Identification of Montmorillonite (smectite)

Clay Minerals (1971) 9, I.
Institute of Geological Sciences, 64-78 Gray’s Itvt Road, London WCI
(Read at the Spring 1970 meeting of the Clay Minerals Group
and the Basic Science Section of the British Ceramic Society, at
CambrMge; Receh’,ed 27 June 1970).

Mineralogical and physicochemical characterization of Ngaye alluvial clays (Northern Cameroon) and assessment of its suitability in ceramic production

Soureiyatou Fadil-Djenaboua, Paul-Désiré Ndjigui a, Jean Aimé Mbey b,c,∗
a Department of Earth Sciences, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon b Department of Inorganic Chemistry, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon c Laboratoire Interdisciplinaire des Environnements Continentaux, Université de Lorraine, UMR 7360, 15 Avenue du Charmois, B.P. 40, F-54501
Vandoeuvre-lès-Nancy Cedex, France

Original Article:

Mineralogical and chemical characterization of DD3 kaolin from the east of Algeria

Hamza Senoussi a, Hocine Osmani a, Christian Courtois b, Mohamed el Hadi Bourahli a,∗ a Non Metallic Materials Laboratory, Institute of Optics and Precision Mechanics, University Ferhat Abbes, Setif 1 Algeria
b Ceramics Materials and Processes Laboratory, University of Valenciennes and Hainaut-Cambresis, France.

The mineralogical and chemical characteristics, based on X-ray diffraction (XRD) and scanning electron microscopy, of a kaolin known as DD3, from eastern Algeria were examined in the present study.

The results showed that kaolin DD3 has an alumina content of 39%. The SiO2/Al2O3 molar ratio of 2.14 is close to that of a pure halloysite. The hematite concentration is relatively large and the flux oxides ratios remain as acceptable impurities. Microscopic observations showed a predominant tubular halloysite phase, flattened hexagonal platelets corresponding
to the presence of kaolinite and its polymorphs (nacrite, dickite), and hydrated alumina.

The SiO2/Al2O3 molar ratio and tubular DD3 suggest possible uses in technical ceramics and nanotechnology applications.
Analysis by XRD revealed the presence of many phases. Thermal treatment at 450 ◦C and chemical treatment with HCl confirmed the presence of halloysite. The inclusion in the clay of organic molecules (dimethylsulfoxide (DMSO), DMF, and diluted glycerol) showed that the DMSO led to expansion of the inter-planar distance. The intercalation by DMSO molecules resulted in a shift of the basal peak from 10 to 11.02 A˚ and partial displacement of the peak from 3.35 to 3.65 A. ˚ These two peaks are characteristic of halloysite. The presence of residual nacrite was also confirmed by the shift of the peak observed at 3.35 A. ˚
A full analysis of the XRD patterns using the Match software, based on these results, showed that the DD3 clay consists of >60% halloysite.

Original Article at:

Download (PDF, 1.23MB)

Characterization and assessment of Saudi clays raw material at different area

Q. Mohsen a, A. El-maghraby a,b,*
a Materials and Corrosion Lab., Faculty of Science, Department of Chemistry, Taif University, Saudi Arabia
b Ceramic Department, National Research Center, Tahrir Str., Dokki, Cairo, Egypt
Received 7 April 2010; accepted 10 June 2010
Available online 17 June 2010

Original Article at:

Assessment of saudi clays by various methods

Pot Filter Arsenic Removal with Bone Char Attachment

Link to original article:

A Sustainable and Simple Solution in Resource-poor Settings

Stephen D. Passman – Saint Louis University
Tyler J. White, MPH – Saint Louis University
Roger D. Lewis, PHD, CIH – Saint Louis University

The results suggest that the designed test filter has a significant potential for removing arsenic concentrations to below both WHO and EPA drinking water standards. In addition, the clay pot filter alone demonstrated substantial reduction in the concentration of arsenic. Further research must be done to investigate longevity and practicality of the test filter, and to explore the extent to which reduction in arsenic concentration is attributable to the additional bone char layer versus the clay pot filter.
Our research team aims to continue investigating the new design to maximize removal of arsenic, other harmful metals, and bacteria. Further development will also include finding the optimal pore size and surface area for maximum arsenic adsorption to the bone char layer and the clay pot itself. Given the variance in manufacture methods of different communities producing the clay pot filters, identifying physical characteristics that result in optimal arsenic adsorption can help promote best practices for improving the effectiveness of the filters. Finally, connecting with NGOs working in resource-poor communities is critical to improving POU clay pot water filters for enhanced filtration and better health outcomes.

