Filtration
Filtration
by gravity water filter which is filled with ceramic candle filter having 0.9 µm
porosity, most bacteria, parasitic micro organism, and suspended particles can
be removed from the water but not dissolved salt.
Specification of gravity water filter:
1.
10 liters capacity
with output of 40 liters/24 hours.
2.
Felted with two
ceramic self sterilizing tersely candle filters of 0.9 µm porosity
3.
No external plumbing
required
4.
Easily cleaned and
maintained,
Use and maintenance of a gravity filter:
Container:
1.Leave the water to
stand in a container for overnight and this will allow the larger particle to
sediment. Then filter the upper layer of water.
2.Empty the upper and
lower container and clean a gravity filter.
3.It should be cleaned
every week or more if indicated .
4.Carefully unscrew each
filter.
5.Hold the screw end of
the filter then clean it with a stiff brush and clean water.Do not use soap,
detergent or clearing fluid.
6.Clean the upper and
lower containers and rinse the lower container with boiled filtered water,
7.Re- assembles the
filters and discard the first 200-500 ml of filtered water.
Deionization:
Deionization is the process in
which impure water is passed through anion and cation exchange resins to
produce ion-free water.
Demonized
has an electrical conductivity near neutral Ph
and free from water soluble salts(but pyrogen-free or sterile)
It is
not practical or cost –effective to use demonizing resins without first
filtering the water. the use of unfiltered water will lead to rapid
contamination and exhaustion of the restins.The life of the resins can be
maximized by using rainwater.
Low cost method of demonizing filtered water:
In the
district laboratory filter water is demonized by passing water through a
laboratory deionizer column using mixed bed color change depolarizer resin.
This type of resin contains both action and anion resins and an indicator that
change color as the resin becomes exhausted.
A
column of 150 gm resin measuring 45-50 gm in diameter and 135 mm long is
contained in apolythene plastic tube suspended below the top of a Berkefeld
gravity filter. The resin is made of prolife, MB-400 : QR/2048.
Maintenance of the demonized resin:
1. Keep the deionizer tube out of sunlight to
avoid inactivating the indicator.
2. When
the deionizer is not in use then store it in a dark place.
3. When first use after storage discard the
water passing through the column for the first 5 minutes.
4. Keep unused resin in an opaque sealed airtight plastic bag or tin.