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CDN WQ

STAKEHOLDERS WORKSHOP St Mary's Pastoral Centre , Nakuru 27 th May 2010 Topic: Fluoride, Fluorosis and Defluoridation by Linda Korir . CDN WQ. Catholic Diocese of Nakuru, Water Quality Section. CATHOLIC DIOCESE OF NAKURU (Water Quality Program ).

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CDN WQ

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  1. STAKEHOLDERS WORKSHOP St Mary's Pastoral Centre , Nakuru27th May 2010Topic: Fluoride, Fluorosis and Defluoridation by Linda Korir CDN WQ Catholic Diocese of Nakuru, Water Quality Section

  2. CATHOLIC DIOCESE OF NAKURU (Water Quality Program ) • It is a development program under Catholic Diocese of Nakuru • It is one of the subsection in the water program the others are water drilling and water supply • Established in 1998 to research, develop and implement an appropriate technology for fluoride removal • Most of the drilled bore hole had high fluoride content exceeding the recommended WHO guideline of 1.5 mgF/L

  3. Fluorosis No medical cure Prevention

  4. Fluoride in the world CDN WQ > 200 Mio. people live in fluorotic areas

  5. Kenya Map Showing Boreholes with Fluoride Concentrations at Differing levels Key <1.5mgF/L 1.5-2.5mgF/L >2.5mgF/L

  6. Defluoridation Technology Bone char technology has been in use since 1998 There was a problem of the lifespan of the filter This lead to the development of the Ca phosphate based contact precipitation method to prolong filter life The technology is promising and full scale implementation started in 2006-Kenya Further requirement for research has lead to the CDN WQ – Eawag collaboration Joint research, documentation and dissemination CDN WQ has the lead

  7. Ca PO4 F Pellets How contact precipitation works (CP) Contact precipitation (CP) PO4 Ca CDN F Bone char 1991 1996 2004 – 2006 2006 to date First scientific publication on CP and its ability to remove fluoride (Christoffersen et al., 1991) Pilot plant in Tanzania. Due to high maintenance effort plant was abandoned (Dahi, 1996) CDN WQ develops pellets Field and laboratory testing

  8. Production of filter materials Crushing Sieving Washing Curing Washing Sprinkling

  9. Laboratory experiments • PVC columns with 260 ml filter material; Contact Precipitation (CP), Pellets:Bonechar ratio of 3:1; • Pellet size:2-6.3mm; Bone Char(BC) size:1-4mm • Flowrate 10Bv/day • Distilled Water spiked with 6mgF/l used at Eawag and Natural ground water with 6.2 mgF/l used in Kenya

  10. Research findings Column experiments show a variation in uptake capacity between 0.5 mg/g – 4.3 mg/g depending on experimental conditions

  11. Household Filter(Defluoridation only)

  12. Household filter (Combined Filter)

  13. Institutional Filter

  14. Community Filter

  15. Remote Area Filter

  16. Results: Community Filter • Design modified reduced phosphate concentrations in the outlet • Approximately 1000m3 treated until 1.5 mgF/L(WHO guideline) • The difference in design on laboratory scale and field brings about the differences in the uptake capacity (20% lower in the field than in the laboratory)

  17. The technology is promising and filter life is prolonged by 3-6 times The maintenance cost of such filters is reduced Contact precipitation is complex with adsorption, dissolution and precipitation reactions. Optimization is currently ongoing so as to enhance filter performance Summary and conclusions

  18. THANK YOU

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