title: Potential of combining mechanical and physicochemical municipal wastewater pre-treatment with direct membrane filtration.
abstract: At a full-scale wastewater treatment plant, raw municipal wastewater from the sand trap outlet was mechanically and physicochemically pre-treated before microfiltration (MF) in a large pilot-scale study. MF was performed using a low transmembrane pressure (0.03 bar) without backflushing for up to 159 h (∼6.6 d). Pre-filtration ensured stable MF operation compared with the direct application of raw wastewater on the membrane. The combination of physicochemical pre-treatment, such as coagulation, flocculation, and microsieving, with MF meets the European and Swedish discharge limits for small- and medium-sized wastewater treatment plants (WWTPs). The specific electricity footprint was 0.3-0.4 kWh·m-3, which is an improvement compared to the median footprint of 0.75 kWh·m-3found in 105 traditional Swedish WWTPs with sizes of 1500-10,000 person equivalents. Furthermore, the biological treatment step can be omitted, and the risk of releasing greenhouse gases was eliminated. The investigated wastewater treatment process required less space than conventional wastewater treatment processes, and more carbon was made available for biogas production.
authors.affiliation: a VA SYD , Malmö , Sweden.|b Sweden Water Research AB , Lund , Sweden.|c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
authors.forename: Tobias
authors.initials: T
authors.lastname: Hey
authors.affiliation: c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.|d Hydrotech Veolia Water Solutions and Technologies AB , Vellinge , Sweden.
authors.forename: Janne
authors.initials: J
authors.lastname: Väänänen
authors.affiliation: e Alfa Laval Nakskov A/S , Nakskov , Denmark.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Heinen
authors.affiliation: c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
authors.forename: Jes
authors.initials: J
authors.lastname: la Cour Jansen
authors.affiliation: c Water and Environmental Engineering at the Department of Chemical Engineering , Lund University , Lund , Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Jönsson
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry; D004560:Electricity; D005374:Filtration; D005427:Flocculation; D008567:Membranes, Artificial; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater / Q000032:analysis / Q000737:chemistry
chemical_list: D000536:Aluminum Hydroxide; D008567:Membranes, Artificial; D062065:Wastewater; C016213:aluminum oxychloride
keywords: Direct membrane filtration; energy savings; low transmembrane pressure; pre-treatment; wastewater treatment