Sustainable Environmental InfrastructureSustainable Environmental Infrastructure

Patrick Hettiaratchi, PhD, PEngProfessor of Environmental EngineeringDepartment of Civil Engineering & CEERE ( Center for Environmental

Engineering Research & Education)Schulich School of Engineering, University of Calgary

August 5, 2006Bangkok, Thailand

Sustainable DevelopmentSustainable Development(UN, 1987)(UN, 1987)

Development without destructionCurrent development (and resource utilization) should consider the needs of future generations; social/political, environmental and economicalConsider Triple Bottom Line (Social, Environmental and Economical), instead of the Single Bottom Line (economics).

Environmental InfrastructureEnvironmental Infrastructure

Water Supply Systems (source, treatment, distribution networks)

- Wastewater Management Systems (collection networks and treatment plants)

- Air Pollution Control Systems

- Solid Waste Management Systems(more complicated because required infrastructure are highly site-specific)

Reduce

RecycleResource Recovery

Disposal

Reuse

The Inverted Pyramid of ISWMThe Inverted Pyramid of ISWM

Waste Management 101Waste Management 101

Landfill is the “center” of waste management

Other waste management techniques are “built around” a “good Landfill”

Modern conventional “dry-tomb type” Sanitary Landfills are designed and constructed to eliminate problems associated with “Open Dumps”

Construction of Dry-tomb Landfills

Final cover

Daily cover

Intermediate cover

Leave it alone !!!!!

R I PR I P

Sanitary Landfill Cell: Calgary, Alberta, Canada

Rincon Verdes Landfill, Tlaliniplanta, Mexico (with gas extraction etc)

Problems with Dry-tomb Landfillls

Un-sustainable??? Loss of Space. Need to find new space every few years (Toronto, Edmonton)

Long-term liability: Need to monitor potential impact for a long- time (until waste stability is achieved)

Landfill gas

Solution: Sustainable Landfill or Biocell

First, operate a Cell in the Anaerobic mode for maximum methane production for energy recovery by leachate recirculation

Then, convert the operation to:Aerobic Bioreactor (in-ground composter)Biocell Mining

Stabilize the waste quickly (Anaerobic and Aerobic)“Mine” the cell, and extract recyclables & compostReuse the space………….

Holistic approach (not “piece-meal”)

Biocell – 1st Stage

Anaerobic Reactor

Biocell – 2nd Stage

Aerobic Reactor

Sustainable Landfills/Biocells: Are we there yet???

Not really…..

Although there are some Anaerobic Bioreactors (and a few Aerobic Bioreactors) in operation, no one has tried the sequential operation (Sustainable Landfill or Biocell), yet…

A number of operational problems needs to be resolved before Biocell can be universally applied.

NOTE: These problems are common to all types of Bioreactors!!

THE CALGARY BIOCELL: Operate a Pilot landfill cell

sequentially, as Anaerobic and Aerobic

Bioreactors, followed by Mining to Recover Resources and Space

- First of its kind in Canada

Calgary Pilot Biocell ProjectPartners:

• City of Calgary (primary funding of more than $2 million),

• Stantec Ltd (Cell design and project management)

• University of Calgary and collaborators (Research; funding

from NSERC-Strategic Grant)

A one hectare cell capable of taking 55,000 tonnes of

residential and commercial organic waste

Unique project – “coined” the term “landfill bio-cell (LBC)”

AerobicYear 5

AerobicYear 4

AnaerobicYear 3

AnaerobicYear 2

AnaerobicYear 1

Mining/Space Recovery

Year 6

The Calgary Biocell Concept

Unique Features of Biocell Design

Biocell Construction

Leachate/Gas collection systems

Research/Monitoring/Sensors

Temperature

Settlement (plates at 4 levels)

Loads (pressure transducers/pressure

plates)

Leachate head (piezometers)

Moisture in waste (TDR)

Pore pressure measurements

Settlement plates

Monitoring/Sensors; Layout

Leading-edge Research

Waste settlement (issue: high settlement rates; changes

waste density and permeability profile. Develop models

to predict behavior during early stages of Biocell

operation; consider biodegradation, and gas production)

Lateral migration of leachate (impact of intermediate

covers)

Intermediate thin biocovers (TBCs)

ConclusionsWaste disposal has progressed from “open dumps” (in the past) to “dry-tomb sanitary landfills” (present).

Biocell (or Sustainable Landfills) could be the future because it has the potential to solve the most pressing problem;lack of space in urban centers in developed and developing countries.

Biocell landfilling follows a holistic approach. Consider waste as a resource; extract “biogas energy” and other resources, and space. It is consistent with the “sustainable development” principles.

Several technical challenges need to be overcome, before Biocell (or Bioreactor) concept could be universally applied.

Thank You…