oSIST prEN 12255-9:2021

SLOVENSKI STANDARD
01-oktober-2021
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: prEN 12255-9
ICS:
13.060.30 Odpadna voda Sewage water
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2021
ICS 13.060.30 Will supersede 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 draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 165.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12255-9:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 8
5 Design principles . 8
5.1 General. 8
5.2 Sources and nature of odours . 9
5.3 Odour measurement . 10
5.4 Planning . 11
5.4.1 Preliminary considerations . 11
5.4.2 Detailed planning . 12
5.4.3 Criteria for selection . 13
5.5 Design requirements . 14
5.5.1 General. 14
5.5.2 Materials selection . 14
5.5.3 Chemical or biological addition . 14
5.5.4 Treatment of odorous air . 15
5.5.5 Design of covers . 18
5.5.6 Design of ventilation plant . 19
5.6 Process requirements . 19
5.7 Maintenance and Operation. 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 (prEN 12255-9:2021) has been prepared by Technical Committee CEN/TC 165 “Waste
water engineering”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 12255-9:2002.
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. EN 12255 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.
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 below:
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 may 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.
prEN 12255-14:2021, Wastewater treatment plants — Part 14: Disinfection
EN 16323, Glossary of wastewater engineering terms
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 terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
olfactometry
measurement of the response of assessors to olfactory stimuli
Note 1 to entry: See EN 13725 for details.
[SOURCE: EN 16323:2014-07, term 2.1.3.2]
3.2
odour concentration
number of European Odour Units in a cubic metre of gas at standard conditions
EXAMPLE If a sample has 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.
[SOURCE: EN 13725]
3.3
odorant flow rate; odour emission rate
quantity of odorous substances passing through a defined area per unit time
Note 1 to entry: The odorant flow rate has the symbol q . It is the product of the odour concentration c , the outlet
od od
velocity v and the outlet area A or the product of the odour concentration cod and the pertinent volume flow rate V .
Its unit can be expressed as ouE/h, ouE/min or ouE/s.
Note 2 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 13725:2003-07, term 3.1.42]
3.4
volatile organic compound
VOC
organic compound with an initial boiling point less than or equal to 250 °C measured at a standard
pressure of 101,3 kPa
[SOURCE: EU Directive 2004/42/CE]
3.5
capital expenditure
CAPEX
money used to purchase and install and commission a capital asset
[SOURCE: ISO 15663-1:2000, term 2.1.6]
3.6
operational expenditure
OPEX
recurrent expenditure required to provide a service or product
[SOURCE: ISO/TS 55010:2019, term 3.9]
3.7
empty bed residence time
EBRT
total time air is retained in a considered unit in average conditions
3 3
Note 1 to entry: The EBRT is calculated as V/Q, where V (m ) is the total internal volume of the unit and Q (m /s)
is the air flow rate. The EBRT calculation assumes that the unit is empty, regardless the presence of packings or
other solid elements.
3.8
specific ozone demand
required ozone concentration in the odours air (g O /m or g O /l) to achieve a level of odour reduction
3 3
3.9
contact tank
tank for providing the required retention time for certain reactions to take place
[SOURCE: Modified from EN 16323:2014, term 2.3.9.4, to extend to use with gases]
3.10
advanced oxidation process
AOP
chemical process generating hydroxyl or oxygen radicals
3.11
UV efficiency (UV-C radiation conversion efficiency)
ability of a UV-C lamp to convert electrical power into UV-C radiation
Note 1 to entry: The ratio is the UV-C radiation power accounting for the electrical power of the UV-C lamp. The
UV-C conversion efficiency of a low pressure UV-C lamp at 253,7 nm is between 25 % and 45 %. The UV-C
conversion efficiency should not be less than 30 % in an air disinfection field under all circumstances due to energy
consumption of the system.
Note 2 to entry: The measurements of the output shall be performed by the manufacturer in accordance to
ISO 15727.
[SOURCE: ISO 15727:2020, term 3.6]
3.12
UV radiation demand
sum of the UV output (W)
...