ENGAGED MATERIAL/
PHENOMENAL URBANISM







Algenosphere


 Mehek Usman, Niki Gotzev, Aarav Shroff

Air-Purification Of Toxins Via Vacuum-formed Algae Growing Panels Within A Dual-Layer Timber Gridshell

Abstract The communities of East Harlem have historically faced some of the highest numbers of air pollutants in all of New York City, with long-term effects such as asthma and lung-related chronic illnesses that continue to impact the livelihood of the community today (EJNYC). We believe that algae, a fast-growing microorganism, along with sunlight and water, can sequester the pollutants in the air efficiently. The algae, held in a photobioreactor panel system of cross-braced wooden members and inflated algae ‘pouches,’ receives pressurized air via a trompe pump system that utilizes water from the East River. The panels themselves form a topographical needs-based system that stretches across the River’s walkway, providing clean air, seating, and shade to passers by. This large-scale system aims to generally improve the air quality and provide clean oxygen to those using the Harlem River walk/bike path.
Background


Why the Harlem River Drive Walkway?
The Harlem River Drive walkway, compared to much of the rest of the East River front development, lacks the infrastructure and amenities for people to comfortably convene and connect with their community. However, the space has the potential to provide much needed relief to the community from the bustling streets of NYC. East Harlem has the highest rates of PM 2.5 & Ozone related ER Visits in all of New York City (EJNYC Report, 2024). It does not have the highest concentration of these air particulates. However, the combination of these pollutants, in house pollutants, smoking, and the general demographics of East Harlem that make these communities more vulnerable than the rest. In addition, the neighborhood’s proximity to the Harlem River Drive results in daily air pollution.

Problem PM2.5 small particles that can settle far into the lungs, resulting in long term lung damage. 
  • The source: Commercial Cooking, Motor Vehicle Emissions, and Industrial Truck Emissions. 
Nitrogen Oxides (NOx) high temperature combustion particles, incredibly common. 
  • The source: Combustion of boilers and fossil fuels, motor traffic.
Ozone (O3) Nitrogen oxides that come in contact with prolonged sunlight. Short term exposure can lead to shortness of breath! 
  • The source: Levels of NOs, lack of tree cover. 

The listed pollutants have resulted in the most visits to the ER in East Harlem vs any other region in NYC (EJNYC REPORT). These pollutants have plagued the area for a long time, and due to the lack of attention from the government, have managed to infiltrate the livelihoods of the people living in East Harlem, with it having some of the highest rates of Lung Cancer, Childhood Asthma, amd more.

Solution
 The Photobioreactor
    1. Air containing CO₂ and pollutants (like VOCs, particulates, or nitrogen oxides) is directed into the photobioreactor. This can be indoor air (from offices, schools, factories) or outdoor polluted air.
    2. Inside the photobioreactor, algae are suspended in water-filled transparent tubes, tanks, or panels. These algae are microalgae (e.g., Chlorella or Spirulina) that grow rapidly and are highly efficient at photosynthesis.
    3. With exposure to light (natural sunlight or artificial LEDs), algae perform photosynthesis: They absorb CO₂ from the incoming air. Using light energy, they convert CO₂ and water into oxygen (O₂) and biomass (algal growth).
    4. As CO₂ is removed oxygen rich air is released back into the environment. Some photobioreactors are designed with filters or biofilms, where algae also help trap fine dust and degrade certain toxins (depending on species used).
    5. Polluted air keeps flowing in, algae keep photosynthesizing, and cleaner, oxygen-rich air flows out. As algae grow, their biomass accumulates.
    6. The excess algae can be harvested and used for: Biofuel (biodiesel, biogas), Nutritional supplements (spirulina power, protein-rich additives), Fertilizers or bioplastics.




    Experiments
    Algae Growth

    In order to grow and experiment with algae, the initial test was set up as simply as possible: providing an algae culture sample with an LED light + turbulence via a mechanical system (aquarium pump) in an open tank. The tank was fitted with a mesh screen to prevent large contaminants from entering, and fed every other day after the 48h grow period.



    Testing/AnalysisThe Test: Air quality testing done via an air quality monitor over 25 minutes testing for PM2.5, PM10, AQI, and base factors such as temperature and humidity, in a non-controlled environment and based off of proximity revealed an exponential decay in the critical values (AQI, PM2.5, and PM10), a steady rate of HCHO at 0.01, and a gradual decrease in temperature and an inversely increasing humidity.

    The Conclusion:PM2.5, PM10, and AQI levels see a significant decrease when placed in proximity to the open algae culture. The next steps will require a more controlled test, with the algae transferred into a closed container, and a controlled chamber for the air quality monitor.

    Material System Design/Development The final goal of the system is to be entirely passive, so the next set of tests involved passive strategies that could help provide turbulence to the algae system. While there are other methods of simply generating hydraulic power/ using public flowing water sources, this is the most passive system that can be developed, meaning our project will likely need to be along the river.

     

    Materials/ System                                                                                                   The new material system utilizes a classic gridshell structure and the way its laid out in order to provide organization and structural integrity to the system. The panels are introduced as their own framed pieces that can be introduced into the system via a series of connector points.



    1
    2
    1.
    The steel bracket connection to the ground allows for versatile usage along the esplanade. The structure itself is relatively  undistrubed in form,and the steel plates can be standardized and provided as needed, (i.e., how many anchor points there are).

    2.
    The nozzles are designed to sit within the material system assembly, and can be interchanged depending on program and form, in order to provide wide scale oxygen or immediate oxygenated relief.

    Final Prototype


    Urban/Financial Speculation

    The Algenosphere system has the capability to provide for the community beyond its growing time. The spirulina that is harvested can be exchanged at local delis and cafes, and can also be converted to biochar (a soil fertilizer and fuel). The carbon sequestration can also prove finanially beneficial as carbon emissions become increasingly taxed. Using current stats and values, the revenue was calculated for the growth period of the algae (approx 243 days). The total potential value per panel is approximately 5- 25 dollars a year.



    CASE STUDIES: EAST HARLEM



    Program    In order to clean the air and provide clean, healthy oxygen to the community in East Harlem, the AlgenoSphere system should be integrated along a significant length of the River. The system undulates and changes in its global form as the needs along the river change, providing shade, seating, and storage.