Point-of-Use Water Filtration for Arsenic:

Download (PDF, 600KB)

Filter setter project timeline

Pan Ring Setters 2
Version 1: Pan ring
– Currently in use in some factories manufacturing round bottom filters.
– Round bottom filters nest deeply allowing for denser stacking.
– Hand pressed into molds.
– Variation, using pieces of cut rejected filters.
– Weight is distributed onto filter rims in 3 point compression.
– Weight of stacked filters is distributed in compression cumulatively onto filter rims below.

Version 2: Interlocking setter block
Abandoned during prototype process due to complex moldmaking process.
– Weight distributed in compression consecutively onto setters.
– Individual filter weight distributed in 3 point compression on rims.
– Interlocking nodes assist with locating setters.
– Hand pressed into plaster molds.

Version 3: Ring Setter
Abandoned during firing testing.
– Weight of stacked filters is distributed in compression cumulatively onto filter bottoms below.
– Wheel thrown
– Firing test failed due to stress fractures. Possible cause: shrinkage differential, faulty weight contact distribution.

Verion 4: Pitet Setter
Currently in prototype phase.
– Original master was jiggered, causing various difficulties.
– Proposed masters to be Lathed (CNC) or 3DP.
– Individual filter weight distributed in 3 point compression on rims.
– Interlocking nodes assist with locating setters.
– Weight distributed in compression consecutively onto setters.
– Potential to be manufactured from filter medium.

Preliminary prototype manufacturing method allows for reasonable minimum daily production, however not all materials necessary to build the mechanism are widely available (8″ plastic pipe).
First test firing results proof of concept passed. Next phase begins field trials and feedback process.
Field trials will select a partner CWF factory to produce and test the setters on a production scale. Comparisons will be made in terms of durability, labor time, fuel reduction, packing density, and applicability to various filter shapes.

Video link:

Setters update.

Here is an update on the filter setters project.

Our first problem was that of alignment. This is something that we struggle with in designing appropriate technology pressing equipment. Finding a cheap and simple mechanism to keep the two halves of the mold aligned
throughout the pressing cycle.

In the case of the filter setter press, the pressures are not extreme, I wish we could figure out how to calculate the pressure curve in solidworks, anyone? facebook
In this case the difficulty of finding 2 pieces of pipe that fit together closely, caused us to try and make the outer pipe to spec. with concrete. We used a piece of 200mm green sewer pipe (expensive at $80) for the main structure. It was wrapped with 4 layers of 6 mil plastic sheet but not taped to the pipe, so the pipe could slide freely. Then placed the parts into a 12″ sonotube and cast quickrete around it.
We also cut holes into the top to fit a branch of maple for the handle.

The inner pipe slid out easily (rotated just as the concrete had hardened green), and then the plastic.
We cut a bottom part of the green pipe now for the female mold.

For the male mold, after trying various other methods, we had it machined from aluminum at Armstrong Machine

This way it could thread directly onto the end of the 5/8″ threaded rod. The cutter is being made now, 1/2″ flat bar and a piece of pipe welded onto some 3mm steel plate. Can I borrow a MIG in Vernon? facebook
This will be cast into quickrete or plaster (running out of quickrete) inside the top part of the green pipe.

Making the female mold was a bit more complicated. We figured out after many tries to cut a profile out of arborite (countertop material $4 for offcuts at homehardware (coated fiberglass)) and to cut a master on a plaster lathe. We used hydrocal here because the pottery plaster from winrock was dead and I didnt want to drive back to Kelowna to return it. It turns out Hydrocal might be better anyway.

Since doing this last time we figured out a better way to cast the female mold. As you can see from the photos the mold is unnecessarily in 3 parts since the level was off on the pouring of the second half (tape blowout, oops). It took quite a bit of time to get it to slide in and out of a whole pipe section easily but tightly.
It was scraped with the edge of a fresh Olfa blade.

The green pipe was a bit warped so it doesnt spin around in the concrete casting as well as hoped. about
100deg but not all the way around. Should still work.

Here are all the photos together on gplus:

Fall 2014 News

UNC Chapell Hill, October 2014
Ceramic technician Burt Cohen will be presenting at the University of Chapel Hill conference on Water and Health.

