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.
