FIELD OF INVENTION
The present invention relates to a multi layer bed filtering device for
the removal of arsenic (As3+) from arsenic contaminated water.
BACKGROUND OF THE INVENTION
The concentration of arsenic in drinking water is caused by either
anthropogenic contamination or weathering of naturally occurring
subsurface materials. The problem of high arsenic level in ground
water is predominant in eastern India and all over the parts of
Bangladesh. The arsenic level in those areas could be as high as few
thousands of ppb (parts per billion). The arsenic is generally present in
nature in either organic or inorganic form. The organic form of arsenic
is present in sea food, which is not so harmful and can be easily
resisted by the human body. But the inorganic arsenic, which is mainly
present as arsenite (As3+) and arsenate (As5+), which is very harmful
to the human body as it is poisonous. Due to the toxic and poisonous
nature of arsenic, it is therefore important to develop a technique that
will remove the arsenic from arsenic contaminated water. The World
Health Organization (WHO) has pronounced a limit of maximum

contamination level (MCL) for arsenic in drinking water to 10 ppb for
safety of human beings.
There are several techniques commercially available in the market for
arsenic removal from arsenic contaminated ground water. These are
mainly based on the techniques such as adsorption, membranes, ion
exchange and coagulation sedimentation.
The adsorption of arsenic by activated alumina is an effective
technique for the removal of arsenate (As5+), but is not so effective for
the removal of arsenite (As3+). The activated alumina can be used only
one time and it requires a disposal every time which is the main
drawback of this technique.
In coagulation precipitation technique, the arsenic can be removed by
coagulation with ferric salts followed by the precipitation. This
technique is very costly and requires a trained operator. The disposal
of a large volume of contaminated sludge is the main drawback of this
technique.
The reverse osmosis and nano-filtration membranes techniques are
also available. But these techniques are not economically viable,
because of their high operational cost. However, these above

mentioned techniques are neither suitable for actual field nor
economically affordable by common man. [Hossain et al, 2005].
A simple and less expensive form of arsenic removal system has been
reported which is known as the Sono arsenic filter, wherein using 3
pitchers containing cast iron turnings and sand in the first pitcher and
wood with activated carbon and sand in the second pitcher [Abul
Hussam et al. and Abul K.M., 2007]. Moreover, all these technologies
are mainly for the removal of As(V) but very little data are available
for As(III). As(III) is more toxic than As (V) and may cause skin
cancer and neurological damage of human body. To reduce the As (III)
concentration in water, the pre-treatment oxidation of arsenite (As3+)
into arsenate (As5+) have been reported, but this can increase the
overall cost for the technique. There is an urgent need to develop a
low-cost system for the purpose of reducing As (III) for supplying
potable water, without pre-treatment of oxidation.
OBJECTS OF THE INVENTION
It is therefore, an object of the present invention to propose a
multilayer bed filtering device to remove arsenic from arsenic

contaminated water which eliminates the disadvantages of the existing
state of art.
Another object of the present invention is to propose a multilayer bed
filtering device to remove arsenic from arsenic contaminated water
which has a low cost of manufacturing.
A further object of the present invention is to propose a multilayer bed
filtering device to remove arsenic from arsenic contaminated water
which is portable and handy.
A still further object of the present invention is to propose a multilayer
bed filtering device to remove arsenic from arsenic contaminated
water which reduces arsenic concentration to below 5 ppb (less than
WHO standard 10 ppb).
SUMMARY OF THE INVENTION
According to present invention there is provided a device for the
removal of arsenic from arsenic contaminated water comprising:

two buckets filter system, containing the four layers made by plaster
of paris, sand and integrated steel plant industry CRM fines;
filtering the arsenic contaminated water by this system to produce
decontaminated potable water.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Fig.l - shows a schematic diagram of multi layer bed filtering device
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF
THE INVENTION
The multi layer bed filtering device comprises two plastic/stainless
steel buckets, one bucket disposed at the top of the other bucket. In
the top bucket, four holes are provided at the bottom surface through
which filtered water pass on to bottom bucket for storing and arsenic
contaminated water (prepared in laboratory) is poured from the top of
the upper bucket. The top bucket contains four layers of filtering
materials and the filtering layers 1,2,3,4 are disposed one above
another such that filtering layer 1 is at the bottom and layer 4 is at the
top.

