Print Email Facebook Twitter Application of dynamic current density for increased concentration factors and reduced energy consumption for concentrating ammonium by electrodialysis Title Application of dynamic current density for increased concentration factors and reduced energy consumption for concentrating ammonium by electrodialysis Author van Linden, N. (TU Delft Sanitary Engineering) Spanjers, H. (TU Delft Sanitary Engineering) van Lier, J.B. (TU Delft Sanitary Engineering) Date 2019 Abstract Ammonium (NH4+) can be recovered from water for fertiliser production or even energy production purposes. Because NH4+ recovery is more effective at increased concentrations, electrodialysis (ED) can be used to concentrate NH4+ from side streams, such as sludge reject water, and simultaneously achieve high NH4+ removal efficiencies. However, the effect of osmosis and back-diffusion increases when the NH4+ concentration gradient between the diluate and the concentrate stream increases, resulting in a limitation of the concentration factor and an increase in energy consumption for NH4+ removal. In this study, we showed that operation at dynamic current density (DCD) reduced the effect of osmosis and back-diffusion, due to a 75% decrease of the operational run time, compared to operation at a fixed current density (FCD). The concentration factor increased from 4.5 for an FCD to 6.7 for DCD, while the energy consumption of 90% NH4+ removal from synthetic sludge reject water at DCD remained stable at 5.4 MJ·kg-N−1. Subject AmmoniumBack-diffusionCurrent efficiencyElectro-osmosisElectrodialysisOsmosis To reference this document use: http://resolver.tudelft.nl/uuid:1d0bede4-4e0f-4b39-92f2-7a051a39fc92 DOI https://doi.org/10.1016/j.watres.2019.114856 ISSN 0043-1354 Source Water Research, 163 Part of collection Institutional Repository Document type journal article Rights © 2019 N. van Linden, H. Spanjers, J.B. van Lier Files PDF 1_s2.0_S0043135419306220_main.pdf 1.63 MB Close viewer /islandora/object/uuid:1d0bede4-4e0f-4b39-92f2-7a051a39fc92/datastream/OBJ/view