The Ceramic Pot Filter side session is scheduled for Friday, Oct 17, 8:30am – 12:00pm. The purpose of the side session is to bring together those involved in ceramic pot filter manufacturing, marketing, dissemination and research in order to share successes and challenges over the past year and discuss future directions.

Filter Setter
We are currently forming a second prototype filter setter. The filter setter is used for stacking the filters together inside the kiln in a dense configuration. The setter not only nests the filters closely together, but should distribute the weight of the filters onto the support, rather than onto each other. A denser kiln stacking will allow more efficient use of space, reduce fuel costs, and improve the productivity of existing kilns. We hope that this setter will be able to be formed on the filter press.

Prototype mold Set
UK donor, Howells Llc. has produced an ovoid mold set of cast aluminum. This prototype set has a flat bottom but rounded sides, and incorporates several other small changes to the filter form. We hope that this prototype will improve strength and flow rate capabilities of the filter without requiring special drying and handling practices. Several rounds of experiments will be preformed before the mold set reaches the field-testing stage.

Prototype Press
Howells Llc. has also manufactured a prototype press which incorporates some potential advancements. Specifically, the press uses a flipping action for ejection, and is designed to be adaptable to manual, electric, or pneumatic hydraulic pistons for automation. It is hoped that this ejection method will lead to a method of ejection which will not require plastic bags, however, none of the experimental mold-release agents have yielded successful results so far.

Guinea Bissau
Although parts of West Africa have been heavily affected by the Ebola virus, our partners in Bissau are now in advanced stages of building the factory enclosure. We hope to begin batch tests and establish production in 2015. This project continues to benefit from area specific fund raising efforts including generous donations by the Canadian charity “Active Compassion” which helped pay for the first pound of colloidal silver. That’s enough silver for over 3300 filters.


Robert W. Dies
Bachelor of Applied Science
University of British Columbia, Canada, 2001
Submitted to the Department of Civil and Environmental Engineering
In Partial Fulfillment of the Requirements for the Degree of
at the
June 2003

© 2003 Robert Dies.
All right reserved.
The author hereby grants to MIT permission to reproduce and distribute publicly paper and electronic copies of this thesis document in whole and in part.



Countries like Nepal face tough challenges in terms of providing safe, clean drinking water for their citizens. The World Health Organization estimates that nearly 5 million people in Nepal lack access to safe drinking water while globally, 1.1 billion lack access to improved water supplies. Point-of-use water treatment technologies, such as household ceramic water filters, offer an affordable and effective means of treating water to standards suitable for drinking. The fact that ceramic water filters can be manufactured and produced by local ceramists with local materials makes ceramic filters particularly attractive as a point-of-use treatment technology that is affordable, appropriate, and sustainable.

This thesis examines existing ceramic water filter technologies, production processes, and methods for bringing a low-cost ceramic water filter to market in Nepal. Three types of disk filters and five types of candle filters are evaluated in terms of microbiological removal efficiency and flow rate. A red-clay grog disk filter coated with colloidal silver and three of the five candle filters (Katadyn􀀀 Ceradyn, Katadyn􀀀 Gravidyn, and the Hari Govinda white-clay candle filter capped on both ends) also coated with colloidal silver, performed the best in terms of microbiological removal efficiency (>98%) and flow rate (ranging from 641 mL/hr/candle (Ceradyn) to 844 mL/hr/candle (Gravidyn)).

In addition to filter testing, a guideline for developing a ceramic water filter in preparation for bringing a product to market is presented, along with a discussion on the importance of laboratory and field testing to ensure overall product performance. A step-by-step summary of the production process is also presented along with a comparison of the theoretical flow rate through a candle filter versus a disk filter. Recommendations for future work include testing and modifying the current disk-filter prototype design and research on the most appropriate filter element for the proposed prototype.

Download (PDF, 3.1MB)


Hydration for Health from an Early Age – How Ceramic Water Filters Can Help

Hydration for Health from an Early Age

Water is one of the most essential nutrients for health, and yet many developing countries still have vast numbers of the population who do not have access to fresh clean drinking water. Water that is contaminated by bacteria can become, rather than a lifesaving ingredient, a cause of disease and even death. Although there are various initiatives around the world designed at promoting the availability of clean water, such as ceramic water filters, the problem remains in many communities and ongoing support for these initiatives is vital. Lack of clean water and the ensuing dehydration can lead to chronic health conditions; having only enough water to save from complete dehydration will keep a person alive, but the quality of that life will be severely reduced. If the water available is unclean, the exposure to health risks is even greater. The effects are particularly potent in young children, severely impacting on their development.

