1、7 CEN EN*ISO*LOb34 95 6 3404589 OLL7050 892 BRITISH STANDARD Water quality - Guidance for the preparation and treatment of poorly water-soluble organic compounds for the subsequent evaluation of their biodegradability in an aqueous medium Product code 00642128 ICs 13.060.40 3s EN IS0 10634 : 1996 BS
2、 6068 : Section 5.18 : 1996 - CEN EN*ISO*LOb34 95 E 3404589 OLL705L 729 E BS EN Is0 10634 : 1996 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technicai Committee Em, Water quality, to Subcommittee EW5, Biological methods, upon which the f
3、oilowing bodies were represented: BLWA Ltd. (The Association of the Laboratory Supply Industry) Department of Economic Development (Northern ireland) Department of Health Department of the Environment (Water Directom) Freshwater Biologicai Association Institution of Water and Environmental Managemen
4、t Minishy of Agriculture, Fisheries and Food National Rivers Authority Royal Society of Chemistry Scottish Natural Heritage Soap and Detergent Industry Association Water Research Centre Water Services Asmaah on of England and Wales This British Standard, having been prepared under the direction of t
5、he Heaith and Environment Sector Board, was published under the authority of the standards Board and comes into effect on 15 January 1996 8 BSI 1996 Amendments issued since publication The foiowing BSI references relate to the work on this standard: Committee reference EM Draft for comment 9358818 D
6、C ISBN O 080 25114 4 - _ CEN EN*ISO*LOb3Y 95 3404589 OLL7052 665 BS EN IS0 10634 : 1996 Contents page Committees responsible Inside front cover National foreword ii Foreword 2 introduction Method 1 Scope 2 Normative references 3 Directaddition 4 Ultrasonic dispersion 5 Adsorption on an inert support
7、 3 6 Dispersion with an emulsifying agent 7 7 Test report 8 A (informative) Examples of biodegradation curves 9 Annex Figures A.l Biodegradation curves when dusooctylphthdate is used as the test A.2 Biodegradation curves when anthraquinone is used as the test compound compound 9 10 O BSI 1996 i CEN
8、EN+ISO*LOb34 95 m 3404587 OLL7053 5TL m BS EN IS0 10634 : 1996 National foreword This British Standard has been prepared by Subcommittee EW5. It is the English language version of EN IS0 10634 : 1995 Water quality - Guidance for the prepamtion and treatment of poory water-soluble organic compounds f
9、or the subsequent evaluation of ih%r biodegmdability in an aqueous medium published by the European Committee for Standardization (CEN), which endorses IS0 10634 : 1995, published by the International Organization for Standardization OSO). Cross-references Publication referred to Corresponding Briti
10、sh Standard IS0 9408 : 1991 BS EN 29408 : 1993 Water quality. Evaluation in an aqueous medium of the ultimate aerobic biodegradability of organic cmpounds: method by determining the oxygen demand in a closed respimter BS EN 29439 : 1992 Water qwllity. Evaluation in an aqueous medium of the ultimate
11、aerobic biodegmdability of organic compounds: method by analysis of released carbon dioxide IS0 9439 : 1990 Compliance with a British Standard does not of itself confer immunity from legai obligations. CEN EN*IS0*10634 75 = 3404587 O117054 43 = EUROPEAN STANDARD ENZSO 10634 Nom EUROPENNE EUROP - ult
12、rasonic dispersion (clause 4): this technique may be applied to non-volatile liquid and solid compounds; - adsorption on an inert support (clause 5); - dispersions or emulsions with an emulsifying agent (clause 6). The subsequent tests on biodegradability are primarily methods using the analysis of
13、the released carbon dioxide (see IS0 9439) and the determination of the oxygen consumption (see IS0 9408). This Inter- national Standard does not describe the test methods: it is restricted to describing the techniques for intro- ducing the test substances into the test medium and to keep them in a
14、dispersed state. These techniques are implemented while observing the experimental conditions described in the standardized methods for evaluating biodegradability. It should be noted that volatile chemicals may not be tested by the carbon dioxide method specified in IS0 9439. 2 Normative references
15、 The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publica- tion, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Stand
16、ard are encouraged to investigate the possibility of applying the most re- cent editions of the standards indicated below. Members of IEC and IS0 maintain registers of cur- rently valid International Standards. IS0 9408: 1991, Water quality - Evaluation in an aqueous medium of the “ultimate “ aerobi
17、c bio- degradability of organic compounds - Method by determining the oxygen demand in a closed respirome ter. IS0 9439:1990, Water quality - Evaluation in an aqueous medium of the “ultimate“ aerobic bio- degradability of organic compounds - Method by analysis of released carbon dioxide. 3 Direct ad
