natgillin/translations-raw huggingface dataset:
Brugen af den specifikke nitrifikationsinhibitor, ATU, giver mulighed for direkte vurdering af testkemikaliers inhibitoriske virkninger på den heterotrofe iltning og for beregning af virkningerne på nitrifikationshastigheden ved at trække iltoptagelseshastigheden med ATU fra den samlede optagelseshastighed (uden ATU).
The foaming can be controlled by simple mechanical methods (e.g. occasional manual stirring using a glass rod) or by adding a surfactant-free silicone emulsion antifoam agent and/or use the shake flask aeration method.
Der fremstilles to sæt reaktionsblandinger i henhold til de testdesign for ECx eller NOEC, der er beskrevet i punkt 41, men ATU tilsættes desuden til hver blanding i et sæt til en slutkoncentration på 11,6 mg/l, som har vist sig helt at hæmme nitrifikation i slam med koncentrationer af opslæmmede faststoffer på op til 3000 mg/l (4).
If the problem is associated with the presence of the synthetic sewage, the sewage composition should be modified by including an antifoam reagent at a rate of e.g. 50 μl/l.
Iltoptagelseshastigheden måles efter eksponeringsperioden;
If foaming is caused by the test chemical, the quantity needed for abatement should be determined at the maximum test concentration, and then all individual aeration vessels should be identically treated (including those, e.g. blank controls and reference vessels where foam is absent).
disse direkte værdier repræsenterer kun den heterotrofe respiration, og forskellene mellem disse og den tilsvarende samlede respirationshastighed repræsenterer nitrifikation.
If antifoam agents are used, there should be no interaction with inoculum and/or test chemical.
Derefter beregnes de forskellige hæmningsgrader.
TEST PROCEDURE
Målinger
The inhibition of three different oxygen uptakes may be determined, total, heterotrophic only and that due to nitrification.
Efter eksponeringsperioden/-perioderne overføres en prøve fra den første beluftningsbeholder til iltelektrodecellen (figur 1 i tillæg 2), og koncentrationen af opløst ilt måles straks.
Normally, the measurement of total oxygen uptake inhibition should be adequate.
Hvis et system med flere elektroder er tilgængeligt, kan målingerne foretages samtidig.
The effects on heterotrophic oxygen uptake from the oxidation of organic carbon, and due to the oxidation of ammonium are needed when there is a specific requirement for such two separate end-points for a particular chemical or (optionally) to explain atypical dose-response curves from inhibition of total oxygen uptake.
Det er afgørende, at omrøringen (ved hjælp af en overtrukket magnet) foregår ved samme hastighed, som når elektroden kalibreres, med henblik på at sikre, at sonden reagerer med minimal forsinkelse på ændringer i iltkoncentrationerne, og give mulighed for regelmæssige og reproducerbare iltmålinger i målebeholderen.
The test should be performed at a temperature within the range 20 ± 2 °C.
Normalt er visse iltelektroders system med en selvomrørende sonde tilstrækkeligt.
Test mixtures
Cellen bør skylles med vand mellem målingerne.
Test mixtures (FT as in Table 1) containing water, synthetic sewage feed and the test chemical should be prepared to obtain different nominal concentrations of the test chemical (See Table 1 for example of volumes of constituents).
Alternativt kan prøven fyldes i en BOD-kolbe (figur 2 i tillæg 3) udstyret med en magnetomrører.
The pH should be adjusted to 7,5 ± 0,5, if necessary;
En iltsonde med en muffeadapter indsættes derefter i kolbens hals, og magnetomrøreren startes.
mixtures should be diluted with water and the inoculum added to obtain equal final volumes in the vessels and to begin the aeration.
I begge tilfælde måles koncentrationen af opløst ilt regelmæssigt og registreres i en periode, normalt 5-10 minutter eller indtil iltkoncentrationen falder til under 2 mg/l.
Reference mixtures
Elektroden fjernes, blandingen hældes tilbage i beluftningsbeholderen, og beluftningen og omrøringen fortsættes, hvis det er nødvendigt med måling efter længere eksponeringsperioder.
