"Water and Sanitation is one of the
primary drivers of public health. I often refer to it as “Health 101”, which
means that once we can secure access to clean water and to adequate sanitation
facilities for all people, irrespective of the difference in their living
conditions, a huge battle against all kinds of diseases will be won." Dr LEE
Jong-wook, Director-General, World Health Organization.
Swimming pools
Swimming is one the best possible excises you can
undertake, as long as the water quality and atmospheric conditions in the
pool are safe. If you can enter a swimming pool and you can still
smell the chlorine after 2 minutes, then do not enter. If you go
swimming and your eyes sting, then we recommend that you leave the pool.
The characteristic swimming pool smell and sore eyes is not caused by
chlorine but by a chlorine reaction product called
trichloramine.
AFM ( Activated Filter Media) is a key product to Dryden Aqua.
In the European swimming pool industry, the design of the systems are such that
high levels of trichloramines and THM`s can be produced and discharged
into the atmosphere. Reports published by the European Respiratory Society
claim that children that go swimming experience the same lung damage as an
adult smoker as measured by biochemical indicators. We also know that
trichloramines strips off the mucous lining
from your lungs and predispose children (and
adults) to infection. Trichloramines can also initiated
a sensitised reaction to dust, pollen or
virtually any chemical which can develop into
to asthma or respiratory problems latter in life.
In addition to
trichloramines, UVc disinfection and ozone are being promoted to the swimming
pool industry, however both processes increase the chlorine demand by up
to 500% and increase not only the trichloramine level in the atmosphere
but a second chemical called
THM`s (trihalomethane) which are highly carcinogenic. The use of UVc and
ozone should not be permitted in chlorinated
systems.
The problems in swimming pools are caused by the use of
sand in the sand
filters, UVc and Ozone, there are other factors such as water
flow rates and operational procedures. However at Dryden Aqua we were the first company to
determine the mechanism for he production of trichloramines.
Once you understand how something works, it then gives you
the tools to solve the problem. At Dryden Aqua we have almost
eliminated the production of trichloramines and reduced THM`s by 80%
and this is achieved simply by replacing the sand in the sand filters with AFM.
We have advised the authorities around Europe of our findings and a copy of the
report is available (click here) In Scotland, Germany, Switzerland and Spain AFM is being
implemented rapidly, however the authorities and industry in the England are
still actively promoting the use chemicals, ozone and UVc systems.
click here for swimming
pool section of web site.
By using AFM and adopting Dryden Aqua
procedures for running swimming pool water treatment systems, there will be on
average an 80% reduction in chemical consumption, and production of chlorine
reaction products. We do not know the long term health implications or chlorine
reaction products but it can only be good for the public as well as the
environment if we can reduce or eliminate the use of chemicals.
Drinking Water
In the UK and the rest of Europe, most of our drinking water
supplies are treated by adding a coagulant such as Aluminium Sulphate, or PAC (
poly aluminium chloride), polyelectrolytes may also be used, but the predominant
coagulant is PAC because it is effective and a low cost. The water is then
passed through sand filters, after which chlorine may be added. It is now
also becoming common place to add ammonium to the water. The reason
for adding ammonium is that in around 25% of the water treatment systems can
not comply with the European Directives with regards to the concentration
of THM`s. The water industry therefore adds ammonium to the water to form mono-chloramine with chlorine, which then prevents the chlorine reacting
with dissolved organics to form THM`s. This is a ridiculous situation.
It is impossible to prevent bacterial fouling of the sand in a
sand filter, the bacteria excrete a muco-saccharide alginate which eventually
start to glue to sand grains together which leads to the development of stable
channels down through the filter bed. Most sand filters used for the treatment
of drinking water will experience channelling from time to time. This
means that there is a conduit through which untreated water will pass, carrying
bacteria and parasites. However the situation is worse than un-treated water
because the water will also contain aluminium (which may be linked to
Alzheimer's disease), the high level of organics will also increase the
concentration of toxic chlorine reaction products. The graph opposites
shows that there is 30% more solids discharged during a back-wash from AFM as
opposed to a parallel system using sand. The system had only be running for 10
weeks. AFM performance stays the same , however sand filtration performance
gradually deteriorates, after 24 months AFM can be removing as much as 80% more
matter from the water than sand.
