Hydroponic Green Wall Research

Researcher Dr. Stephanie Melles and graduate student Corbin Sparks are undertaking a study to test the biofiltration capacity of a hydroponic green wall system and its ability to remove volatile organic compounds (VOCs) from the air. VOCs are a rising component of indoor air pollutants. In addition to that inorganic pollutants and particulate matter from industrial combustion, many VOCs (i.e., toluene, ethylbenzene, xylene, and benzene) are known carcinogens. VOCs are released from various materials commonly found in homes (in carpet, drapes, furniture, insulation, house cleaning products, etc.). Given the rising concern about air pollution and carcinogens in our environment worldwide, air quality enhancing techniques are becoming more critical. 

New Earth Solutions, external link (external link)  (NES) has designed a green wall system called Respira, external link (external link) . Research out of Finland showed that hydroponic walls can remove pollutants, and our urban water research team has set out to test the Canadian NES system’s effectiveness in removing common VOCs.

The study comprises two stages. The first stage is to assess the baseline contaminant removal abilities of the green wall system in varying time periods and conditions. The second stage is to identify and describe the microbial ecosystem that exists in the hydroponic root system of the unit. Currently, the project has received financial support from Mitacs and Ontario Centres of Excellence grants and the team has grown to include microbiology and molecular biology experts Drs. Martina Hausner and Kimberley Gilbride. Preliminary results are in-line with previous literature, demonstrating that the green wall system reduces non-chlorinated VOC concentrations over time. In this experiment, four non-chlorinated VOCs (acetaldehyde, benzene, toluene, and m-xylene) and two chlorinated VOCs (tetrachloroethylene and chloroform) are tested. To date, experimentation was performed on a commercial green wall unit. As the study continues, the team will begin to include work on the residential green wall system.