1. Human Powered Producing Potable Water for Developing Countries
Reverse Osmosis
Dustin Drake, Alfonso Liguori, Jeremy Smith
Florida Atlantic University
Department of Ocean and Mechanical Engineering

2. Global Water Crisis
One billion people do not have access to clean drinking water.
3.6 million people die each year from water-related diseases.
98% of water-related deaths occur in the developing world.
A person can only live for a few days without water.

3. Human Powered RO System
Purpose:
Create a device capable of providing potable water to people in developing nations
Focus:
Low cost
Portability
Quality
Efficient

4. Human Power Supply

5. Human Power Supply For long duration / low intensity operations
Human input = 0.1 hp
Very sustainable for a healthy person
Short duration / low intensity operations will not overly tire the operator
For short duration / high intensity operations
Human input = 0.2 hp
Sustainable for durations less than 3 hours
Will leave the operator very tired after extended operation

6. Human Input Mechanism Design Goals: Simple, natural motion
Pedal driven
Efficient transfer of mechanical energy
Portability
Rigid Construction

7. Positive Displacement Pump
Design Goals:
High pressure (100 psi)
Low flow rate (0.3 gpm)
Low maintenance

8. Reverse Osmosis
Two liquids of different concentrations separated by semi-permeable membrane
Less saturated naturally flows into more
saturated
Pressure is applied to reverse this
process and is known as reverse
osmosis or RO
Dirty water flows through
membrane thereby filtering it
dirty water  clean water

9. Reverse Osmosis Purifier
Highly efficient
Relatively low cost
4 stages of filtration:
Sediment filter
Activated carbon filter
RO membrane

10. RO Numerical Analysis 𝑷=𝑸∙𝒑 Power requirement: 𝑝=100 psi 𝑄=0.37 gpm
(𝑃 : Power, 𝑄 : volumetric flow rate, 𝑝: pressure)
𝑝=100 psi
𝑄=0.37 gpm
𝑃=0.019 Hp

11. UV Purification Disables reproduction of microorganisms
RO system filters then filters them out
Most effective at nm wavelength
Different microorganisms require different intensities
Intensity approx. 30 mJ/cm2
Power required depends on exposure time, affected by:
Size of bulb and pipe
Flow rate of water

12. Electrical Generation
Provide electrical power to UV lamp
Design Criteria:
14 watt UV bulb
Expected efficiency = 40%
Human input = hp

13. Practical Feasibility
Only Hp needed
Person can provide 0.10 Hp for 8 hrs
1 gallon produced in 10 minutes
One person needs ½ gallon daily
5 min per person per day

14. Discussion Uses: Considerations: Developing nations
Camping/backpacking
Emergency disaster response (e.g. FEMA)
Considerations:
Approx. $500 total
RO membrane can last for 3-4 years
Small village could have clean water with one system

15. Conclusion
Viable
Efficient
Economical
Effective