Urban Algae: Redefining Urban Spaces and Infrastructure Through Microalgae Ecological and Biophilic Values

Abstract

Microalgae, such as the blue-green algae Spirulina, are one of the best carbon fixers on earth and have high bioremediation potential to uptake pollutants and heavy metals that are adverse to human health and natural habitats. Accordingly, this manuscript proposes an algae photobioreactor façade system that can capture greenhouse gasses and clean nutrient-rich urban water in the tropical climate of urban Honolulu, Hawai‘i. The algae façade design presented in this paper immobilizes the microalgae Spirulina in a low-tech photobioreactors system. This system creates opportunities to activate the vertical landscape in cities – large blank walls that are underutilized - to grow microalgae for mutual ecological and programmatic benefits. Applied data suggests each algal photobioreactor module can capture as much carbon dioxide as two mature trees. Learning from nature, the proposed algae façade design mimics patterns found in nature to collect and filtrate urban stormwater, which can serve multifold benefits of providing free nutrients to the microorganism while reducing the concentration of common urban pollutants. Moreover, the dynamic and innovative living façade has the potential to reduce building operational costs through the system’s insulation properties.