3. Existing Techniques
MSF/Reverse Osmosis
Solar Stills
Electrodialysis
Micro and nano-filtration
ADIRA (MEDRC)
4. Our Idea
Inspiration from available natural
resources & processes
Use of wood charcoal for water purification
Characteristics of coconut shell charcoal :
100% organic
Renewable resource
Higher calorific heat value
Environmental friendly
Ready availability especially in coastal areas
5. Experimental Setup
Preparation of coconut-shell charcoal
Earth kiln
Limited supply of air
60-70 whole shells 2.5 kg of charcoal
Sieve size : 2mm-20mm
Thorough washing; drying
6. Contd.
Preparation of salty water samples:
Typical concentration of NaCl ~ 35gm/l
Samples made in lab, conc. = 30gm/l
Column setup (fig. 1)
7. Contd.
Fig 1. Apparatus for charcoal-based desalination
8. Observations
30000
25000
20000
15000 Sodium (mg/l)
Chloride (mg/l)
10000
TDS (mg/l)
5000
0
Original After 3 After 6
Sample days days
Reduction in dissolved ion concentration after charcoal treatment
Sample Analysis done at CWRDM, Calicut
9. 30
25
20
15
Salinity (ppt)
10
5
0
Original After 3 After 6
sample days days
Reduction in salinity after charcoal content
10. Results
Reduction in chloride ion concentration : 40.9%
Reduction in sodium ion concentration : 42.0%
Reduction in TDS (total dissolved salts) : 45.1%
Reduction in salinity : 42.9%
11. Experimentation with mauritius grass
Species : veteveria zizanioides (vetiver)
Combination of charcoal and mauritius grass
Reduction in chloride ion concentration : ~90%
Reduction in sodium ion concentration : ~30%
12. Conclusion
Desalination Filtration
Adsorption of dissolved Removal of organic
salts contaminants &
Attributed to the pathogenic micro-
surface characteristics organisms
of charcoal Attributed to the macro-
pores in the charcoal
structure
13. Features
Ease of manufacture
Eco-friendly solution
Safe disposal/reuse of charcoal
Household utility (esp. coastal/rural areas)
Cost effective solution
Energy efficient
14. Future Work & Challenges
Improvisation of adsorption characteristics of
charcoal by thermal treatment
Finding natural resources like mauritius grass
with required desalination characteristics
Effective design of the apparatus