IWA World Water Congress

10 -14 September 2006Beijing, China

M. Fujiwara, ◎N. Hayashi, K. Kanai, M. Kiyozuka, (Japan Water Research Center); Y. Matsui, (Hokkaido University); K. Mori, (Ebara Corporation); Y. Sakakibara, (Nihon Suido Consultants Co., Ltd)

Application of Life Cycle Assessment (LCA) to Water Purification Facilities

Water purification: Conventional ⇒ “Coagulation Sedimentation & Sand Filtration” Newly ⇒ “Membrane Filtration ”, a measure against Cryptosporidium

Introduction

A few cases in Japan in which a purification process was selected by considering the environmental loads.I present a case study in which inventory analysis, as an element of life cycle assessment (LCA), choosing from the two alternatives processes.

Water supply facilities need a great amount of energy.

Selection of purification process involves such conventional indexes as treatability, maintainability or cost: ⇒Very conventional approach

Establishment of a research technique of a purification plant considering reduction of environmental loads

Background

Being worked on under the e-Water project

Quantitative identification and evaluation of environmental impact ⇒Insufficient

What is e-Water ?BackgroundEnvironmental, Ecological, Energy-saving and

Economical Water Purification SystemResearcher: Japan Water Research Center Subsidization: Ministry of Health, Labour and WelfareParticipants: Academia, Waterworks Utilities, and Private

companies

Detailed Info: go to Poster Gallery, Poster No.27

Research Cost: $ 6 MillionResearch Period: fiscal 2002-2004

Scope of ResearchScope：Purification Plant: Construction Stage - Operation Stage

Scope of Research

Construction Stage

Procurement and Construction

Fabrication and Assembly

Operation Stage

Used as Purified Water

Power, Fuel and Chemicals

Disposal Stage

Demolition and Disposal

Future Tasks

Items：Life Cycle Energy Consumption (LC-E)Life Cycle CO2 Emissions (LC-CO2 )

Scope of ResearchRaw Water

Coagulant and ChlorineChlorine

To water Distribution

To Disposal of Sludge

Water Receiving

Basin

Coagulation Sedimenta-tion Basin

Rapid Filtration

Basin

Clean Water Reservoir

Discharging Basin

Sludge Settling Basin

Thickening Tank

Sludge Dehydrator

Returned Water

Purified Water

Sludge

Supernatant Supernatant

Administration Building and Electric

Instrumentation Equipment

Typical Rapid Filtration

Scope of Research

Raw Water

Coagulant and Chlorine

To Water Distribution

To Disposal of Sludge

Water Receiving

Basin

Membrane Filtration

Clean water Reservoir

Sludge Dehydrator

Chlorine

Administration Building and Electric

Instrumentation Equipment

Coagula-tion Basin

Membrane Filtration

Structuring of Scope of ResearchC

onst

ruct

ion Civil

EngineeringWater

Receiving Basin

Building Frame

Pipes/Valves

Earthwork

Reinforced Concrete Casting (21-8-25)

Paddled Short Pipes (φ600×1,000)

Excavation and Machines

Major Sector Classification

Middle Classification

Small Classification

Detailed Classification

Sedimenta-tion Basin

Filtration Basin

・ ・ ・ ・ ・

・ ・ ・ ・ ・

・ ・ ・ ・ ・990 items

Mechanical Equipment

Electric Equipment

Building

Ope

ratio

n

・ ・ ・ ・ ・・ ・ ・ ・ ・

Calculation Conditions and MethodPurification Treatment FlowCoagulation Sedimentation ＋ Sand Filtration （typical flow, based on an actual plant), Membrane Filtration (virtual plant)Treatment Capacity20,000 m3/d (av. treatment capacity of Rapid Filtration in Japan)Characteristics of Purification PlantGravity flow from water receiving basin to clean water reservoirScope of ResearchConstruction and operation stage of facilities and equipment in the plant

⇒ Energy and CO2Research Method →LCA ⇒ Unit Process Analysis

Embodied Intensities (Basic Unit)Values taken from existing literature (e.g. 3EID) are mainly used

LC-E and LC-CO2 Calculation Sample

♨ Energy：562m3×2,020.2MJ/m3=1,135,352MJ♨ CO2：562m3×62.97kg-c/m3=35,389kg-C

Calculated using the basic units for concrete of temporary plant

Life Cycle Period

Civil engineering structures: 60 yearsMechanical equipment: 15 yearsElectric equipment: 20 yearsBuilding utilities: 50 years

To convert energy consumption and CO2 emissions to an annual total:

♨ The same calculation method is used for other items

LC-CO2 of Major Sector Classification

35%

Construction(civil engineering)

Construction (building)

20%

9% Construction (mechanical)

Construction (electric)

3%

Operation(electric)

14%

Operation(mechanical)

19%

Results of Research

LC-CO2 of Major Sector Classification

44%

Construction (civil engineering)

Construction (electric)

Construction (mechanical)

6%Construction

(building)

Operation(mechanical)

45%

Operation(electric)

5%

Results of Research

Life Cycle CO2

Construction stageCoagulation Sedimentation + Sand Filtration 67％

Membrane Filtration 50％

Results of Research

Operation stageCoagulation Sedimentation + Sand Filtration

⇒ Mechanical ＋ ElectricMembrane Filtration ⇒ Mechanical

LC-E of Major Sector Classification

Construction (building)

19%

Construction(Civil engineering)

18%

Construction (mechanical)

5%

Construction (electric)

3%

Operation(electric)

24%

Operation(mechanical)

31%Construction (mechanical)

33%

Construction (building)

4%Operation

(mechanical)57% Operation

(electric)

6%

Results of Research

Life Cycle Energy

Construction stageCoagulation Sedimentation + Sand Filtration 45％

Membrane Filtration 37％

Results of Research

Operation stageCoagulation Sedimentation + Sand Filtration

mechanical＋electricMembrane Filtration

mechanical

LC-E Analysis for Middle Sector Classification ItemsResults of Research

Rapid Filtration Membrane FiltrationImprovement work in the

compound

Land development workStandby generator

Substation

Monitoring control and instrumentation

Power and control

Administration building

On-site piping

Dehydrator

Discharging basin and thickening tank

Clean water reservoir

Sedimentation basin and filtration basin

Chemical feeding equipment

Chemical mixing tank

Substation

Monitoring control and instrumentation

Power and control

Administration building

Membrane module

Membrane filtration facility

Chemical feeding equipment

Chemical mixing tank

Water receiving basin MJ / Y / m3MJ / Y / m3

Conclusions

LC-E and LC-CO2 for the life cycle of a water purification plant (materials, construction, operation and maintenance) were calculated by applying LCA.

The calculation results were obtained under special prerequisites; they will vary depending on the calculation conditions.

LC-E and LC-CO2 of the Membrane Filtration facility is highly likely to be equal to that of the conventional Coagulation Sedimentation + Sand Filtration facility.

Thank you for your attention.