Mixtures (FR) should be prepared with the reference chemical, e.g. 3,5-dichlorophenol, in place of the test chemical in the same way as the test mixtures.
Kontrol af testkemikaliekoncentrationen
Blank controls
Til nogle formål kan det være nødvendigt at måle testkemikaliekoncentrationen i testbeholderne.
Blank controls (FB) should be prepared at the beginning and end of the exposure period in tests in which the test beakers are set up sequentially at intervals.
Det skal bemærkes, at hvis der bruges stamopløsninger af:
In tests performed using equipment which allows simultaneous measurements of oxygen consumption to be made, at least two blank controls should be included in each batch of simultaneous analysis.
stoffer med ringe vandopløselighed,
Blank controls contain an equal volume of activated sludge and synthetic medium but not test or reference chemical.
blandinger med komponenter med forskellig vandopløselighed eller
They should be diluted with water to the same volume as the test and reference mixtures.
stoffer med god vandopløselighed, men hvor koncentrationen af stamopløsning ligger tæt på den maksimale vandopløselighed,
If necessary, for example if a test chemical is known or suspected to have strong reducing properties, a mixture FA should be prepared to measure the abiotic oxygen consumption.
er den opløste andel ukendt, og den reelle koncentration af testkemikaliet, som overføres til testbeholderne, er ikke kendt.
The mixture should have the same amounts of test chemical, synthetic sewage feed and the same volume as the test mixtures, but no activated sludge.
Der er brug for en analytisk vurdering af testkemikaliekoncetrationen i testbeholderne for at bestemme eksponeringen.
General procedure and measurements
For at forenkle proceduren foretages den analytiske vurdering inden tilsætning af inokulummet.
Test mixtures, reference mixtures and the blank and abiotic controls are incubated at the test temperature under conditions of forced aeration (0,5 to 1 l/min) to keep the dissolved oxygen concentration above 60 - 70 % saturation and to maintain the sludge flocs in suspension.
Fordi kun opløste andele overføres til testbeholderne, kan de målte koncentrationer være meget lave.
Stirring the cultures is also necessary to maintain sludge flocs in suspension.
For at undgå tidskrævende og dyre analyser anbefales det blot at afveje testkemikaliet direkte i testbeholderne og bruge den oprindelige afvejede nominelle koncentration i efterfølgende beregninger.
The incubation is considered to begin with the initial contact of the activated sludge inoculum with the other constituents of the final mixture.
Det er ikke nødvendigt at sondre mellem opløste, uopløste og adsorberede andele af testkemikaliet, fordi alle disse andele forekommer under faktiske betingelser i et spildevandsrensningsanlæg, og andelene kan variere afhængigt af spildevandets sammensætning.
At the end of incubation, after the specified exposure times of usually 3 hours, samples are withdrawn to measure the rate of decrease of the concentration of dissolved oxygen in the cell designed for the purpose (Fig.2 of Appendix 3) or in a completely filled BOD bottle.
Formålet med testmetoden er at give et realistisk skøn over en ikke-hæmmende koncentration, og metoden er ikke hensigtsmæssig til detaljeret undersøgelse af, hvilke andele der bidrager til hæmningen af organismerne i det aktiverede slam.
The manner in which the incubations begin also depends on the capacity of the equipment used to measure oxygen consumption rates.
Beregning af iltoptagelseshastighederne
For example, if it comprises a single oxygen probe, the measurements are made individually.
Iltoptagelseshastighederne beregnes på grundlag af gennemsnittet af de målte værdier, f.eks. den lineære del af kurverne over iltkoncentration som funktion af tid, hvilket begrænser beregningerne til iltkoncentrationer mellem 2,0 mg/l og 7,0 mg/l, eftersom højere og lavere koncentrationer i sig selv har indvirkning på forbrugshastighederne.
In this case, the various mixtures needed for the test in synthetic sewage should be prepared but the inoculum should be withheld, and the requisite portions of sludge should be added to each vessel of the series.
