Influences of mechanical pretreatment on the non-biological treatment of municipal wastewater by forward osmosis.
Municipal wastewater treatment involves mechanical, biological and chemical treatment steps for protecting the environment from adverse effects. The biological treatment step consumes the most energy and can create greenhouse gases. This study investigates municipal wastewater treatment without the biological treatment step, including the effects of different pretreatment configurations, for example, direct membrane filtration before forward osmosis. Forward osmosis was tested using raw wastewater and wastewater subjected to different types of mechanical pretreatment, for example, microsieving and microfiltration permeation, as a potential technology for municipal wastewater treatment. Forward osmosis was performed using Aquaporin Inside™ and Hydration Technologies Inc. (HTI) membranes with NaCl as the draw solution. Both types of forward osmosis membranes were tested in parallel for the different types of pretreated feed and evaluated in terms of water flux and solute rejection, that is, biochemical oxygen demand (BOD7) and total and soluble phosphorus contents. The Aquaporin and HTI membranes achieved a stable water flux with rejection rates of more than 96% for BOD7and total and soluble phosphorus, regardless of the type of mechanical pretreated wastewater considered. This result indicates that forward osmosis membranes can tolerate exposure to municipal waste water and that the permeate can fulfil the Swedish discharge limits.
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.
Tobias
http://orcid.org/0000-0001-5233-836X
T
Hey
d Department of Environmental Engineering , Technical University of Denmark , Kongens Lyngby , Denmark.
Agata
http://orcid.org/0000-0003-4323-3050
A
Zarebska
d Department of Environmental Engineering , Technical University of Denmark , Kongens Lyngby , Denmark.|e Aquaporin A/S , Kongens Lyngby , Denmark.
Niada
http://orcid.org/0000-0003-4796-8652
N
Bajraktari
e Aquaporin A/S , Kongens Lyngby , Denmark.
Jörg
J
Vogel
d Department of Environmental Engineering , Technical University of Denmark , Kongens Lyngby , Denmark.|e Aquaporin A/S , Kongens Lyngby , Denmark.|f Laboratory for Water Biophysics and Membrane Processes, Faculty of Chemistry and Chemical Engineering , University of Maribor , Maribor , Slovenia.
Claus
http://orcid.org/0000-0002-9392-7133
C
Hélix-Nielsen
c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
Jes
http://orcid.org/0000-0002-3336-9416
J
la Cour Jansen
c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
Karin
http://orcid.org/0000-0001-6316-6938
K
Jönsson
D005374:Filtration; D008567:Membranes, Artificial; D009995:Osmosis; D062065:Wastewater; D018508:Water Purification
D008567:Membranes, Artificial; D062065:Wastewater
Biomimetic membrane; forward osmosis; membrane fouling; microfiltration; microsieving; wastewater treatment