As an efficient, inexpensive, low-tech way to treat water, Dr. James Amburgey’s research could bring clean, safe drinking water to potentially millions upon millions of people.
Simplicity is the primary objective of the rapid sand filter system Amburgey is developing. “The idea is to make it as simple as possible,” he said. “All that is needed is some PVC pipe, sand and inexpensive treatment chemicals. The only way to practically deploy a system to the people of less developed countries is for it to be inexpensive and simple.”
Amburgey, an assistant professor of Civil and Environmental Engineering, specializes in drinking and recreational water treatment. He has done work in the past with slow sand filters, but his latest research with rapid sand filters is demonstrating the ability to clean water much more effectively and 30 to 50 times faster.
“One significant challenge with sand filters is in removing Cryptosporidium oocysts,” Amburgey said. “One ‘crypto’ is five microns in diameter, but the gaps between grains of sand are approximately 75 microns. So, we have to get the crypto to stick to the sand grains.”
To achieve this, Amburgey has developed a chemical pretreatment scheme based on ferric chloride and a pH buffer that is added to the water. In its natural state, Cryptosporidium is negatively charged, as are sand grains, so they repel one another. The chemical pretreatment changes the Cryptosporidium surface charge to near neutral, which eliminates the natural electrostatic repulsion and causes it to be attracted to and stick to the sand grains via van der Waals forces.
In research using a prototype of this system in his lab, Amburgey and his students have done preliminary tests on waters from local rivers, creeks and wastewater treatment plants. Their results are typically greater than 99 percent removal for Cryptosporidium-sized particles.
“A common problem in drinking water treatment facilities is that changing water quality requires changes in the chemical pretreatment dosages,” Amburgey said. “Our tests, so far, have shown that this system utilizing only a single set of chemical pretreatment dosages is effective on all waters tested to date.”
Another advantage of the system is that it can be adapted by using local sands or crushed rock that are indigenous to a particular region of the world.
Paul Nowell | Newswise Science News
Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta
Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
18.01.2018 | Life Sciences
18.01.2018 | Life Sciences
18.01.2018 | Earth Sciences