Field installation of ion exchange technology for purification of retention reservoirs from nitrogen-based nutrient contamination

Abstract

N- and P-nutrient contamination is recognised as one of the key factors that reduces the quality of water. In this context, a new water purification installation was set up in the Turawa reservoir (district Opole, Poland). The process involves ion exchange columns operated in twin configuration: once one column filtrates water, the second one regenerates. The installation design is modular, and the devices are placed in a container station. This enables efficient water purification in various locations and further offers scalability. The research focused on the design and optimization of the installation, as well as environmental assessment of how the installation influenced the quality of water. This technology afforded a decrease in the concentrations of NO3− ions, suggesting an apparent selectivity. The removal of NO3− reached 97 % and was maintained for over 100 m3 of purified water. In turn, the removal of PO43− was not effective; however, the collected data allowed the installation design to be adjusted such that the cascade arrangement of ion exchange columns can be considered. The technology was assessed over all four seasons in the two-year test period (2020−2021). This revealed that environmental factors, such as season, air temperature, wind, and relative humidity, influence the operation of the installation. The installation functions optimally in spring with an average air temperature of 11–20 °C, high relative humidity of 90–100 %, and an average wind speed of 2 m/ s. The implementation of the technique could easily broaden the perspectives of Earth's water preservation and sustainability.