EN 12255-9:2023

SLOVENSKI STANDARD
01-januar-2024
Nadomešča:
SIST EN 12255-9:2002
Čistilne naprave za odpadno vodo – 9. del: Kontrola vonja in prezračevanje
Wastewater treatment plants - Part 9: Odour control and ventilation
Kläranlagen - Teil 9: Geruchsminderung und Belüftung
Stations d’épuration - Partie 9 : Maîtrise des odeurs et ventilation
Ta slovenski standard je istoveten z: EN 12255-9:2023
ICS:
13.060.30 Odpadna voda Sewage water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12255-9
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2023
EUROPÄISCHE NORM
ICS 13.060.30 Supersedes EN 12255-9:2002
English Version
Wastewater treatment plants - Part 9: Odour control and
ventilation
Stations d'épuration - Partie 9 : Maîtrise des odeurs et Kläranlagen - Teil 9: Geruchsminderung und Belüftung
ventilation
This European Standard was approved by CEN on 29 October 2023.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12255-9:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 9
5 Design principles . 9
5.1 General. 9
5.2 Sources and nature of odours . 10
5.3 Odour measurement . 11
5.4 Planning . 12
5.4.1 Preliminary considerations . 12
5.4.2 Detailed planning . 13
5.4.3 Criteria for selection . 14
5.5 Design requirements . 15
5.5.1 General. 15
5.5.2 Materials selection . 15
5.5.3 Chemical or biological addition . 15
5.5.4 Treatment of odorous air . 16
5.5.5 Design of covers . 19
5.5.6 Design of ventilation . 20
5.6 Process requirements . 20
Annex A (informative) Odour potential and odour emission capacity, measurement of odour
emission rate . 21
A.1 Odour potential and odour emission capacity . 21
A.2 Measurement of odour emission rate . 21
Bibliography . 23

European foreword
This document (EN 12255-9:2023) has been prepared by Technical Committee CEN/TC 165 “Waste
water engineering” the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2024, and conflicting national standards shall be
withdrawn at the latest by May 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12255-9:2002.
The main changes compared to the previous edition EN 12255-9:2002 are listed below:
— comprehensive revision and additions in all sections;
— adaptation to the current state of the art;
— updating of the Normative references;
— updated bibliography;
— editorial revision.
It is the ninth part prepared by Working Group CEN/TC 165/WG 40 relating to the general
requirements and processes for treatment plants for a total number of inhabitants and population
equivalents (PT) over 50. The EN 12255 series with the generic title “Wastewater treatment plants”
consists of the following parts:
— Part 1: General construction principles
— Part 3: Preliminary treatment
— Part 4: Primary settlement
— Part 5: Lagooning processes
— Part 6: Activated sludge process
— Part 7: Biological fixed-film reactors
— Part 8: Sludge treatment and storage
— Part 9: Odour control and ventilation
— Part 10: Safety principles
— Part 11: General data required
— Part 12: Control and automation
— Part 13: Chemical treatment — Treatment of wastewater by precipitation/flocculation
— Part 14: Disinfection
— Part 15: Measurement of the oxygen transfer in clean water in aeration tanks of activated sludge
plants
— Part 16: Physical (mechanical) filtration
NOTE For requirements on pumping installations at wastewater treatment plants see EN 752, Drain and
sewer systems outside buildings — Sewer system management and EN 16932 (all parts), Drain and sewer systems
outside buildings — Pumping systems.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Introduction
Differences in wastewater treatment throughout Europe have led to a variety of systems being
developed. This document gives fundamental information about the systems; this document has not
attempted to specify all available systems. A generic arrangement of wastewater treatment plants is
illustrated in Figure 1:
Key
1 preliminary treatment C discharged effluent
2 primary treatment D screenings and grit
3 secondary treatment E primary sludge
4 tertiary treatment F secondary sludge
5 additional treatment (e.g. disinfection or G tertiary sludge
removal of micropollutants)
6 sludge treatment H digested sludge
7 lagoons (as an alternative) I digester gas
A raw wastewater J returned water from dewatering
B effluent for re-use (e.g. irrigation)

Figure 1 — Schematic diagram of wastewater treatment plants
Detailed information additional to that contained in this document can be obtained by referring to the
bibliography.
The primary application is for wastewater treatment plants designed for the treatment of domestic and
municipal wastewater.
1 Scope
This document specifies design principles and performance requirements for odour control and
associated ventilation for wastewater treatment plants serving more than 50PT.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 12255-14, Wastewater treatment plants — Part 14: Disinfection
EN 13725:2022, Stationary source emissions — Determination of odour concentration by dynamic
olfactometry and odour emission rate
EN 16323:2014, Glossary of wastewater engineering terms
EN 16841-1, Ambient air — Determination of odour in ambient air by using field inspection — Part 1:
Grid method
EN 16841-2:2016, Ambient air — Determination of odour in ambient air by using field inspection — Part
2: Plume method
ISO 1629, Rubber and latices — Nomenclature
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 16323 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
olfactometry
measurement of the response of assessors to olfactory stimuli
[SOURCE: EN 16323:2014, 2.1.3.2]
Note 1 to entry: See EN 13725 for details.
3.2
odour concentration
number of European odour units in a cubic metre of gas at standard conditions for olfactometry
[SOURCE: EN 13725:2022, 3.1.30 but with added example and notes]
EXAMPLE If a sample needs to be diluted by a factor of 300 to reach the detection threshold, the odour
concentration of the sample is cod = 300 ouE/m .
Note 1 to entry: The odour concentration has the symbol c and the unit ou /m .
od E
Note 2 to entry: The value of the odour concentration is the dilution factor that is necessary to reach the detection
threshold. At the detection threshold, the odour concentration of the mixture is 1 ouE/m by definition.
3.3
odour emission rate
odour flow rate
quantity of European odour units which crosses a given surface per unit of time
Note 1 to entry: For point sources, the surface is the sampling plane. The odour flow rate is calculated as the
product of the odour concentration cod, the outlet velocity v and the area of the sampling plane A or as the product
of the odour concentration cod and the pertinent volume flow rate V.
Note 2 to entry: The unit of odour flow rate is ou /s (or ou /min or ou /h).
E E E
Note 3 to entry: The odour flow rate, expressed in ou /s, is the quantity equivalent to the mass flow rate,
E
expressed in kg/s, as used in dispersion models for example.
Note 4 to entry: Diffuse sources such as unaerated wastewater or sludge surfaces, do not have a defined waste air
flow, although they can emit odorants. In these cases, a special sampling procedure is necessary which is
discussed in EN 13725 (see Annex A). Odorant flow rates can be used in an analogous fashion to mass flow rates
when modelling the impact from a source. All odour sources will have an odorant flow rate, even where no air
flow rate is easily identifiable.
[SOURCE: EN 13725:2022, 3.2.8 modified by the addition of Note 4]
3.4
volatile organic compound
VOC
organic compound with an
...