Development of a Carbon-Capturing Concrete Coating Using Pseudomonas nitroreducens for Urban Heat Mitigation
Michael Jiho Jun
Seoul Foreign School, Seoul, South Korea
Publication date: November 20, 2025
Seoul Foreign School, Seoul, South Korea
Publication date: November 20, 2025
DOI: http://doi.org/10.34614/JIYRC2025II17
ABSTRACT
Urban heat islands (UHI) elevate cooling demand and associated greenhouse gas (GHG) emissions. Building on prior work with microbial and material-based carbon-capturing or cooling coatings, this study evaluates a bench-scale concrete coating that embeds the non-pathogenic bacterium Pseudomonas nitroreducens in a 10% polyethylene glycol (PEG) matrix. The assessment covered bacterial retention on concrete, thermal response under controlled heat-lamp exposure, a qualitative CO₂-interaction assay, and a simple phytotoxicity screen. Relative to uncoated controls, PEG–P. nitroreducens–coated concrete exhibited lower roof-surface temperatures (up to ~4.5 °C reduction over a 21-min exposure) and sustained higher bacterial recovery over 17 days than alternative carriers tested. A pH-strip assay using carbonated water suggested surface-dependent differences in acidity, providing only preliminary indication of CO₂ interaction. Water conditioned with the PEG–bacteria coating produced seed germination rates comparable to controls, suggesting no acute phytotoxic effects under these conditions. These findings position PEG-assisted P. nitroreducens coatings as one candidate within the broader class of microbial/material surface treatments for moderating concrete thermal behavior, while highlighting the need for follow-up studies with quantitative gas-flux measurements, PEG-only controls, durability testing, real-sunlight trials, and statistical analyses before any claims about scalability or urban energy savings can be made.
Urban heat islands (UHI) elevate cooling demand and associated greenhouse gas (GHG) emissions. Building on prior work with microbial and material-based carbon-capturing or cooling coatings, this study evaluates a bench-scale concrete coating that embeds the non-pathogenic bacterium Pseudomonas nitroreducens in a 10% polyethylene glycol (PEG) matrix. The assessment covered bacterial retention on concrete, thermal response under controlled heat-lamp exposure, a qualitative CO₂-interaction assay, and a simple phytotoxicity screen. Relative to uncoated controls, PEG–P. nitroreducens–coated concrete exhibited lower roof-surface temperatures (up to ~4.5 °C reduction over a 21-min exposure) and sustained higher bacterial recovery over 17 days than alternative carriers tested. A pH-strip assay using carbonated water suggested surface-dependent differences in acidity, providing only preliminary indication of CO₂ interaction. Water conditioned with the PEG–bacteria coating produced seed germination rates comparable to controls, suggesting no acute phytotoxic effects under these conditions. These findings position PEG-assisted P. nitroreducens coatings as one candidate within the broader class of microbial/material surface treatments for moderating concrete thermal behavior, while highlighting the need for follow-up studies with quantitative gas-flux measurements, PEG-only controls, durability testing, real-sunlight trials, and statistical analyses before any claims about scalability or urban energy savings can be made.