Udsving ind i koncentrationsområder under eller over disse værdier er af og til uundgåelige og nødvendige, f.eks. når respirationen er voldsomt hæmmet og dermed meget langsom, eller hvis aktiveret slam respirerer meget hurtigt.
Each incubation should be started in turn, at conveniently timed intervals of e.g. 10 to 15 minutes.
Det kan accepteres, hvis optagelseskurvens forlængede dele er lige, og deres gradienter ikke ændrer sig, når de passerer 2,0 mg/l- eller 7,0 mg/l O2-grænserne.
Alternatively, the measuring system may comprise multiple probes that facilitate multiple simultaneous measurements;
Eventuelle buede dele af kurven indikerer, at målingssystemet stabiliserer sig, eller at optagelseshastigheden ændrer sig, og må derfor ikke bruges til beregning af respirationshastigheden.
in this case, inoculum may be added at the same time to appropriate groups of vessels.
Iltoptagelseshastigheden udtrykkes i milligram pr. liter pr. time (mg/l/t.) eller milligram pr. gram tørslam pr. time (mg/g/t.).
The activated sludge concentration in all test, reference and blank (but not abiotic control) mixtures is nominally 1,5 g/l of suspended solids.
Iltforbrugshastigheden, R, i mg/l/t. kan beregnes eller interpoleres fra den lineære del af den registrerede kurve over iltfald i henhold til ligning 1:
The oxygen consumption should be measured after 3 hours of exposure.
er iltkoncentrationen i begyndelsen af den udvalgte del af den lineære fase (mg/l)
Additional 30-minute exposure measurements should be performed as appropriate and previously described in paragraph 5.
er iltkoncentrationen i slutningen af den udvalgte del af den lineære fase (mg/l)
Nitrification potential of sludge
er tidsrummet mellem disse to målinger (min).
In order to decide whether sludge nitrifies and, if so, at what rate, mixtures (FB) as in the blank control and additional “control” mixtures (FN) but which also contain N-allylthiourea at 11,6 mg/l should be prepared.
Den specifikke respirationshastighed (Rs) udtrykkes som den mængde ilt, der forbruges pr. gram slam (tørvægt) pr. time (mg/g/t.) i henhold til ligning 2:
The mixtures should be aerated and incubated at 20 °C ± 2 °C for 3 hours.
Rs = R/SS
Then the rates of oxygen uptake should be measured and the rate of oxygen uptake due to nitrification calculated.
hvor SS er koncentrationen af opslæmmede faststoffer i testblandingen (g/l).
Test designs
De forskellige indekser for R, der kan kombineres, er:
Range-finding test
S specifik hastighed
A preliminary test is used, when necessary, to estimate the range of concentrations of the test chemical needed in a definitive test for determining the inhibition of oxygen consumption.
T samlet respirationshastighed
Alternatively, the absence of inhibition of oxygen consumption by the test chemical in a preliminary test may demonstrate that a definitive test is unnecessary, but triplicates at the highest tested concentration of the preliminary test (typically 1000 mg/l, but dependent on the data requirement) should be included.
N hastighed som følge af respiration ved nitrifikation
Examples of mixtures for the preliminary test
H hastighed som følge af heterotrof respiration
Reagent
A hastighed som følge af abiotiske processer
Original Concentration
B hastighed baseret på blindprøver (gennemsnit)
Test chemical stock solution
Beregning af iltoptagelseshastigheden som følge af nitrifikation
10 g/l
Forholdet mellem samlet respiration (RT), respiration ved nitrifikation (RN) og heterotrof respiration (RH) er givet ved ligning 3:
Synthetic medium stock solution
er den målte hastighed for blindkontrollens iltoptagelse uden ATU (FB) (mg/l/t.)
See paragraph 16
er den målte hastighed for blindkontrollens iltoptagelse med ATU (FN) (mg/l/t.).