18、dition Any of the following techniques can be used - The test compound is weighed and directly intro- duced into the test vessels which are subjected to continuous agitation. NOTE 1 Some organic compounds which are spar- ingly soluble in water dissolve more readily when alkali or acid is added. They
19、 may be introduced as an acid or CEN EN*ISO*LOb34 95 M 3404589 Qll058 083 M alkaline stock solution, provided that no substantial re- action of the test compound takes place. The test me- dium is adjusted to neutral before the inoculum is added. - The test compound is weighed onto a suitable inert s
20、upport and introduced into the test vessels which are subjected to continuous agitation. - A solution of the test compound is prepared in a volatile organic solvent and is introduced into the test vessels which are subjected to continuous agitation. The solvent, which shall be used in minimal amount
21、s, is then removed, if possible completely, by agitation before the test medium is added. 3.1 Reagents A volatile organic solvent is selected for its capacity to dissolve the test compound. The chosen solvent shall not react with the test compound or with any component of the medium. The solvent sha
22、ll be non-biodegradable and non-toxic to bacteria under the conditions of the subsequent biodegradability tests, especially if it cannot be re- moved sufficiently. Suitable solvents are acetone or dichloromethane 3.2 Apparatus 3.2.1 Inert supports, which may be introduced into the test vessels, e.g.
23、 microscope slides. 3.2.2 Stirrers, in sufficient numbers to ensure that all the test vessels used in the respective biodegrad- ability tests can be agitated. Stirrer-rods shall be of such a material that no in- gredients of a plastics coat will contaminate the test medium and no adsorption of test
24、compounds will occur. Heating up the test vessels by stirring and raising the test temperature shall be avoided. 3.3 Procedure 3.3.1 Direct addition Test compounds with crystalline structures may be weighed and directly added to the test vessels. Non-viscous liquid compounds may be added with a high
25、 precision volumetric syringe. Page 5 EN IS0 10634 : 1995 Test compounds which are sufficiently soluble in wa- ter under acidic or alkaline conditions may be intro- duced as stock solution. Prepare a stock solution of such a test compound in deionized water adjusted with inorganic acid or alkali to
26、a sufficiently high or low pH. Add an appropriate amount of the stock solution to the test medium to obtain the desired concen- tration of the test compound in the test vessels. Measure the pH of the medium and adjust it as necessary before the inoculum is added. 3.3.2 Using a support Grind solid te
27、st compounds as finely as possible be- fore weighing them. Weigh the liquids, including viscous substances, without treatment or, if possible, solidify in liquid nitrogen and grind finely before weighing. Weigh onto the support (3.2.1) a quantity of the compound corresponding to the initial concenta
28、tion or organic carbon required by the test method to be used. Introduce a support into each of the test vessels, and also introduce a support without the test compound into each of the control vessels. Maintain agitation using the stirrers (3.2.2) throughout the biodegradability test. 3.3.3 Using a
29、 solvent Prepare a solution of the test compound in a mini- mum of the chosen organic solvent (3.1). Introduce, into the test vessels, the quantity of sol- ution needed to obtain the initial concentration of or- ganic carbon required by the test method used. Introduce the same quantity of the solven
30、t, without any test compound, into each of the control vessels. Evaporate the solvent, if possible completely, by ap propriate methods. NOTE 2 The test solution may be spread over the base of the test vessels and the system is then purged with gas and/or stirred. The last traces of solvent are diffi
31、cult to re- move. Interferences may occur if the solvent is biodegrad- able or inhibitory to bacteria. Then carry out the biodegradability test. 4 Ultrasonic dispersion An emulsion or dispersion of the compound to be tested is prepared using an ultrasonic probe and is CEN EN*ISO*10634 95 3404589 011
32、7059 TLT Page 6 EN IS0 10634 : 1995 I introduced into the test vessels, which are continu- ously agitated (see 3.2.2). 4.1 Apparatus 4.1.1 Ultrasonic transducer, capable of producing a frequency of approximately 20 kHz. 4.1.2 Stirrers, in sufficient numbers to ensure that all the test vessels can be
33、 agitated (see 3.2.2). centration of organic carbon required by the test method to be used. Sustain the agitation throughout the biodegradability test. NOTE 5 It may be difficult to obtain a stable emulsion or dispersion. Special care is therefore required when aliquots are distributed to the test v
34、essels. If it proves impossible to obtain a sufficiently stable emulsion or a sufficiently high concentration to carry out the test, the test compound may be introduced directly into the test medium and be dis- persed ultrasonically in the test vessels before the inoculum is added. 4.2 Procedure 5 A
