(691f) Zero-Energy Osmotic Water Purifier for Ethiopia: Providing Clean Drink to Vulnerable Populations

Globally, 894 million people do not have access to the basic amount of freshwater needed for drinking, cleaning and cooking. This is a catastrophe because water directly impacts every measure of development used by the Human Development Index (HDI): healthcare, education, and the economy.  Many of the afflicted populations are also victims of natural disaster or migration.  Refugees in particular are vulnerable populations that desperately need clean, sterile fluids for hydration and nutrition. Many water purification technologies are commercially available, but few are suitable for implementation in the rural of developing countries.  Traditional methods of distillation, filtration, and disinfection require electrical inputs or chemical feed stocks that are difficult, if not impossible, to supply to rural areas. Some low tech options, such as sand filtration, offer an inexpensive solution to filtering large contaminants from water but do very little to remove harmful heavy metals and other dissolved contaminants.

 This study investigates Ethiopia as a possible site for implementing a commercial forward osmosis process for producing a clean, nutritious drink from any fresh or brackish water surface water.  Forward osmosis (FO) is an emerging technology that could be used to remove biological, organic, and inorganic contaminants from water.  It works by utilizing an osmotic pressure gradient created by a “draw solution” to pull water via osmosis across a selectively permeable membrane while rejecting contaminants. For the specific process to be evaluated here, a sugar-nutrient-electrolyte solution mixture is used as the draw solution.  This solution is diluted during osmosis, thus producing a clean, lightly sweetened, safe and nutritious drink. The concentrated contaminated water is returned to the source. Since this process occurs naturally, no energy input is required and since there is no exhaustive media (such as with adsorption), there is no hazardous waste associated with maintenance. The water is taken directly from a pond, stream or river with the concentrate being returned and diluted into the source.

The objective of this project was to assess the efficacy of a commercial forward osmosis system intended for use in rural Ethiopia and Ethiopian refugee camps.    The particular system used during this study is the Hydration Technology Innovation’s (HTI) Village System for its claimed field durability and capacity (200 liters of nutritious drink per day).  The system employs a membrane capable of removing dissolved solids (organic and inorganic) and biological organisms (bacteria and viruses), though these performance metrics have yet to be tested and widely disseminated. In fact, no peer reviewed study has ever evaluated this system when functioning under real conditions. UCONN Engineers without Borders has teamed up with HTI to evaluate their system performance under real conditions (in this case, purifying water from an on-campus lake).   This study will show our preliminary pilot scale studies of using the HTI system hybridized with other low-tech options for pretreatment in order to preserve membrane life and performance.  We will also present our findings from an assessment trip to Ethiopia to better understand how such a system can be implemented.