Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mineralization of sand particles boosts microbial water filtration

13.10.2014

Mineral coatings on sand particles actually encourage microbial activity in the rapid sand filters that are used to treat groundwater for drinking, according to a paper published ahead of print in Applied and Environmental Microbiology. These findings resoundingly refute, for the first time, the conventional wisdom that the mineral deposits interfere with microbial colonization of the sand particles.

"We find an overwhelmingly positive effect of mineral deposits on microbial activity and density," says corresponding author Barth F. Smets, of the Technical University of Denmark, Lyngby.

Mineral coating develops on the filter grain surface when groundwater is treated via rapid sand filtration in drinking water production. Coating certainly changes the physical and chemical properties of the filter material, but little is known about its effect on the activity, colonization, diversity and abundance of microbiota

Until now, rapid sand filters have been a bit of a black box, says first author Arda Gülay,one of Smets' graduate students.

"In rapid sand filters, a combination of chemical, biological, and physical reactions help in the removal and precipitation of the impurities—iron, manganese, ammonia, and methane, for example," says first author Arda Gülay,one of Smets' graduate students. In time, the sand filter grains become coated with minerals, much of which the system managers remove, periodically, via backwashing.

It turns out that the minerals form an abundant matrix around the sand particles, sort of honeycomb-like. "Bacterial cell density in these structures can be very high, and can be boosted further when extra ammonium is provided," says Smets. The bacteria are normally engaged in removal of ammonium, manganese, and other impurities from the groundwater.

In fact, during the investigation, the ammonium-removal activity increased as the mineral deposits grew. "These positive mineral-microbe interactions suggest protective and supportive roles of the deposits," says Smets. The investigators also measured a high diversity of ammonium and nitrite-oxidizing species.

The researchers' direction involved a serendipitous twist. Early on, they discovered an unexpected positive correlation between the number of bacteria, and the degree of mineral coating of the sand particles, says Smets. "This was deemed worthy of further investigation, but we thought it would be a high risk effort. It was not until we saw actual cross sections of the mineral phases, which clearly reveal microbial cell like structures inside the deposits that we became aware of the unique discoveries we were making."

A major question the research raises is whether the microbes influence the development of the microporosity, or simply take advantage of it, says Gülay. Either way, it could lead ultimately to steering the mineralization to create micro-structures designed to house microbial cells to perform specific functions.

###

The manuscript can be found online at http://bit.ly/asmtip1014a. The final version of the article is scheduled for the November 2014 issue of Applied and Environmental Microbiology.

Applied and Environmental Microbiology is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.

Garth Hogan | Eurek Alert!

More articles from Ecology, The Environment and Conservation:

nachricht Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>