1. Arsenic Leaching From Mulch Made from Recycled C&D Wood Arsenic Leaching From Mulch Made from Recycled C&D Wood a 1 Tomoyuki Shibata, 1 Helena Solo-Gabriele, 2 Timothy Townsend and 2 Brajesh Dubey 1 University of Miami and 2 University of Florida Objectives: Quantifying the releases of arsenic from C&D wood mulch and evaluation of the effect of colorant on arsenic leaching

2. FAQ: Mulch Roles Roles –Prevention of Evaporation of moisture & soil erosions Evaporation of moisture & soil erosions –Aesthetic Applications Applications –Gardens, parks, Playgrounds Made of Made of –Trees, leaves, straws, peat, or recycled C&D wood

3. Wood Recycling Facility Facilities, Florida USA Facilities, Florida USA –CCA up to 30 % –Will increase

4. Colored Mulch Red dye (popular in FL) –Iron oxide Combine with As May inhibit As leaching ?

5. Materials & Methods Collection & Sorting C&D wood Shredding wood Mixing mulchLeachate generation

6. Mixing handmade mulch Coloredmulch Mulch mulch% treated wood Noncolored0%mulch 5%mulch 100%mulch

7. Materials & Methods Collection & Sorting C&D wood Shredding wood Mixing woodLeachate generation 0% treated wood MulchMulch 5% treated wood MulchMulch 100% Treated wood MulchMulch

8. Leachate Generation SPLP leachate University of Florida Field leachate University of Miami Non-coloredColored 0 %treated 5 % 100 % 5 cm mulch (800g/box) Geotextile

9. EPA 7060A & GFAA Field leachate: 1 year monitoring

10. SPLP Leachate Field leachate Average/year %CCAmulchNonColoredColoredNonColoredColored 0 % (untreated)<0.012 < 0.012 < 0.003 5 % 0.9200.380 0. 341 0.258 0.258 100 % 9.851.32 4.49 4.49 3.49 3.49 Results: As in the leachate (mg/L) -59% -73%-22% -24%

11. Discussions From 100%CCA From 5%CCA From 0%CCA FL GWCTL 0.05 mg/L A half year colorant effect %CCA, time, pH of rainfall Detection limit 0.003 mg/L

12. Mathematical model %CCA, time, pH r = 0.836 ~ 0.954 from non-colored much As = %/100(2+40t -0.7 +32(7-pH rain ) 5 /t 2 ) from colored much As = %/100(1+40t -0.7 +12(7-pH rain ) 5 /t 2 )

13. Conclusion 5%CCA mulch 5%CCA mulch Colorant Colorant  Sorting C&D wood before the production

14. Acknowledgements Funding Agency Funding Agency –Florida Center for Solid and Hazardous Waste Management Extra Help Extra Help –Gary Jacobi, Geoff Klug, Michael Laas, Caitlin Feikle, Colleen Block, Yuki Sotome, and Alicia Muniz: University of Miami Thank you