Dehydration in Infants and Children

Children become dehydrated more quickly than adults due to their higher bodily percentage of water and a lesser ability to regulate body temperature, as well as immature kidneys and body processes. In young children with an undeveloped immune system the potential of succumbing to infections from drinking dirty water is higher, and the infant mortality rate for infants living in areas where the water supply is unclean is very high. Babies are at particular risk; although breastfeeding is generally considered to be the best diet for infants up to six months, this guideline generally applies to breastfeeding mothers who are themselves healthy. Where the mother is dehydrated herself and drinking contaminated water the benefits of breastfeeding are significantly reduced, with a severely dehydrated mother unable to produce breast milk. The only other option is to make up infant formula milk – where there is access to it – with contaminated water. Although infants and very young children are at a higher risk of death, children of all ages require clean water and proper hydration for optimal development.

Effects of Dehydration on Development

Even moderate dehydration has been shown to cause exhaustion and lethargy, lower the immune system and even impair cognitive function, which then impacts on learning and skills development. Chronic dehydration over time can lead to digestive problems, rheumatism, anemia, growth impairment and even premature aging in children. Drinking dirty water only makes the problem twofold, as the bacteria present often cause diarrhea, which has an incredibly dehydrating effect on the body, and at it’s worst can kill. The sufferer will feel painfully thirsty, yet the only water available will cause further diarrhea and dehydration in a vicious circle. Continued drinking of unclean water can cause fatal disease, with thousands of children every year dying from drinking dirty water. Overcrowded cities without toilets and running water are particular danger spots. A clean fresh water supply and proper hydration for children is crucial. WaterAid has previously described these issues as one of the biggest problems in world health today.

How Ceramic Water Filters Can Help

Inexpensive and effective, ceramic water filters rely on the small pore size of the ceramic to filter out harmful bacteria. In developing countries, this technology is utilized with clay pot filters that can be made and used easily and are a strong safeguard against harmful bacteria contaminating drinking water, although they are believed to be less effective against viruses. The making of clay pot filters can also be a sustainable business for developing countries, helping to minimize poverty for some families and communities and as they are culturally acceptable there are few barriers to their use. By keeping out the majority of bacteria and other pathogens the pots enable drinking water to be cleaned and filtered effectively. Clean drinking water of course means less dehydration, impacting on the development of third world children. Although an often overlooked factor in dietary recommendations for children water intake is in fact a vital and integral part of optimal nutrition. Hydration is an important factor in nutritional development and may be particularly important in the diet of children from developing countries whose nutritional intake is likely to be poor in other areas.

Although the problem of contaminated water supply also needs to be tackled by raising awareness and helping countries and people implement proper sanitation and access to fresh water, ceramic filters are an excellent way to help struggling families quickly and effectively, ensuring the water they give their children is as clean as possible.

Guest Writer: Lisa Major

Firing Temperature and Shrink Tests

CWF Clay Test
Test tiles 2cmx10cmx0.5cm



The first round of tiles for the filter clay temperature and shrinkage tests. Over 60 tiles to test at 925 950, 975, and 1000 degrees Celsius. We were sent between 250 and 500 grams of each sample, which turned out to be a little small. It took 100grams to make 4 tiles 2cmx10cmx5mm thick. and each time the particle analysis test was preformed we used 100grams as well. The particle analysis test takes 24hours to complete, and the firings about 6 hours, not to mention the prep and wait times. Our scale turned out to be giving bad readings so it threw off a lot of the data we collected. now we begin again.

Kiln Building: The Mani Kiln

Ceramic Pot Water Filter Kiln Building Resources

Building the Mani Kiln

Kiln building: The Mani kiln is an improved design for a wood burning kiln with a capacity of 50 ceramic pot water filters. Designed and distributed by Manny Hernandez – Northern Illinois University.

