title: Modeling organic matter and nitrogen removal from domestic wastewater in a pilot-scale vertical subsurface flow constructed wetland.
abstract: Constructed wetlands have become an attractive alternative for wastewater treatment. However, there is not a globally accepted mathematical model to predict their performance. In this study, the VS2DTI software was used to predict the effluent biochemical oxygen demand (BOD) and total nitrogen (TN) in a pilot-scale vertical flow constructed wetland (VFCW) treating domestic wastewater. After a 5-week adaptation period, the pilot system was monitored for another 6 weeks. Experiments were conducted at hydraulic retention times (HRTs) in the range of 2-4 days with Typha latifolia as the vegetation. The raw wastewater concentrations ranged between 144-430 and 122-283 mg L(-1) for BOD5 and TN, respectively. A first-order kinetic model coupled with the advection/dispersion and Richards' equations was proposed to predict the removal rates of BOD5 and TN from domestic wastewater. Two main physical processes were modeled in this study, porous material water flow and solute transport through the different layers of the VFCW to simulate the constructed wetland (CW) conditions. The model was calibrated based on the BOD5 and TN degradation constants. The model indicated that most of BOD and TN (88 and 92%, respectively) were removed through biological activity followed by adsorption. It was also observed that the evapotranspiration was seen to have a smaller impact. An additional data series of effluent BOD and TN was used for model validation. The residual analysis of the calibrated model showed a relatively random pattern, indicating a decent fit. Thus, the VS2DTI was found to be a useful tool for CW simulation.
authors.affiliation: a Graduate Program in Environmental Applied Science and Management, Ryerson University , Toronto , Ontario , Canada.
authors.forename: Ciro Fernando
authors.initials: CF
authors.lastname: Bustillo-Lecompte
authors.affiliation: b Department of Chemical Engineering , Ryerson University , Toronto , Ontario , Canada.
authors.forename: Mehrab
authors.initials: M
authors.lastname: Mehrvar
authors.affiliation: c Faculty of Engineering, University of Cartagena, Cartagena de Indias , Colombia.
authors.forename: Edgar
authors.initials: E
authors.lastname: Quiñones-Bolaños
authors.affiliation: c Faculty of Engineering, University of Cartagena, Cartagena de Indias , Colombia.
authors.forename: Claudia Fernanda
authors.initials: CF
authors.lastname: Castro-Faccetti
mesh_terms: D003105:Colombia; D058440:Denitrification; D008962:Models, Theoretical; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D010865:Pilot Projects; D032401:Typhaceae / Q000378:metabolism*; D055549:Volatile Organic Compounds / Q000378:metabolism*; D062065:Wastewater / Q000032:analysis / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D053833:Wetlands
chemical_list: D009584:Nitrogen; D055549:Volatile Organic Compounds; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: BOD; VS2DTI; constructed wetland; nitrogen; wastewater treatment