Use of a hollow fiber dialyzer based device to provide pure water in villages

Nathan W. Levin, Linda Donald, Seth Johnson, Ben Lipps, Jochen G. Raimann, Daniel Sackey

Easy Water for Everyone NGO, New York, USA

Background

The provision of pure water to villages without power or functioning boreholes is difficult since inhabitants must rely on rainwater, wells, local streams and lakes. Faecal contamination of water, including of wells and boreholes, is very common and results in high incidences of diarrhea, dehydration, acute kidney failure and death, particularly in young children.

Methods

An NGO, “Easy Water for Everyone” has been established to purify water in villages, initially in Ghana, utilizing a unique device which repurposes once used hollow fiber hemodialyzers as the means of filtering external water sources (Fig. 1). These are sterilized and assembled in parallel in a device. An 8 dialyzer device can produce pure water at a rate of 500L/hr with manual pumping and at 250L/hr with a gravitational system, which requires the use of a small gasoline pump that pumps polluted water to an elevated tank which drains into the device below (Fig. 2). The pore size of the dialyzer membrane is 0.003 microns, which does not permit passage of viruses, bacteria and parasites. Regular backwashing is needed, depending on the degree of sediment in the water, and protection from sunlight is achieved by using dark tubing in the device, to prevent algal growth. The high quantitative performance of the device is due to the presence of over 10,000 hollow fibers totaling a membrane surface area close to 2 square meters. The devices can be used to purify water from streams, lakes and from already contaminated wells and boreholes, and are established in a central location available to all in the village. When water in excess of drinking requirements is produced it can be used for handwashing, which up to now has been impracticable in these islands. In rural schools in many regions pure water for handwashing has not been available. We hope to encourage a practice of all children washing their hands as they arrive at school and after all uses of sanitation facilities and to further initiate educational initiatives emphasizing the importance of hygiene.

Results

As of March 2019, 16 village sites have been equipped with the device in Ghana: 3 in Ashanti Ghana around Kumasi, and 13 on different estuarial islands of the Volta River close to Big Ada. Records of diarrheal episodes in individual households and local clinics are included in a central database providing an analysis of public health effects of these devices on communities. Further, data collection and analysis will allow understanding of effect modifiers and possible roadblocks to their adequate use. Because of its efficiency and considerably low cost, the device is very suitable for use in rural communities with limited infrastructure. The efficacy of the technology to remove pathogens from contaminated water is expected to substantially reduce the incidence of diarrhea, AKI and of mortality, particularly in children less then 5 years of age.

Discussion & Conclusion

The potential for rapid spread of this technology to the many villages without power is substantial, including those where well and borehole water is polluted. Marked improvement in hygiene is possible, simultaneously resulting in a marked reduction in diarrheal illness and its serious consequences. Prospects for further expansion in Ghana and to other African countries are good. Preliminary results show a reduction in diarrhea of at least 25%.

Providing pure drinking water in rural areas with contaminated water sources and no power by repurposing reprocessed hemodialyzers.

Jochen G. Raimann, Joseph Marfo Boaheng, Philip Narh, Seth Johnson, Linda Donald, Hongbin Zhang, Nathan W. Levin.

Easy Water for Everyone; City University New York School of Public Health

Background

The drinking of water polluted with fecal material leading to diarrhea is the second most common cause of death worldwide in children younger than five.  The absence of sanitation and of effective hand washing also contribute to the high incidence of diarrhea.  Easy Water for Everyone (EWfE), a US NGO, brings an innovative water-purifying device to isolated villages that have no electricity or other power supply to filter the villages’ contaminated water from rivers, streams, lakes, wells and boreholes, and changes it into pure water ready to drink!

EWfE follows the  brilliant, patented  idea of Professor Yoram Lass of Tel Aviv University, utilizing the hollow fiber hemodialyzer to purify water. The disposal of millions of hemodialyzers annually is a huge medical waste issue. To be repurposed for water purification, once-used hemodialyzers are resterilized and installed in the device as filters, taking advantage of the porosity of this synthetic membrane (polysulphone) and the robustness of its structure. The absolute pore size is 0.003 microns, which renders it impassable to all bacteria, viruses and parasites, essential for use in hemodialysis treatments and perfect for making pure drinking water.

The volume of water produced is determined by the number of filters in the device and the rate of moving contaminated water through it.   For example, an eight-filter device can produce 250 liters/hr. using a gravity system, where the contaminated water flows from an elevated tank down to the device installed at a lower position; and  500 liters/hr. with an easy to use hand pump.

 Since the development of the gravity system, the need for manual pumping has been eliminated.  The pumping was generally done by the boys and women of the village but now with the gravity system, anyone can open a tap!  In addition to the normal operation of purification, the filters need to be backwashed at set intervals (about 3 times a day for 5 - 10 minutes) due to the source water often containing sediment. Backwashing can also be done with the use of the gravity system. EWfE has found it most efficient in its routine operation to support a technical assistant in each village, at a cost of $40 USD per month, to keep the 1000-liter tank full (accomplished by using a small gasoline fueled pump, taking under 5 minutes to pump up the contaminated water) and to perform the backwashing.

 The connection between the quality of the water and  diarrheal illness  has to be understood by the villagers, before widespread acceptance of EWfE’s approach. Education of mothers and children, concerning the benefits of water purification is vital.