Complete drawings are included in the following PDF

Download (PDF, 4.08MB)

2012 Year End Activity Report

Field Work:

UNICEF Feasibility StudyBurt Cohen was sent to East Africa to study the feasibility of developing additional ceramic water filter production in Kenya. Burt visited the Turkana and Garissa regions and uncovered valuable information for future water filter projects in the area. We have partnered with UNICEF and other NGO’s in the region to expand production of CWF, such as the Rwanda factory established in 2005. At the moment we are waiting for funding and human resources to become available from these partners to continue this work.
German Red Cross/Red Cresent – SomalilandBurt Cohen and Kai Morrill traveled to Somaliland to work at the Biyo Miire CWF factory in Hargeisa, run by the Somaliland Red Crescent Society. During their short stay they were able to troubleshoot several issues, and expand production significantly. The key component in this visit was the construction of an improved propane kiln which fires over 100 filters at a time. Burt will be returning to the factory this spring to do safety evaluations, review production and see if we can assist the factory in making further advances. Read more about this at: (
Healdsburg Community Church – Guinea BissauKai Morrill traveled to Guinea Bissau in November to undertake a feasibility study. He reports that the hosting Christian organization “Central Social”, was very welcoming and Kai was impressed with their administrative capabilities. Guinea Bissau has been suffering from political instability and lack of public sanitation infrastructure. The country has an extremely young population with slow economic development, the majority of the population suffers from water borne disease, avoidable by the use of ceramic pot filtration. If funds are located to develop the proposed factory, thousands of lives could be saved, and the world will be a better place. To donate to this project, or any other PWB endeavor, you can do so through our website, you may add specific details in the comment box. (

“BISSAU, 31 March 2009 (IRIN) – With 80 percent of the Guinea Bissau capital’s water contaminated with harmful bacteria, residents are used to outbreaks of cholera and other deadly diarrheal diseases, but donors say they can fund major infrastructure projects only if stability can be guaranteed.” UN Humanitarian News.

Research and Development:

Factory MappingEarlier this year we began an effort to collect the contact information of all the factories we communicate with and this information has now been added to a single Google map, making contact with regional factories much easier. International buyers and others interested in the technology are now able to locate and connect with factories in their areas. It will also facilitate the development of safety standards for ceramic water filters. (
Particle AnalysisRaw clays used in filter-making are dug from natural sources. The location for digging is chosen based on its regular consistency and the volume of supply; having a steady supply of clay available for factories’ production and expansion is very important to the long term success of the factory. There is a certain amount of variability in all natural clay sources; from week to week, the clay can vary significantly as the collection location moves along the vein. In order to maintain consistency, two or more clays of different qualities are often blended together. Clay bodies of variable particle distribution can be blended in appropriate proportions so that a more homogeneous mixture can be maintained.

This summer we published a set of protocols to establish a standard method for classifying clays for filter manufacturing. This procedure uses a standardized hydrometer to measure clay particle distribution as batches enter the factory and adjust the mixtures accordingly. For more information, and to download a copy of the protocols look here: (

The “Kosim Water Keg”Beginning in 2011 PWB has been helping researchers from MIT and Pure Home Water in Ghana to develop an improved ceramic filter unit which uses negative pressure to increase flow rates. We produced several prototype models that were shipped to American researchers who assembled and tested them. You can follow their results at: (

On The Road:

NCECAIn March, we sent Burt Cohen and Kai Morrill to the conference of the National Council on Education for the Ceramic Arts (NCECA) in Seattle. This is a large conference and trade show of industry, university, and ceramic arts professionals which meets once a year to hold workshops, demonstrations, and exhibitions. We shared a table with our colleagues from Potters For Peace and held meetings with several ceramic filter consultants. We also raised money for projects, spoke about our work, and signed up new members. (


Howells UKThrough a partnership with Howells Railway Products, LLC. in Manchester, UK we were able to begin distribution of press and mold sets to Ethiopia, Somaliland, and Cameroon. The quality of the equipment is much improved from units manufactured in the field. Unfortunately, due to the challenges of moving equipment across multiple national borders, the implementation has been slower than hoped. We are actively working with local partner NGOs to get the molds into place and ready for production.
CameroonAn agreement has been reached with the African Center for Renewable Energy & Sustainable Technology (ACREST) to begin preliminary project development in Cameroon. ACREST is looking for stable funding partners to develop a factory as soon as is viable. The organization currently operates a factory which produces improved cook-stoves. This facility is an ideal candidate to diversify into CWF production because the materials and processes are similar. It is estimated that about $20,000 is required to initiate the new enterprise. Towards this end, a press and set of molds are already on the way from Europe.


