Unformatted text preview: MIT OpenCourseWare http://ocw.mit.edu 2.500 Desalination and Water Purification
1 OUTLINE Our framework for evaluation the project Proposed solutions: short term solutions Bringing RO in third world countries SEE Solar still Conclusion and recommendations
Investment cost Operating cost Repairing cost Defining the criteria to assess the project Cost of system Our assesment: 10L/family/day (drinking) Our units: Cost: $/family/year Level of expertise required for the maintenance Level of expertise required for the operation Easiness of operation Bacteria/ viruses removal. Final level of salt. Contamination after treatment Sensitivity of the system to variation of feed water quality?
3 Reliability of the water produce Existing solutions Assessment of the existing situation
What? Buying the sweet water (for cooking/ drinking/ domestic use). Specifications? 5 bucket /family /day How much? 45 $ / year / family Why not?: There is no distinction in quality between drinking water and domestic use It costs too much for some families It may not be safe 45$ / year /family 4 Short term suggestions Education
Importance of the education -> water problem awareness classes. Aim 1: drinking water vs cooking water vs other uses Aim 2: pollution water (bacteria vs salts vs taste and odor) and assessment of safe water water Aim 3: Importance of drinking enough water to stay healthy 5 Long term solutions Bringing RO to Third World countries
Step 1: Remove the clamp from the water tube Step 2: Fill the inside of the water tube with salt water Step 3: Put the 2 tube inside the tire. Step 6: Water runs along the permeate carrier Step 5: The water goes though the membrane Step 4: Inflate the air tube to 6 bars. Step 7: Water goes into the water valve Step 8: Deflate the air valve after 10min (time for achieving aimed recovery) Step 9: Pull the tubes out of the tire, pour the concentrate out Start again 6 Long term solutions Bringing RO to Third World countries
What? Building a RO plant from bicycle parts. Specifications? 1L/30min (not a continuous process) Can run for 1 family drinking water (10L/day) How much? 10$ investment. 5$ for membrane replacement every year. Why not?: No prototype have been build Not a good estimation of the membrane life time ?? 15$ / year /family 7 Long term solutions Single effect evaporation 8 Long term solutions Single effect evaporation
What? Specifications? How much? Using heat power source 6L/ 1Kg of wood 30$ investment (pot+ (wood, sugarcane charcoal copper tube). from the "Ecole du 96$ of wood a year / charbon") to evaporate family water from a pot into a copper tube. Why not?: Price of energy!!! (if no alternative combustible is possible) pollution 10-100$ / year /family 9 Long term solutions Solar still + Rain harvester Whole view of the solar still Section view of the still
10 Long term solutions Solar still + Rain harvester
What? Building a solar still + rain harvester (one per family). Specifications? 4.3 m2 of active area per family 10L of water a day (for the solar still) How much? 65$ investment (black PVC film + wood frame + Transparent film). Running rime: 5years. Why not?: Contamination of the solar still by dust / rain Rely on the sun what about drinking water an a cloudy day 13$ / year /family 11 CONCLUSION- RECOMMENDATIONS INFORMATION/ EDUCATION of the population and need to separate drinking water to domestic use Evaporation using sugarcane charcoal RO self made system: a further assessment of the lifetime of membrane need to be done Solar Still: our prefer solution, but variability of sunshine 12 QUESTIONS? 13 ...
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- Spring '09
- Drinking water, long term solutions