There is therefore a risk from treated Drinking Water, from
bacteria and parasitic disease, chronic aluminium toxicity and possibly
dementia, and a cancer risk from THMs. While the risk is small, at Dryden
Aqua we believe that it is significant. We are all living longer, and as
biologists we know that if you are exposed to a chemical or a virus then it may
take 10, 20 or 50 years before there is an impact from the exposure. From WHO 6%
of all disease in Europe is caused by our drinking water, and of these
infections 50% is due to the protozoan parasite Cryptosporidium, this tells us
that there is a problem.
Most of the problems with the water treatment systems are
linked to bacterial fouling of the sand and channelling of water through the
filter bed. Dryden Aqua AFM water filtration media is certified to replace the
sand in sand filters. Indeed AFM is the only water filtration media
certified under Reg31 for the treatment of Drinking Water. Simply by
changing the sand in the water filters to AFM media, we will eliminate most of
the water treatment problems described above. However in the UK
there is huge inertia in the water industry to change, consequently most of our
work with drinking water treatment has been out-with the UK.
click
here for a report |
click here
for drinking water section. The situation will eventually change because
AFM provides major life cycle cost benefits, chemical consumption will be
reduced by up to 80% and the public will have much safer and cleaner water.
Wastewater treatment
The principal source of environmental water pollution is
effluent for sewage works. The Royal Commission Standards were set in the UK
over 100 years ago, however very few treatment works are actually in compliance
with a 100 year old standard. Prior to the 1960`s, waste water comprised
mainly of organic matter, nitrogen and phosphates. The waste matter would
cause pollution and eutrophication of the environment. In addition
to the nutrient load there were also disease issues, however there were
few persistent chemical problems. Since the 1960`s there has been a huge
explosion in the number and type of chemicals used by the public and by
industry. Some of these chemicals, referred to as
List 1 chemicals, are persistent and will bio-accumulate in the environment.
Sewage works are not permitted to discharge list 1 chemicals,
however if they are discharging solids, then there will also be list 1
chemicals, albeit at a very low level.
The concentration of list 1 chemicals discharged does not
matter, even if it is below detection levels by the analytical procedures used,
the levels will still be too high. By way of example, PCB`s ( polychlorinated
biphenyl's) enter the waste water, the chemical gets adsorbed by bacteria
in the effluent treatment system. A small proportion of the bacteria are then
discharge to a river or the marine environment. Protozoa eat the bacteria,
zooplankton eat the protozoa, fish eat the zooplankton and people catch the
fish. At each stage the concentration of the list 1 chemicals may increase
by an order of magnitude. The fish may be consumed directly, and in the UK
the Government issued a public health warning, that you should not eat any more
than 2 oily fish from the North Sea each week. Pregnant women should
restrict intake to one fish per week. We know the health
benefits of omega 3 & 6 fatty acids from fish, however if you eat fish
high in these oils, your intake of list 1 carcinogenic chemicals may be too
high. Fish are also caught and turned into fish meal and then fed to
chickens and cattle etc, so it is difficult to escape from consuming list 1
chemicals.
At Dryden Aqua we consider the discharge of bio-accumulated list
1 chemicals to be the greatest threat to the environment and public health. Also,
we must remember that probably in excess of 90% of carbon dioxide (greenhouse
gas) absorption and
oxygen production is by the sea. Trees, rain forest and terrestrial plants are
of course very important but the main driver is the plant and animal life in our
seas and oceans. List 1 chemicals don't go away, they will always be
recycled back into the food chain, it may take decades but it will happen. We
therefore feel very strongly that sewage effluent should be treated to a very
high standard and that tertiary filters must be installed. Special moving
bed sand filters are sometimes used on sewage effluent, however they are
expensive and can be problematic. Rapid gravity sand filters are also used, but
in most cases they do not work effectively. Sewage effluent is the perfect
environment to grow bacteria, and considering that heterotrophic bacterial can
double in population biomass every 15 to 30 minutes, it makes it very
difficult to run sand filters. AFM however rejects biofouling, so it can
and is being used in regular low cost pressure filters and RGF filters to
achieve really good sewage effluent water quality. We have not completely
solved the problem, however the photo on the right shows a typical example of
sewage effluent before and after AFM filtration.
For a pdf file covering the above points
click here we even provide a solution to Global warming which may have some
merit.
