The first indication of the presence of Hydrogen sulphide is the noxious odour.

In most cases Hydrogen sulphide or the “Rotten Egg” smell will be
greatly depleted, or even absent by the time the sample arrives at the
lab. For this reason it can be quite difficult to quantify the
problem. I have even been sent on water analysis reports where there
is no mention of the problem and it is only through a site visit or
from quizzing the customer that I became aware that there was an odour
problem at all.

Always report the presence of an odour when submitting a water sample.
If a quotation by any water treatment professional is based on the
water analysis, and no mention of a sulphur smell is reported, then
the quotation would be based on the facts as reported. This may result
in the treatment of all other contaminants except for hydrogen
sulphide, or the cost of treatment increasing, probably quite
dramatically!

I have heard accounts of houses where the smell is so bad that if
anyone flushes the toilet at night-time, all of the occupants have to
go and sleep downstairs because the smell is so bad!

In extreme cases such as this, oxidation is always required as the
first step to elimination of the problem.

Oxidation at or near the source of the well allows for the smell to be
neutralised away from the house, usually in the pump house or garage.
In extreme cases this involves the use of a water tank, such as an
attic tank, an air pump and a membrane for the distribution of the air
bubbles.

The water is plumbed to the tank using a ball-cock, such as the attic
tank situation. The air pump is set to operate on a timing mechanism
to operate at various stages during the day. The membrane distributes
the air through the water, causing the hydrogen sulphide to oxidise
and return to it’s gas form.

The gas needs to have a means of escape, so often these tanks will
have an open top with mesh to protect the water from further
contaminants etc. Alternatively, a flue type set up can be used to
transport the gas outside.

At this point the worst of the sulphur smell will normally be gone.

In medium to extreme cases the requirement for further treatment often exists.

The form this will take will vary depending on the presence of iron
and / or manganese and other contaminants.

Some common follow on treatments include:

Activated Carbon

Pyrolox

KDF

These can be used in isolation or in combination with each other. They
tend to be used in tall vessels to ensure good “contact time” between
the media and the water as it travels through the media.

The life and efficiency of these systems can often be extended, and
performance improved by the use of an automatic backwash valve to
eject any silt, sand or other particles trapped by the media column.

For any queries or questions you may have in relation to water treatment please contact us at any time and we will respond as soon as possible. For any water treatment questions please click this contact us link or the button below.

Please remember that waterdoc.ie is always available to provide total water treatment solutions in a friendly and understanding manner at any time.

Surface (screen ) filtration uses a straining technique similar to a
sieve, whereby anything small enough to pass through the screen does,
while larger items are trapped on the surface of the screen. The major
drawback with this type is the restriction and eventual blocking of
the filter, much like the cover over the storm water drain gradually
filling with leaves after a storm.

Depth filtration is where a tank type filter is filled with loose
media which form irregular pathways for the water to pass through. In
addition some media, such as activated carbon are highly porous
particles offering micro-filtration of some micro-organic molecules.

It is possible by using different layers of media to reduce the size
of the pathways to reduce the size of the particles passing through.

Basic drinking water filtration.

For drinking water systems there are a variety of filter materials
which are readily available. These vary from a basic sediment
cartridge to activated carbon either in granulated or block form, to
ceramic and other specialist cartridges.

Examples & Applications:

String wound or blown polypropylene
Sediment removal, removal of grit
and other foreign bodies.
Activated Carbon
Reduction of bad taste
and odour, removal of hydrocarbons, chlorine removal etc.
Blown polypropylene and Activated carbon
Reduction of both of the above.
Activated Carbon and KDF
Reduction of bad taste and
odour, also hydrogen sulphide in low doses.
Pleated Paper cartridge
As with sediment filters
above, but washable for longer life.
Plastic or Metal mesh
Used as a screen to knock
out grit and solids from well supply. Washable.
Softening cartridge
Cartridge with
softening resin for removal of hardness for drinking water / kettle.
Ceramic
Exclusion of viruses
and cysts such as cryptosporidium.

These are some of the uses for filter cartridges in our daily life.
There are many more specialised combination filter cartridges, hollow
fibre and membrane technologies for the removal of everything from
viruses to sodium, heavy metals and pesticides, the list is endless.

