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nanotimes News in Brief

A dose of carbon nanotubes more than doubles the growth rate of plant cell cultures. Mariya V. Khodakovskaya and colleagues explain that their previous research demonstrated that so-called mul- tiwalled carbon nanotubes (MWCNTs) can pene- trate through the thick coatings on seeds, stimulate germination of the seeds and stimulate the growth of certain plants. MWCNTs are wisps of pure car- bon so small that thousands would fit on the period at the end of this sentence. Those discoveries “have the potential to transform agricultural practices in the near future and to provide solutions to some of the most serious problems related to plant growth and development,” the scientists said. Their new re- search focused on how MWCNTs affect the growth of model tobacco plant cell cultures.

12-03 :: March/April 2012

Scientists described a new and more efficient version of an innovative device the size of a home washing machine that uses bacteria growing in municipal sewage to make electricity and clean up the sewage at the same time. Their report here at the 243rd National Meeting & Exposition of the American Chemical Society (ACS), suggested that commercial versions of the two-in-one device could be a boon for the developing world and water-short parts of the US.

“Our prototype incorporates innovations so that it can process five times more sewage six times more efficiently at half the cost of its predecessors,” said Orianna Bretschger, Ph.D., who presented a report on the improved technology at the ACS meeting.

Image © ACS Nano/ Mariya V. Khodakovskaya

Mariya V. Khodakovskaya, Kanishka de Silva, Alexandru S. Biris, Enkeleda Dervishi, and Hector Villagarcia: Car- bon Nanotubes Induce Growth Enhancement of Tobacco Cells, In: ACS Nano, Vol. 6(2012), Issue 3, March 27, 2012, Pages 2128-2135, DOI: 10.1021/nn204643g: http://dx.doi.org/10.1021/nn204643g

“We’ve improved its energy recovery capacity from about 2% to as much as 13%, which is a great step in the right direction. That actually puts us in a re- alm where we could produce a meaningful amount of electricity if this technology is implemented commercially. Eventually, we could have wastewa- ter treatment for free. That could mean availability for cleaner water in the developing world, or in southern California and other water-short areas of the United States through the use of more wastewa- ter recycling technologies,” she said.

Bretschger reported that the new device is also more than six times as efficient as its predecessor, turning 13% of the usable energy in the sludge into electricity. While this only generates a small current, Bretschger explained that a large device running at 20-25% efficiency could produce enough power to operate a conventional wastewater treatment plant. A typical sewage treatment plant may consume