Reinvent the Toilet Fair and Grand Challenges Explorations Grantees Workshop, Seattle, WA, August 12, 2012 (Poster)

1. “NO WATER”
TREATMENT OF FECAL WASTE
OBJECTIVE
CONCLUSIONS
Trichuris trichiura egg destruction
VISCOUS HEATING AND SHEAR STRESS TO DISINFECT HUMAN STOOL
EFFECT OF SHAFT RPM ON OUTLET TEMPERATURE
(SPACING = 0.75 MM)
E ggs count * (e g g s /g r a m)
SHEAR STRESS (PA)
TEMPERATURE(DEG˚C)
RPM
• Motor with solar power & battery is sufficient for small-scale
• Shear stress and temperature controlled by adjusting rpm and spacing
• Paper, grass and saw dust can increase viscous heating
Gary L. Foutch, AJ Johannes, Jagdeep T. Podichetty, Md. Waliul Islam, Mason Reichard, David Van
O K L A H O M A S TAT E U N I V E R S I T Y, S T I L LWAT E R O K L A H O M A
VISCOUS HEATING SHEAR STRESS
600
4 min ~200° C
DEBRIS
SPACING
EGG
INNER
ROTATING
CONE
BUBBLE
2,000
4,000
18,000
16,000
14,000
12,000
10,000
8,000
6,000
2 min
1 min
200
180
160
140
120
100
80
60
40
20
800 1,000 1,200 1,400 1,8001,600
T E M P E R AT U R E (° C) P R E -T R E AT M E N T P O S T T R E AT M E N T % K I L L
4 2 1 0 7 8 9 3
5 1 1 6 7 2 9 9
8 6 5 8 3 9 5
* P R E L I M I N A R Y D ATA