Activated sludge stock suspension
Dette forhold gælder for blindværdier (RNB, RTB, RHB), abiotiske kontroller (RNA, RTA, RHA) og prøver med testkemikalier (RNS, RTS, RHS) (mg/g/t.).
3 g/l of suspended solids
Den specifikke respirationshastighed beregnes på grundlag af:
Components of mixtures
RHS = RH/SS
Dosing into test vessels [3]
Hvis RN er uden betydning (f.eks. < 5 % af RT i blindkontroller) i en indledende test, må det antages, at den heterotrofe iltoptagelse er lig med den samlede optagelse, og at der ikke forekommer nitrifikation.
Test chemical stock solution (ml)
En alternativ kilde til aktiveret slam ville være nødvendig, hvis testene skulle anvendes til at vurdere virkningerne på heterotrofe og nitrificerende mikroorganismer.
(paragraphs 19 to 21)
Der udføres en endelig test, hvis der konstateres hæmmede iltoptagelseshastigheder med forskellige testkemikaliekoncentrationer.
Synthetic sewage feed stock solution (ml)
Beregning af hæmningen i procent
(paragraph 16)
Hæmningen i procent, IT, af det samlede iltforbrug ved hver koncentration af testkemikaliet er givet ved ligning 7:
Activated sludge suspension (ml)
Tilsvarende er hæmningen i procent af den heterotrofe iltoptagelse, IH, ved hver koncentration af testkemikaliet givet ved ligning 8:
(paragraphs 26 to 29)
Endelig er hæmningen i procent af iltoptagelsen som følge af nitrifikation, IN, ved hver koncentration givet ved ligning 9:
(paragraph 15)
Hæmningen i procent af iltoptagelsen afbildes mod logaritmen for testkemikaliekoncentrationen (hæmningskurve, se figur 3 i tillæg 4).
Total volume of mixtures (ml)
Hæmningskurver afbildes for hver beluftningsperiode på tre timer eller yderligere efter 30 min. Den testkemikaliekoncentration, der hæmmer iltoptagelsen med 50 % (EC50), skal beregnes eller interpoleres på grundlag af kurven.
Concentrations in the mixture
Hvis der foreligger passende data, kan man beregne eller interpolere 95 % konfidensgrænser for EC50, kurvens hældning og værdier, som er egnede til at markere begyndelsen af hæmningsintervallet (f.eks. EC10 eller EC20) og slutningen af hæmningsintervallet (f.eks. EC80 eller EC90).
Test suspension (mg/l)
Det skal bemærkes, at det i lyset af den variabilitet, der ofte konstateres i resultaterne, i mange tilfælde kan være vanskeligt også at udtrykke resultaterne i størrelsesorden, f.eks.:
Activated sludge
1 mg/l til 10 mg/l
(suspended solids) (mg/l)
10 mg/l til 100 mg/l
The test should be performed using at least three concentrations of the test chemical, for example, 10 mg/l, 100 mg/l and 1000 mg/l with a blank control and, if necessary, at least three abiotic controls with the highest concentrations of the test chemical (see as example Table 1).
> 100 mg/l
Ideally the lowest concentration should have no effect on oxygen consumption.
Fortolkning af resultater
The rates of oxygen uptake and the rate of nitrification, if relevant, should be calculated;
ECx-værdier, herunder deres øvre og nedre 95 % konfidensgrænser for parameteren, beregnes med passende statistiske metoder (f.eks. probabilistisk analyse, logistisk funktion eller Weibull-funktion, Trimmed Spearman-Karber-metoden eller simpel interpolation (11)).
then the percentage inhibition should be calculated.
En ECx-værdi opnås ved at indsætte en værdi, der svarer til x % af kontrolgennemsnittet, i den fundne ligning.
Depending on the purpose of the test, it is also possible to simply determine the toxicity of a limit concentration, e.g. 1000 mg/l.
For at beregne EC50 eller enhver anden ECx-værdi skal middelværdierne for hver behandling (x) underkastes regressionsanalyse.
If no statistically significant toxic effect occurs at this concentration, further testing at higher or lower concentrations is not necessary.
