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Mercury wouldn't be banned in the lighting industry

H

Hyper Smiley

Jan 1, 1970
0
Mercury wouldn't be banned unless a feasible alternative was found. There are higher traces of mercury in other consumer products. But you never know. I recently had a HID metal halide rupture both envelopes in a DLP projector. Imagine something like that near a kid and his parents. Preventing that and reclamation and recycling should be a high priority in any industry. Where should consumers send their hazardous waste?
 
V

Victor Roberts

Jan 1, 1970
0
Mercury wouldn't be banned unless a feasible alternative was found. There are higher traces of mercury in other consumer products. But you never know. I recently had a HID metal halide rupture both envelopes in a DLP projector. Imagine something like that near a kid and his parents. Preventing that and reclamation and recycling should be a high priority in any industry. Where should consumers send their hazardous waste?

The amount of mercury in one fluorescent or metal halide lamp is very
small and should not be of concern. Consumers are generally exempted
from mercury waste disposal regulations as long as they are disposing
of only a few lamps. To properly dispose of mercury and other
hazardous materials search the Web using "mercury disposal" or visit
the EPA's "mercury home page" at: http://www.epa.gov/mercury/.
 
A

Andrew Gabriel

Jan 1, 1970
0
Mercury wouldn't be banned unless a feasible alternative was found.
There are higher traces of mercury in other consumer products.

The majority of the mercury released into the environment comes
from one single source -- mercury amalgam teeth fillings, averaging
3g per cremated or buried body.
 
V

Victor Roberts

Jan 1, 1970
0
On another front, there are some significant developments in phosphors
that are stimulated by the uv bands available from pure xenon. I'm
curious if anyone in this newsgroup is involved with this research and
if there are links they might provide to come up to speed with this
interesting area.

There has been and continues to be work in this area but I don't know
of any significant developments. The resonance line of Xenon has a
wavelength of 172 nm which translates to an energy of 7.214 eV per
photon. If you had a phosphor with a quantum efficiency of 1.0, you
would lose 66% of the photon energy when converting it to visible
light. We have to solve two key problems before we can have an
efficient Xe-based fluorescent lamp: First, we need a phosphor that
has good color rendition and a high quantum efficiency when excited by
172 nm photons, and this quantum efficiency must be significantly
greater than 1.0. Second, we need some sort of Xenon reservoir that
will serve the function now served by the excess liquid mercury we put
in all fluorescent lamps. (The active gas, be it Hg or Xe, will be
"consumed" through physical and chemical attachment and therefore must
be replaced to have long lamp life.)

Developments in quantum splitting phosphors suitable for use in
fluorescent lamps were discussed in the summer of 2001 at LS:9, The
9th International Symposium on the Science and Technology of Light
Sources, held at Cornell University. At that time, there were no
phosphors suitable for use in Xe-based fluorescent lamps. LS:10 is
scheduled for summer of 2004 at the University of Toulouse. (See:
http://www.ls-symposium.org/.) Hopefully more progress will be
reported at that time.
 
V

Victor Roberts

Jan 1, 1970
0
There has been and continues to be work in this area but I don't know
of any significant developments. The resonance line of Xenon has a
wavelength of 172 nm which translates to an energy of 7.214 eV per
photon. If you had a phosphor with a quantum efficiency of 1.0, you
would lose 66% of the photon energy when converting it to visible
light. We have to solve two key problems before we can have an
efficient Xe-based fluorescent lamp: First, we need a phosphor that
has good color rendition and a high quantum efficiency when excited by
172 nm photons, and this quantum efficiency must be significantly
greater than 1.0. Second, we need some sort of Xenon reservoir that
will serve the function now served by the excess liquid mercury we put
in all fluorescent lamps. (The active gas, be it Hg or Xe, will be
"consumed" through physical and chemical attachment and therefore must
be replaced to have long lamp life.)

Well, some of the information I posted in the note above is incorrect,
and I'm surprised that no one caught the error :)

The resonance line of Xenon has a wavelength of 147 nm, not 172 nm. My
excuse for quoting 172 nm is that I had just finished reading a very
interesting brochure on the new Osram Sylvania LINEX linear excimer
lamp that uses Xenon excimer radiation instead of mercury to excite a
phosphor. The xenon excimer radiates at 172 nm and sloppy thinking
lead me to use 172 nm instead of 147 nm as the resonance radiation of
atomic Xenon when I prepared the note above.

147 nm photons have an energy of 8.441 eV, so the average Stokes Shift
energy loss converting one of these UV photons to a visible would be
71% instead of the 66% calculated for the 172 nm Xenon excimer photon.
 
K

Kenny Greenberg

Jan 1, 1970
0
Huh? This is virtually always understood in meaningful "discussions".

It has not been raised in any lighting industry discussions I've taken
part in. So I guess these were the unmeaningful discussions. ;-)

But the mercury in organic compounds was released to the biosphere as
metallic mercury or inorganic, mercury-containing compounds.

Absolutely true, which is why I don't minimize the problem.
This is inaccurate hyperbole and oversimplification.

