Small-scale water supply system (SSS) for remote and rural areas in developing countries

The Waterbackpack PAUL -Portable Aqua Unit for Life Saving- is a water treatment unit based on the Ultra-Low Pressure Ultrafiltration (ULP-UF) technology and is since 2010 successfully applied as a fast response to get safe water during natural disasters or emergencies in more than 2 000 cases worldwide. In addition, PAUL has demonstrated that the ULP-UF technology can be used in permanent decentralised drinking-water supply for remote and rural areas, as it is easy to handle and does require neither chemicals nor energy consumption nor spare parts on a regular basis. Hence, the ULP-UF is an appropriate solution in the process of reaching the Sustainable Development Goals (SDGs), ensure by 2030 access to safe drinking water worldwide. However, during long-term uses and under certain water characteristics, the ULP-UF faces some operational and maintenance challenges. The biofouling adhered to the membrane surface may lead to severe flux reduction. In addition, some re-growth of bacteria may take place on the permeate side because of the presence of high content of natural organic matter (NOM) in the raw water, especially Biopolymer and Humic Acids. Therefore, the aim of this study was to integrate some appropriate treatment steps before the ULP-UF technology, so that a reduction of attachment of NOM and biofilm to the membrane could be achieved and thus an increase of permeate flux and a reduction of potential regrowth of bacteria on permeate water could be accomplished.