1. Mr. Patrick Sharrock Université de Toulouse, Mines ALBI FRANCE

2. Nacira Belaicha 1, Wahiba Lemlikchi 1, Med Oimar Mecherri 1, Patrick Sharrock 2, Ange Nzihou 2

4. Real permeable barrier construction….

5. Reactive barrier contents: ZVI Zeolites, clays, Organic matter Calcium phosphates?

6. Chanvre Hemp

7. hydroxyapatite, Ca 5 (PO 4 ) 3 OH, fluoroapatite, Ca 5 (PO 4 ) 3 F photo by Alain Darbellay, GGGems.com.GGGems.com Stable products of calcium and phosphorous Phosphate ores comprise animal bone residues

8. Reaction mechanism HYDROXYAPATITE (Ca 5 )(PO 4 ) 3 OH CONTAMINANTS Zn 2+ (Ca,Zn) 5 (PO 4 ) 3 OH Thermodynamically favorable reactions. (Ca,Pb) 5 (PO 4 ) 3 OH Pb 5 (PO 4 ) 3 Br Zn 5 (PO 4 ) 3 F Cu 5 (PO 4 ) 3 OH Cd 5 (PO 4 ) 3 OH Ca 5 (AsO 4 ) 3 OH (UO 2 ) 3 (PO 4 ) 28H 2 O

9. Mineral surface layers Water Adsorption Co-precipitation Surface precipitation Mechanisms of Metal Interaction at the Mineral-Water Interface xZn2+ + Ca10(PO4)6(OH)2  (10-x)Ca2+ + Ca10-xZnx(PO4)6(OH)2

10. Composites tested: Plaster + hydroxyapatite (HA or duck bone) Plaster + hydroxyapatite + fibers

11. use two parts plaster to one part water

13. Natural porosity of plaster…

15. Experimental set-up for testing porous plaster filter

16. 1% fibers 2% fibers

17. Mechanical strength of synthetic Ha

18. Mechanical strength of duck bone calcinated Ha

19. Tensile strength decreases when bone HA increases

20. Tensile strength decreases as porous bone HA increases

25. Plaster-HA composite retains zinc ions

26. Composite with more HA retains more zinc

27. Amount of zinc removed decreases with increase in flow rate

30. Composite material can retain heavy metals and avoid dispersion of fine metal phosphates