WASTE FLOW ANALYSIS AND LCA OF INTEGRATED WM SYSTEMS AS PLANNING

TOOLS: APPLICATION TO OPTIMISE THE SYSTEM

OF THE CITY OF BOLOGNAS. TUNESI – STRATEGIC ENVIRONMENTALCONSULTINGS. BARONI - HERAMBIENTES. BOARINI - HERA SPA DSA BO

The City of Bologna (Italy) decided to increase recycling of municipal waste and to eliminate big waste collection containers in the historical centre.

Esthetic considerations were relevant for decision makers in choosing a new organisation for segregated collection : shift to ‘door to door’and build underground banks.

food waste

paper and board residual

140 UNDERGROUND BANKSOPEN ALL THE TIME

DOOR TO DOOR BY PLASTIC BAGS (1/7)

The public WM company HERA asked the question “what is the relevance of the environmental considerations in this choice?”

Compare 2 WM scenarios: 2013 and 2017 when changes in collection’s organization and infrastructures are going to be completed.

Relevant objectives of this study were to:

1. test how to support decisions at the City’s scale (so far used at regional scale): focus on waste collection as part of a wider system

2. assess the capability of Life Cycle Assessment to identify specific elements that impact on collection’s environmental performance

WASTESarisings,

composition

1. INPUT of RESOURCES and ENERGY2. Costruction; Operation; Maintenance; Dismantling

HomeComposting

COLLECTIONcontainers, bags, cards

TRANSPORT vehicles

distances

MATERIAL RECOVERY

ANAEROBIC DIGESTION,

COMPOSTING

LANDFILLS hazardous

non–hazardous

2. EMISSIONS and WASTES to environment: air; soil; water; ….

3. RECOVERY

of MATERIALS

and ENERGY from wastePR

EVEN

TION

Consumption of electrical energy, of gas for heating and transport.

Fertilisers, soil conditioners for agriculture

Recycling of materials in industries, the building sector, roads.

THERMAL TREATMENTS

energy recovery

INTERMEDIATE PLANTS:

banking /MRFs

pre-TREATMENT of residual waste

(MBT)

OVERALL impact = S DIRECT impacts (1+2) - S AVOIDED impacts (3)

Graph Modified from Gentil E C et al. (2010) Models for waste LCA: Review of technical as sumptions Waste Management 30: 2636-2648.

1. CHOOSE THE APPROPRIATE DEFINITION FOR THE INTEGRATED WM SYSTEM

2 SCENARIOS 2013 2017WASTE MANAGEMENT STEP % %

Segregated collection of dry fractions 22 28Food waste from SC to Composting or Anaerobic Digestion 9 19

Segregated collection of green waste 2 2Textile to reuse /recycling 0.4 0.4

Thermal treatment with energy recovery from residual waste 38 44Pre-treatment mechanical biological 2 7

Residual waste to landfill 26 noOther waste to landfill (sorting plants rejects; dry and wet

fractions out of pre-treatment)almost

doubled

Total 100 100

2. QUANTIFY THE CHANGES IN THE BOLOGNA’S WM INTEGRATED SYSTEM

Describing complicated things is not easy. So how did we describe the WM system of Bologna? Looking only at collection? No, need a tool adequate to confront the complexity of WM.