Filtering layer 1 having a thickness 2-5 cm is made of a mixer of sand
and plaster of paris in water medium in 2:1 weight ratio. This layer
acts as a filter for water which assures that the iron oxide free water
come out of it and stored at the bottom bucket.
Filtering layer 2 having a thickness 2-3 cm is made of a dry mixture of
CRM fines having a particle size of 100-300 nm and sand in 1:10 ratio.
In this layer the arsenic get adsorbed by CRM fines and the later
provides the medium for removal of arsenic from arsenic contaminated
water.
Filtering layer 3 having a thickness 2-5 cm is made of a mixture of
sand and plaster of paris in 2:1 weight ratio and a small amount of
CRM fines (5g of CRM fines per 500 gm of plaster of paris) of particle
size 100-300 nm in water medium. This layer also provides a medium
for the partial adsorption of arsenic from arsenic contaminated water.
Filtering layer 4 having a thickness of 1-2 cm is made of a mixture of
sand and plaster of paris in 2:1 weight ratio in water medium. Further
the ~70 ppb of arsenic contaminated water has filter the top bucket
and collected in a bottom bucket. The bottom bucket is provided with a

tap through which filter water is catered. The arsenic concentration in
filter water collected from bottom bucket was tested by using Mercke
Chemical (Merchoquant 117927) arsenic kit which reveals the final
concentration of arsenic in water is ~ 0-5 ppb which is much below
than the World Health Organization's specified limit for arsenic 10 ppb
in safe drinking water for human beings.

WE CLAIM
1. A multi layer bed filtering device for removal of arsenic from
arsenic contaminated water comprises:
- two tiers composite buckets, one top bucket disposed above a
bottom bucket;
- top bucket provided with four holes at the bottom surface and
water is poured from the top and contains four layers of filter
materials viz. layer 1,2,3,4
- the bottom bucket collects and stores filter water passing on
from the top bucket;
- the bottom bucket is provided with a tap for catering arsenic free
filter water;

2. The filter device as claimed in claim 1, wherein a filter layer 1 is
disposed on the bottom surface of top bucket having a thickness
of filter layer of 2-5 cm and made up of a mixture of sand and
plaster of paris in 2:1 weight ratio.
3. The filter device as claimed in claim 1, wherein a filter layer 2 is
disposed on the filter layer 1 having a filter material thickness 2-

3 cm and made up of a mixture of CRM fines of 100-300 nm size
and sand in 1:10 weight ratio which provided an arsenic
absorption medium.
4. The filter device as claimed in claim 1, wherein a filter layer 3 is
disposed on the filter layer 2 having a thickness 2-5 cm and
made up of a mixture of plaster of paris and sand in 1:2 weight
ratio and CRM fines of 100-300 nm size (5 gm CRM fines per 50
gm of plaster of paris) which provides a partial arsenic
adsorption medium.
5. The filter device as claimed in claim 1, wherein a filter layer 4 is
disposed on the filter layer 3 having a filter materials thickness
1-2 cm and made up a mixture of plaster of paris and sand in
1:2 weight ratio in water medium which is used to encapsulate
the arsenic adsorption medium.
6. The filter device as claimed in claim 1, wherein the buckets are
made of plastic materials/stainless steel.

7. The filter device as claimed in claim 1, wherein the filter water
stored in bottom bucket contains 0-5 ppb arsenic which is a safe
drinking water for human beings.

The present invention relates to a multi layer bed filtering device for removal of arsenic from arsenic contaminated water comprises of two
tiers composite buckets, one top bucket disposed above a bottom bucket and top bucket provided with four holes at the bottom surface and water is poured from the top and filters through four layers of filter materials viz. layer 1,2,3,4 and the bottom bucket collects and stores filter water passing on from the top bucket and the bottom bucket is provided with a tap for catering arsenic free filter water.