SIST EN 12255-7:2002
(Main)Wastewater treatment plants - Part 7: Biological fixed-film reactors
Wastewater treatment plants - Part 7: Biological fixed-film reactors
This European Standard specifies the design principles and performance requirements for secondary treatment by biological fixed-film reactors at wastewater treatment plants for more than 50 PT.
The primary application is for wastewater treatment plants designed for the treatment of domestic and municipal wastewater.
Biological fixed film reactors include biological trickling filters, rotating biological contactors, submerged bed reactors and biofilters.
Differences in wastewater treatment throughout Europe have led to a variety of systems being developed. This standard gives fundamental informations about the systems; this standard has not attempted to specify all available systems.
Detailed information additional to that contained in this standard may be obtained by referring to the Bibliography.
Kläranlagen - Teil 7: Biofilmreaktoren
Diese Europäische Norm legt Grundsätze der Planung und Anforderungen an Biofilmre-aktoren als zweiten (biologischen) Reinigungsteil von Kläranlagen über 50 EW fest.
Die Anwendung bezieht sich in erster Linie auf Kläranlagen, die zum Reinigen von häuslichem und kommunalem Abwasser geplant werden.
Biofilmreaktoren umfassen Tropfkörper, Rotationstauchkörper, Biofilmreaktoren mit getauchtem Trägermaterial und biologische Filter.
Die Unterschiede in Planung und Bau von Kläranlagen in Europa haben zu einer Vielzahl von Anlagenausführungen geführt. Diese Europäische Norm enthält grundsätzliche Angaben zu den Anlagenausführungen; sie beschreibt jedoch nicht alle Einzelheiten jeder Ausführungsart.
Die in den Literaturhinweisen aufgeführten Unterlagen enthalten Einzelheiten und Hinweise, die im Rahmen dieser Norm verwendet werden dürfen.
Stations d'épuration - Partie 7: Réacteurs biologiques a cultures fixées
La présente Norme européenne spécifie les principes d'étude et les prescriptions de performances applicables au traitement secondaire des eaux usées par réacteurs biologiques a cultures fixées dans des stations d'épuration pour plus de 50 EH.
La principale application concerne les stations d'épuration conçues pour traiter des eaux usées domestiques et municipales.
Le terme réacteurs biologiques a cultures fixées recouvre les lits bactériens, les disques et tambours biologiques, les réacteurs a lit immergé et les biofiltres.
Des différences en matiere de traitement des eaux usées résiduaires a travers l'Europe ont conduit au développement de systemes variés. La présente norme donne les informations de base sur les systemes et n' a pas eu pour objectif d'essayer de spécifier tous les systemes disponibles.
Des informations détaillées, complémentaires a celles contenues par la présente norme, peuvent etre obtenues en se reportant a la bibliographie.
Čistilne naprave za odpadno vodo – 7. del: Biološki reaktorji s pritrjeno biomaso
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kläranlagen - Teil 7: BiofilmreaktorenStations d'épuration - Partie 7: Réacteurs biologiques a cultures fixéesWastewater treatment plants - Part 7: Biological fixed-film reactors13.060.30Odpadna vodaSewage waterICS:Ta slovenski standard je istoveten z:EN 12255-7:2002SIST EN 12255-7:2002en01-december-2002SIST EN 12255-7:2002SLOVENSKI
STANDARD
SIST EN 12255-7:2002
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12255-7January 2002ICS 13.060.30English versionWastewater treatment plants - Part 7: Biological fixed-filmreactorsStations d'épuration - Partie 7: Réacteurs biologiques àcultures fixéesKläranlagen - Teil 7: BiofilmreaktorenThis European Standard was approved by CEN on 9 November 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 12255-7:2002 ESIST EN 12255-7:2002
EN 12255-7:2002 (E)2ContentspageForeword.31Scope.52Normative references.53Terms and definitions.54Requirements.64.1General.64.1.1Biological fixed film processes.64.1.2Trickling filters.64.1.3Rotating biological contactors.64.1.4Submerged bed reactors and biofilters.74.2Planning.74.3Process.74.3.1Design.74.3.2Modes of operation.84.3.3Selection of support media.84.3.4Dimensions.94.3.5Flow distribution.104.3.6Oxygen supply.104.3.7Clarification and solid separation.114.3.8Additional considerations.114.4Detailed design.114.4.1Structures.114.4.2Mechanical and electrical equipment.12Bibliography.14SIST EN 12255-7:2002
EN 12255-7:2002 (E)3ForewordThis European Standard has been prepared by Technical Committee CEN/TC 165 "Wastewater engineering", thesecretariat 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 orby endorsement, at the latest by July 2002, and conflicting national standards shall be withdrawn at the latest byDecember 2002.It is the seventh part prepared by the Working Groups CEN/TC 165/WG 42 and 43 relating to the generalrequirements and processes for treatment plants for a total number of inhabitants and population equivalents (PT)over 50. The Parts of the series are as follows: Part 1: General construction principles Part 3: Preliminary treatment Part 4: Primary settlement Part 5: Lagooning processes Part 6: Activated sludge processes 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) filtration1)NOTEFor requirements on pumping installations at wastewater treatment plants, provided initially as part 2 "Pumpinginstallations for wastewater treatment plants", see EN 752-6 "Drain and sewer systems outside buildings — Part 6: Pumpinginstallations”.The parts EN 12255-1, EN 12255-3 to EN 12255-8 and EN 12255-10 and EN 12255-11 were implementedtogether as a European package (Resolution BT 152/1998).
1) In preparation.SIST EN 12255-7:2002
EN 12255-7:2002 (E)4According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,Sweden, Switzerland and the United Kingdom.SIST EN 12255-7:2002
EN 12255-7:2002 (E)51 ScopeThis European Standard specifies the design principles and performance requirements for secondary treatment bybiological fixed-film reactors at wastewater treatment plants for more than 50 PT.The primary application is for wastewater treatment plants designed for the treatment of domestic and municipalwastewater.Biological fixed film reactors include biological trickling filters, rotating biological contactors, submerged bedreactors and biofilters.Differences in wastewater treatment throughout Europe have led to a variety of systems being developed. Thisstandard gives fundamental informations about the systems; this standard has not attempted to specify all availablesystems.Detailed information additional to that contained in this standard may be obtained by referring to the Bibliography.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN 752-6, Drain and sewer systems outside buildings — Part 6: Pumping installations.EN 1085, Wastewater treatment — Vocabulary.EN 12255-1, Wastewater treatment plants — Part 1: General construction principles.EN 12255-6, Wastewater treatment plants — Part 6: Activated sludge processes.EN 12255-10, Wastewater treatment plants — Part 10: Safety principles.EN 12255-11, Wastewater treatment plants — Part 11: General data required.3 Terms and definitionsFor the purposes of this European Standard, the terms and definitions given in EN 1085 and the following apply.3.1wastewater dosevolume of wastewater discharged on to a trickling filter from a single pumping cycle or a single siphoning from afilter dosing chamber3.2flushing intensitysurface hydraulic loading rate divided by the number of arms of a rotary distributor and divided by the number ofrevolutions per hourNOTEThis value gives information on the hydraulic forces to wash excess sludge out of the bed.3.3submerged bed reactorbed of packed or suspended inert media which is typically open structure plastic and is submerged in the flow toallow the active biological film attached to the media to purify the wastewaterSIST EN 12255-7:2002
EN 12255-7:2002 (E)6NOTEA clarifier can be required.4 Requirements4.1 General4.1.1Biological fixed film processesBiological fixed film processes may include: trickling filters; rotating biological contactors; submerged bed reactors; biofilters.Biological fixed-film processes can treat the following types of influent: primary treated wastewater; finely-screened or sieved wastewater; effluent from secondary treatment.These are processes in which support media is used to support growth of a film of microorganisms which flocculateand biodegrade soluble, colloidal and suspended matter in wastewater.The processes can operate under aerobic and/or anoxic or anaerobic conditions and provide intimate contactbetween influent and the biological film. Solids present in treated effluent should be removed before final discharge.In the case of biofilters the solids are retained within the reactors.4.1.2Trickling filtersIn trickling filters, wastewater is distributed over and percolates down through a bed of support media, contactingthe biological film growing on the surface of elements of the media. The bed shall contain continuous open spacesbetween elements of support media to promote natural or induced ventilation. Operating conditions on the bedshall support the growth of larger organisms such as protozoa and macro-invertebrates, often termed ‘grazingorganisms', to control the growth of biological film and reduce surplus sludge. Humus tanks should be used toclarify wastewater discharged from the filter.4.1.3Rotating biological contactorsA rotating biological contactor consists of discs or packs of support media, which are arranged along a shaft andare partially immersed in wastewater.The shaft rotates, enabling biological film, which grows on the support media, to alternately contact wastewater andair and bring about treatment. Performance can be improved by adopting the principle of a plug flow system.Rotating biological contactors may be supplied either as stand-alone biological treatment units or as packageplants, incorporating primary and secondary settlement zones. Plant shall be designed to ensure that sludge flowsto points that provide practical access for its removal.SIST EN 12255-7:2002
