A Critical Review on Microalgae-Enhanced Fountain Landscapes for Urban Carbon Capture

Achieving carbon-neutral cities requires innovative strategies that integrate technological carbon capture, sustainable urban infrastructure, and proactive public engagement. While microalgae-based systems have shown promise for CO₂ sequestration and resource recovery, their scalability remains constrained by high costs and energy-intensive photobioreactor (PBR) designs. Here, we propose the retrofit of existing urban fountains into high-efficiency microalgae cultivation systems-microalgae-enhanced fountain landscapes-as an integrated solution that bridges ecological function and social outreach. This approach capitalizes on ubiquitous fountain infrastructure to minimize deployment costs, employs advanced fountain-style cultivation technology to enhance biomass productivity, and leverages strategic locations in high-footfall urban zones to actively elevate public carbon literacy and motivate low-carbon behavioral shifts through immersive engagement-a vital step toward city-wide participatory climate action. We critically analyze the feasibility of this system, highlighting its potential for multi-stakeholder value creation across developers, municipalities, and citizens. Furthermore, we synthesize recent advances in suspended microalgae cultivation, building-integrated PBRs, and microalgae-informed landscape design to contextualize the development pathway of fountain-based systems. By uniting technical efficiency with civic education, this work establishes a replicable framework for scalable urban deployment-simultaneously advancing carbon mitigation, public awareness, and circular resource flows in the transition toward climate-resilient cities.