September 2006 Update

The pottery filter project of Nairobi's Eastleigh Community Centre is being undertaken in their stoneware pottery. In the foreground is the filter project co-ordiantor, Vivian Maina, seen waxing stoneware mugs.

New projects in Alfred strive for innovation

Several projects at Alfred University aim to develop innovations in the household water technologies of appropriate, ceramic water filters. Those involved include two faculty champions in addition to their researchers and students.

An honors seminar, entitled, Global Sustainability and Clean Water is being taught by Dr. William LaCourse, professor of Glass Science. Students in the course include several in ceramics and in biomedical engineering, as well as majors in business and environmental science. An object of the course is to characterize and optimize ceramic systems, including those that are both monolithic and particulate.

Research work being done by Dr. William Carty, professor of Ceramic Engineering, is on filters that are high in feldspar. These filters are 80/20 and 70/30, feldspar/ clay. Under some circumstances the high feldspar filters will be advantageous to those that are 100% clay (i.e. 50/50 grog to clay). This is because not all pottery clays are useful for filter production.

For the 'pottery purifier' of SCS new projects are told to locate four or five different pottery clays, from different locations, since it is likely that one or more of these clays will fail, not fusing adequately at the upper temperatures. Thus strength becomes inadequate.

Feldspars should be more uniform in terms of the certainty that they will be useful for filter production. Feldspar is a very common material, the world over, however, in many locations this has not been identified. In such places the technology of the pottery purifier would offer the best approach. The pottery purifier would also be appropriate for project start-up, prior to identifying the sources of feldspar.

Soon to come - a small press for forming pottery filters

SCS is in the final stages of the development of a small press, for the pressing of purifier disks and candles. The press is suitable either for new project startup or for the purpose of demonstration. It is relatively small, at 54 ins. height and 17 ins. width, and is light weight at 150 lbs.

The press is adapted from a 'shop press' of one of the large importers of equipment, in this case Harbor Freight Tools. This can be seen at the link:

All that is necessary to the adaptation of the press is a second, horizontal stage, with a vertical shaft, enabling force to be applied from both top and bottom. This dual force necessitates the use of several coil springs, since the upper stage moves up and down. For anyone who is interested in the press a further update will soon be available.

A comment on the need for testing - ceramic filter projects should now be viable, additional types of testing implicit

Part of the exhortation of the Bangkok Conference, of the International Network to Promote Household Water Treatment, was for small, POU water projects to conduct much of their own testing. But testing for the viability of technologies has been largely limited to that of water quality. For ceramic filters other kinds of tests are needed for quality control and project start-up, and these can be performed in-country by a project.

There was a clear message in Bangkok that new projects in any of the POU technologies, in whatever country, need to have the capacity for testing water quality with low cost testing media. This may arouse the ire of professional laboratories, since their personnel have been trained to 'think clean' and professional in every situation. Granted, backup testing by professional labs is an essential requirement, but to overlook capacity building in the nations of the South, in the use of simple testing media, may put the POU water projects at risk. Project budgets could be substantially higher if excessive attention were given to expensive testing, so there would be fewer projects.

Similarly, in the case of ceramic filters several other tests will be needed, beyond those of water quality. Using existing capacity, tests can be performed for the effectiveness of Fe3+ or silver, as disinfectants, and to insure that residuals of such materials are not getting into the filtered water. Fe3+ might always be preferred, since this removes viruses as well as E coli. But inexpensive tests are generally available as indicators of residuals of these materials. Tests should be performed during the production and quality control of ceramic filters, also with the important backup of professional labs.

New projects in ceramic filters can have their own tests for Fe3+ or silver performed in-country, for residuals. This should be considered a perfectly legitimate approach to project start-up.

New developments highlight viability of pottery water filters, complimenting the other POU water technologies

There are a number of current activities towards the development of pottery water filters, as per the objectives of the Millennium Development Goals. Among these are: 1. successful prototype development of a new project in Kenya, 2. ongoing academic activities, towards characterization and optimization, and, 3. development of simplified equipment for production.