Beregning af NOEC
It should be noted that poorly water soluble substances, mixtures with components of different water solubility and adsorptive substances should be directly weighed into the test vessels.
Hvis NOEC skal bestemmes ved statistisk analyse, er det nødvendigt med statistikker pr. beholder (individuelle beholdere anses for replikater).
In this case, the volume reserved for the test substance stock solution should be replaced with dilution water.
Passende statistiske metoder anvendes i overensstemmelse med OECD Document on the Current Approaches in the Statistical Analysis of Ecotoxicity Data:
Definitive test
Generelt undersøges negative virkninger af testkemikaliet sammenlignet med kontrollerne ved hjælp af en ensidet (mindre) hypotesetest ved p ≤ 0,05.
Inhibition of total oxygen uptake
Testrapporten skal indeholde følgende oplysninger:
The test should be carried out using a range of concentrations deduced from the preliminary test.
generisk navn, kemisk navn, CAS-nummer, renhed
In order to obtain both a NOEC and an ECx (e.g. EC50), six controls and five treatment concentrations in a geometric series with five replicates are in most cases recommended.
testkemikaliets fysisk-kemiske egenskaber (f.eks. log Kow, vandopløselighed, damptryk, Henrys konstant (H) og eventuelt oplysninger om testkemikaliets skæbne, f.eks. adsorption til aktiveret slam)
The abiotic control does not need to be repeated if there was no oxygen uptake in the preliminary test, but if significant uptake occurs abiotic controls should be included for each concentration of test chemical.
Testsystem
The sensitivity of the sludge should be checked using the reference chemical 3,5-dichlorophenol.
kilde, driftsforhold i spildevandsrensningsanlægget og indløbet hertil, koncentration, forbehandling og vedligeholdelse af det aktiverede slam
The sludge sensitivity should be checked for each test series, since the sensitivity is known to fluctuate.
testtemperatur, pH under testen og eksponeringsfasens/-fasernes varighed
In all cases, samples are withdrawn from the test vessels after 3 hours, and additionally 30 minutes if necessary, for measurement of the rate of oxygen uptake in the oxygen electrode cell.
Resultater
From the data collected, the specific respiration rates of the control and test mixtures are calculated;
kontrollernes specifikke iltforbrug (mg O2/(g slam × t.)
the percentage inhibition is then calculated from equation 7, below.
alle målte data, hæmningskurve(r) og metode til beregning af EC50
Differentiation between inhibition of heterotrophic respiration and nitrification
og om muligt 95 % konfidensgrænser, eventuelt EC20, EC80;
The use of the specific nitrification inhibitor, ATU, enables the direct assessment of the inhibitory effects of test chemicals on heterotrophic oxidation, and by subtracting the oxygen uptake rate in the presence of ATU from the total uptake rate (no ATU present), the effects on the rate of nitrification may be calculated.
eventuelt NOEC og anvendt statistisk metode, hvis EC50 ikke kan bestemmes
Two sets of reaction mixtures should be prepared according to the test designs for ECx or NOEC described in paragraph 41, but additionally, ATU should be added to each mixture of one set at a final concentration of 11,6 mg/l, which has been shown to inhibit nitrification completely in sludge with suspended solids concentrations of up to 3000 mg/l (4).
resultater for samlet hæmning og, hvis det er relevant, for heterotrof hæmning og hæmning ved nitrifikation
The oxygen uptake rates should be measured after the exposure period;
abiotisk iltoptagelse i eventuel fysisk-kemisk kontrol
these direct values represent heterotrophic respiration only, and the differences between these and the corresponding total respiration rates represent nitrification.
referencekemikaliets navn og resultater med dette kemikalie
The various degrees of inhibition are then calculated.
alle observationer og afgivelser fra standardproceduren, som kan have haft indflydelse på resultatet.
Measurements
I denne testmetode anvendes følgende definitioner:
After the exposure period(s) a sample from the first aeration vessel should be transferred to the oxygen electrode cell (Fig.
