Nanotechnology Now







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

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

Graphene

New class of 3D-printed aerogels improve energy storage April 22nd, 2015

'Holey' graphene for energy storage: Charged holes in graphene increase energy storage capacity April 22nd, 2015

Dispersion Stability Test Aids Characterisation of Functionalised Graphene Materials April 21st, 2015

Yale-NUS, NUS and UT Austin researchers establish theoretical framework for graphene physics: Making strides towards using graphene to create new electronic devices April 20th, 2015

Discoveries

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Surface matters: Huge reduction of heat conduction observed in flat silicon channels April 23rd, 2015

Announcements

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Surface matters: Huge reduction of heat conduction observed in flat silicon channels April 23rd, 2015

Water

Quantum model reveals surface structure of water: National Physical Laboratory, IBM and Edinburgh University have used a new quantum model to reveal the molecular structure of water's liquid surface April 20th, 2015

Dais Analytic Corporation Appoints Eliza Wang to Board of Directors: Company's Newest Director Brings Expertise in Commercial and Legal Matters Both in the United States and China; Joins on the Heels of Successful Business Development Trade Mission to China April 18th, 2015

Iranian Scientists Produce Magnetic Recyclable Photocatalyst to Purify Polluted Water April 8th, 2015

Water makes wires even more nano: Rice University lab extends meniscus-mask process to make sub-10 nanometer paths April 6th, 2015

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