1、- STD-ES1 EIS EN Lfl77-2-ENGL 1998 lb24hb9 07442U3 334 II BRITISH STANDARD Water quality - Determination of biochemical oxygen demand after n days Part 2: Method for undiluted samples The European Standard EN 18892:1998 has the status of a British Standard ICs 13.060.01; 13.060.30 NO COPYING WITHOUT
2、 BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 1899-2:1998 BS 6068-2.64: 1998 STD.BSI BS EN 1877-2-ENGL $978 m Lb24bb7 07411202 270 D BS EN 1899-21998 National foreword This British Standard is the English language version of EN 1899-21998. Together with BS EN 18941:1998 it supersedes BS
3、 6068-2.141990 which is withdrawn. The UK participation in its preparation was entrusted by khnicai Committee EW3, Water quality, to Subcommittee EW3/2, Physical, chemical and biochemical methods, which has the responsibility to: - aid enquirers to understand the text; - present to the responsible E
4、uropean rommiaee any enquiries on the interpretation, or proposais for change, and keep the UK interests informed, - monitor reiated international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretar
5、y. 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 1 to 7, which, together w
6、ith Part O, are listed below. Part o Part 1 Part 2 Part 3 Part 4 Part 6 Part 6 Part 7 Introduction Glossary pnysical, chemical and biochemical methods RadWlogicd mew Microbiological methods BWoghimethods Sampling A.ecision ami accumiy This Brit3sh Standard, having been prepared under the direction o
7、f the Heaith and Environment sedor Committee was published under the authority of the Standards Committee and comes into effect on 16 November 1998 Q BSI 1998 NOTE The tests described in this British Standard should only be ded out by suitably qualined persons with an appropriate level of chemical e
8、xpertise. Standard chemical procedures should be followed throughout Fiutber information Users of this standard are informed that the UK submitted a vote of disapproval on the nal voling stage of the draft EN for the foiowing reasons: - Aithough we are in general technical agreement with the basis o
9、f the draft, we are still 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 6 day one and a 7 day one. This would thereby avoid any possible confusion when quoting the standard or reporting the results
10、 of anaiysis. - We also strongur recommend deletion of the reference to Is0 58151989 in the tide as it serves no purpose and could be misleading. The Is0 standard is for 6 days oniy and it is thus wrong to ciaim in the Foreword that it has been approved with common modications with no reference to t
11、he 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 Standards Catalogue under the section entitied International Standards Correspondence index, or by using the Find fac
12、ility of the BSI Standards Electronic Catalogue. A British Standard does not purport to indude all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Strndard does not of itself confer immunity from legal obliga
13、tions. Summary of pages This document comprises a hnt cover, an inside front cover, page 1 to 10, an inside back cover and a back cover. Amendments issued since publication I Date Amd. No. Textaffected ISBN O O80 29880 7 I I EUROPEAN STANDARD NOFWE EUR0PEE”E EUROP it is equal to 5 or 7. NOTE For the
14、 purpose of this European standard, biochemical oxidation“ is taken to mean “biological oxidation“. This denition is similar to the definition of Is0 6107-2. 4 principle Equiiibration of the sample of water to be analyzed to 20 OC foliowed by, if nec-, aeration, Incubation at 20 OC for a defined per
15、iod, 5 or 7 days, in the dark, in a completely lled and stoppered boale. Determination of the dissolved oxygen concentration before and after incubation. Calculation of the mass of oxygen consumed per litre of sample. 6 Apparatus 6.1 Incuba- boies, BOD bottles, with giass stoppers, For example, pref
16、erably 250 ml to 300 ml or 100 ml to 125 mi, with stoppen and preferably with straight shoddem, or any equivalent bottles. It is important that the bottles are thoroughly cleaned before use. If the idometsic method (i accordance with EN 25813) for determining dissolved oxygen is used, it is, for exa
