in biomedical, biotechnology, chemical, food, petrochemical, pharmaceutical and water treatment industries to separate/purify/concentrate liquid solutions or cellular suspensions or gaseous mixtures.

Typically Sirkar works with miniscule membranes, smaller in size than nanometers.

Sirkar has been leading the effort in membrane separations and biotechnology at NJIT since1992. He is the director for the Center for Membrane Technologies at NJIT and is the Foundation Professor of Membrane Separations. Sirkar has authored more than 140 peer-reviewed articles that have appeared in AIChE Journal, Biotechnology and Bioengineering,, Chemical Engineering Science, Industrial and Engineering Chemistry Research; Journal of Membrane Science; Polymer; Biotechnology Progress; Journal of American Chemical Society; Journal of Controlled Release and more. Sirkar graduated with a bachelor's degree with honors in 1963 from the Indian Institute of Technology, Kharagpur, India. He received his master's degree and his doctorate from the University of Illinois, Urbana.

Although Sirkar has no crystal ball, he envisions many future applications for his process. "Desalinating seawater to stimulate economic development and create potable water always has an attentive audience," he said.

Source: New Jersey Institute of Technology

Explore further: New University of Texas System database connects government and industry to researchers

Related Stories

Architects to hatch Ecocapsule as low-energy house

1 hour ago

Where people call home depends on varied factors, from poverty level to personal philosophy to vanity to community pressure. Ecocapsule appears to be the result of special factors, a team of architects applying ...

California farmers agree to drastically cut water use

4 hours ago

California farmers who hold some of the state's strongest water rights avoided the threat of deep mandatory cuts when the state accepted their proposal to voluntarily reduce consumption by 25 percent amid ...

Apple may deliver ways to rev up the iPad, report says

5 hours ago

MacRumors last month said that the latest numbers from market research firm IDC's Worldwide Quarterly Tablet Tracker revealed Apple stayed on as the largest vendor in a declining tablet market. The iPad ...

Recommended for you

The legacy of John Nash and his equilibrium theory

19 hours ago

The American mathematician John Nash, who died in a taxi accident at the weekend, is probably best known to the wider public through Russell Crowe's portrayal of him in the 2001 movie A Beautiful Mind. ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.