Could not adopt the abstract vision of the materials recovery supply-chain

3. DEVELOP THE APPROPRIATE TOOL TO COMPARE SCENARIOS

FIGURA ECOMONDO

Ecomondo

PaP

Prossimità

Centri diRaccolta

RICICLAGGIOnon-ferrosi

RICICLAGGIOCARTA

RiciclaggioEstero

TYPES OF WASTE

DOOR TO DOOR

COLLECTION CENTRES

ROAD COLLECTION

INTERNATIONAL RECYCLING

RECYCLING NON-FERROUS

RECYCLING PAPER

LCA Comune Bologna SC 2017-A

RSU da URBANI

RSU da INDROVERI

RSU da TARGET

RIR Prf 5 IIn

PRIVATI aCdR

RIR CS 14 IInt

CdR CAAB

CdR BORGO

CdR STRADELLI

CdR Tolmino

RIR TargetCassoni

C M_SGR a AKR

CC da Target

C da TARGET

RD PIAZZOLA

RD CS NEGOZI eTARGET

C assml aAK

C Piazzola aAK

ORG a DA Heramb

CC ass iml a AK

C Roveri aAK

PL PIazzola AK

PL ROV aAK

PL C+R PaP a AK

PL M_SGR aAK

PL neg aAK

L a EcoLgn

V+L da UNiv aEMRot

RIR ROVERI

PL da TRAGET

RIR C+R a SAT

RD ABITI da RD ABITI

V+L Perf + (C+R)CAMP

L da ROVERI

L da target

VERDE da target

ABITI

R abb a TITAN

RIR Piazzola

RD StGuelfi

RIR a SG

V e L EmilRott

FE CdR a RotINd

ECOLEGNO BO PREPx REC

L Rov a EcoL

RIR SGR

RIR CS aTITAN

RIR M_SGR

C SGR

Sacc C CS come2013

AKRON GRANAROLO

PL SGR

ad AK G

Discarica 3M

C C+R adAKSacc C C+R

Sacc PL C+R42,58

VERDE CompgPrivati

bio-Sacc C+R ScAl

DISC PER ASACastelMagg

Fe daTM

Vetro

non-FE

Compost Verdecompost daVERDE

CC CdR T

ScVg CdR Caab

Legno

Ferros i

L CdR CaabPL CdR CAAB

C+C CdR CAAB

C da CDR aAK

L CdR a ECOLgn

ScVg CdR aStAg

L CdR SG

PL da CdR SG

Scarti RD

TT MO per COBO

Sacc RIR CS LDPERECY

CS IsI V+L

CS IsI V+L

OTHEROTHER

Three main flows from which to recover materials and energy and formulate scenarios:

Dry fractions to recycling

Segregated collection of food waste

Residual waste

3. DEVELOP THE APPROPRIATE TOOL TO COMPARE SCENARIOS

LCA Comune Bologna SC 2017-A

RSU da URBANI

RSU da INDROVERI

RSU da TARGET

RIR Prf 5 IIn

PRIVATI aCdR

RIR CS 14 IInt

CdR CAAB

CdR BORGO

CdR STRADELLI

CdR Tolmino

RIR TargetCassoni

C M_SGR a AKR

CC da Target

C da TARGET

RD PIAZZOLA

RD CS NEGOZI eTARGET

C assml aAK

C Piazzola aAK

ORG a DA Heramb

CC ass iml a AK

C Roveri aAK

PL PIazzola AK

PL ROV aAK

PL C+R PaP a AK

PL M_SGR aAK

PL neg aAK

L a EcoLgn

V+L da UNiv aEMRot

RIR ROVERI

PL da TRAGET

RIR C+R a SAT

RD ABITI da RD ABITI

V+L Perf + (C+R)CAMP

L da ROVERI

L da target

VERDE da target

ABITI

R abb a TITAN

RIR Piazzola

RD StGuelfi

RIR a SG

V e L EmilRott

FE CdR a RotINd

ECOLEGNO BO PREPx REC

L Rov a EcoL

RIR SGR

RIR CS aTITAN

RIR M_SGR

C SGR

Sacc C CS come2013

AKRON GRANAROLO

PL SGR

ad AK G

Discarica 3M

C C+R adAKSacc C C+R

Sacc PL C+R42,58

VERDE CompgPrivati

bio-Sacc C+R ScAl

DISC PER ASACastelMagg

Fe daTM

Vetro

non-FE

Compost Verdecompost daVERDE

CC CdR T

ScVg CdR Caab

Legno

Ferros i

L CdR CaabPL CdR CAAB

C+C CdR CAAB

C da CDR aAK

L CdR a ECOLgn

ScVg CdR aStAg

L CdR SG

PL da CdR SG

Scarti RD

TT MO per COBO

Sacc RIR CS LDPERECY

CS IsI V+L

CS IsI V+L

OTHEROTHER

The method tested is theWASTE FLOWS ANALYSIS

of an INTEGRATED WM system

provides a visual tool

supports in defining scenarios and quantifying infrastructural needs

facilitates the use of LCA and the comparison of alternative complex scenarios

3. DEVELOP THE APPROPRIATE TOOL TO COMPARE SCENARIOS

The Waste Flows Analysis of an integrated WM system was considered appropriate and used as the basis for the quantification of environmental impacts by LCA for the Bologna WM system.