Thanks very much to Beth Campbell of Ontario for fostering the work of Potters Without Borders. Beth spoke with communities about the organizations work.

Thanks to all those who attended the fundraiser at O’Keefe Ranch last summer, your assistance has helped expand projects that continue to bring filter technology to desperate areas.

Congratulations to Juliette Arabi of Hogar De Christo in Ecuador for beginning filter production at the Guyaquil filter factory!

Thanks to Tia McLennan and John Hatten for assisting with the newsletters, your help is much appreciated.

Why become a member?

Joining PWB allows us all to have a disproportionate impact in the world compared to our small size. Communities served by the factories which we assist have no alternative methods of getting safe water. We want to keep putting donations towards project specific expenses, in order for this to happen we need the membership dues for operating the Registered Charity. Each year we pay for the Website, Accounting expenses, Postage, Insurance, and Printing costs. It is our dues that keep the “organization” running. By paying dues you provide the basic operational structure necessary, for advancing our mission of fostering the building of ceramic water filter factories. We have no paid administrators, the only way we can continue to be sustainable is with with your help.

We are recruiting directors and other volunteers

Do you have experience or skills applicable to this position? Know someone who does? Contact:

In particular, we are looking for volunteers with a background in accounting, law, organizational development, grant writing, and, most of all, who have energy and passion for helping Potters Without Borders grow and succeed in our mission. (

Investigation of Ceramic Pot Filter Design Variables

Original link to document:

Download (PDF, 1.35MB)


Investigation of Ceramic Filter Design Variables

Molly Klarman

Background: Over four billion cases of diarrhea occur worldwide each year that result in about 2.2 million deaths. Household water treatment and safe storage (HWTS) methods, such as ceramic pot water filters, are one of four proven HWTS methods and have been shown to reduce diarrheal prevalence by an average of 45% among users in a randomized control field trial. Although ceramic filters have been proven effective for improving water quality, users and implementers often express concern over their inability to produce a sufficient quantity of water due to their slow flow rate of approximately 1-2 liters per hour (L/H). If flow rate could be increased by altering the current filter design, it would improve the ceramic pot filter’s viability as a scalable HWTS option.

Objective: The main objective of this study was to determine if the flow rate of ceramic pot filters could be increased without sacrificing filter effectiveness, in terms of bacterial removal, by examining the effect of altering specific design variables.

Methods: At the FilterPure ceramic manufacturing facility in the Dominican Republic, eight new filter designs were created by changing one of three design variables: 1) type of combustible material, 2) the ratio of combustible material to clay, or 3) the size of the screen used to sift combustible material. These eight new filter designs were produced in triplicate, along with six control filters. Local river water was passed through the filters daily, and they were tested once a week for five weeks for total coliforms (TC), turbidity, pH, conductivity, and flow rate. 

Results: The flow rate of all filter designs increased from the first to fifth week by an average of 44.1%. The filters made with alternative combustible materials (coffee husks and rice husks) had average flow rates of 9.9 and 5.0 L/H and average TC reductions of 96.1% and 97.6%. The control filters had an average flow rate of 0.95 L/H and average TC reduction of 99.8%. As the proportion of clay to combustible material decreased from 60% clay:40% sawdust to 40% clay:60%sawdust, the average flow rate increased from 0.38L/H to 5.9L/H and the percent reduction of TC decreased from >99.9% to 98.1%. Once initial flow rate increased above 1.7L/H, TC reductions fell below 99%.

Discussion:Minor alterations in filter design or raw materials can affect the performance of locally produced ceramic pot filters to thepoint where their ability to produce safe drinking water is compromised. The results of this research suggest that the maximum initial flow rate for a properly functioning FilterPure filter is 1.7 L/H. None of the alternative designs, that had faster flow rates had better TC reduction than the control filters. This indicates FilterPure should not produce filters with a clay to sawdust ratio lower than 53% clay to 47% sawdust and different combustible materials cannot be used interchangeably without first identifying optimal proportions.



