Micropollutant removal through nanofiltration in the treatment of rainwater and stormwater for recreational purposes

Rational management of water resources is crucial in all aspects of human life. For instance, using rainwater in recreational facilities is an example of sustainable water consumption. The purpose of the study was to evaluate the nanofiltration process as a potential component of a rainwater treatment system - "SwimmInRain", which could be used in swimming pool facilities to prepare water to compensate for water losses. The rainwater was collected from the roof of a sports facility located in an urban area in Upper Silesia, Poland. The filtration process was conducted using a semi-industrial installation equipped with tubular polyamide membrane AFC30 or AFC80 from PCI Membrane System Inc. The rainwater was analyzed before and after treatment using a gas chromatograph with mass detection to identify organic micropollutants that could be harmful upon direct contact with individuals. The obtained results indicated that the rainwater contained micropollutants belonging to various groups of compounds. The toxicity evaluation indicated a low toxic nature of the sample. Therefore, rainwater should be subjected to in-depth treatment before its future use. The nanofiltration process with the AFC80 membrane allows to obtaining of water quality parameters that meet the quality requirements for swimming pool water.