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: Weekends are the best time to buy airline tickets, researchers find

add to favorites email to friend print save as pdf

Related Stories

Encouraging signs for bee biodiversity

3 hours ago

Declines in the biodiversity of pollinating insects and wild plants have slowed in recent years, according to a new study. Researchers led by the University of Leeds and the Naturalis Biodiversity Centre in the Netherlands ...

NASA's BARREL mission launches 20 balloons

8 hours ago

(Phys.org) —In Antarctica in January, 2013 – the summer at the South Pole – scientists released 20 balloons, each eight stories tall, into the air to help answer an enduring space weather question: ...

Amazon plans greenhouse-style headquarters

8 hours ago

US online giant Amazon has unveiled plans for a futuristic greenhouse style headquarters "where employees can work and socialize in a more natural, park-like setting."

Recommended for you

The ascent of man: Why our early ancestors took to two feet

May 24, 2013

A new study by archaeologists at the University of York challenges evolutionary theories behind the development of our earliest ancestors from tree dwelling quadrupeds to upright bipeds capable of walking and scrambling.

Challenging the public's view of gender and science

May 24, 2013

According to She Figures 2012, which analyses gender equality in research, in 2010 women accounted for only 10 % of university rectors in Europe and 15.5 % were heads of institutions of the higher education ...

User comments : 0

More news stories

Submerged structure stumps Israeli archaeologists

The massive circular structure appears to be an archaeologists dream: a recently discovered antiquity that could reveal secrets of ancient life in the Middle East and is just waiting to be excavated.

Mais non! French universities may teach in English

In France, there's a brewing debate over whether to speak anglais in universite. The National Assembly on Wednesday was taking up an education reform bill that would allow public universities to hold some courses—like science ...