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Access to safe drinkable water is a basic human right and an international goal. Since 1996, AQUAPOT international project, has researched and developed low cost, easy to use and effective water treatment technologies able to be used in developing countries. Recently, the project has carried out the design of three potabilization units based on membrane technology and its installation in rural areas of Ecuador with no access to safe water. Field experience has shown that maintenance and cleaning of spiral wound ultrafiltration membranes is not done properly what can reduce the membrane’s life due to biofilm growth. In a medium term, this growth would affect the quality and the volume of the pure water produced by the drinkable water treatment facility. An applied research has been initiated to study several cleaning solutions that allow to recover an optimum permeate flow. For the preliminary test, samples from UF membrane were used. Methodology includes static assays in which membrane’s samples were immersed in a cleaning solution for over 12 or 24 h at a temperature of 25 to 40°C. The study has allowed to select the most effective membrane’s cleaning solutions and the optimum conditions for its application. In addition, the study has allowed to verify the efficiency of the cleaning reagent in a drinkable water treatment plant.

Main conclusions after the static test were: – Membrane autopsy allowed to observe membrane superficial fouling (specially due to suspended or emulsified materials presents on raw water) along all its surface as a consequence of an inefficient cleaning and maintenance. – For higher concentrations (0.5 to 10%) and temperatures (cleaning solution at 40°C), the most efficient cleaning solutions have been oxidizing agent, sodium hypochlorite and Auxiclean B.13. – For lower concentracions (0.1 to 0.5%), oxidizing agent keeps its efficiency for removing foulants from active layer at 40°C and sodium hypochlorite at 25°C. – Due to the fact that oxidizing agent and sodium hypochlorite gave similar results at 25°C for concentrations of 0.5 and 0.4%, both cleaning reagents have been selected for next test that will be performed in a flat module at a pilot plant scale in order to verify the recovery of membrane permeability. – Application of the selected cleaning agents in the drinking water treatment facilities already installed is a suitable option, due to these chemicals are widespread and easy to use.