To support the comparison of appropriate scenarios, this method requires to:

define the boundaries of the WM system being planned: avoid partial flows

reconstruct ALL waste flows and follow the waste till the last treatment / operation: such as the energy recovery of rejects from SC sorting plants

describe in DETAIL all operations and phases of WM

waste composition must be well defined

COLLECT A HIGH AMOUNT OF GOOD QUALITY DATA

3. DEVELOP THE APPROPRIATE TOOL TO COMPARE SCENARIOS

CO2 AC

-12000

-10000

-8000

-6000

-4000

-2000

0

2000

4000

Normalised values2013

2017

Sc-17B - modifies Sc-17: recycled-LDPE bags are substituted with

non-recycled-LDPE for ‘door to door’ collection of residual waste in the HC

Sc-13 Sc-17 Sc-17B*

Global Warming Potential (t CO2-eq year-1) 21 949 - 11 416 -11 169

Global Warming Potential (t CO2-eq · t waste-1) 0.123 -0.064 0.063

Abiotic Resources Depletion (t antimonyeq· year-1) - 403 -525 -520

Abiotic Resources Depletion (t antimony eq · t waste-1) -2.3 10-3 - 3.0 10-3 -2.9 10-3

Acidification Potential ( t SOx eq · year-1) -285 -365 -364

Acidification Potential (t SOx eq · t waste-1) -1.6 10-3 -2.1 10-3 -2.0 10-3

OVERALL PERFORMANCES OF SCENARIOS

4. WHAT ABOUT ESTHETIC VS ENVIRONMENTAL CONSIDERATIONS ?

The analysis of the WM integrated

system shows that even if Sc-17

improves, the impact of the collection

phase increases

SC-13 SC-17

-350,000

-300,000

-250,000

-200,000

-150,000

-100,000

-50,000

0

50,000

consumption/saving of abiotic resources

The set of changes applied by 2017 will result in a significant improvementof the environmental performance mainly as an effect of high integration between materials and energy recovery from waste

4. WHAT ABOUT ESTHETIC VS ENVIRONMENTAL CONSIDERATIONS ?

SGR resid

ual

SGR paper

SGR plastics

bio-bags food to

SGR

SGR food

bags resid

ual HC LDPE non-re

c

bags paper H

C

bags plasti

cs HC

bring bank g

lass Resid

ential

bio-bags HC to

Underground Containers

Underground tanks

glass HC ste

el

Underground tanks

food HC steel

Underground tanks

glass HC sto

ne

Underground tanks

food HC stone

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

CO2-eq direct emissions for waste containerskg

CO

2 e

q.

10,578,859 MONOUSE bio-plastics bagsin periphery

Sc-17A

4. WHAT ABOUT ESTHETIC VS ENVIRONMENTAL CONSIDERATIONS ?

high number of MONOUSE bags used in this collection:

5,356,410

Sc-17B

10 years

1. Waste Flow Fnalysis and LCA can provide relevant planning recommendations at city’s scale when an integrated WM system is considered and appropriate scenarios are designed and compared.

2. Given the highly infrastructured WM system serving Bologna, the impact of the collection phase is only a fraction of the overall environmental impact: so esthetic factors can have their place in collection.

2. But this detailed analysis shows that choice of the containers is environmentally relevant (together with cost and working conditions considerations) and thus the new collection style could be improved:

beware of the materials forming the mono-use bags used for ‘door-to-door’ collection: e.g. for non-recycled LDPE bags 22 kg CO2-eq (tonne of waste)-1;

relatively low environmental impacts associated to underground banks, that could collect for any waste fraction: 4 kg CO2-eq (tonne of waste)-1;

relatively low impact of big street containers with respect to plastic bags: 2.6 kg CO2-eq (tonne of waste)-1.

5. HOW THIS ANALYSIS ANSWERED THE ORIGINAL QUESTIONS

Strategic Environmental Consulting simonetta.tunesi@gmail.com

1. DESCRIBE THE CHANGES IN THE BOLOGNA’S WM INTEGRATED SYSTEM:

ALTERNATIVE SCENARIOS 2013 VS. 2017INCREASE SEGREGATED COLLECTION AMOUNT AND % Begin food segregated collection in HC (SC): underground banks Increase interception rate for (glass + cans): underground banks Residual waste: begin ‘door to door’ in historic centre (plastic bags; 1/7) Increase SC – paper, plastics, food – in the residential periphery by use

of ‘restricted opening’ on big residual W containers

INFRASTRUCTURE CHANGES Anaerobic digestion of food waste replaces composting: biogas recovery NO residual waste directly to landfill Increase % of residual waste thermal treatment with energy recovery Slags from thermal treatment to recovery