Navigation Links
How do green algae react to carbon nanotubes?
Date:11/4/2011

This release is available in French and German.

Carbon nanotubes (CNTs) are up to 100,000 times thinner than a human hair and as light as plastic. Despite this they have a higher tensile strength than steel, are harder than diamond and conduct electricity better than copper. These properties make CNTs a raw material with a very promising future. All over the world possible applications are being investigated, including use in solar cells, plastics, batteries, medical technology and the purification of drinking water.

With the increasing industrial production of CNTs now reaching the level of hundreds of tons per year, the quantity of these particles which could be released into the environment has also risen. Certain studies have raised the possibility that CNTs lodged in the lungs might cause similar health effects as do asbestos fibers. An interdisciplinary team of scientists from Empa and the Agroscope Reckenholz-Taenikon (ART) Research Station have now begun investigating the fundamentals of how CNTs behave when they are deposited in waterways and lakes.

Algae remain healthy but grow slower

In the course of the project, which is financed by the Swiss National Funds, researchers further developed a standard chemical method in order to measure the growth and photosynthetic activity of green algae exposed to CNTs. They discovered that even in the presence of high concentrations of CNTs the algae retain normal levels of photosynthesis, although growth rates are reduced. Also noticeable was that when CNTs are added to the algae suspension, its color darkens and the algae forms clumps with the nanotubes. Despite this there is no evidence that the nanotubes are absorbed by the plants.

The investigators came to the conclusion, therefore, that the algae grow more slowly because they stick together as a result of the presence of CNTs and therefore receive less light. To prove this, they developed two further tests which allowed them to measure quantitatively the shadowing and agglomeration effects the nanotubes had on the algae. The results show that the slower growth of the organisms is in actual fact primarily due to these two factors. The conclusion is therefore that CNTs are not directly toxic to green algae, as earlier studies indicated. In the presence of CNTs, algae simply do not enjoy ideal growth conditions because, like land plants, they need sufficient room and light to do so. The clumping and shadowing effects which were observed only manifest themselves at elevated CNT concentrations of more than one milligram per liter, however. These levels of carbon nanotubes concentrations are currently unlikely to be met in the environment.

Our study shows how difficult is to understand in detail the effect of nanomaterials on organisms, says Empa and ART researcher Fabienne Schwab. The results will help to test other nanoparticles to ensure that the safety of humans and their environment is guaranteed. Empa researcher Bernd Nowack advises that until comprehensive, long term results are available for complex organisms such as green algae, nanoparticles (particularly unbound nanoparticles) should not be released into our environment.


'/>"/>

Contact: Fabienne Schwab
fabienne.schwab@empa.ch
41-443-777-197
Swiss Federal Laboratories for Materials Science and Technology (EMPA)
Source:Eurekalert  

Related biology news :

1. Nano-tech makes medicine greener
2. Prehistoric greenhouse data from ocean floor could predict earths future, MU study finds
3. Extreme melting on Greenland ice sheet, reports CCNY team
4. Rutgers professor uses lichen to help cities go green
5. Academy of Natural Sciences receives Green Power award
6. Production of biofuel from forests will increase greenhouse emissions
7. Stanford researchers examine impact of green politics on recent national elections
8. Specialized courts for environment cases among proposals as law experts mull green governance
9. NYU biologists use Sinatra-named fly to show how to see the blues -- and the greens
10. National Museum of the American Indian awarded prestigious LEED Green Building Certification
11. Green tea helps mice keep off extra pounds
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
How do green algae react to carbon nanotubes?
(Date:1/8/2016)... MANCHESTER, United Kingdom , Jan. 8, 2016 ... innovative sensor-based diagnostic products, today announced the closing of a ... existing investors.  Proceeds from the financing will be used to ... hand-held device for detecting early-stage pressure ulcers. ... after receiving CE Mark approval. The device,s introduction has ...
(Date:1/7/2016)... , Jan. 7, 2016 This BCC Research ... for biometric technologies and devices, identifying newer markets and ... various types of biometric devices. Includes forecast from 2015 ... Identify newer markets and explore the expansion of the ... Examine each type of biometric technology, determine its current ...
(Date:1/7/2016)... -- A United States District Court in Illinois ... to interpret a biometric privacy statute in a decision ... photo website Shutterfly brought by the law firm Carey Rodriguez ... SHUTTERFLY, INC.; and THISLIFE, INC ( N.D. Ill ., ... Illinois Biometric Privacy Act by collecting and scanning face ...
Breaking Biology News(10 mins):
(Date:2/3/2016)...   ViaCyte, Inc ., a leading, privately-held ... cell-derived islet replacement therapy for the treatment of ... that ViaCyte and Janssen Biotech, Inc., one of ... have agreed to consolidate the assets of the ... ViaCyte with an exclusive license to all BetaLogics ...
(Date:2/3/2016)... BRUNSWICK, N.J. , Feb. 3, 2016 /PRNewswire-USNewswire/ ... grants totaling more than $1 million for researchers ... are working on health-related research that demonstrates exciting ... this round of funding for the New Jersey ... for faculty members at these educational institutions— Princeton ...
(Date:2/3/2016)... MEDFORD, Mass. , Feb. 3, 2016  Silk Therapeutics, ... A2 financing round. Silk Therapeutics has now raised a total ... progress made by the company. The Series A2 round was ... Foxboro, Massachusetts , with participation from new investors Lear ... Sheri and Roy P. Disney ; Richard Sackler ...
(Date:2/3/2016)... ... February 03, 2016 , ... Big games come and go, but ... much for our country. CereScan, a nationally recognized brain diagnostics and technology company, will ... Football Team (WWAFT) vs. NFL Stars Flag Football Game on February 6, 2016. ...
Breaking Biology Technology: