title: Evaluation of direct membrane filtration and direct forward osmosis as concepts for compact and energy-positive municipal wastewater treatment.
abstract: Municipal wastewater treatment commonly involves mechanical, biological and chemical treatment steps to protect humans and the environment from adverse effects. Membrane technology has gained increasing attention as an alternative to conventional wastewater treatment due to increased urbanization. Among the available membrane technologies, microfiltration (MF) and forward osmosis (FO) have been selected for this study due to their specific characteristics, such as compactness and efficient removal of particles. In this study, two treatment concepts were evaluated with regard to their specific electricity, energy and area demands. Both concepts would fulfil the Swedish discharge demands for small- and medium-sized wastewater treatment plants at full scale: (1) direct MF and (2) direct FO with seawater as the draw solution. The framework of this study is based on a combination of data obtained from bench- and pilot-scale experiments applying direct MF and FO, respectively. Additionally, available complementary data from a Swedish full-scale wastewater treatment plant and the literature were used to evaluate the concepts in depth. The results of this study indicate that both concepts are net positive with respect to electricity and energy, as more biogas can be produced compared to that using conventional wastewater treatment. Furthermore, the specific area demand is significantly reduced. This study demonstrates that municipal wastewater could be treated in a more energy- and area-efficient manner with techniques that are already commercially available and with future membrane technology.
authors.affiliation: a VA SYD , Malmö , Sweden.|b Sweden Water Research AB, Ideon Science Park , Lund , Sweden.|c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
authors.forename: Tobias
authors.identifier: http://orcid.org/0000-0001-5233-836X
authors.initials: T
authors.lastname: Hey
authors.affiliation: d Aquaporin A/S , Kongens Lyngby , Denmark.|e Department of Environmental Engineering , Technical University of Denmark , Kongens Lyngby , Denmark.
authors.forename: Niada
authors.identifier: http://orcid.org/0000-0003-4796-8652
authors.initials: N
authors.lastname: Bajraktari
authors.affiliation: c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
authors.forename: Åsa
authors.identifier: http://orcid.org/0000-0002-2981-6551
authors.initials: Å
authors.lastname: Davidsson
authors.affiliation: d Aquaporin A/S , Kongens Lyngby , Denmark.
authors.forename: Jörg
authors.initials: J
authors.lastname: Vogel
authors.affiliation: f Department of Chemistry and Bioscience , Aalborg University , Copenhagen , Denmark.
authors.forename: Henrik Tækker
authors.identifier: http://orcid.org/0000-0002-2498-8709
authors.initials: HT
authors.lastname: Madsen
authors.affiliation: d Aquaporin A/S , Kongens Lyngby , Denmark.|e Department of Environmental Engineering , Technical University of Denmark , Kongens Lyngby , Denmark.|g Laboratory for Water Biophysics and Membrane Processes, Faculty of Chemistry and Chemical Engineering , University of Maribor , Maribor , Slovenia.
authors.forename: Claus
authors.identifier: http://orcid.org/0000-0002-9392-7133
authors.initials: C
authors.lastname: Hélix-Nielsen
authors.affiliation: c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
authors.forename: Jes la Cour
authors.initials: JC
authors.lastname: Jansen
authors.affiliation: c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
authors.forename: Karin
authors.identifier: http://orcid.org/0000-0001-6316-6938
authors.initials: K
authors.lastname: Jönsson
mesh_terms: D005374:Filtration / Q000379:methods*; D008567:Membranes, Artificial; D009995:Osmosis; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis
chemical_list: D008567:Membranes, Artificial; D062065:Wastewater
keywords: Biogas production; forward osmosis; membrane filtration; seawater; wastewater treatment