17、mple, normally sufficient to rinse the boale severai times with tap water then deionized water. However, if the electrade method (i accordance with EN 25814) is used, a more stringent cleaning procedure, for example, as follows, is reqUirea Add to the empw boale 5ml to 1Oml of a wash solution (for e
18、xample 2,5 g of iodine plus 12,6 g of potassium iodide per litre of 1 % (VIV) sulfuric acid) shaking weii to coat the bottle walls. Let stand for 15 min, pour off the solution and rinse thoroughly with tap water and finay deionized water. 6.2 I BODd second BOD, determination of sample. Consider the
19、upper control iimit as where: 3,2678 * F % (4) F is the average value of q-dues. The repeatabiiity variation coefficient (CVd can be calculated as: - CV,=- ?-% (5) 1 ,128 NOTE 1 After incubation, the residual dissolved oxygen concentmion should be between the limit of determination of the laboratory
20、 for BOD and twMhirds of the initial oxygen concentraton. NOTE 2 Care should be taken that representative samples are collected. 8 Calculation and expression of results Calculate the biochemical oxygen demand after n days (BOD c2 is the dissolved oxygen concentration of this same test sample after n
21、 days, in milligrams per litre. Page 6 EN 1899-21998 9 Ifueness and precision The standard deviation of the BODndetennination was determined by an inter-laboratom comparison in 1992 where 76 laboratones from nine countries performed 2 to 4 analyses on two stabilized fresh, surface water samples and
22、two locally collected fresh, surface water samples. In this inter-laboratory comparison, a repeatability standard deviation of (OJO to 0,B) mg/i of oxygen and a reproducibility standard deviation of (0,26 to 0,94) mgll of oxygen was found. It is possible to establish factors for conversion between B
23、OD5 and BOD7 data within a smgle type of water. The due of conversion factors can be obtained for each water type from parailel analyses of BOD5 and BOD7 measurements of the same samples. If a factor is not adable the correlation between BOD5 and BOD7 can be estimated from the above mentioned Europe
24、an inter-laboratory comparison. The results are shown in Table 2. 10 hst report The test report shail include the following infomation: a) a reference to this European Stan c) the results in milligrams per litre of oxygen (reported as described in clause 8); d) for results below the working range, a
25、 documentation for an adequate limit of determination; e) any special details which may have been noted during the test; f) details of any operations not specified in this European Standard, or regarded as optional, such as aeration (see 7.1), alternative incubation (BOD2+5) (in accordance with anne
26、x A) and modications such as freezing and homogenization (i accordance with annex B). The results shall be reported to two significant figures, e.g. 4,5 mgll of oxygen. O BSI 1998 STD.BS1 BS EN 1877-2-ENGL 1998 W Lb24bb9 0744208 799 Page 6 EN 18992:1998 S2Z22282 3- o- o- o- o- o- o- 0- b li b 01 ni
27、i z 1 ni B il z 8 i z 1 ni B z il t 2 z 1 i! z b P b z P 2 z 1 c z 1 z ni i 1 z c il z 8 B z 1 ni i z 1 8 i 1 z 8 f z 1 P 2 1 z i! f! z 1 O BSI 1998 STD.BS1 BS EN L79-2-ENGL 2198 Hl Zb24bb7 0744209 b25 9 Sample type BODE, mg/i of oxygen Median Page 7 EN 1899-21998 BOD, mg/l of oxygen Median Table 2
28、- Inteplaboratory comparison 461992 - Comparison of BOD5 and BOD7 determinations Significant difference*) Number of BOD,/BODE, laboratories included in calculations Stablihed fresh water Natwal fresh water Natural fresh water A 2,15 2,57 B 4,87 5,82 cs 0768 0790 cj 1,29 1950 D, 4,69 5,51 Di 3.03 4,7
29、4 Yes 71 Yes 171 I JI I I I l *) significance level a = 0,05 Yes 1: i 1,32 Yes 1,16 1,28 YeS 28 1.56 Annex A (normative) Alternative incubation periods and temperatures The rate of oxidation of carbon during the rst stage of the BOD test is expressed by Phelps law: log10 rx Lkt where: L istheuitimae
30、BODatinfinitetimeinmilligrams per iitre of oxygeq x is the BOD at time tin milligrams per litre of Oxy!% t isthetime,indays; k is the rate constant, expressed as the reciprocal is the dissolved oxygen concentration of the seeded test sample after n days in milligrams per is the dissolved oxygen conc
