1、- STD-BSI BS EN LB99-L-ENGL 1778 lb24bb9 0737793 72q BRITISH STANDARD Water quality - Determination of biochemical oxygen demand after n days Part 1: Dilution and seeding method with allyl thiour e a addition The European Standard EN 1889-1:1998 has the status of a British Standard ICs 13.060.01; 13
2、.060.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 1899-1: 1998 BS 6068-2.63: 1998 STD*BSI BS EN 1877-L-ENGL 1978 Lb24bb7 0737772 bbD Amd. No. Date BS EN 1899-1:1998 Text affected National foreword This British Standard is the English language version of EN 1899-1:1
3、998. It supersedes BS 6068-2.141990 which is withdrawn. The UK participation in its preparation was enirusted by Technical Committee Em, Water quality, to Subcommittee EH/3/2, Physical, chemical and biochemical methods, which has the responsibility to: - - aid enquirers to understand the text; prese
4、nt 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. - A list of organizations represented on this subcommittee can be obtained
5、on request to its secretary. BS EN 1899-1 is one of a series of standards on water quality, others of which have been, or will be, published as Sections of BS 6068. This standard has therefore been given the secondary identifier BS 60682.63. The various Sections of BS 6068 are comprised within Parts
6、 1 to 7, which, together with Part O, are listed below. Part o Part 1 Part 2 Part 3 Part 4 Part 5 Part 6 Part 7 Introduction Giossaw Physfcal, chemical and biochemical mwds adiobgical methods Microbiological methods Biological methods Sampling Precision and accuracy NOTE The tests described in this
7、British Standard should only be carries out by suitably qualified persons with an appropriate level of chemical expertize. Standard chemical procedures should be followed houghout Further information Users of this standard are informed that the UK submitted a vote of disapproval on the nal voing sta
8、ge of the draft EN for the following reasons. - Although we are in general technical agreement with the basis of the dra we are stili submitting a negative vote as this standard contains two methods. We therefore consider that it should be published as two separate standards, i.e a 5 day one and a 7
9、 day one. This would thereby avoid any possible confusion when quoting the standard or reporting the results of analysis. -We also strongly recommend deletion of the reference to IS0 58151989 in the title as it serves no purpose and could be misleading. The IS0 standard is for 5 days only and it is
10、thus wrong to claim in the Foreword that it has been approved with common modifications with no reference to the major change in test conditions. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standar
11、ds Catalogue under the section entitled Intemaional Standards Correspondence Index, or by using the Find facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their
12、correct applicaon. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, page 1 to 12, an inside back cover and a back cover. O BSI 1998 ISBN O 680 29680 6 EUROPEAN STANDARD NOW EUR
13、OPm EUROPmHE NOFM EN 1899-1 March 1998 ICs 13.060.01 Descriptors: water tests, water, chemical analysis, determination of content, biochemical oxygen demand, dilution English version W it is equal to 5 or 7 NOTE This denition is similar to the definition of IS0 6107-2. For the purpose of this Europe
14、an Standard, “biochemical oxidation“ is taken to mean “biological oxidation“ (BODn) 4 Principle Pre-treatment of the sample of water to be analysed and dilution with varying amounts of a dilution water rich in dissolved oxygen and containing a seed of aerobic microorganisms, with suppression of nitr
15、ification. Incubation at 20 OC for a defined period, 5 or 7 days, in the dark, in a completely Wed and stoppered bottle. Determination of the dissolved oxygen concentsation before and after incubation. Calculation of the mass of oxygen consumed per litre of sample. 6 Reagents 6.1 Geneml Throughout t
16、he text, use only reagents of recognized analytical quality. 6.2 Water Use only grade 3 water (i accordance with EN IS0 3696). However, the water shall not contain more than 0,Ol mg/l of copper, nor chlorine or chloramines. 6.3 Seeding water If the test sample does not contain, by itself, sufcient a
17、dapted microorganisms, seeding water, obtained in one of the following ways, shall be used a) Urban waste water of maximum COD (chemical oxygen demand measured in accordance with IS0 6060) 300 mg4 or TOC (total organic carbon measured in accordance with IS0 8245) 100 mgIl, collected from a main sewe
18、r or from a sewer of a residential zone he nom significant industxiai contamination. Decant or filter the water through a coarse filter, b) River or lake water containing urban waste wateq c) Setted effluent from a waste water treatment Plant; d) Water taken downstream from the discharge of the wate