Kemikalie betyder et stof eller en blanding.
1 of Appendix 2) and the concentration of dissolved oxygen should immediately be measured.
ECx (effektkoncentration for x % virkning) den koncentration, der har en virkning på x % på testorganismer inden for en angiven eksponeringsperiode sammenlignet med en kontrolprøve.
If a multiple electrode system is available, then the measurements may be made simultaneously.
er f.eks. en koncentration, der skønnes at have en virkning på et testendepunkt hos 50 % af en eksponeret population i en defineret eksponeringsperiode.
Stirring (by means of a covered magnet) is essential at the same rate as when the electrode is calibrated to ensure that the probe responds with minimal delay to changing oxygen concentrations, and to allow regular and reproducible oxygen measurements in the measuring vessel.
NOEC (nuleffekt-koncentration, no observed effect concentration) den testkemikaliekoncentration, hvor der ikke observeres nogen virkning.
Usually, the self-stirring probe system of some oxygen electrodes is adequate.
I denne test har den koncentration, der svarer til NOEC, ingen statistisk signifikant virkning (p < 0,05) inden for en angiven eksponeringsperiode sammenlignet med kontrolprøven.
The cell should be rinsed with water between measurements.
LOEC (laveste koncentration med observeret effekt, lowest observed effect concentration)
Alternatively, the sample can be used to fill a BOD bottle (Fig.
Eksempel på måleenhed
2 of Appendix 3) fitted with a magnetic stirrer.
Signaturforklaring:
An oxygen probe with a sleeve adaptor should then be inserted into the neck of the bottle and the magnetic stirrer should be started.
1 aktiveret slam
In both cases the concentration of dissolved oxygen should continuously be measured and recorded for a period, usually 5 to 10 minutes or until the oxygen concentration falls below 2 mg/l.
4 luft
For some purposes, it may be necessary to measure the concentration of the test chemical in the test vessels.
5 blandebeholder
It should be noted that if stock solutions of:
6 magnetomrører
poorly water soluble substances,
7 celle til iltmåling
mixtures with components with different water solubility, or
8 iltelektrode
substances with good water solubility, but where the concentration of the stock solution is near the maximum water solubility,
9 instrument til iltmåling
are used, the dissolved fraction is unknown, and the true concentration of the test chemical that is transferred into the test vessels is not known.
10 skriver
In order to characterise the exposure, an analytical estimation of the test chemical concentrations in the test vessels is necessary.
Eksempel på måleenhed med en BOD-kolbe
To simplify matters, analytical estimation should be performed before the addition of the inoculum.
1 Testbeholder
Due to the fact that only dissolved fractions will be transferred into test vessels, measured concentrations may be very low.
2 iltelektrode
To avoid time-consuming and expensive analytics, it is recommended to simply weigh the test chemical directly into the test vessels and to refer to the initial weighed nominal concentration for subsequent calculations.
3 instrument til iltmåling
A differentiation between dissolved, undissolved or adsorbed fractions of the test chemical is not necessary because all these fractions appear under real conditions in a waste water treatment plant likewise, and these fractions may vary depending on the composition of the sewage.
Eksempler på hæmningskurver
The aim of the test method is to estimate a non inhibitory concentration realistically and it is not suitable to investigate in detail which fractions make a contribution to the inhibition of the activated sludge organisms.
X koncentration af 3,5-dichlorphenol (mg/l)
Finally, adsorptive substances should be also weighed directly into the test vessels;
Y hæmning (%)
and the vessels should be silanised in order to minimise losses through adsorption.
hæmning af heterotrof respiration med nitrificerende slam
Calculation of oxygen uptake rates
hæmning af nitrifikation med nitrificerende slam
The oxygen uptake rates should be calculated from the mean of the measured values, e.g. from the linear part of the graphs of oxygen concentration versus time, limiting the calculations to oxygen concentrations between 2,0 mg/l and 7,0 mg/l, since higher and lower concentrations may themselves influence rates of consumption.