The author of this thesis is:
NAME: Molly Klarman
Address: 32 Lovejoy RD
Andover, MA 01810
The advisor for this thesis is:
NAME: Christine Moe, PhD
Rollins School of Public Health
ADDRESS: 1518 Clifton Road
Atlanta, Georgia 30322
Other committee members for this thesis are:
NAME: Daniele Lantagne, PE
Centers for Disease Control and Prevention
ADDRESS: 1600 Clifton Rd.
Atlanta, GA 30333

Molly Klarman
BA Lewis and Clark College

A thesis submitted to the Department of Environmental and Occupational Health and the Hubert
Department of Global Health
Rollins School of Public Health
Emory University
in partial fulfillment of the requirements
for the degree of Master of Public Health
May, 2009



The following questions highlight steps you can take to ensure your project’s success:

A. Understanding the local situation is key to a successful project.

  • What water sources do most locals use?
  • What are the impurities that must be removed?
  • Do people currently filter, boil, chlorinate, or otherwise purify their water?
  • What other purification methods are locally available? At what price?
  • What studies have been done to learn if people in the local community are receptive to the idea of using this or any kind of water filter?

  • Have they traditionally used ceramic water jugs for storage in the past?
  • What is the climate? Is there a rainy season?
  • How long?
  • Is the area politically stable?
  • Identify local laboratories capable of conducting water quality tests.

B. We recommend partnering with an existing pottery or brick-making workshop, ideally one that would have experience with marketing and health. Utilizing competent local potters will help ensure project success.

  • Is there presently a relationship between the potters or pottery collective and the sponsoring organization?
  • What kind of pottery do they produce?
  • What temperature do they fire to?
  • Do they have a history of being able to meet quotas?
  • Do local potters also have the experience and ability to fabricate lidded clay receptacles with a five to seven gallon capacity?
  • How far are the potters’ sites from the sponsoring organization’s operations?
  • How will management of the facility be structured? It will be very important to have a highly involved liaison responsible for management and communications between the two groups.
  • How will employees/skilled labor be paid?
  • By whom?
  • What is the distance between the factory site and the market (projected distribution area)?

C. Having a sustainable marketing plan is even more critical than the initial level of funding.

  • Who will provide the financial resources ($25,000-$30,000 USD) for start up?
  • How many visits by PWB consultants including airfare, per diem and stipend have been budgeted?
  • Who will provide the on-going business loans or subsidies for marketing?
  • For inventories of plastic components?
  • How large is their in-country staff?
  • What is the procedure for attaining approval and/or quality recognition from the Ministry of Health?

Identify local health promoters/NGOs through which the filter can be marketed in bulk. Contact them to evaluate their interest in the product.
Identify a local print shop to make brochures; instructional stickers; and educational, health, and marketing materials.

D. Communications

  • Does the ceramic workshop communicate through the internet?
  • Does the site have Internet access within or nearby?
  • Do they have a website?
  • Does anyone there speak, read and write English or Spanish?

E. The availability of facilities and suppliers can also determine project sustainability.

  • How far from the workshop is an adequate and affordable clay supply?
  • Is the clay plastic and of good quality?
  • How do the potters presently process their clay?
  • How far away is the site located from an adequate and affordable source of fuel and combustible (burnout) materials?
  • How will the clay, fuel, and combustible materials be transported, by whom, and at what cost?
  • Does the site have electricity? For how many hours a day?
  • What voltage and amperage is consistently available?
  • Does the site have piped water or a consistent water supply? How often is water unavailable?
  • Are high quality bricks available for kiln building? What sizes are available?
  • Is there a machine shop where repair items can be fabricated nearby?
  • Are there any restrictions on the importation of colloidal silver?
  • Is there a nearby source of affordable plastic bags?

Identify your local or foreign supplier of plastic five gallon pails and oversized lids; price, and availability.
Identify your local or foreign supplier of plastic faucets; price, and availability.

Needed Equipment
Please study the list and pictures. Is there:

  • A hammer mill
  • A hydraulic press
  • A clay mixer
  • A pug mill
  • Potters wheels
  • A kiln (please indicate interior size, type of fuel used, and firing temperature)
  • Production and storage space (indicate square footage of each)
  • Shelving for 1000 filters

The Workshop:

  • Date established
  • Type of production
  • Forming or production method(s) utilized
  • Number and size of kilns
  • Equipment currently installed
  • Electrical: Voltage and amperage available
  • Water availability
  • Number of men and women workers
  • Vehicles
  • How is pottery presently is marketed and distributed?