19、r to be analysed or water containing microorganisms adapted to the water to be analysed and cultivated in the laboratory (i the case of industxial effluents containing substances which degrade with diffculty); e) Commercially available seeding material. 6.4 Salt solutions 6.4.1 General The following
20、 solutions are stable for 6 months and shall be stored in giass bottles at O OC to 4 OC in the dark They shall be discarded at the rst sign of precipitation or biological growth. 6.4.2 Phosphate, hflr solution, pH 7,2 Dissolve 8,5 g of potassium dihydrogen phosphate H2PO4), 21,75 g of dipotassium hy
21、drogen phosphate (xZHP04), 33,4 g of disodium hydrogen phosphate heptahydrate (Na2HPO47H20) and 1,7 g of ammonium chloride J aerate for at least 1 h ushg a suitable equipment. Take every precaution not to contaminate it (see 6.7), in particular by the addition of organic matter, metals, oxidinng or
22、reducing substances, to ensure that the dissolved oxygen concentration is at least 8 mg/l. The water shall not be supeisaturated with oxygen - let it stand 1 h in an unstoppered container before use. Use this solution within 24 h of preparation and discard any remaining solution, unless laboratory e
23、xperience andlor the control values show that the water is acceptable for a longer time period 6.6 Seeded dution water Add, according to its source, 5 mi to 20 ml of the seeding water (see 6.3) per litre of dilution water (see 6.6). Store the seeded dilution water thus obtained at about 20 OC. Prepa
24、re immediately before use and discard any remaining solution at the end of the working day, unless the laboratory experience and/or the control values (see 8.6) show that the seeded dilution water is acceptable for a longer time period. The oxygen consumed over n days, at 20 OC of the seeded dilutio
25、n water, which is the blank value (see 8.3), shall not exceed 1,5 mgA of oxygen. O BSI 1998 STD.BSI BS EN 1879-L-ENGL 1998 M 1b24bb7 0737797 342 D * * VI 5.7 Hydrochloric acid (Ha) or dfuric acid, (HBO4), solution, c(H2SO4) = 0,25 mom, c(HC1) = 0,50 moM, or as appropriate. 6.8 Sodium hydrox+.de (NaO
26、H), solution Approximately 20 g/i or as appropriate. 6.9 Sodium sulfite (Na$30$, solution Approximately 50 g/i or as appropriate. 6.10 Glucose-glutamic acid, conCr01 solution Dry some anhydrous D-glucose (Ca12O6) and some Lglutamic acid (C5HgN04) at (105 f 5) OC for 1 h. Weigh (150 f 1) mg of each,
27、dissolve in water, dilute to 1 o00 ml and mix. The theoretical oxygen demand of this solution is 307 mg/i oxygen (the empirical BOD5 is (210 f 20) mg4 of oxygen and the BOD7 is (225 f 20) mg/l of oxygen). Prepare the solution immediately before use and discard any remaining solution at the end of th
28、e working day. The solution may also be frozen in small amounts. The thawed solution shal be used immediately after thawing. 6.11 AUylthioureu (m), soluton, 1,OgR Dissolve 200 mg of allylthiourea (C4HsN2S) in water, dilute to 200 ml and mix. Store the solution at 4 OC. The solution is stable for at
29、least two weeks. This compound is toxic and should therefore be handed with care. 6 Apparatus 6.1 Geneml The glassware used shall be clean, i.e. free of adsorbed toxic or biodegradable compounds, and shall be protected from contaminati on. 6.2 Idath bottles, BOD bottles, with stoppers, for example p
30、referably 250 mi to 300 ml or 100 mi to 125 mi with stoppers and preferably with straight shoulders, or any equivalent bottles. It is important that the bottles are thoroughly cleaned before use. If the iodometric method (EN 25813) for determining dissolved oxygen is used, it is for example normally
31、 sufficient to rinse the bottle severai times with tap water then deionized water. If the electrode method EN 25814 is used, a more stringent cleaning procedure, for example, as follows, is required. Add to the empty bottle 5 ml to 10 mi of a wash solution (for example 2,5 g of iodine plus 12,5 g of
32、 potassium iodide per litre of 1 % (VIV) sulfuric acid shalung well to coat the bottle walls. Let stand for 15 min, pour off the solution and rinse thoroughly with tap water and finally deionized water. 6.3 Dilution water vessel, glass or plastics. Measures shall be taken to ensure the vessel is kep
33、t clean and free from microorganism growths. Check that plastic vessels do not cause elevated blank values (see 8.3). Page 5 EN 1899-1:1998 6.4 Idator, capable of being maintained at 6.5 Equipment for determining dissolved oxygen concentmth, in accordance with EN 25813 or EN 25814. 6.6 Means of wfig
34、wation, (O to 4) OC, for transport and storage of the sample. 6.7 Dilution vessel, a stoppered glass flask of a capacity dependent on the volume of the diluted sample used with graduation of between 2,5 mi and 10 ml or any appropriate vessel allowing for dilution. 6.8 Aeration equipment, a bottle of
