Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > 'Coated sand' excels at water purification: Rice University-led research uses nanomaterials to enhance plain sand for filtering

Rice University graduate student Wei Gao is researching ways to enhance plain sand with nanomaterials to improve its ability to remove contaminants from water. (Credit: Jeff Fitlow/Rice University)
Rice University graduate student Wei Gao is researching ways to enhance plain sand with nanomaterials to improve its ability to remove contaminants from water. (Credit: Jeff Fitlow/Rice University)

Abstract:
Researchers at Rice University are spinning a bit of nano-based magic to create "coated sand" that has enhanced properties for water purification. The breakthrough may benefit developing countries where more than a billion people lack clean drinking water.

'Coated sand' excels at water purification: Rice University-led research uses nanomaterials to enhance plain sand for filtering

Houston, TX | Posted on June 24th, 2011

Beds of sand are commonly used throughout the world to filter drinking water. The particle size of sand and surface modifications determine the efficiency of sand in removing contaminants from water.

The Rice researchers' technique makes use of graphite oxide, a product in the chemical exfoliation process of graphite (aka pencil lead) that leads to single-atom sheets known as graphene via subsequent reduction.

A team from the Rice lab of Professor Pulickel Ajayan published a report in the American Chemical Society journal Applied Materials and Interfaces describing a process to coat coarse grains of sand in graphite oxide; the resulting material is several times more efficient at removing contaminants than sand alone.

Nanosheets of graphite oxide can be tailored to have hydrophobic (water-hating) and hydrophilic (water-loving) properties. When mixed in a solution with sand, they self-assemble into coatings around the grains and keep the hydrophilic parts exposed. Adding aromatic thiol molecules to the coatings enhances their ability to sequester water-soluble contaminants.

Ajayan, a Rice professor in mechanical engineering and materials science and of chemistry, and his collaborators from Australia and Georgia conducted experiments to compare this coated sand with plain sand and activated carbon granules used by municipalities and in-home filtration systems.

The researchers ran two model contaminants -- mercury (at 400 parts per billion) and Rhodamine B dye (10 parts per million) -- through sand and coated sand placed into filtration columns. They found coarse sand's adsorption capacity of mercury was saturated within 10 minutes.

The coated sand continued removing mercury for more than 50 minutes and resulted in filtered water with less than one part per billion. (The Environmental Protection Agency's maximum contaminant level goal for mercury in drinking water is two parts per billion.)

Results for water treated with Rhodamine B dye were similar.

The researchers found coated sand sequestered contaminants just as well as the commercially available active carbon filtration systems they tested.

The lab is looking at ways to further functionalize graphite oxide shells to enhance contaminant removal. "By attaching different functional moieties onto graphite oxide, we could engineer some form of a 'super sand' to target specific contaminants species, like arsenic, trichloroethylene and others," said Rice graduate student Wei Gao, primary author of the paper.

Co-authors are senior research scientist Lawrence Alemany, postdoctoral researcher Tharangattu Narayanan, and recent graduate Miguel Ibarra, all of Rice; Mainak Majumder, a former postdoctoral researcher at Rice, now a lecturer at Monash University, Clayton, Australia; and Bhabendra Pradhan, chief scientific officer at Nanoholdings LLC of Marietta, Ga.

Nanoholdings supported the research.

####

For more information, please click here

Contacts:
David Ruth
713-348-6327


Mike Williams
713-348-6728

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the abstract at:

Related News Press

News and information

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Graphene/ Graphite

GraphExeter illuminates bright new future for flexible lighting devices June 23rd, 2016

A new form of hybrid photodetectors with quantum dots and graphene June 19th, 2016

Drum beats from a one atom thick graphite membrane June 15th, 2016

Discovery of gold nanocluster 'double' hints at other shape changing particles: New analysis approach brings two unique atomic structures into focus June 15th, 2016

Discoveries

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Announcements

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Water

Mille-feuille-filter removes viruses from water May 19th, 2016

First single-enzyme method to produce quantum dots revealed: Biological manufacturing process, pioneered by three Lehigh University engineers, produces equivalent quantum dots to those made chemically--but in a much greener, cheaper way May 9th, 2016

Understanding tiny droplets can make for better weather forecasts: Climate change models also benefit from understanding fundamental thermodynamics of water droplets May 6th, 2016

Engineers create a better way to boil water -- with industrial, electronics applications May 5th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic