November 2008 Update

Indonesia Training

A training was recently conducted in the production of pottery water filters and pottery cook stoves, in Jogjakarta, Indonesia. The sponsoring organization is the Indonesian NGO, the Society for Health, Education, Environment and Peace (SHEEP). Further support has come from the U.S. N.G.O., Friends Peace Teams. Indonesia is now a third country in which such pottery systems are in use, along with similar efforts in Nepal and Kenya.

Together, pottery water filters and pottery cook stoves allow for a synergistic approach to health, for the issues of household water treatment and indoor air quality. Without such interventions as these pottery products offer, those of low income in countries like Indonesia, Kenya and Nepal face serious health threats. These threats are from the diarrheal illnesses, that are associated with water, and the respiratory illnesses that are associated with the smoke of wood fires in the kitchens.

The pottery candle system of the Indonesia workshop is that of , and this continues to be an excellent option, suitable for people who do not have piped water. The pottery candle filter is treated with a tiny amount of silver, providing a guarantee of the virtual 100% removal of pathogens.

Studies have indicated that the users of the systems find these to be both appropriate and easy to maintain. The system price, depending on location, should not exceed US$7.00 or $8.00, which should be affordable to those of low income. Following are video clips of the workshop, and these techniques are widely replicable, in almost any location.

The pottery cook stoves of the training are of two types, both of which are made from an insulating pottery, subsequently clad in metal. The first type of stove is bowl shaped stove, which has been used in many different countries. The second type of stove is the ‘rocket stove', which is highly fuel efficient, therefore saving the users a lot of money.

Video Clips

1. Pressing a Candle Filter

The pottery filter candle is small and robust, and the filter system is inexpensive, its production being sustainable. Since this is made of pottery clay, and other common resources, systems of this type can be fabricated almost anywhere.

2. Filling Candle Dies and Pressing

The dies for the pressing of the candle are filled, using a composition of 50% clay and 50% ‘grog.’ Grog is a granulate powder, made of pre-fired pottery.

3. Pressing Pottery Filters – Release

Once the candle has been fired, it needs to be released, in a two step process. First is to push downwards and out the tapered spindle, which occupies the space of the inside of the cylindrical candle. Second is to push the candle downwards and out.

4. Crushing Pottery Filters – Strength Test

The candles are quite robust, but without proper quality control, these may have less strength. It’s an issue that different clays have different properties, so it’s necessary to make certain that the correct clay is used. Because the quality of clays used will vary, this simple test is necessary, in order to be certain that there is adequate compressive strength.

5. Silver Treating Pottery Filter Candles

Following the firing of the candles these are placed into a solution of silver nitrate. After this step the candles are fired to the low temperature of 500 C, and this way the nitrate burns off.

6. Silver Treating Pottery Surfaces

There is a common tradition, around the world, of drinking water that is stored in pottery containers; however the inner surface can be a breeding ground for pathogens. A very dilute solution of silver nitrate should be applied to the inner surface, then the container is fired normally, to 500 C. Thus the nitrates are burned off.

7. Silver Treated – Pottery Water Storage Containers

Pottery containers were treated with the silver nitrate solution, prior to testing for removal of E coli. The inner surface of the container will then disinfect against E coli. Note that pottery water containers are much loved around the world, since there is a serious cooling effect, when air currents blow against the damp outer surface.

8. Ceramic Plaques for Workshop Participants

The calligrapher of the pottery makes ceramic plaques, as certificates for the participants.

9. Interpreting Results of E coli Plates

The tests for the numbers of colonies of E coli were as expected. While the contaminated water indicated sixty colonies on the plate, four surfaces that had been treated with silver indicated zero colonies. The four control filters, that had not been treated with silver, indicated small numbers of colonies, between one and seven.

10. Cooking with the Pottery Rocket Stove

Indoor air quality is of urgent importance, just as is the case with household water treatment and the simple technology of pottery addresses both issues. Otherwise, those who are doing the cooking breath a lot of smoke, and this leads to respiratory illness. The pottery rocket stove shown, drastically cuts fuel use, and should be used in a well ventilated area.


11. Building the Pottery Rocket Stove

The pottery rocket stove can be built using light weight, insulating brick, of curved shape, and these bricks are fired in a low temperature kiln, at 500 C. Note that there are nine bricks that go around, inside the sheet metal cladding, so that every third brick can contain a pot rest.

12. Pressing a candle filter – for a second time

Here is a second look at the pressing of a candle filter.