35、 compressed air or a compressor. The air quality shali be such that the aeration does not lead to any contamhation, especiaiy by the addition of organic matter, oxidizing of reducing materials, or metals. If a contamhation is suspected, the air shall be filtered and washed. (20 I 1) OC 7 Storage of
36、the sample Store the sample at a temperature (O to 4) OC in a fiiled and hermetically stoppered bottle immediately after sample collection and until the analysis is performed Begin the determination of the BOD, as soon as possible and within 24 h of completion of sample collection. Regardmg freezing
37、 of samples, see special cases in clause 11. Ensure that the sample bottles do not give rise to elevated blank values. 8 Procedure 8.1 Pretreatment 8.1.1 Neutralization of sample If the pH of the sample after dilution is not between 6 and 8, neutralize it after hawig performed any necessary predilut
38、ion and after hawig detemiined by a separate test the volume of hydrochloric acid solution (6.7) or of sodium hydroxide solution (5.8) necessary to be added. Ignore any precipitate which is formed 8.1.2 Presence of free and/or combined chlorine Remove any free and combined chlorine in the sample by
39、adding the required volume of sodium sulfite solution (5.9). Take care to avoid adding an excess. NOTE For free and combined chlorine see IS0 7393-1 and IS0 7393-2. 8.1.3 Homogenization Homogenization by disruption of particles with for example a laboratory blender is not recommended for routine use
40、 but consider its use when testing a sample containing large particles and requiring a high dilution factor. When samples have been frozen (see clause li), homogenization shall take place after thawing of the samples. O BSI 1998 - STD-BSI BS EN L899-L-ENGL L796 I LbZLibbS 0737798 289 1000to3000 2 o0
41、0to6o00 Page 6 EN 1899-1:1998 500 I lo00 I 8.1.4 Presence of algae Consider filtering samples containing algae to avoid producing unusually high results. A filter pore size of 1,6pn is appropriate. Filtering can change BOD resuits radically and it shail only be performed if deemed necessary in the e
42、valuation of the quality of the water. If fdtration was carried out, the filter pore size shall be recorded in the test report. 8.2 Preparation of test solutions Bring the sample (or pretreated sample) to a temperature of (20 2) “C and if necessary (depending on the origin of the sample) shake in a
43、half-filled vessel so as to eliminate any possible supersaturation with oxygen. Place a known volume of the mple (or pretreated sample), the test portion, in the dilution vessel (6.7), add 2 ml of allylthiourea solution (6.11) per litre of diiuted sample and fiil to the mk with seeded dilution water
44、 (5.6). If the dilution factor to be used is greater than 100, carry out seriai dilutions in two or more steps. Total organic carbon (see IS0 8245) 1 TOWBOD Mix gently to avoid enimpment of air bubbles. NOTE 1 in some samples an inhibition by chlorine is seen even after removal, due to chiorine prod
45、ucts that are not removed. NOTE 2 The extent of dilution should be such that, after incubation, the residual dissolved oxygen concentxition will be between one-third and two-thirds of the initiai concentration. In view of the difficulty of selecting the right degree of dilution, severai different di
46、lutions are recommended, varying according to the dilution factor and encompassing the dilution corresponding to the expected BOD, (see Table 1). Determinations of the btal organic carbon (TOC) (see IS0 8245), the permanganate index (see IS0 8467), or the chemical oxygen demand (COD) (see IS0 6060)
47、can give useful information in this respect. Table 2 shows typical intervals for R, the ratio of TOC or COD to BOD, dependent on the sample type. Permanganate Chemical oxygen demand indexBOD (COD)/BOD (see IS0 6060) (see IS0 467) Table 1 - npical dilutions for determination of BOD, Untreated waste w
48、ater Biologically treated waste water Expected BOD, mgA of oxygen 3to6 4to 12 10 to 30 20to 60 40 to 120 100 to 300 200to600 400 to 1200 1,2 to 2,8 42 to 1,5 0,s to 0,65 0,3 to 1,O 0,5 to 1,2 0,20 to 0,35 Dilution factor) Examples of waters-) I I between 1,l and 2 2 5 10 20 50 100 200 * ) R River wa
49、ter, E Biologically purified municipal sewage; S: Clarified municipal sewage or lightiy contaminated industrial effluent; C Raw municipal sewage; I: Heavily contaminated industrial effluent. Table 2 - Spica1 values of dilution ratios I1 O BSI 1998 STD-BSI BS EN 1899-L-ENGL 1998 S Lb2qbb7 0737797 LI5 An appropriae R-value should be selected from Table 2, to calculate the expected BOD, value: where: Expected BOD, value: R - 9 y is the chemical oxygen demand, permanganate index or the TOC value. NOTE 3 Care should be taken that the test samples are represenative.
