• Aucun résultat trouvé

Allocating an environmental load to wastewater sludge when sludge status moves from “waste” to “product”, a methodological challenge

N/A
N/A
Protected

Academic year: 2021

Partager "Allocating an environmental load to wastewater sludge when sludge status moves from “waste” to “product”, a methodological challenge"

Copied!
2
0
0

Texte intégral

(1)

HAL Id: hal-02603643

https://hal.inrae.fr/hal-02603643

Submitted on 16 May 2020

HAL is a multi-disciplinary open access

archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Allocating an environmental load to wastewater sludge when sludge status moves from “waste” to “product”, a

methodological challenge

M. Pradel, Lynda Aissani, J. Villot, J.C. Baudez, V. Laforest

To cite this version:

M. Pradel, Lynda Aissani, J. Villot, J.C. Baudez, V. Laforest. Allocating an environmental load to wastewater sludge when sludge status moves from “waste” to “product”, a methodological challenge. SETAC Europe 26th Annual Meeting, May 2016, Nantes, France. pp.1, 2016. �hal-02603643�

(2)

Product  x  => generic allocation factor bc’

g(k,l)

with matrix shape

bc’

g(k,l)

=

𝛿′

1

𝛼

1,1

… 𝛿′

1

𝛼

1,𝑙

… 𝛿′

1

𝛼

1,𝑞

𝛿′

𝑘

𝛼

𝑘,1

… 𝛿′

𝑘

𝛼

𝑘,𝑙

… 𝛿′

𝑘

𝛼

𝑘,𝑞

𝛿′

𝑝

𝛼

𝑝,1

… 𝛿′

𝑝

𝛼

𝑝,𝑙

… 𝛿′

𝑝

𝛼

𝑝,𝑞 Process 1 Contribution of product parameters  to

product production for each process k

=> matrix A (αk,l)

System modelling depends on

 Product parameters 

- Physical, chemical, stoichiometric properties - Flux/flow properties

- Used as main allocation properties between coproducts - « Product-related burden »

 Process parameters 

- Process operation parameters (pressure, temperature…) - Associated to process functioning

- « Process-related burden »

Allocating an environmental load to wastewater

sludge when sludge status moves from “waste” to

“product”, a methodological challenge

National Research Institute of Science and Technology for Environment and Agriculture

Conceptual framework for allocating an environmental burden to coproducts of an

indivisible system

Calculation of generic and specific allocation factors

Challenge for sludge-based products

Identify product and process parameters

 Product parameters can be based on stoichiometric equations for Carbon, Nitrogen (nitrification + denitrification) and Phosphorus treatments

 Process parameters can be based on process treatment functioning (oxygenation rate and aeration duration)

Conclusion

 A methodological framework has been developed to allocate an environmental load to several product in a joint-production system.  Generic and specific allocation factors are based on product and process parameters and inventory matrices.

 Sludge-based products can therefore be compared with fossil-based products as their production is charged with an environmental burden. When sludge status moves from “waste” to “product”, the wastewater treatment plant can be seen as a joint production system generating two

indivisible coproducts : the sludge and the clean water (Pradel et al., 2015). Assessing the environmental impacts of the two coproducts implies to allocate the environmental burden of the system to each of them. This is a methodological challenge that we propose to solve with the use of generic and specific allocation factors.

System modelling conceptual framework

Product 1 Product 2 Process k  Process 1 Process 2  Contribution of all process parameters  to each process k => δ′k = nj=1nβj,k

B’

process

= 𝑖𝑏𝑐′

𝑖,𝑘

or B’

product

= 𝑖𝑏𝑐′

𝑖,𝑙

Environmental burden calculation

Where B’process / B’product = environmental burden allocated to process k or product l ; i = input/output value bc’i,k / bc’i,l= allocation factor per process k or product l (bc : burden coefficient) ; bc’i,k / bc’i,l = f(𝛿′𝑘, 𝛼𝑘,𝑙)

Need to specify if input/output i is related to the production of

each product l : inventory matrix

’ x generic allocation factor

𝑏𝑐′

𝑖,𝑙

Specific allocation factor

Generic allocation factor

𝑏𝑐′

𝑖,𝑘

Inventory matrix  (i,k) : relation between inputs/outputs i and

process k Inventory matrix ’ (’i,l) : relation

between inputs/outputs i and product l

Allocation factors

 Generic allocation factor to be used for generic inputs/outputs

- To be used for common inputs/outputs to all the process (infrastructures…)

- To be used when inputs/outputs cannot be specified to one or several process

 Specific allocation factor to be used for specific inputs/outputs

- To be used for specific inputs/outputs

- Can also be used as generic allocation factor

build with 1 and 0 : 1 = presence

0 = absence

Marilys Pradel1,3, Lynda Aissani2, Jonathan Villot3, Jean-Christophe Baudez1

and Valérie Laforest3

marilys.pradel@irstea.fr

1 Irstea, UR TSCF, France; 2 Irstea, UR OPAALE, France;

3 Université de Lyon, Ecole des mines de Saint-Etienne, I. Fayol, UMR 5600 EVS, France

PRADEL, M., AISSANI, L., VILLOT, J., BAUDEZ, J.C. , LAFOREST, V., 2015. From waste to product: a paradigm shift in LCA applied to wastewater sewage sludge. SETAC Europe 25th Annual Meeting, Barcelona, Spain, 3-7 May 2015.

Product 1 Product 2   Process 2 Product 1 Product 2  Input/output i Allocation factor /process bc’i,k i : input/output k : process, l : product Allocation factor /product bc’i,l

Generic allocation factor for

each process and each product Generic allocation factor for each product

Generic allocation factor for each process

Need to specify if input/output i is specific to each process k :

inventory coefficient

i,k

multiplied with previous result

x matrix A

Specific allocation factor

/ process

Specific allocation factor

/ product

Need of an environmental burden to the production of sludge-based products to allow system comparison

Production Use Manufactured product End-of-life Waste as raw material Use End-of-life Production Use End-of-life Sludge-based product  

Références

Documents relatifs

Background: Through identification of highly expressed proteins from a mixed culture activated sludge system this study provides functional evidence of microbial

By generalizing the presented method in the introductory example, we generate the 2 p submodels of a multiple model characterized by the p premise variables which are partitioned

There can be harmful effects of sewage-sludge utilization in agriculture However, these can be overcome by treatment of the sludge and by appropriate farm-management practices

apply for a pardon (up to 10 years for some applicants); complete exclusion from the process for those applicants with more than three indictable offence convictions,

Accumulation of heavy metals in the soil: The analysis of the soil realized after the last cutting of the Ray Grass (Figure 3), shows a significant decrease of the content

The elimination of the organic matter and the volume reduction of sludge can be obtained by oxidation of the organic matter, especially by the advanced

Mengovirus has been used as a surrogate for human hep- atitis A (HAV) and other enteric viruses in several publica- tions and as an external control when virus is detected in food

Comparabilité, composant relationnel, état relationnel, imprécision, non ordre, pseudo-ordre, pouvoir discriminant, quasi-ordre, preference, rassembleur, relation,