Navigation Links
Biological selenium removal: The solution to pollution?
Date:9/15/2008

MADISON, WI, AUGUST 25, 2008 Selenium has been referred to as an "essential toxin" due to the fact that it shows only a marginal line between the nutritious requirement and toxic effects upon exposure. The steep dose response curve due to bioaccumulation effects have lead to the characterization of selenium as a "time bomb" that can be fused by exceeding a narrow threshold concentration in ecosystems through anthropogenic activities. Ironically, an estimated 0.5 to 1 billion people worldwide suffer from selenium deficiency, whereas areas of toxicity can be separated from selenium deficient areas by only 20 km.

The microbiological treatment of selenium - so called "dissimilatory metal reduction" - could supersede this problem, as selenium-reducing microorganisms are highly selective for selenate, reducing it to insoluble, less-toxic elemental selenium that can potentially be recovered from the process.

A study funded by the European Union, published in the September-October issue of the Journal of Environmental Quality, demonstrates that the biological treatment is indeed efficient for selenate reduction, and substantial amounts of selenate are converted to methylated selenium species or nano-sized elemental selenium particles. The emission of nano-sized selenium particles is problematic, as these can become bioavailable by direct assimilation or reoxidize to selenite and selenate. Dimethlyselenide and dimethyldiselenide, two species with unknown ecotoxicological long-term effects, contributed substantially to selenium dissolved in the effluent. Their formation was induced by minor temperature changes during biological reduction, thus a careful process control might drastically increase removal success of existing biotreatment systems for selenium and is a prerequisite for successful removal in full scale applications.

Consequently, remediative systems aiming at minimizing ecotoxicological risks on the one hand and selenium recovery and reuse on the other hand should be implemented. Due to the "high volume - low concentration" character, no sustainable solution has been found yet to treat selenium-contaminated drainage waters originating from the San Joachin Valley, one of the agriculturally most productive areas of the US (a comprehensive report by the USGS is available at http://pubs.usgs.gov/pp/p1646/pdf/pp1646.pdf).


'/>"/>

Contact: Sara Uttech
suttech@soils.org
608-268-4948
Soil Science Society of America
Source:Eurekalert

Related biology news :

1. Mate selection more biologically determined in some human populations
2. Interdisciplinary volume on biological rhythms serves as both primer and in-depth resource
3. Biological invasions increasing due to freshwater impoundments, says CU-Boulder study
4. Study shows more genes are controlled by biological clocks
5. Light receptors in eye play key role in setting biological clock, study shows
6. Francisella tularensis: Stopping a biological weapon
7. Tips on how to build a better home for biological parts
8. Genomics of large marine animals showcased in the biological bulletin
9. Securing the future of Europes biological data resources
10. Religion and the narrative of biological science
11. AIBS honors outstanding contributions to the biological sciences
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/16/2016)... FRANCISCO , June 16, 2016 ... size is expected to reach USD 1.83 ... by Grand View Research, Inc. Technological proliferation and ... banking applications are expected to drive the market ... ) , The development of advanced ...
(Date:6/9/2016)...  Perkotek an innovation leader in attendance control systems is proud to announce the ... employers to make sure the right employees are actually signing in, and to even ... ... ... ...
(Date:6/7/2016)...  Syngrafii Inc. and San Antonio Credit Union ... integrating Syngrafii,s patented LongPen™ eSignature "Wet" solution into ... result in greater convenience for SACU members and ... existing document workflow and compliance requirements. ... Highlights: ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Cancer Foundation (PCF) is pleased to announce 24 new Young Investigator (YI) ... of the Class of 2016 were selected from a pool of 128 applicants ... the Class of 2016 PCF Young Investigators ... ... ...
(Date:6/23/2016)... ... June 23, 2016 , ... Supplyframe, the Industry Network ... Supplyframe Design Lab . Located in Pasadena, Calif., the Design Lab’s mission is ... projects are designed, built and brought to market. , The Design Lab is ...
(Date:6/23/2016)... , June 23, 2016 Apellis Pharmaceuticals, ... 1 clinical trials of its complement C3 inhibitor, ... and multiple ascending dose studies designed to assess ... of subcutaneous injection in healthy adult volunteers. ... either as a single dose (ranging from 45 ...
(Date:6/23/2016)... June 23, 2016 On Wednesday, June ... 4,833.32, down 0.22%; the Dow Jones Industrial Average edged 0.27% ... at 2,085.45, down 0.17%. Stock-Callers.com has initiated coverage on the ... Nektar Therapeutics (NASDAQ: NKTR ), Aralez Pharmaceuticals Inc. ... BIND ). Learn more about these stocks by ...
Breaking Biology Technology: