1、BRITISH STANDARD BS EN 12255-8:2001 Incorporating Corrigendum No. 1 Wastewater treatment plants Part 8: Sludge treatment and storage The European Standard EN 12255-8:2001 has the status of a British Standard ICS 13.060.30 BS EN 12255-8:2001 This British Standard, having been prepared under the direc
2、tion of the Sector Committee for Building and Civil Engineering, was published under the authority of the Standards Committee and comes into effect on 15 July 2001 BSI 13 December 2004 ISBN 0 580 37451 3 National foreword This British Standard is the official English language version of EN 12255-8:2
3、001. The UK participation in its preparation was entrusted to Technical Committee B/505, Wastewater engineering, which has the responsibility to: National annex NA provides further guidance on design and loading data for use in the UK. A list of organizations represented on this committee can be obt
4、ained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility
5、 of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. a
6、id enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document c
7、omprises a front cover, an inside front cover, the EN title page, pages 2 to 16, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments 15294 Corrigendum No. 1 13
8、 December 2004 Addition of National annex NAEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12255-8 May 2001 ICS 13.060.30 English version Wastewater treatment plants Part 8: Sludge treatment and storage Stations dpuration Partie 8: Stockage et traitement des boues Klranlagen Teil 8: Schlammbeh
9、andlung und -lagerung This European Standard was approved by CEN on 8 March 2001. 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
10、bibliographical references concerning such national standards 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 translation under the responsibility
11、 of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, N
12、orway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CEN All rights of exploitation in any form and by any means reserved worldw
13、ide for CEN national Members. Ref. No. EN 12255-8:2001 EContents Page Foreword. 3 1 Scope. 3 2 Normative references. 4 3 Terms and definitions 4 4 Planning 4 5 Process requirements 5 5.1 General 5 5.2 Thickening. 5 5.3 Disinfection 6 5.4 Stabilization and pseudo stabilization . 7 5.5 Sludge dewateri
14、ng. 10 5.6 Composting . 11 5.7 Handling and storage 12 6 Construction principles . 12 6.1 Service life. 12 6.2 Pipelines 13 6.3 Sludge pumps . 13 7 Safety. 13 Bibliography 14 Page2 EN122558:2001Foreword This European Standard has been prepared by Technical Committee CEN/TC 165, Waste water engineeri
15、ng, 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 November 2001, and conflicting national standards shall be withdrawn at the latest by December 2001. It
16、 is the eighth part prepared by the Working Groups CEN/TC 165/WG 42 and WG 43 relating to the general requirements and processes for treatment plants for over 50 PT. The parts of the series are as follows: Part 1: General construction principles; Part 3: Preliminary treatment; Part 4: Primary settle
17、ment; 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 1) ; Part 13: Chemic
18、al treatment; Part 14: Disinfection 1) ; Part 15: Measurement of the oxygen transfer in clean water in aeration tanks of activated sludge plants; Part 16: Physical (mechanical) filtration 1) . NOTE For requirements on pumping installations at wastewater treatment plants, provided initially as Part 2
19、: Pumping installations for wastewater treatment plants, see EN 752-6, Drain and sewer systems outside buildings Part 6: Pumping installations. The parts EN 12255-1, EN 12255-3 to EN 12255-8 and EN 12255-10 and EN 12255-11 became implemented together as a European package (Resolution BT 152/1998). T
20、he date of withdrawal (dow) of all conflicting national standards is 2001-12-31. Until the date of withdrawal is reached, the national and the already published European standards both coexist. This standard includes a Bibliography. According to the CEN/CENELEC Internal Regulations, the national sta
21、ndards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 1 Scope T
22、his European Standard gives design principles and specifies construction requirements for sludge treatment and storage facilities in wastewater treatment plants for more than 50 PT. Other sludges and organic wastes may be treated together with the municipal sewage sludge. Differences in wastewater t
23、reatment 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 referri
24、ng to the bibliography.1) In preparation. Page3 EN122558:20012 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereaf
25、ter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 1085, Waste
26、water treatment Vocabulary. EN 12176, Characterization of sludge Determination of pH-value. prEN 12255-1:1996, Wastewater treatment plants Part 1: General construction principles. prEN 12255-4:1997, Wastewater treatment plants Part 4: Primary settlement. EN 12255-5, Wastewater treatment plants Part
27、5: Lagooning processes. prEN 12255-6:1997, Wastewater treatment plants Part 6: Activated sludge processes. prEN 12255-9:1999, Wastewater treatment plants Part 9: Odour control and ventilation. EN 12255-10, Wastewater treatment plants Part 10: Safety principles for the construction of wastewater trea
28、tment plants. EN 12880, Characterization of sludges Determination of dry residue and water content. EN ISO 5667-13, Water quality Sampling Part 13: Guidance on sampling of sludges from sewage and water treatment works (ISO 5667-13:1997). 3 Terms and definitions For the purposes of this European Stan
29、dard the terms and definitions given in EN 1085 and the following apply. 3.1 psychrophilic process conditions for organisms which are active below 30 C 3.2 mesophilic process conditions for organisms which are active at temperatures between 30 C and 45 C, with an optimum of 32 C to 37 C 3.3 thermoph
