A small-scale arsenic and iron removal plant
Practical Action
precipitates out. Water then passes through chambers C2 and C3. These chambers are filled
with different types and size of filter media that arrest the arsenic and iron particles by
adsorption and filtration.
Finally, water free from arsenic and iron arrives in the last chamber C4. In this process a 70
to 75 percent reduction in arsenic can be achieved. Therefore, water that has 100–150 ppb
(parts per billion) of arsenic could be treated to an acceptable level by the AIRP technology.
[Bangladesh standard for allowable arsenic contamination is 50ppb.]
AIRP construction
The following criteria should be used in selecting the site for an AIRP.
The site for the AIRP should be near the tubewell yielding water contaminated with arsenic
and iron
The plant should be located on flood-free high land
There should be proper drainage facilities/opportunities
The plant should be located in a place easily accessible by the community
Materials required for constructing an AIRP are listed in Table 1.
Sl Name of
Quantity Units Usages/placement
Remarks
# construction and
media materials
Construction materials
01 Filling sand
0.75
Cubic Foundation bed of the
m plant
Based on the site condition
Bricks
02 (Size: 240 mm x
115mm x 70mm)
350-
450
Nos. Structure of the plant
Depends on site condition,
drainage facilities
03 Medium Sand
2.0
Cubic Masonry and casting
m works
04 Cement
3-4 Bag
‘’
05
Cement additive
(Padlu)
0.5
Kg Plaster works
To make the plant water
proof
06
38 mm dia steel
pipes
1.6
m
Outlets and intra
chamber connection
In between walls of chamber
C1-C2 and C2-C3
07 End cap (38 mm)
04
Nos. Outlet pipe
One with each chambers
08
PVC Pipe (100mm
dia)
1.0 to
1.5
m
Feeding water to
chamber C1
Distance from the source
(tubewell)
09 Plastic net
1.0 Sq. m Wear GI pipes
To protect passing of media
materials during cleaning
10
Strainer pipe (38mm
dia)
1.0
m
In between walls of
chamber C3-C4
To pass water slowly to the
chamber C4 resting media
materials
11 Tap/Bib-Cock
01
Nos.
Outer side of the
chamber C4
Fit at a convenient height for
users to draw water easily
12 Steel sheet
2.5 Sq. m As cover of the plant
12
25 mm Flat bar
(5mm thick)
15
m
‘’
Media/filling materials and operation instruments
14
12mm down graded
brick chips
0.25
Sq. m Chamber C1
For one time
6mm down graded
15 stone chips/pea
0.25
Sq. m Chamber C2
“
gravels
16
Course sand (FM-
2.0 to 2.5)
0.25
Sq. m Chamber C3
“
17 Iron nails
200-
400
gm Chamber C1
(If iron contamination is low
in raw water)
18 Pipe wrench
01 No. To open/close outlets
Table 1: Construction materials and filter media required for an AIRP suitable for 10
households
2