400-500 tons per year emitted are annually into the atmosphere by gold and
silver processing and 1000-1500 tons from power plants (among other
sources).

For what it's worth my source is the EPA's 1997 Mercury Study Report
to Congress. To quote:

coal-fired electric utilities are the largest source of human-caused
mercury air emissions in the U.S. Utilities are followed by:

1. Municipal waste combustors (19 percent)
2. Medical waste incinerators (10 percent)
3. Hazardous waste combustors (4+ percent)


I won't pretend to have fully surveyed or evaluated all reports. I
would be interested in the source of your information as I am trying
to compile safety info on my website. My intent was not to
hyperbolize. It was simply to state that mercury in the lighting
industry does not seem to be anywhere near the high end of the Hg
waste generation problem. I did also offer info on the means for
disposing Hg lamps if you are a small watse generator. Clearly it is
important to do our share in preserving future generations' health.

Kenny
 
Hi Kenny,

I agree with most everything you write below in response to my comments.
Your concern for the environment is commendable.

In the post I responded to, you wrote: " ... power utilities. They account
for virtually all of the hg pollution in the world." apparently using
US-only data as if the US were the world.

Gold mining/refining is a major global source. Atmospheric transport of
mercury is global.

I was involved very peripherally in the scientific head-scratching in the
early 1980's over why fish in remote Minnesota lakes had high
concentrations of mercury. This was before the role of atmospheric
transport, now well elucidated, had been identified.

Below are selected references. The primary and secondary literature are
large.

270-year North American mercury atmospheric deposition record :
http://toxics.usgs.gov/pubs/FS-051-02/pdf/fs-051-02.pdf

Global cycling:
http://www.chem.unep.ch/mercury/Report/Chapter6.htm

World-wide emissions by source (1995)
http://eurotrac.ivl.se/MEPOP/Chp2 .pdf

Long-range global transport
http://www.ec.gc.ca/mercury/bf-t-e.html#AC


HTH ... Marc
[email protected]
 
|
| > By far the
| >largest sources of this problem by a huge degree are the exhaust
| >systems of power utilities. They account for virtually all of the hg
| >pollution in the world.

Is this just coal, or does oil contain heavy metals too?
|
| This is inaccurate hyperbole and oversimplification.
|
| 400-500 tons per year emitted are annually into the atmosphere by gold and
| silver processing and 1000-1500 tons from power plants (among other
| sources).

What countries? I doubt EPA allows either to release significant heavy metals.
|
| And to confuse current emissions with the entire extent of the problem
| ("all of the hg pollution")is itself misstating the problem because it
| does not account for the large amount in storage within the mercury cycle
| and non-anthropogenic ('natural") sources.
|

On what basis do you "doubt EPA allows either to release significant heavy
metals" ? This has always been a reality of coal combustion. It jist took
us a few centuries to figger it out.

The mercury emissions from gold processing are not in the US, but the power
plant emissions are. Mercury is the most widespread reason for health
advisories against eating fish taken from US lakes and rivers.

The Bush administration just _today_ snuck in relaxed air regs between the
tenure of departed EPA Administrator Christine Todd Whitman and whoever
they install as a new one.

It has been said by others that Whitman was a dim bulb in an otherwise dark
room, so this discussion may not be entirely off-topic for s.e.l. ;-)

Cheers ...Marc
[email protected]
www.ECOntrol.org
 
I know when I'm done with a thread when the level of discussion sinks to
this point.

"Power plants are the only major source of mercury that the federal
government does not regulate. The EPA announced in December 2000 that it
would propose mercury regulations for power plants by December 15, 2003 and
issue regulations by December 15, 2004.
http://www.epa.gov/ttn/oarpg/t3/fact_sheets/fs_util.pdf

"The Mercury Policy Project has modeled the extent of mercury transport
from power plants, predicting that 10 percent of mercury emissions deposit
locally (within 60 miles), 50 percent travels approximately 600 miles, and
the rest is transported regionally and globally.
http://www.mercurypolicy.org/emissions/documents/mercury_source_facts.pdf

"Deposition of 1/70th of a teaspoon of mercury per year is sufficient to
contaminate a 25-acre lake to the point that the fish are not safe to eat.
A typical 100 megawatt coal-burning power plant emits approximately 50
pounds of mercury a year"
http://www.mercurypolicy.org/emissions/documents/mercury_source_facts.pdf


Done with this thread in this group.

.... Marc
[email protected]
www.ECOntrol.org
 
What the hell is you point? The US currently has strong emission controls
on fossil fuel plants. Stop changing the topic.

The point is exactly what I wrote. Despite whatever you may incorrectly
think, the US has no emissions controls on mercury at this time.. Blather
on about "strong emission controls on fossil fuel plants" if you must but
you simply make yourself look foolish.

What part of my previous citations don't you understand:

"Power plants are the only major source of mercury that the federal
government does not regulate. The EPA announced in December 2000 that it
would propose mercury regulations for power plants by December 15, 2003
and issue regulations by December 15, 2004.
http://www.epa.gov/ttn/oarpg/t3/fact_sheets/fs_util.pdf

Marc
[email protected]
 
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