This document summarizes a project to prevent and recycle drywall waste from construction sites. It describes three phases: 1) reducing drywall waste through 3D modeling and optimization, 2) composting drywall waste, and 3) using the composted drywall to reclaim disturbed soil. Preliminary results found that upfront design reduced drywall waste by 0.58%, composting drywall was successful and improved soil quality, and composted drywall had no detrimental effects and improved plant growth in reclaimed soils.
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