Arsenic Leaching From Mulch Made from Recycled CD

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

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

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

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

Materials & Methods Collection & Sorting C&D wood Mixing mulch Shredding wood Leachate generation

Mixing handmade mulch % Non Colored treated colored wood 0% mulch 5% mulch Mulch 100% mulch

Materials & Methods Collection & Sorting C&D wood 0% treated Mulch 5% treated Mulch wood 100%Treated. Mixing Mulch wood Shredding wood Leachate generation

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

Field leachate: 1 year monitoring EPA 7060 A & GFAA

Results: As in the leachate (mg/L) SPLP Leachate Field leachate Average/year %CCA mulch 0% Non Colored <0. 012 < 0. 012 Non Colored < 0. 003 0. 341 0. 258 (untreated) 5% 0. 920 0. 380 -59% 100 % 9. 85 1. 32 -73% -24% 4. 49 3. 49 -22%

Discussions A half year colorant effect %CCA, time, p. H of rainfall From 100%CCA FL GWCTL 0. 05 mg/L Detection limit 0. 003 mg/L From 5%CCA From 0%CCA

Mathematical model %CCA, time, p. H from non-colored much As = %/100(2+40 t-0. 7+32(7 -p. Hrain)5/t 2) from colored much As = %/100(1+40 t-0. 7+12(7 -p. Hrain)5/t 2) r = 0. 836 ~ 0. 954

Conclusion n 5%CCA mulch n Colorant ØSorting C&D wood before the production

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