5
Numerical Simulation as a Tool to Improve
Subsurface-Flow Constructed Wetlands for Water
Treatment
G. Langergraber, R. Haberl, 1. Laber
Department for Sanitary Engineering and Water Pollution Control (IWGA-S/G);
University of Agricultural Sciences Vienna (BOKU), Muthgasse /8, / /90 Vienna,
Austria e-mail: langergraber@iwga-sig.boku.ac.at, Tel: +43-1-36006-5814,
Fax: +43-1-3689949
Abstract
The term constructed wetlands as used here describes artificial wetlands designed
to improve water quality. The general characteristics such as utilisation of natural
processes, simplicity in construction, operation and maintenance, and process stability allow the application of constructed wetlands with different quality of influent water and under various climatic conditions. Although constructed wetlands
are now used widely, their design is based mostly on rules of thumb, providing a
specific area requirement per person. A simulation model for subsurface-flow
constructed wetlands was developed to provide a better understanding of the processes within the black box "constructed wetland" and to optimise the design of
constructed wetlands. The multi-component reactive transport model CW2D describes the elimination and transformation processes of the main constituents of
wastewater: organic matter, nitrogen and phosphorus. The model description
comprises 9 processes and 12 components. The simulation results for a pilot-scale
constructed wetland for wastewater treatment show a good match with the measured data for both flow and reactive transport simulations.
1 Introduction
The term constructed wetlands as used here describes artificial wetlands designed
to improve water quality. Constructed wetlands can be classified into two main
types: surface-flow and subsurface-flow constructed wetlands. The main
disadvantages of surface-flow constructed wetlands are the large area requirement
and the possibility of freezing in temperate climates. Subsurface-flow constructed
wetlands can be subdivided into horizontal-flow (HF) and vertical-flow (VF) constructed wetlands. The major limitation of HF constructed wetlands is the poor
H. Rubin / P. Nachtnebel / J. Fuerst / U. Shamir
Preserving the Quality of Our Water Resources
© Springer-Verlag Berlin Heidelberg 2002
Numerical Simulation as a Tool to Improve
Subsurface-Flow Constructed Wetlands for Water
Treatment
G. Langergraber, R. Haberl, 1. Laber
Department for Sanitary Engineering and Water Pollution Control (IWGA-S/G);
University of Agricultural Sciences Vienna (BOKU), Muthgasse /8, / /90 Vienna,
Austria e-mail: langergraber@iwga-sig.boku.ac.at, Tel: +43-1-36006-5814,
Fax: +43-1-3689949
Abstract
The term constructed wetlands as used here describes artificial wetlands designed
to improve water quality. The general characteristics such as utilisation of natural
processes, simplicity in construction, operation and maintenance, and process stability allow the application of constructed wetlands with different quality of influent water and under various climatic conditions. Although constructed wetlands
are now used widely, their design is based mostly on rules of thumb, providing a
specific area requirement per person. A simulation model for subsurface-flow
constructed wetlands was developed to provide a better understanding of the processes within the black box "constructed wetland" and to optimise the design of
constructed wetlands. The multi-component reactive transport model CW2D describes the elimination and transformation processes of the main constituents of
wastewater: organic matter, nitrogen and phosphorus. The model description
comprises 9 processes and 12 components. The simulation results for a pilot-scale
constructed wetland for wastewater treatment show a good match with the measured data for both flow and reactive transport simulations.
1 Introduction
The term constructed wetlands as used here describes artificial wetlands designed
to improve water quality. Constructed wetlands can be classified into two main
types: surface-flow and subsurface-flow constructed wetlands. The main
disadvantages of surface-flow constructed wetlands are the large area requirement
and the possibility of freezing in temperate climates. Subsurface-flow constructed
wetlands can be subdivided into horizontal-flow (HF) and vertical-flow (VF) constructed wetlands. The major limitation of HF constructed wetlands is the poor
H. Rubin / P. Nachtnebel / J. Fuerst / U. Shamir
Preserving the Quality of Our Water Resources
© Springer-Verlag Berlin Heidelberg 2002