EN 12255-7:2002 (E)74.1.4Submerged bed reactors and biofiltersIn these reactors, wastewater flow should be uniformly distributed through a submerged bed of support media. Airutilised for aeration should be supplied by a blower and distributed from pipework. The design of the aerationsystems should distribute the air evenly over the fixed bed.Denitrifying submerged bed reactors shall have a system for controlling deposits of sludge accumulating on thebottom or inside the bed of media.In submerged bed reactors using an open structure media backwashing is not required, as the excess sludge isremoved by aeration. Backwashing is typically required if media of a granular type is used.Carbonaceous oxidation, nitrification and denitrification can be carried out in single or separate stages ofbiofiltration as well as achieving suspended solids removal.Biofilters may be designed for upward or downward flow of wastewater. They may be required to be taken out ofservice for backwashing or may operate continuously with a separate washing system. The media may be single ormulti-layer and can have a specific gravity greater or lower than that of water.4.2 PlanningThe following factors shall be considered in the design: characteristics of incoming wastewater; the capacity and dimensions of the biological reactors; the prevention of dead zones and detrimental deposition in tanks/channels; the establishment of multiple lines/units or other technical means to ensure maintenance of required finaleffluent quality if one or more line/unit is out of operation; the surface area, volume and depth of the clarifiers where used; the treatment and final destination of the sludge produced; the head loss to be minimised; measurement and control; media specification.Reference should be made to EN 12255-1, EN 12255-6, EN 12255-10 and EN 12255-11 for further considerations.4.3 Process4.3.1 DesignThe following operational parameters shall be considered and shall be appropriate for the type of treatmentrequired: volumetric loading rate [kg/(m3 ·d)] (as BOD5, COD, NH4-N or NO3-N); mass surface loading rate [kg/( m2·d)] (as BOD5, COD, NH4-N or NO3-N); support media specific surface [m2/ m3]; recirculation ratio;SIST EN 12255-7:2002
EN 12255-7:2002 (E)8 surface loading rate [m3/( m2· h)]; flushing intensity [mm], interval between backwashing (biofilters).NOTE The references in the Bibliography give further information.4.3.2 Modes of operationThe plant may be configured in one of the following modes: single stage treatment in which the wastewater passes through only one reactor followed by clarification; two stage treatment in which the wastewater passes through two reactors in series and which can includeclarification after both stages or only after the second stage;NOTE Biofilters do not require intermediate or final clarification. alternating double filtration in which the sequence of flow through trickling filters is alternated so that each setof filters treat in successive periods either settled wastewater or effluent from the first stage. This limitsexcessive growths of biological film, which might otherwise develop in the upper layers of the first stagetrickling filter when treating a high strength wastewater.The types of treatment that may be provided are as follows: carbonaceous oxidation; nitrification, which occurs after carbonaceous removal and is achieved by operating plant either at a lowerloading rate or using a separate stage; denitrification, which is typically established in a two stage step system, where the first stage step is used fordenitrification and the second stage for BOD removal and nitrification. These flow schemes need a recycle ofnitrified wastewater from the effluent of the second step to the influent of the first step. Simultaneousnitrification and denitrification in a one step system requires a specific design and operation of the aeration. Toachieve downstream denitrification a supplementary carbon source will be req
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