The most common filter used in domestic applications today in Irish
homes is of the carbon variety. From water filter jugs to in-line
undersink filters to the most recent trend of filtered water in
American style refrigerators.

The humble filter-jug is an inefficient, slow and unwieldy alternative
to the in-line, mains fed tap at the kitchen sink. The advantage of
the water being fresh and cool, directly fed from the mains and
therefore pressurised means that you always have good tasting water at
the turn of a tap. The capacity of the in-line cartridge means that
you are likely to get six to twelve months out of a cartridge, as
opposed to 6 – 8 weeks from the jug filter. You can save a good bit
annually on filter changes and get a better, fresher supply of water.

American style fridges tend to have an external filter situated at the
rear of the fridge. In most cases these can be substituted for an good
quality in-line cartridge of higher quality at a fraction of the price
for the appliance branded one. As the fridge manufacturers recommend
six monthly changes, a saving of 75 or 80 euros can be had.

In the case of the integral filter units with proprietary filter
cartridges, it is worthwhile to see if the integral filter can be
by-passed. If so, it is available to the fridge owner to fit a
different cartridge, receive better quality water and still save
money.

For the owner of refrigerators where the integral filter cannot be
by-passed ( ie. if the fridge has internal plumbing ) you will
probably have to stick with the manufacturer’s proprietory unit at a
higher ownership cost.

For any queries or questions you may have in relation to water treatment please contact us at any time and we will respond as soon as possible. For any water treatment questions please click this contact us link or the button below.

Please remember that waterdoc.ie is always available to provide total water treatment solutions in a friendly and understanding manner at any time.

The continuous cycle whereby water falls from the sky in the form of
rainfall, through percolation where the water passes through the soil
and substrate to join the groundwater. This groundwater joins
underground streams and eventually feeds rivers.

The sun causes evaporation to occur and the moisture returns to the
sky to condense and fall again.

As the rainwater passes through the soil and rock on it’s way to the
underground streams, the process of filtration has already begun. Many
of the suspended solids, the impurities contained in the water are
left behind.

Depending on the uses we have for the water, various techniques can be
employed to improve the quality to the point whereby it is suitable
for purpose.

For example, for agricultural applications where the water is being
used for irrigation, there may be no further filtration required.
Whereas if the water is to be used for human consumption there will be
various treatments required to ensure that the water is fit for use.

Filtration describes the process or processes of separating suspended
matter from a liquid. In it’s simplest form it involves passing the
liquid through a column of granular media. These granular materials
are selected for their differing abilities to trap particles based
primarily on their size.

By utilising this principle a multi stage filter, beginning with a
coarse media will trap large particles, if the next stage uses a finer
media it will trap smaller particles and so on.

Other materials are used to achieve other results. Mechanical screens
of varying mesh sizes will offer different outcomes. In some cases
porous materials such as paper are used, much in the way we would use
to filter coffee, where they allow the full flavour through, but
retain the coffee grounds.

In some cases, depending on the size of the contaminants present it
may be necessary to use paper, polypropylene or even a membrane
material to remove undissolved suspended particulates.

Where these contaminants discolour, cloud or otherwise effect the
clarity of the water this is known as turbidity. A list of the “usual
suspects” where turbidity is present would be fine silt, sand, organic
matter such as tannins in boggy country. Also precipitated iron,
bacteria or algae, which may be present in both surface and well water
sources.

Well designed tank type media filters are capable of removing these
suspended solids down to about 10 micron and with specialist media are
able to take this down to around 3 micron.

Filters for the home and business:

Filters used in these environments are based on the same principles as
large industrial filter systems. The main difference being that
industrial filter systems often require ongoing maintenance and
attention to ensure optimum performance.

In small business and domestic applications, the robustness of the
design so as to require minimal maintenance is a major consideration
in selecting equipment and media. Where regular monitoring and
maintenance are not a realistic expectation it is essential that
system design reflects this.

Apart from cartridge changes on a six monthly or annual basis for
drinking water kits most maintenance on water treatment equipment
would be annual and should be carried out by trained personnel.

For any queries or questions you may have in relation to water treatment please contact us at any time and we will respond as soon as possible. For any water treatment questions please click this contact us link or the button below.

Please remember that waterdoc.ie is always available to provide total water treatment solutions in a friendly and understanding manner at any time.