Modeling of Iron Enhanced Rain Gardens

Faculty Sponsor

Zuhdi Aljobeh




Civil Engineering

ORCID Identifier(s)


Presentation Type

Poster Presentation

Symposium Date

Spring 4-23-2016


Numerous lakes and rivers in urban areas suffer from excessive loading of phosphorus carried by stormwater runoff. This excess phosphorous results in undesirable conditions in these water bodies including bloom of algae and eutrophication. Rain gardens and sand filters can remove contaminants such as heavy metals and sediments. However, they are not effective in removing phosphorous. One new method to remove phosphorous from stormwater runoff is through the implementation of iron enhanced rain gardens. In this best management practice, the sand layer in a rain garden is mixed with iron shavings at a 5% by weight. The purpose of this project is to develop computer models to simulate the phosphorous removal process of rain gardens. The project involves researching the chemical and physical parameters of the different elements of rain gardens and their interaction with the different forms of phosphorous. These characteristics will be used to build graphical and numerical models of rain gardens. Two models; the first representing a traditional rain garden and the second representing an iron enhanced rain garden are developed. COMSOL Multiphysics®, an advance finite element analysis software will be used to solve the numerical models. Experimental data will be used to calibrate the computer models. The models can then be used to study or predict the removal efficiencies of rain gardens under different phosphorous loading conditions without the need for conducting further field or laboratory experimentation studies. Upon verification that the model accurately reflects the phosphorous removal, it can then be used as a tool to assist in the design of similar rain gardens for phosphorous removal applications.

Biographical Information about Author(s)

Seth Strelow is a senior civil engineering student. The coursework that has interested him most is in the field of water resources. Being a resident of a lake town in Minnesota, he is familiar with the problems of waterways impaired by excess phosphorous. He has conducted research with iron enhanced sand filters (IESFs) in the past as a research assistant at the University of Minnesota where he monitored several implemented IESFs.

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