EN 12255-9:2002

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.UDþHYDQMHKläranlagen - Teil 9: Geruchsminderung und BelüftungStations d'épuration - Partie 9: Maîtrise des odeurs et ventilationWastewater treatment plants - Part 9: Odour control and ventilation13.060.30Odpadna vodaSewage waterICS:Ta slovenski standard je istoveten z:EN 12255-9:2002SIST EN 12255-9:2002en01-december-2002SIST EN 12255-9:2002SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12255-9January 2002ICS 13.060.30English versionWastewater treatment plants - Part 9: Odour control andventilationStations d'épuration - Partie 9: Maîtrise des odeurs etventilationKläranlagen - Teil 9: Geruchsminderung und BelüftungThis European Standard was approved by CEN on 20 December 2001.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the 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 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12255-9:2002 ESIST EN 12255-9:2002

Odour potential and odour emission capacity, measurement of odour emissionrate.14A.1Odour Potential and Odour Emission Capacity.14Bibliography.16SIST EN 12255-9:2002

1) In preparation.SIST EN 12255-9:2002

— Vocabulary.3 Terms and definitionsFor the purposes of this European Standard, the terms and definitions given in EN 1085 and the following apply.3.1olfactometrymeasurement of the response of assessors to olfactory stimuli (see ISO 5492). Definition according to prEN 137253.2odour concentrationthe number of European Odour Units in a cubic metre of gas at standard conditions. The odour concentration hasthe symbol cod and the unit ouE/m3 (see prEN 13725)NOTE
The value of the odour concentration is the dilution factor that is necessary to reach the detection threshold. At thedetection threshold, the odour concentration of the mixture is 1 ouE/m³ by definition.EXAMPLE
If a sample has to be diluted by a factor of 300 to reach the detection threshold, the odour concentration of thesample is cOD = 300 ouE/m3.SIST EN 12255-9:2002

Diffuse sources such as unaerated wastewater or sludge surfaces, do not have a defined waste air flow, although theycan emit odorants. In these cases, a special sampling procedure is necessary which is discussed in prEN 13725 (see annex A).Odorant flow rates can be used in an analogous fashion to mass flow rates when modelling the impact from asource. All odour sources will have an odorant flow rate, even where no air flow rate is easily identifiable.4 Design principles4.1 GeneralGiven the nature of wastewater it is not possible to guarantee that a wastewater treatment plant will be totally odourfree. A well-designed plant minimises the potential for odour problems.The potential for odour generation shall be considered at the earliest stages in the design of wastewater treatmentworks. The likelihood of odour emission, its impact and ease of treatment shall be considered in all aspects ofdesign, especially:a) Minimise the septicity of the raw wastewater by considering the sewerage system.b) Process selection – e.g. if septic wastewater is anticipated, possibilities to minimise odour are for example: minimise the retention time of the sludge in the primary settlement tank; having no primary settlement (thus avoiding a major source of odour) and applying extended aeration; select a covered process.c) By locating the major sources of odour, wherever possible, away from the most sensitive locations surroundingthe plant. For planning the direction and speed of winds local to the installation shall be taken into account.NOTE
Situations with light wind or no wind and stable atmospheric conditions are most unfavourable for the dispersion ofodours. Thus, if these situations happen very often, then the local wind direction during these situations is relevant instead ofthe generally prevailing wind direction.d) By considering the location of unit processes relative to each other it may be possible to use a single abate-ment process to treat more than one source of odour or to use the odorous air from one process as process orcombustion air in an adjacent process. Any decision to treat odorous air will require a process to be coveredand ventilated with the vented air ducted to treatment. Covering, venting and treatment shall be designed asan integrated package.Where treatment plants are not covered or housed in buildings and the effect of odour is difficult to quantify prior tocommissioning designs should allow for covering and/or ventilation at a later date.When tanks or processes are covered careful consideration is required of:a) explosion risk;b) corrosion prevention;c) health and safety of operators;SIST EN 12255-9:2002
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