31、entration of the seeding water diluted with water at time zero in miiigrams per like; is the dissolved oxygen concentration of the seeding water diluted with water after n days in milligrams per litre; is the volume of seeding water, in miliitres, per litre of seeded test sample; is the volume of se
32、eding water in milliiitres per iitre of seeding water diluted with water. litre; For samples with low content of saits there may be a need to add sait solutions. For this purpose add 1 ml of each of the sait solutions (B 2.3.2, B 2.3.3, B 2.3.4 and B 2.3.6) per iitre of sample. For specific investig
33、ations of BOD, in undiluted samples there may be a need for suppression of nib-ication For this purpose add 2 ml of allylthiourea solution (B.2.4) per litre of sample. Neutralizaton may be required if the pH of the sampl is not between 6 and 8. Perform neutralization after having determined by a sep
34、arate test the volume of hydrochloric acid solution (B.2.6) or of sodium hydroxide solution (B.2.6) necessary. Ignore any precipitate which may be found Neutralizaton of any excess of free and combined chlorine in the sample may be required. Perform neutralizaton by adding the required volume of sod
35、ium sulfite solution (B.2.7). Take care to avoid adding an excess. NOTE For free and combined chlorine measurement see IS0 7393-1 and IS0 7393-2. Carry out homogenization with a laboratory blender or equivalent if found necessary for specific purposes, e.g.: a) when testing a sample containing large
36、 particles; b) when samples have been frozen (see cause 10). Ntmtion of samples containing algae may be required to avoid producing unusually high results. Filtering can change BOD results radically, and it shall oniy be performed if deemed necessary in the emhation of the quaty of the water. A iter
37、 pore size of 1,6 pm is appropriate. Record the specifications of particle sizes detained by tration with the test report. B.2 Reagents B.2.1 General Use oniy grade 3 water (in accordance with EN IS0 3696). However, the water is not to contain more than 0,Ol mg/l of copper, nor chorine or chloramine
38、s. B.2.2 Seeding water Obtain seeding water in one of the following ways: a) settled effluent from a waste water treatment Plant; b) commercially available seeding material B.2.3 Salt solutions B.2.3.1 Geneml The following solutions are stable for at least 1 month and shall be stored in glass bottle
39、s in the dark. Discard them at the fi& sign of precipitation or biological growth. O BSI 1998 Page 10 EN 1899-2:1998 B.2.3.2 Phosphate, wer solution, pH 7,2 Dissolve 8,5 g of potassium dihydmgen phosphate (XH2PO4), 21,75 g of dipotassium hydrogen phosphate (KzHFQ), 33,4 g of disodium hydrogen phosph
40、ate heptahydrate (Na2Hp04 f7H20) and 1,7 g of ammonium chloride mC1) in about 500 mi of water. Dilute to1ooOmlandmix. NOTE The pH of this buffer solution should be 7,2 without further adjustment. B.2.3.3 Magnesium wate heptahydrate, 22,5 s/l sducion Dmive 22,5 g of magnesium sulfate heptahydrate (Mg
41、S4.7H20) in water. Dilute to 1 OOOml and mix. B.2.3.4 Calcium chloride, 27,5 g/i solution Dissolve 27,5 g of anhydrous calcium chloride (CaCl2) (or equivalent, if hydrated calcium chloride is used (for example 36,4 g of CaC12 2H20) in water. Dilute to1ooOmiandmix. B.2.3.6 IroncIii) chlomde hahydmte,
42、 0,25gl ducion Dissoive 425 g of iron0 chloride hexahydrate 6H2O) in water. Dilute to 1 ooO mi and mix. B.2.4 Aylthiourea (.I, solution Dissolve 200 mg of aliylthiourea (C4&N2S), in water, dute to 200 mi and mix. Wre the solution at 4 OC. B.2.5 Hydrochlomc & (Ha) m su.* acid (H2so4, solution, c(H2SO
43、4) = 0,25 moii, c(HC1) = 0,5 moM, or as appropriate. B.2.6 Sodium hydmxie I“), solution, approximately 20 g/l or as appropriate. B.2.7 Sodium &ite (NaBOd, solution, approximately 0,5 moii or as appropriate. Annex C (informative) Bibliography IS0 7393-1, Water quality - Determination of flee chlomne
44、and total cWm -Part 1: l%?rim& method using N,N-diethycl,4. IS0 739S2, Water quality - Determination of flee chlorine and total chlorine - Part2: Co2orimecric method using N,Ndethyl-1,4-phenyiamim, fm routine concrd purp0S. BS EN 1899-2:1998 BS 6068-2.64: 1998 BSI 389 Chiswick High Road London w4 4A
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