Environmental chemistry

Hydrogen cars some time off yet
Submitted by WebElements on 22 March 2007 - 9:50am.Many agree that replacing conventional petrol driven cars with hydrogen is a good idea provided the hydrogen does not originate in a process involving oil as the only product from hydrogen burning is water, rather than carbon dioxide.
However the road to hydrogen-powered vehicles will not be easy, industry experts state. Representatives of European and American car and energy companies at the National Hydrogen Association convention said hydrogen technology is feasible, but faces big challenges to become commercially viable.

Manganese blocks hydrogen sulphide in water systems
Submitted by WebElements on 3 October 2006 - 7:55am.Trace amounts of manganese is essential to human health. Now, a team of scientists from the University of Delaware, Scripps Institution of Oceanography, the University of Hawaii, and Oregon Health and Science University has found that a dissolved form of manganese, Mn(III), is important in waterways such as the Black Sea and Chesapeake Bay. It can keep toxic hydrogen sulfide (sulphide) zones in check.
The research is based on research conducted in 2003 that explored the chemistry of the Black Sea. Nearly 90% of the mile-deep system is a no-oxygen "dead zone," containing large amounts of naturally produced hydrogen sulfide (sulphide), which is lethal to most marine life. Only specialized microbes can survive in this underwater region.

Record ozone loss over South Pole
Submitted by WebElements on 2 October 2006 - 9:28pm.Ozone measurements made by the European Space Agency Envisat satellite reveal the ozone loss of 40 million tons by 2 October in 2006 and that this exceeds the record ozone loss of about 39 million tons for the whole of 2000. The size of this year's ozone hole is 28 million square km.

The Ozone layer is a protective layer found about 25 kilometres above us mostly in the stratospheric stratum of the atmosphere that acts as a sunlight filter shielding life on Earth from harmful ultraviolet rays. Over the last few years the effective thickness of the ozone layer declined, increasing the risk of skin cancers, cataracts and harm to marine life. The thinning of the ozone layer is caused by the presence of pollutants in the atmosphere originating from, for instance, chlorofluorocarbons (CFCs), which have still not vanished from the air although banned under the 1987 Montreal Protocol.
"Such significant ozone loss requires very low temperatures in the stratosphere combined with sunlight. This year’s extreme loss of ozone can be explained by the temperatures above Antarctica reaching the lowest recorded in the area since 1979," European Space Agency Atmospheric Engineer Claus Zehner said.
Background Information
Ozone (O3) is another allotrope of oxygen. It is bent with a O-O-O angle of about 123° It is formed from electrical discharges or ultraviolet light acting on O2. It is an important component of the atmosphere (in total amounting to the equivalent of a layer about 3 mm thick at ordinary pressures and temperatures) which is vital in preventing harmful ultraviolet rays of the sun from reaching the earth's surface. Aerosols in the atmosphere have a detrimental effect on the ozone layer. Large holes in the ozone layer are forming over the polar regions and these are increasing in size annually. Paradoxically, ozone is toxic! Undiluted ozone is bluish in colour. Liquid ozone is bluish-black, and solid ozone is violet-black.
For chemical robots
IUPAC Name: ozone
Canonical SMILES: [O-][O+]=O
InChI: InChI=1/O3/c1-3-2
Links
- European Space Agency
- European Space Ozone story (2 October 2006)
- WebElements oxygen page

Throwing out the sulfur
Submitted by David Bradley on 1 April 2005 - 7:44pm.Dutch researchers have figured out why the activity of catalysts used to produce clean fuels gradually falls. Read David Bradley's report on the findings in Reactive Reports together with other chemistry articles

Titan's methane springs
Submitted by WebElements on 1 February 2005 - 7:44pm.Lands, rivers and methane springs: latest images of Titan. Titan's atmosphere is mostly nitrogen but there is also methane and many other organic compounds.

First Genesis Spacecraft Samples Shipped to Researchers
Submitted by WebElements on 30 January 2005 - 7:44pm.Scientists at NASA's Johnson Space Center in Houston have shipped pieces of the Genesis polished aluminum collector to researchers at Washington University in St. Louis, marking the first distribution of a Genesis scientific sample from JSC since the science canister arrived there Oct. 4, 2004. Read all about it at NASA.
While much of the solar wind is hydrogen, it is hoped that Genesis captured samples of many elements in the periodic table. An analysis of these elements will help to determine the sun's composition in detail.

Special interests threat to ozone layer?
Submitted by WebElements on 26 March 2004 - 7:44pm.The BBC report here that special interests in a number of developed countries wish to to be allowed to continue using a bromine containing gas, methyl bromide, for various purposes such as crop fumigation. Methyl bromide is known to destroy ozone, O3, (an allotrope of oxygen, O2) and this is being debated at an international meeting in Canada. The Montreal Protocol does allow continued use of ozone-destroying gases for purposes agreed to be "critical", but is this really critical?

Metal plated Venus?
Submitted by WebElements on 14 January 2004 - 7:44pm.The BBC reported a few weeks ago that parts of Venus may be lead plated. David Whitehouse reports that
"The highlands of Venus are covered by a heavy metal 'frost', say planetary scientists from Washington University.
Because it is hot enough to melt lead at the surface, metals vaporise and condense at cooler, higher elevations.
This may explain why radar observations made by orbiting spacecraft show that the highlands are highly reflective.
Detailed calculations, to be published in the journal Icarus, suggest that lead and bismuth are to blame for giving Venus its bright, metallic skin."
