Lecture Notes: Breathing with Plants in a Sealed Environment

Introduction

• Scenario: Trapped in a spaceship with failed life support
• Immediate need for oxygen while stuck in a sealed environment
• Question: Can plants convert enough CO2 to O2 to keep a human alive?

Origin of the Idea

• Inspired by a social media post claiming 6-8 snake plants can sustain a human in a sealed room
• Personal curiosity sparked by the movie "Mission to Mars"
• Practical consideration due to Earth's rich flora being cut down

Experimental Setup

• Goal: Determine how many plants are required to keep a person alive in a sealed room
• Constructing an airtight room in the basement
  • Made from faux wood board, materials already available
  • Completely sealed with Gorilla Tape for airtight conditions
  • Equipped with necessary monitoring tools like CO2 meter and stopwatch

Initial Baseline Test (No Plants)

• CO2 levels monitored: start at baseline of 670 ppm
• Unsafe CO2 level set at 2000 ppm
• Result: Reached 2000 ppm in 30 minutes, CO2 saturation rate: 44.4 ppm per minute

Testing Snake Plants

• Starting with 6 snake plants (minimum from social media claim)
  • Same CO2 saturation rate, little to no effect
  • Increased to 12 snake plants with no significant improvement
  • Conclusion: Post about snake plants is misleading

Turning to Algae as a Solution

• Found that algae like Chlorella Vulgaris might be more effective
• Secretly started growing algae batches in background
  • Initial attempts (small-scale): yellowing, slow growth
  • Shift to 2-liter bottles and later 4-gallon bottles for effective growth

Photo Bioreactor Trials

• Movement from snake plants to algae, implemented first portable photo bioreactor
  • 5 2-liter bottles, aerated with air pumps
  • Test with 100% reactor showed comparable CO2 rise
  • Next test included additional 5 4-gallon algae tanks
  • CO2 levels noticed to have a slower rise

Extensive Algae Setup

• Constructed larger reactors considering lessons learned from previous experiments
  • 55-gallon food-grade barrels for scalable solution
  • DIY light systems within barrels for maximized algae growth
  • Setup included efficient air pumping to facilitate CO2 conversion
• Notable Results: CO2 levels slower to increase, larger batch significantly more efficient

High-Volume Algae Execution

• Required massive setup for proper respiratory balance
  • Multiple tests with over 100 gallons of algae setup
  • Continuous CO2 scrubbing, adding more air pumps
  • Measured effectiveness, observed sustained lower CO2 levels

Preparation for Extended Test

• Final preparations to spend an entire day in sealed room
  • Involved oxygen gas meter for accurate O2 measurement
  • Plan to simulate real and expanded scenarios through continuous monitoring

Conclusion

• Preliminary results suggest viability in principle, yet demanding substantial algae volumes and equipment
• A significant step forward in understanding plant-based life support specifically in closed environments