35、dsorption on an inert support Add, for example, 10 g or 10 ml of the test compound to a 500 ml beaker containing approximately 400 ml of deionized water. The test compound shall be present in excess so that a saturated solution is obtained. Install the ultrasonic transducer (4.1 .I) in such a way th
36、at its tip is as close as possible to the interface between the water and the test compound. Use a stirrer (4.1.2) to agitate the beaker so that the compound is drawn down to the bottom. Set the transducer to give a frequency of about 20 kHz and maintain this for about 30 min. Switch off the transdu
37、cer and leave the emulsion or dispersion to settle for 15 min to 30 min, then decant it off from the excess test compound into another container. NOTES 3 The proponions and figures are given only as a guide. They depend on the characteristics of the test compound. 4 Some substances are subjected to
38、thermal decompc- sition if heat generation occurs at the probe tip. This may also lead to an increase in the temperature of the bulk sol- ution. This problem may be avoided by measuring and controlling the temperature, reduction of the power of the sonifier or intermittent sonification. In some case
39、s, prob lems may be encountered because of the destruction of the chemical. If this is the case, a different method should be used. Using an appropriate analytical method specific analysis or total organic carbon (TOC) analysis, ana- lyse an aliquot of the emulsion or dispersion obtained and determi
40、ne the concentration of the test com- pound. Introduce an appropriate volume of emulsion or dis- persion into the test vessels to obtain the initial con- The test compound is adsorbed onto an inert support and introduced into the test vessels. It is kept dis- persed in the medium by continuous agita
41、tion. 5.1 Reagents 5.1.1 Inert support Silica gel, glassfibre filters or other non-biodegradable inert supports which do not release organic or inor- ganic carbon into the aqueous medium may be used. It should be validated by preliminary work that the support is inert and carbon-free; to avoid or mi
42、nimize surface area effects, the quantity of the support shall be minimal. The test compound should be adsorbed on the surface but not be adsorbed and fixed too in- tensively on the support. NOTE 6 supports are suitable: For example, if silica gel is used, the following - silica gel used for thin-la
43、yer chromatography (15 pm particle size); - silica gel used for column chromatography (200 pm to 500 pm particle size). 5.1.2 Solvent A volatile solvent is selected for its capacity to dis- solve the test compound. It shall be non-toxic to bacteria and, if possible, non- biodegradable under the cond
44、itions of the subsequent biodegradability tests. This shall be tested in advance or in the subsequent biodegradability test. Depending on the test compound, acetone or dichloromethane may be suitable. CEN EN*ISO*10634 95 = 3404589 OLL7060 731 5.2 Apparatus 5.2.1 all the vessels can be agitated (see
45、3.2.2). Stirrers, in sufficient numbers to ensure that 5.3 Procedure Prepare the quantity of test compound to be impregnated on the support required by the bio- degradability test method to be used. For example, mix together, by agitation in a 250 ml vessel for 2 h, 30 g of the support (5.1.1) and 1
46、50 ml of a solution of 1 g/i of the test compound in the chosen solvent (5.1.2). At the same time, carry out the same procedure using only the support and the solvent as a control. In both cases, recover the support and dry by totally evaporating the solvent. This may be performed us- ing, in succes
47、sion, a rotary evaporator, a ventilated oven and a vacuum oven at about 45 “C. NOTE 7 The last traces of solvent may be difficult to re- move. Interferences may occur if the solvent is biodegrad- able or inhibitory to bacteria. Determine the amount of the compound impregnated on the support in three
48、 samples of 1.5 g or more, using one of the following methods: - elemental quantitative analysis of the amount of carbon originating from the compound, using a high-temperature total carbon analyser, and then deducting the values obtained for the support treated with solvent only; - determination of
49、 the chemical oxygen demand of the compound impregnated on the inert support and then deducting the values obtained for the support treated with solvent only; - extraction of the compound using an organic sol- vent and quantitative analysis using a specific analytical method. From the amount of test compound on the support, determine the quantity of support to be introduced into the test vessels to obtain the initial concentration of organic carbon of the test compound required by the test method used. Introduce the same quantity of support treated with the solvent alon