 At EWfE sites we are also collecting public health data quantifying the incidence rates of diarrhea and consequent hospitalizations for each village before and after device installation. Data collection, including house visits and screening of health center data for visits and stays, availability of sanitation facilities and of household size, has been approved by local authorities and Institutional Review Boards.  These data can serve the longitudinal analysis of the outcomes with multi-level statistical models.  In the recent World Congress of Nephrology held in April in Melbourne two abstracts were presented, both in poster sessions and one as an oral presentation.  The poster session abstract is called; Use of Hollow Fiber Dialyzer Based Device to Provide Pure Water in Villages and the poster session abstract which was also an oral presentation was called; Decentralized Water Purification Using Membrane Filtration Reduces the Incident of Diarrhea in Communities in Developing Countries.

The spread of power (electrical or solar) to isolated rural villages in developing countries is slow and undoubtedly EWfE devices will be needed for a long time. EWfE currently has single devices functioning fully in 15 villages in Ghana. Two of these devices have been running continuously for over 4 years (May 2015), and the others have been installed sequentially.  Of the current devices, 13 are located in villages on estuarial islands of the Volta River, providing approximately 6,500 people with clean water. We plan to include all 22 communities on these islands (reachable only by boat) with the EWfE devices by mid-2019, resulting in about 10,000 people having pure drinking water. Of note, this can be accomplished at an extremely low cost. Based on a December 2018 year-to-date calculation including the cost of the following; the device, shipping/import, pre-filters, small gasoline pump, 1000-liter storage tank, as well as the following assumptions; the device produces 250 liters per hour, the device functions 12 hours per day (can function more if the demand is there) for 365 days per year and has a minimum asset life of 5 years.  With these parameters, the cost of producing 1 liter of pure water is 0.00046 cents. It is assumed that approximately 3 liters daily is consumed for drinking therefore the pure water produced by this device is exceedingly inexpensive.  In addition, the device is unusually efficient in its rate of purification. There is plenty of water for us now to begin educating people of the importance of hand washing to further reduce the possibility of bacterial contamination in homes and schools. 

When we make our biannual visits to the villages since 2015, our reward is to be greeted enthusiastically by the women of the village that there is “NO more DIARRHEA here” and the teachers tell us that children are no longer sent home from school due to diarrhea.  EWfE wants to establish diarrhea free villages everywhere devices are installed.  It should also be noted that the “seed” money for practical application and evaluation of the device came from funds left over in RoFAR (a not for profit research foundation, “Roche Foundation for Anemia Research”) which had completed its mission of funding relevant research related to blood formation, physiology and related diseases.  Roche and the members of the Board of RoFAR, generously approved a grant of approximately 100,000 Swiss Francs to be applied to the general task of water purification in developing countries.  The International Society of Nephrology helped EWfE by kindly agreeing to perform both financial oversight and the disbursement of these funds. 

Conclusion

A device derived from the hemodialysis medical world, uniquely purifies water in villages without power, permitting complete reduction in infection from contaminated water sources, and contributing to hygiene improvement at home and in school, major aspects of the overall problem of diarrhea and its complications.

Decentralized water purification using membrane filtration reduces the incidence of diarrhea in communities in developing countries.

Jochen G. Raimann, Joseph Marfo Boaheng, Philip Narh, Seth Johnson, Linda Donald, Hongbin Zhang, Nathan W. Levin

Background

In rural communities in regions with limited resources the provision of clean water remains difficult. The only water available is that from rain collection, wells, streams and lakes. Fecal contamination of water is very common and results in a high incidence of diarrhea, subsequent acute kidney injury and mortality particularly in the very young and old. Membrane filtration is a practical solution to this problem and recent innovation allows membrane filtration using recycled dialyzers. We, Easy Water for Everyone, have attempted to quantify the systematic effect on health outcomes by providing clean water using a high-volume membrane filtration device with recycled dialyzers.

Methods

Between 06/2015 and 12/2018, 17 communities in rural Ghana (Ashanti-Ghana and Greater-Accra region; village size ranging in size from 5 to 591 people) were provided with high-volume membrane filtration devices (NUF 500; NuFiltration using recycled dialyzers). Health data from household surveys and chart review in local healthcare facilities were collected with approval from Ghana Health Services. Specifically, data was collected on gastrointestinal disease, acute kidney injury and therapeutic interventions. Further data on demographics, village and community characteristics and other potentially relevant aspects were also collected. Incidence rates for 6 months periods before and after implementation of the device were calculated.

Results

Data from 3611 villagers over 17 months from the 12 studied communities in rural Ghana (around 13% 5 years or younger and 6% older than 65 years) were included in this analysis. The overall incidence rate of diarrhea showed a declining trend following the implementation of the filtration device in the village structure and was reduced from 1.5 to 0.8 cases per 1000 person days from the before to the after period (Figure 1). A formal comparison of the rate reduction and detailed multi-level time-series analyses are currently underway.

Discussion

Provision of a membrane filtration device has the potential of significant improvements of health outcomes within rural communities. While our data requires a larger sample size and further statistical analyses accounting for village characteristics, seasonality and subject demographics, the obvious decline in incidence rates supports widespread use of membrane filtration devices, particularly in rural regions. Next to multi-level longitudinal analyses, future studies from our group will include an approach using a stepped-wedge cluster randomized design for the rollout of the device in further sites which will even further increase our understanding in terms of risk and preventive factors modifying the incidence of diarrhea and subsequent acute kidney injury