With the new involvement of new partners there will be additional news over a shorter period. Presentations on such activities are being prepared for several conferences, both international and national. Importance is being associated with the need for solidarity with all who are involved in the several technologies of point-of-use water treatment, but we who are in close proximity to academic ceramists are increasing poised to be ready to do our part.

Kenyan filters certified ready for the market

A recent consultancy in Nairobi, Kenya, for capacity building towards filter production, has led to initial, adaptation of pottery water filters. Working together with the stoneware pottery of the Eastleigh Community Centre, in Nairobi's Eastleigh community, systems of both disk filters and candle filters have been adapted to local resources. Initial filter systems have been certified as ready for the market by the Kenya Bureau of Standards.

The two types of systems of this development have been designed both for disk filters and for candles. The disk system is intended for sale at an inexpensive price, between US$3.00 to $4.00. This system includes a filter disk, mortared into a pottery cylinder, and can be fabricated by village potters, who get the disks from the ECC. Several small, plastic parts convey the filtered water into containers.

A little more up-scale is the candle system, which is similar to that of the initial system of the IDE Nepal project. This is a two tier system, comprising food grade containers, contaminated water above and purified water below. Fortunately, good quality containers are available in Kenya at a good price, so the systems can be expected to be priced at around $8.00 to $10.00.

News of the IDE Nepal Project

The water filter project of International Development Enterprises/ Nepal has demonstrated that pottery filters can be successfully introduced to low income communities, and a second project phase appears to be upcoming. This would expand significantly the numbers of households and communities involved with these pottery filter systems.

When the project started in 2003 the system price was as low as US$5.00, thought to be the lowest price extant, however the wholesale price of the plastic containers has since increased. The flow rate for the systems has been designed for 2.5 liters of purified water per hour, at which amount the ceramic filters are effective, having a lifetime of three years.

Use of the dug-well at right suggests the need for household water treatment, since contaminants can fall into this. By contrast a tube well might be expected to give pure water, with less need for treatment. In this last situation hygiene education would be a key component.

A goal for village potteries: to produce cook stoves, water filters and pottery water storage containers

Use of improved, pottery cook stoves, along with the use of appropriate water filters, can help overcome two major public health problems, those involving domestic pollution of the air and the water. A recent consultancy in Chad was a reminder of the importance of pottery stoves.

The technologies implicit are not complex and in the production there is an important place for the village potter. Village potteries in the nations of the South have been closing, a large part of their product base having been supplanted by plastic products. But for pottery stoves, filters and water jars the village potteries are uniquely suited to production, no threat posed by the plastics.

The consultancy to Chad was organized by Winrock International, a successful prototype of a pottery stove having been developed there during this period. A visit was also made to the arid, extreme north region of Cameroon, where an appropriate well drilling demonstration was put together. Tube wells, like the one of the demonstration can be drilled and installed for as little as US$300.00, more affordable to a village.

Inexpensive treatment of pottery water storage
containers, using hematite or silver, should
permanently disinfect the porous, inner walls.

The well drilling demonstration was a reminder that household water treatment might not always be necessary. Testing might well verify that the water out of the tap of the tube well is pathogen free. In this situation the contamination occurs when the pure water of the well is placed into a pottery water storage container. The inner, porous wall of a pottery container is a breeding ground for bacteria, however these containers are widely preferred since their damp, outer surfaces account for a cooling effect.

Simple, inexpensive treatment of these containers, using either hematite (Fe3+) or some form of silver should prove, per in-country project to remove pathogens. Of great importance is that a parallel project in hygiene education be undertaken along with the introduction of the treated, pottery containers.

Pottery water storage containers are widely accepted, and these should tend to be less expensive than any form of POU treatment. In locations where the water source is already pure, pottery containers with Fe3+ or silver should be a viable alternative to household water treatment.