Asserting carbon offsets from landfill gas flaring at regina’s landfill site
Prevention and recycling_of_clean_drywall_waste
1. Prevention and Recycling of
Clean Drywall Waste
Shouhai Yu
Project Manager, EWMCE
Postdoc Fellow, University of Alberta
Banff, Canada
April 20th , 2010
2. Acknowledgement
• This project was financially supported by:
– Alberta Advanced Education &Technology
– Alberta Environment
– Alberta Agriculture Food and Rural Development
– City of Edmonton
– Alberta Research Council
– University of Alberta
– Clark Builders
– Kasian Architecture Interior Design and Planning Ltd.
– A&L Canada Laboratories Inc.
– Edmonton Waste Management Centre of Excellence
3. Management options
• Landfill
– Consume space
– H2S gas generation
• Incineration
– SO2 gas generation
• Reuse
– ½ sheet or larger
• Recycle
4. Objectives
• To develop a systematic lifecycle
approach for Alberta’s construction
industry to reduce the amount of drywall
waste generated and land‐filled
5. Outline
• Phase I
– Drywall Waste Prevention
• Phase II
– Drywall Recycling through Composting
• Phase III
– Use of Composted Drywall as a Soil
Amendment to Reclaim Disturbed Sites
• Summary
6. Phase I (March 2007 – March 2008)
Drywall Waste Prevention
Dr. Mohamed Al-Hussein
7. Waste identification
Start
Explode Wall Blocks General Procedure:
(Polyfaces))
Waste Identification
Potential Reduction
Identify wall
types Exterior Wall
Sort Continuous Identify Doors, Identify Special cases
Interior Wall Walls and Windows, Connections for doors/windows and
add boundaries and Discontinuities connections
Extrude Structural and
Vary UCS for Create Panels
Extrude Walls Start/End non-structural members
each wall from walls
(Studs, Sills, etc)
Split 3d
Create Shop Drawings Optimization Model Final Cutting List
Model by Floors
End
11. Cutting list
Valid Combinations
Takeoff List
3*C + 2*L = 96”
Waste (S8) = 0”
12. Mathematical optimization
• Analysis Method: Linear Programming
waste
N
• Objective function F(x): min xpsp
p 1
• Constraint equations:
[ x1 , x2 , x3 ,, x N ] LN 9 [100,8,9,85,4,2,2,4,2]T
14. Results of phase I
• Best Management & Practices (BMP)
Guide
• Current results showed that up front
design innovations could affect use of
material in the construction phase
• Software developed is being used by a
local construction company
15. Phase II (March 2007 – July 2008)
Drywall Recycling through
Composting
16. Drywall recycling
• Gypsum wallboard manufacture
• Fertilizer Manufacture
• On Site Land Application
• Off Site Land Application (farmer’s field)
Feb 26, 2008 COMPOSTING MATTERS! 16
17. Apply to soil directly
• Benefits:
– Increases available calcium & sulfur
– Reduces sodium uptake
– Loosens clay soils and allows water & air to
circulate
• Concerns: long term effect
– Exchangeable soil K , Mg
– Chemical compounds
18. Benefits of composting
• Help to keep nitrogen
• Absorb odor compounds
• Increases Cation Exchange Capacity
– Binds Contaminants
– Degrades Compounds
34. Preliminary results indicated
• Drywall compost has no significant
detrimental effects to plant establishment or
growth.
• Compost improved tailings sand as a medium
for plant establishment and growth for each
of the plant species.
• Biosolids with 15 % coarse drywall applied at
50 Mg ha-1 provided favourable results for
density and germination across the three soil
types.
35. Summary
• Drywall reduction from construction site is
practical
• Addition of drywall does not inhibit
composting, might help it.
• Compost improved tailings sand as a
medium for plant establishment and
growth