title: Sand filters for removal of microbes and nutrients from wastewater during a one-year pilot study in a cold temperate climate.
abstract: Onsite wastewater treatment systems (OWTS) are recognised as potential threats to groundwater or other water environments subject to discharged effluents. In this study, the microbiological and nutrient removal properties of three different pilot-scale sand filters (SFs) were followed over a one-year period. Moreover, a separate phosphorus removal unit was tested for six months. For the best treatment system, the average log removals were 2.2-3.5 for pathogenic human noro- and adenoviruses and 4.3-5.2 and 4.6-5.4 for indicator viruses and bacteria, respectively. The system that effectively removed microbes was also efficient at removing nutrients. However, the poorest treatment system yielded substantially lower removals. The remarkable differences noted between the studied SFs highlights the importance of construction materials and the careful planning of the filters. Moreover, seasonal conditions appear to have a clear effect on purification efficiencies, emphasising the vulnerability of these systems especially in cold climates.
authors.affiliation: National Institute for Health and Welfare, Department of Environmental Health, Water and Health Unit, P.O. Box 95, FI-70701 Kuopio, Finland. Electronic address: ari.kauppinen@thl.fi.
authors.forename: Ari
authors.initials: A
authors.lastname: Kauppinen
authors.affiliation: University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio, Finland.
authors.forename: Kati
authors.initials: K
authors.lastname: Martikainen
authors.affiliation: Savonia University of Applied Sciences, Engineering, Teaching and Research, P.O. Box 6, FI-70201 Kuopio, Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Matikka
authors.affiliation: University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio, Finland.
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Veijalainen
authors.affiliation: National Institute for Health and Welfare, Department of Environmental Health, Water and Health Unit, P.O. Box 95, FI-70701 Kuopio, Finland.
authors.forename: Tarja
authors.initials: T
authors.lastname: Pitkänen
authors.affiliation: University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio, Finland.
authors.forename: Helvi
authors.initials: H
authors.lastname: Heinonen-Tanski
authors.affiliation: National Institute for Health and Welfare, Department of Environmental Health, Water and Health Unit, P.O. Box 95, FI-70701 Kuopio, Finland.
authors.forename: Ilkka T
authors.initials: IT
authors.lastname: Miettinen
mesh_terms: D000256:Adenoviridae / Q000302:isolation & purification; D001483:Base Sequence; D003080:Cold Temperature; D003090:Coliphages / Q000302:isolation & purification; D017931:DNA Primers; D005387:Finland; D029322:Norovirus / Q000302:isolation & purification; D010865:Pilot Projects; D060888:Real-Time Polymerase Chain Reaction; D012822:Silicon Dioxide; D062065:Wastewater / Q000737:chemistry* / Q000821:virology*
chemical_list: D017931:DNA Primers; D012822:Silicon Dioxide; D062065:Wastewater
keywords: Enteric viruses; Microbial indicators; Nutrients; Onsite wastewater treatment; Pathogens; Sand filter