On 13/9/2006, Kevin Phyland posted:
http://www.news.com.au/heraldsun/story/0,21985,20405078-661,00.html
We are currently having a bit of a crisis here re water.
What I need to know is the following:
[1] Can boiling the water eliminate the toxic effects of blue-green algal blooms in a water supply?
[2] Can adding a
disinfectant eliminate the toxic effects (so that the water may be used
to just do things like wash dishes or clothes)?
Ray Stephens replied:
I am not certain whether cyanobacteria are toxic by reason of toxic
metabolic products (exotoxins) or by reason of the chemistry of the organism
itself (endotoxins), but if exotoxins are involved the coming suggestion
won't do.
Microfiltration would take care of endotoxins by removing the cyanobacteria
(and any other bacteria) from the water. Boiling might not, because the
dead bacteria may be equally as toxic as the live ones. In the
Enterobacteriaceae of food poisoning, it is the cell wall which is toxic, I
believe.
I'm interested to read better informed replies.
Toby Fiander responded:
arrghhh!!!........
Blue-green algae are a class of organisms, some of which can be toxic at
some parts of their lifecycle. Just because there is bluegreen algae does
not make it toxic, although, if it is toxic, then it can be a neural toxin
which is absorbed through the skin, not just through ingestion. I refused
to use gloves while sampling - no algae was going to affect me. This is
called stupidity and is not recommended - wear rubber gloves is you are
going to do more than poke it with your finger.
To treat water that might be toxic, you need to filter it, and then filter
it again with activated carbon. Expensive and difficult, but you can do it
in one pass with a filter set up to do it. Boiling will only break the
cells and release the contents, and will not denature it. Disinfection will
not do it either... it is not good news, on the whole.
This is an engineer's answer off the top of the head, not a biologists
answer - I will send additional material over the next half day or so. I
will away being a consulting geomorphologist (but not necessarily my usual
role of hydrologist) on the NSW mid-north coast for a day or so.... back, in
effect, on Saturday morning.
Start reading here, I think:
http://www.hc-sc.gc.ca/ewh-semt/water-eau/drink-potab/cyanobacteria-cyanobacteries_e.html#water
or
http://tinyurl.com/zvozc
In the longer term, there is a problem, too, and controlling it well require
control of the inflow of nutrients to the water supply - sounds easy, and
never is. Often the best strategy is to flush to the river, assuming it is
one, but hard to do when water is so precious, and rainfall so intermittent.
When we (our group) had an infestation in wastewater ponds, we had a lot of
trouble making the water usable. We aerated it unsuccessfully - we probably
left it too late to start and if you think about it, the dissolved oxygen is
already high during the day. It is the disturbance of lower layers of water
that is important, I think.
We also tried correcting for the pH which first went very low and then very
high (err.. I think). Wild changes in pH are apparently normal, but in
spite of my chemistry and provado, we did not do much to manage the pH, nor
did we have any success precipitating the phosphorus with ferric alum. We
just used a lot of alum.
Ours was not a good experience, and, apparently this too is normal.
Ray Stephens answered:
For the record, Blue-Green Algae isn't an algae.
Rather, it is among the Prokaryote (Bacteria and Archea) and not the
Eukaryote in spite of its common name.
It is also one of the most primitive and antique forms of life on Earth.
You do not get to be 4 billion years old AND be easy to kill.
Toby Fiander added:
Here is what the Victorian Dept of Human Services has to say on blue-green
algae:
http://www.health.vic.gov.au/environment/water/bluegreenalgae.htm
It references a number of documents including this one, which pretty well
everyone in country Australia ought to read:
http://www.waterquality.crc.org.au/DWFacts/DWFact_Algae.pdf
The Hawkesbury River around here is routinely sampled for a range of
blue-green algae, so there is a usually good notice when there is about to
be a problem. The River can be flushed from Warragamba Dam, but these days
is not routinely flushed. This has some problems and monitoring is more
important as a result - I saw results from a fortnight ago, and there was
not much to show. The recent shower of rain will probably mean that this
season will be OK here... not so in other places.
The Cudgegong River upstream of Mudgee, NSW has a reservoir, Windamere Dam -
I am currently working in the area and I was surprised (well, in one half of
my head) that there are warning signs for blue-green algae around it. You
could not go boating or swimming in the water when I was there a few weeks
ago.
Today, I had a phone call from a client whose wastewater stabilisation ponds
I designed about 6-7years ago, to see if I could come and help him now that
there were low volume of water used in washing down the (large) dog kennels.
I asked him about the blue-green algae problems - this project was one of
the first times I had run into trouble with blue-grean algae. He said it
was no problem, that he kept it under control with copper sulfate. This
might work in the short term, but eventually, you get a layer of metallic
salts on the bottom of the ponds, which means nothing lives there... not the
right answer if you are trying to get some natural processes going there.
and:
Some may think there are only a two kingdoms, plants and animals. Have a
look here for the other three:
http://www.nearctica.com/nathist/phylog.htm
http://www.lenntech.com/eutrophication-water-bodies/algae.htm
http://www.botany.uwc.ac.za/algae/StudentAssignments/janusgoulding96/algae5k.htm
And just in case you thought there was consensus read this, too:
http://en.wikipedia.org/wiki/Kingdom_(biology)
Enough of biology for now - I am feeling a bit dizzy. Is there a biologist
in the house?
Ray commented:
When last trained in microbiology (2003) the division of Domains was two
(but the taxonomy of "Kingdoms" wasn't mentioned); Prokaryote & Eukaryote.
The fundamental difference between the two is the presence, or not, of a
porous nucleus membrane. Archaea and Bacteria do not have this inner
nucleus wall, but all other living things (Eukaryote) do.
Eukaryote also possess organelle within cells not present in the more simple
Prokaryote. Plasmids and Pili don't count.
Perhaps complexity was sacrificed for the simplification of teaching?
In any case Toby, I suspect that the taxonomists aren't finished and that
further understanding of "life" may give Virus and Prions their own Domain
yet. Some things never get finished.
Toby conceded:
I have never understood stamp-collecting... err... taxonomic classification.
But debates about it seemed to rage as if it mattered. So, perhaps it
does... though it is hard to see why from an outsider's point of view.
Peter Macinnis replied:
As one who was rigorously trained in taxonomy -- and I note that Peter
McGauran and others are now saying there are too few of them for AQIS to
function properly -- I counsel against trying from inside. It is almost
as bloody as swimming with sharks or cosmologists.
Taxonomists are either lumpers or splitters.
Put a pile of coins on a table, the lumper will say "There is one
species there: they are all coins".
Splitters will demand that silver and copper be accorded species status,
über-splitters will demand that each denomination be a species, while
the cladists will probably want to divide the coins according to the
amount of wear or some other obscure criterion.
Then there are coins like the 1850s Canadian cents, one inch across, and
a hundred of them weighed one pound -- should we raise a new genus for
such useful coins that have multiple purposes?
Taxonomy should be about information storage and retrieval. We will
always have messy situations with species that are in the midst of
speciation and the like, and it will be even worse with fossils. Each
way of dividing up the coins will be useful in some circumstances.
