Total capacity: 23 litres

Materials used for construction: Ferro-cement body with outer surface mosaic-finished, the candle, made of burning clay, sand and paddy husk and activated alumina (AA) in container.

Manufacturer: Trained Sanitary mart

Treatment Procedure: Water is treated in 2 stages. Firstly, through a special type of candle (prepared by burning clay, sand and paddy husk) to effectively remove iron. Secondly, the water is treated by activated alumina (AA) to remove arsenic.

Treatment capacity: Can remove dissolved iron and arsenic from water very efficiently. Also removes other suspended, colloidal substances including bacterial contamination to a great extent.

Rate of filtration: 3 litre of water per hour

Life: Extremely durable. The filter candle and the container of activated alumina are to be replaced after every 3 years at about Rs. 120/-

Regeneration of activated alumina (AA): The quality of AA supplied with the container, works effectively for 6 months. After 6 months, the container has to be replaced with regenerated AA. The used AA is regenerated at the sanitary marts at a cost of Rs. 25/-

Description of the filter

The filter has two parts; an upper chamber placed vertically above a lower chamber. The upper chamber is covered with a removable cover. The two chambers are held firmly with a circular rubber gasket. An iron removal candle is fixed to the inner base of the upper chamber. The bottom of the candle allows downward flow of the filtrate through a nozzle (in the outside base of the upper chamber) connected with a valve. Eventually, the filtrate passes through a pipe connected to the container of AA.

The container of activated alumina is placed horizontally on a removable circular plate held by protrusions in the inside walls of the upper end of the lower chamber. The circular plate has a hole in its centre that allows filtrate from the AA container to flow downwards. The final filtrate i.e., iron and arsenic free water is collected in the bottom chamber. The lower end of the lower chamber has a tap for collection of filtered water for user's consumption. The various components of the filter are shown in the drawings.

How to use the filter
Operation and maintenance of the filter is very simple. The actions listed below will help to maximize the output ;
i. Wash the filter (both interior and exterior) properly before use. Keep the filter in the kitchen, on a raised platform, at least 8-10 inches above the floor.

ii. Pour water in the upper chamber. Filtration will start immediately and the filtrate (clear water) will be stored in the bottom chamber. Detach the upper chamber and disconnect the container of AA after some time. Dispose off the raw water from the upper chamber. Empty the lower chamber as well by disposing the first filtrate.

iii. The filter is now ready for use. Connect the container of AA and place the upper chamber vertically above the lower chamber with the joint held by the circular rubber gasket.

iv. Clean the iron removal candle with a scrubber after using the filter for a few days to remove deposition of iron slime on its surface.

Maintenance of the filter

Cleaning the Candle:
1. Lift the upper Chamber of the filter and close the valve. Detach the container of activated alumina.

2. Clean the surface of the filter with a scrubber and then with water to clear the iron deposit.

3. Place the upper chamber of the filter over the lower part and pour water in the upper chamber. Please ensure that the iron removal candle is totally submerged. Blow air through the vent on the wall of the upper chamber. Air bubbles will come through the candle. Thus, the candle will be cleaned by backwash with air. Dispose the unclean water.

4. The wastewater should be disposed of carefully as the iron deposited over the candle may also contain some arsenic. The water may be disposed off either in the pan of the latrine or in a pit filled up with sand.

5. Open the valve to check whether the two chamber of the filter are held in position with the rubber gasket. The filter is now ready for use.

Replacing the container of activated alumina (AA):

1. Every six months, the container of activated alumina has to be replaced at the sanitary marts with regenerated AA. Trained personnel of the sanitary mart will do regeneration. For this, the container is to be detached and brought to the sanitary mart. The mart will replace the old one with a regenerated container. The user is to pay Rs. 25 for this regeneration. This will be recorded on the user's card issued by the sanitary mart at the time of purchase.

2. Attach the new container (AA). The filter is now ready for use.

Note:

Since the filter works round the clock, it is suggested that all the filtered water is stored in another vessel before going to bed at night leaving the lower chamber free to collect filtered water throughout the night. This will help to control overflow of filtered water.