Renewable energy powered membrane technology: Design of a photovoltaic hybrid ultra- and nanofiltration membrane mobile laboratory

The design, construction, and performance testing of a mobile, photovoltaic-powered, hybrid filtration system, equipped with both micro-filters and nanofiltration (NF) membranes is described. This ‘mobile lab’ enables autonomous research with a wide range of water sources – from desalination of brackish water to treatment of contaminated low salinity groundwater. Firstly, the system performance was investigated as a function of five different NF membranes and feedwater salinity (1–20 g/L). The importance of choosing the correct set-point in operating pressure for experiments is discussed in order to map out the safe operating window (SOW) of different system configurations (membranes, feed waters). Secondly, a case study was conducted using real water contaminated with naturally-occurring uranium, where the system was able to treat the water to achieve the World Health Organization guideline values at a specific energy consumption of 1 kWh/m 3 . The benefit of using supercapacitor energy storage for buffering soalr power fluctuations was explored. Despite testing a wide salinity range, the system was observed to achieve drinking water standards at salinities as low as 5 g/L with the NF90 membrane, clearly defining a SOW for treating primarily brackish water. Three membranes exhibited limited salt retention and only achieved satisfactory performance at the lowest NaCl salinity (1 g/L), Overall, this work helps pave the way for the design of PV-powered membrane filtration systems for both mobile (disaster relief) and stationary (drinking water provision in remote areas) scenarios supported by research that enables field work and excellent research training opportunities to contribute to solving global challenges. An autonomous and mobile photovoltaic-powered nanofiltration laboratory is tested for both the desalination of brackish water in the lab as well as removing naturally-occurring uranium from low salinity groundwater in the field. • A mobile laboratory for autonomous water treatment testing was developed. • Safe operating window (SOW) was determined for salinities up to 20 g/L NaCl. • The ability to treat water to drinking water was membrane, set-point and pressure dependent. • The PV-UF-NF/RO system was able to treat low salinity groundwater containing uranium. • Supercapacitors are able to further enhance system performance.