Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Membrane filters offer options for cleaner water

18.06.2002


Technology May Help Remove Contaminants from Drinking Water Supplies



Membrane filter technology is helping to remove barriers to cleaner drinking water.

University of Houston researchers are studying how membrane filters, such as those currently used in some home water purification systems, might someday be used on a large scale to remove contaminants and organic compounds that can affect the purity and color of municipal water supplies.


Understanding how such filters interact with various contaminants, including bacteria and other organic materials, will help engineers devise more efficient filters, says Shankar Chellam, assistant professor of civil and environmental engineering at the University of Houston.

"Ultimately, the cost of membrane technology will go down and make it more feasible to be used for large-scale implementation," Chellam says. "As an environmental engineer, I enjoy doing fundamental research, and I hope that what I am doing will at some point lead to practical applications that can make a difference in our lives."

Chellam will present information about his research on membrane filters June 20 in New Orleans at the annual meeting of the American Waterworks Association (http://www.awwa.org/ace2002/). He and his students will present a paper that describes how contaminants are deposited onto filters, how they clog a filter’s pores and the resulting effects on the flow of water.

Chellam this year received a $375,000 CAREER grant from the National Science Foundation to pursue his membrane studies. CAREER grants are awarded each year to promising young faculty nationwide. The Texas Higher Education Coordinating Board and the Texas Hazardous Substance Research Center also have supported his research.

In the lab, Chellam and his students perform experiments on various types of commercial membrane filters, testing them to gauge their performance and determine how they might be adapted for large-scale use. Membranes are made out of various materials and come with different pore sizes, which determine the size of the contaminants that can be filtered out. The goal is to optimize the combination of membrane material and pore size to fit any situation.

"Once we understand the complexities of how these membranes interact with contaminants, we can determine the properties that are needed to build into a filter. Ultimately, we could tailor-make filters for any contaminant in any water source, whether it’s surface water or ground water, for example," Chellam says.

"We have membranes, for example, that can that remove large protozoa such as cryptosporidium, which caused several deaths and many thousands of illnesses in Milwaukee in 1993 when that protozoan got into the city’s water supply. But these membrane filters are expensive, and aren’t as widely used in large-scale operations."

Chellam’s research group is studying various types of novel filtration membranes that might be used to remove the smallest of contaminants dissolved in water.

"The discoloration of water is often caused by dissolved organic matter. When you add chlorine to water for disinfection, it also bleaches the color out of the water. The problem is, when chlorine interacts with the color-causing organic material, the reaction forms cancer-causing compounds," Chellam explains. "Further, a recent report also claims that these compounds can cause birth defects and miscarriages."

The generally followed approach in U.S. water treatment plants is to remove as much of the color-causing organic material from the water first, then add chlorine. However, Chellam says, conventional plants might be able to remove only about 50 percent of these organic materials.

"We are studying nanofiltration membranes that can remove 90 percent or more of natural organic material. In home devices, such filters can be changed after a few months or years, but you cannot do that in a large-scale plant that filters millions of gallons per day. It would be too expensive.

"Our research aims to determine exactly what happens to this organic matter, how it clogs up the filter and what happens to it after filtration, for example, as well as methods to reduce the formation of carcinogenic compounds. The long-term goal is for engineers to use our research to design better large-scale filtration systems," Chellam says.

Chellam and his students not only are examining ways to better purify existing water supplies, but also how to deal with dirtier or more contaminated supplies. One project is focusing on developing portable membrane systems for producing drinking water in Texas border areas.

"As you move away from using the more pristine water supplies, you need more advanced purification processes. In addition, even with existing water supplies, we are learning more and more about chemical and microbiological risks that may be present in the environment. Any way you look at it, you may be forced to invent better water purification methods," Chellam says.

About the University of Houston

The University of Houston, Texas’ premier metropolitan research and teaching institution, is home to more than 40 research centers and institutes and sponsors more than 300 partnerships with corporate, civic and governmental entities. UH, the most diverse research university in the country, stands at the forefront of education, research and service with more than 33,000 students

Amanda Siegfried | EurekAlert!
Further information:
http://www.uh.edu/admin/media/sciencelist.html
http://www.egr.uh.edu/news/
http://www.uh.edu/admin/media/newsroom

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>