Potters Without Borders wants to work with you to create a social enterprise that will be not only sustainable, but profitable for all involved, and especially to the benefit of those most in need of potable drinking water. We have found that the presence of the above conditions all contribute to a successful project, but we recognize that you may not initially be able to obtain them all without help. Please let us know which of these items you will be able to put in place yourself, and which items you think will require our assistance. We look forward to your questions.

Open Source Receptacle Design – Vhembe


This open source receptacle design was the outcome of a Masters in Industrial Design, from the University of Johannesburgs Department of Industrial Design. The Vhembe Water filter receptacle was designed by Martin Bolton, who lectures at the University of Johannesburg.

This WIKI was created as an open-source showcase of Design Development, Design Sketches as well as all relevant Computer Generated Models which can be used for design refinement/ prototyping, tooling, mass production etc.

It is suggested that the MTech dissertation be read to allow for the understanding of how and why this product was developed. Furthermore, all field research, data gathering, data analysis and development of design requirements will be evident.

Design and Development of Ceramic Pot Water Filter Receptacle – Vhembe

Independent Appraisal of Ceramic Water Filtration Interventions in Cambodia: Final Report

Joe Brown and Mark Sobsey
University of North Carolina School of Public Health
Department of Environmental Sciences and Engineering
Submitted to UNICEF – Cambodia, 5 May 2006

This study is an independent follow-up assessment of two large-scale implementations
of the household-scale ceramic water filteration after 2 and 4 years in use.
Approximately 1000 household filters were introduced by Resources Development
International (RDI) in Kandal Province from December 2003 and 1000+ filters by
International Development Enterprises (IDE) in Kampong Chhnang and Pursat provinces
from July 2002. The American Red Cross, CIDA, AusAID, UNICEF, and the World Bank
Development Marketplace Programme have supplied support to these two NGOs for
various parts of the production and distribution cycle of the filters.

In October 2003, IDE completed a field study of the ceramic water filtration devices after one year in use,
yielding promising results. The study used bacterial analyses of water samples and user
surveys to measure the performance, acceptance and use of ceramic water filtration devices in 12 rural villages.
The field study also assessed health improvements, time savings, and expense savings.
In August 2005, RDI completed a similar internal study for the filter distribution in Kandal
province, although findings from this assessment have not yet been released. The
present study follows up on these previous assessments and represents an independent
appraisal of the performance of the ceramic water filtration projects undertaken by IDE and RDI. It is
hoped that the findings produced will aid in assessing the water quality and health
impacts of the ceramic water filtration interventions to date and yield useful information on the
sustainability of the filters as implemented.

The study was carried out in two parts:

(1), a cross-sectional study of households
that originally received filters to determine uptake and use rates and associated factors;

(2), a nested longitudinal prospective cohort study of 80 households using filters and
80 control households to determine the microbiological effectiveness and health impacts
of the filters in household use. We measured (i) the continued use of the filters over
time as the proportion of filters still in use since introduction, and identified factors
potentially associated with filter uptake and long term use; (ii), the microbiological
effectiveness in situ of the filters still being used, as determined by the log10 reduction
values of the indicator bacterium E. coli; and (iii), the health impacts of the filters as
determined by a prospective cohort study using data on diarrheal disease prevalence
proportions among filter users versus non-users. We also collected a variety of other
survey data intended to elucidate successes and challenges facing the long-term
sustainability of this intervention in Cambodia. Stratified analyses, logistic regression,
and log-risk regression with Poisson extension of generalized estimating equations
(GEE) were employed in analysis of cross-sectional and longitudinal data to determine
factors associated with long term filter use and effectiveness of filters currently in use.

Major findings are that (i), the rate of filter disuse was approximately 2% per
month after implementation, due largely to breakages; (ii), controlling for time since
implementation, continued filter use over time was most closely positively associated
with related water, sanitation, and hygiene practices in the home, cash investment in the
technology by the household, and use of surface water as a primary drinking water
source; (iii), the filters reduced E. coli/100ml counts by a mean 95.1% in treated versus
untreated household water, although demonstrated filter field performance in some
cases exceeded 99.99%; (iv), microbiological effectiveness of the filters was not
observed to be closely related to time in use; (v), the filters can be highly effective
against microbial indicator organisms but may be subject to recontamination, probably
during regular cleaning; and (vi), the filters were associated with an estimated 46%
reduction in diarrhea in filter users versus non users (RR: 0.54, 95% CI 0.41-0.71).

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