title: Simulation and verification of hydraulic properties and organic matter degradation in sand filters for greywater treatment.
abstract: To evaluate the treatment performance of vertical flow sand filters, the HYDRUS wetland module was used to simulate treatment in an experimental set-up. The laboratory filters were intermittently dosed with artificial greywater at a hydraulic loading rate of 0.032 m³ m⁻² day⁻¹ and an organic loading rate of 0.014 kg BOD5 m⁻² day⁻¹. The hydraulic properties of the filter were characterised, as were inflow and outflow concentrations of chemical oxygen demand (COD), biochemical oxygen demand (BOD), ammonia, nitrate and total nitrogen. The inverse simulation function of the HYDRUS software was used to calibrate the water flow model. The observed effect of water flowing faster along the column wall was included in the inverse simulations. The biokinetic model was calibrated by fitting heterotrophic biomass growth to measurements of potential respiration rate. Emphasis was put on simulating outflow concentrations of organic pollutants. The simulations were conducted using three models of varying degree of calibration effort and output accuracy. The effluent concentration was 245 mg COD L⁻¹ for the laboratory filters, 134 mg COD mg L⁻¹ for the model excluding wall flow effects and 338 mg COD mg L⁻¹ for the model including wall flow effects.
authors.affiliation: Department of Energy and Technology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7032, Uppsala SE-750 07, Sweden E-mail: susanna.ciuk.karlsson@slu.se.
authors.forename: Susanna Ciuk
authors.initials: SC
authors.lastname: Karlsson
authors.affiliation: Institute for Sanitary Engineering and Water Pollution Control, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, Vienna A-1190, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Langergraber
authors.affiliation: Department of Microbiology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7032, Uppsala SE-750 07, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Pell
authors.affiliation: Department of Energy and Technology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7032, Uppsala SE-750 07, Sweden E-mail: susanna.ciuk.karlsson@slu.se.
authors.forename: S
authors.initials: S
authors.lastname: Dalahmeh
authors.affiliation: Department of Energy and Technology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7032, Uppsala SE-750 07, Sweden E-mail: susanna.ciuk.karlsson@slu.se.
authors.forename: B
authors.initials: B
authors.lastname: Vinnerås
authors.affiliation: Department of Energy and Technology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7032, Uppsala SE-750 07, Sweden E-mail: susanna.ciuk.karlsson@slu.se.
authors.forename: H
authors.initials: H
authors.lastname: Jönsson
mesh_terms: D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D003198:Computer Simulation; D005374:Filtration / Q000295:instrumentation* / Q000379:methods; D008962:Models, Theoretical; D009566:Nitrates; D009584:Nitrogen; D012822:Silicon Dioxide / Q000737:chemistry*; D012984:Software; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D053833:Wetlands
chemical_list: D009566:Nitrates; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; D009584:Nitrogen