Life Cycle Assessment of Life Cycle Assessment of BNR Wastewater - - PowerPoint PPT Presentation

Advanced Wastewater Management Centre

Life Cycle Assessment of Life Cycle Assessment of BNR Wastewater BNR Wastewater Treatment Plants Treatment Plants

Jeff Foley Jeff Foley The University of Queensland, Australia The University of Queensland, Australia

Life Cycle Management 2007, Zurich Life Cycle Management 2007, Zurich 27 27 – – 29 August 2007 29 August 2007

Presentation Outline Presentation Outline

1. 1.

Background Background

2. 2.

Goal and Scope Goal and Scope

3. 3.

Life Cycle Inventory Analysis Life Cycle Inventory Analysis

4. 4.

Life Cycle Impact Assessment Life Cycle Impact Assessment

5. 5.

Interpretation and Conclusions Interpretation and Conclusions

Background Background

• Initially, WWT about protecting public health

Initially, WWT about protecting public health

• 1960s

1960s – – developed biological nutrient removal developed biological nutrient removal

• Today

Today – – BNR capable of TN< 3, TP< 1 BNR capable of TN< 3, TP< 1

• Quality of local water bodies has become community

Quality of local water bodies has become community and regulatory priority and regulatory priority

• No quantitative measure of environmental impacts

No quantitative measure of environmental impacts associated with compliance associated with compliance

LCA Goal and Scope LCA Goal and Scope

• Quantitatively evaluate 34 WWT scenarios

Quantitatively evaluate 34 WWT scenarios

– – 8 different configurations 8 different configurations

• Primary sedimentation + anaerobic digestion

Primary sedimentation + anaerobic digestion

• Activated sludge & Nitrifying activated sludge

Activated sludge & Nitrifying activated sludge

• 3 nitrification

3 nitrification-

• denitrification / phosphorus removal designs

denitrification / phosphorus removal designs

• Membrane bioreactor

Membrane bioreactor

• Anaerobic treatment + post

Anaerobic treatment + post-

• treatment for nutrient removal

treatment for nutrient removal

– – Wide range of effluent qualities Wide range of effluent qualities

• From TN< 50 to TN< 3

From TN< 50 to TN< 3

• From TP< 12 to TP< 1

From TP< 12 to TP< 1

PST + MLE + Anaerobic Digestion Oxidation Ditch 5-Stage Bardenpho Membrane Bioreactor (MBR) EnRec + 5-Stage Bardenpho No TP Target TP < 5 mg/L TP < 1 mg/L 5 10 15 20 25 30 35 40 45 50 Effluent Total Nitrogen (mg/L)

Do Nothing Primary Treatment + Anaerobic Digestion Activated Sludge + Anaerobic Digestion Nitrification + Anaerobic Digestion TN < 20 mg/L TN < 10 mg/L TN < 5 mg/L TN < 3 mg/L

LCA Goal and Scope LCA Goal and Scope

• Functional Unit

Functional Unit – – 10 ML/d for 15 years 10 ML/d for 15 years

Life Cycle I nventory Life Cycle I nventory

• Scenario desktop design:

Scenario desktop design:

– – BioWin BioWin™

™ biological simulation package & proven engineering

biological simulation package & proven engineering design methods design methods

• Operating phase inventory:

Operating phase inventory:

– – Biosolids Biosolids – – Energy and chemical consumption Energy and chemical consumption – – Atmospheric emissions Atmospheric emissions

• Construction phase inventory

Construction phase inventory

– – Based on Eco Based on Eco-

• Invent data for Swiss WWTPs

Invent data for Swiss WWTPs

I MPACT 2002+ Life I MPACT 2002+ Life Cycle I mpact Assessment Cycle I mpact Assessment

I MPACT 2002+ I MPACT 2002+

• Aquatic Eutrophication

Aquatic Eutrophication

– – Primary oxygen consumption in nitrification Primary oxygen consumption in nitrification – – Assume 50% N Assume 50% N-

• limited / 50% P

limited / 50% P-

• limited

limited – – No damage modelling to Ecosystem Quality No damage modelling to Ecosystem Quality

• 100 year horizon for GWP

100 year horizon for GWP

• Fate and exposure modelling based on European

Fate and exposure modelling based on European conditions conditions

• Results normalised against estimated Australian

Results normalised against estimated Australian environmental profile environmental profile

Unweighted Mid Unweighted Mid-

• Point

Point Assessment Assessment

Weighted Mid Weighted Mid-

• Point

Point Assessment Assessment

Unweighted Damage Unweighted Damage Assessment Assessment

I nterpretation & Summary I nterpretation & Summary

• Quantitative comparison of environmental costs of

Quantitative comparison of environmental costs of different WWT technologies and standards different WWT technologies and standards

• Broad environmental trade

Broad environmental trade-

• off for advanced
• ff for advanced

nutrient removal nutrient removal

– – Only justified by implicitly valuing Only justified by implicitly valuing local

local water quality over

water quality over all other global environmental pressures all other global environmental pressures

• Primary anaerobic treatment, with energy recovery:

Primary anaerobic treatment, with energy recovery:

– – Better environmental outcomes than Better environmental outcomes than “ “leading edge leading edge” ” BNR BNR – – Even where importation of chemicals is necessary to Even where importation of chemicals is necessary to improve nutrient removal. improve nutrient removal.

Acknowledgements Acknowledgements

• Advisors:

Advisors:

– – A/Prof. Paul Lant A/Prof. Paul Lant – – Adjunct Prof. Ken Hartley Adjunct Prof. Ken Hartley – – Dr David de Haas Dr David de Haas

• Funding:

Funding:

– – Queensland State Government Queensland State Government

• Questions..?

Questions..?