30、ilic process conditions for organisms which are active at temperatures between 45 C and 80 C, and have an optimum of 55 C to 65 C 3.4 pseudo stabilization process which prevents organic degradation so long as particular conditions (such as pH value or dryness) are maintained, but for which degradati
31、on recommences when the conditions are no longer met 4 Planning Sludge treatment and storage influences subsequent utilization. It may be subject to a variety of regulations dependent upon the site of the treatment plant and the proposed routes for use or disposal. For new works or major upgrading,
32、an environmental impact assessment should be carried out. The choice of the sludge treatment process depends on the size of the treatment plant, the type, origin and characteristics of the sludge to be treated and the final method of utilization or disposal. Processes which allow for more than one s
33、ludge utilization or disposal option are preferable. Page4 EN122558:2001Consideration should be given to the possibility of centralized sludge treatment facilities which allow a wider range of treatment techniques. Special care is needed in respect of extra loads, e.g. of nitrogen generated from slu
34、dge liquors at centralized facilities. Sufficient storage capacity shall be available on the source site for raw or treated sludge to prevent sludge overflow under all likely conditions. The following factors shall be considered in planning sludge treatment: the utilization or disposal route and rel
35、ated quality requirements, e.g. nutrients, harmful substances and calorific value; sludge characteristics; import of sludges and other organic wastes; minimum and maximum daily sludge production (volume and mass); future sludge production; range of solids concentrations (total and volatile solids);
36、physical characteristics (viscosity, temperature); biological properties (degradability, inhibitors and toxicants); aggressive or corrosive conditions; likely emissions including greenhouse gases, and odours (see also prEN 12255-9:1999); removal or disintegration of gross solids which may cause bloc
37、kage or malfunction; effect of abrasive or deposit forming solids such as grit; effect of additives used in wastewater treatment, such as precipitants, coagulants and flocculants and their influence on utilization; impact of return liquors on the wastewater treatment process, e.g. peak loads of ammo
38、nia and phosphorus resolubilization from sludge processing; health and safety of operators and the general public (see also EN 12255-10), e.g. the generation of toxic and/or explosive atmospheres; nuisance, e.g. smell and visual intrusion; environment, e.g. effect of leakage. 5 Process requirements
39、5.1 General Provision shall be made to allow the sampling of input and output for each unit process (see EN ISO 5667-13). Flow measurement for each unit process should be considered. The design shall take account of any requirements for control of odour, noise, vibration and explosive atmospheres in
40、 accordance with prEN 12255-9:1999 and EN 12255-10. 5.2 Thickening 5.2.1 General Sludge thickening is carried out in a continuous or batch mode of operation, using gravity thickeners, mechanical thickening equipment such as filters or centrifuges, or dissolved air flotation. The selection of the thi
41、ckening method and its design shall take account of the following factors: the sludge solids concentration required by subsequent processes; the solids recovery from the process; resolubilization of phosphorus in gravity thickeners; retention times, which when exceeding one day can result in anaerob
42、ic degradation, causing odour emission, foaming, bulking and impaired dewaterability; control of the sludge feed and liquor removal rates; the storage and controlled return of sludge liquor where nitrification or nitrogen removal is required. Due to enhanced viscosity, positive displacement pumps sh
43、ould be used for transferring the thickened sludge. A programme of sludge testing and analysis shall be considered where practicable to assist in the design of gravity thickeners. Page5 EN122558:20015.2.2 Gravity thickening Gravity thickeners should have a depth of at least 3 m, have a bottom slope
44、of at least 50 (conical) or 60 (pyramidal) to the horizontal or be equipped with either an agitator or a rake which includes a bottom scraper (e.g. picket fence). Other features which shall be considered include: retention and removal of scum; supernatant withdrawal at different levels (e.g. using a
45、 vertically moveable device); observing the quality of the supernatant liquor during removal; ventilation and exhaust air deodorization if thickeners are covered. Factors which affect the design of gravity thickeners include: the surface loading rate; the mass surface loading rate; the solids detent
46、ion time; the total depth of the consolidation zone. 5.2.3 Mechanical thickening Where thickening equipment is similar to that used for mechanical dewatering, the relevant construction principles apply. The most common machines for mechanical thickening are: drum filters; belt filters; centrifuges.
47、Mechanical sludge thickening equipment should: normally operate automatically with the facility for manual override; include all equipment required for storage, preparation and dosage of any necessary flocculant; be enclosed or located in adequately ventilated rooms to reduce corrosion and for the h
48、ealth and safety of the operator. The requirements and guidelines for mechanical sludge dewatering equipment in 5.5.2 are also appropriate to mechanical sludge thickening. 5.2.4 Air flotation Waste activated sludge or backwash water from biofilters can be thickened by dissolved air flotation with or
49、 without chemical flocculation. Dimensioning of a dissolved air flotation unit shall take account of the following: the surface loading rate; the mass surface loading rate; the air/solids ratio. 5.3 Disinfection Sludge disinfection may be achieved chemically (see 5.4.4) or thermally. Processes which can achieve disinfection include: thermophilic aerobic digestion; th
