natgillin/translations-raw huggingface dataset:
Under some rare conditions, a test chemical with strong reducing properties may cause measurable abiotic oxygen consumption.
Druga možnost je, da odsotnost zaviranja porabe kisika preskusne kemikalije v predhodnem preskusu lahko kaže na nepotrebnost dokončnega preskusa, vendar je treba vključiti tri ponovitve pri najvišji preskušani koncentraciji predhodnega preskusa (običajno 1000 mg/l, odvisno pa je od zahteve po podatkih).
In such cases, abiotic controls are necessary to discriminate between abiotic oxygen uptake by the test chemical and microbial respiration.
Primeri zmesi za predhodni preskus
Abiotic controls may be prepared by omitting the inoculum from the test mixtures.
Prvotna koncentracija
Similarly, abiotic controls without inoculum may be included when supporting analytical measurements are performed to determine the achieved concentration during the exposure phase of the test, e.g. when using stock solutions of poorly water soluble chemicals with components with different water solubility.
založna raztopina preskusne kemikalije
In specific cases it may be necessary to prepare an abiotic control with sterilised inoculum (e.g. by autoclaving or adding sterilising toxicants).
10 g/l odstavek 18 založna raztopina b) 1 g/l
Some chemicals may produce or consume oxygen only if the surface area is big enough for reaction, even if they normally need a much higher temperature or pressure to do so.
založna raztopina sintetičnega gojišča
In this respect special attention should be given to peroxy substances.
glej odstavek 16
A sterilised inoculum provides a big surface area.
založna suspenzija aktivnega blata
Inoculum
3 g/l suspendiranih trdnih snovi
For general use, activated sludge should be collected from the exit of the aeration tank, or near the exit from the tank, of a well-operated wastewater treatment plant receiving predominantly domestic sewage.
sestavine zmesi
Depending on the purpose of the test, other adequate types or sources of activated sludge, e.g. sludge grown in the laboratory, may also be used at suitable suspended solids concentrations of 2 g/l to 4 g/l.
odmerjanje v preskusne posode [3]
However, sludges from different treatment plants are likely to exhibit different characteristics and sensitivities.
založna raztopina preskusne kemikalije (ml)
The sludge may be used as collected but coarse particles should be removed by settling for a short period, e.g. 5 to 15 minutes, and decanting the upper layer of finer solids or sieving (e.g. 1 mm2 mesh).
(odstavki od 19 do 21)
Alternatively, the sludge may be homogenised in a blender for a ca.
založna raztopina hranil iz sintetičnih odplak (ml)
15 seconds or longer, but caution is needed regarding the shear forces and the temperature change which might occur for long periods of blending.
(odstavek 16)
Washing the sludge is often necessary, e.g. if the endogenous respiration rate is low.
suspenzija aktivnega blata (ml)
The sludge should first be centrifuged for a period to produce a clear supernatant and pellet of sewage solids e.g. 10 minutes at ca.
(odstavki od 26 do 29)
10000 m/s2.
(odstavek 15)
The supernatant liquid should be discarded and the sludge re-suspended in chlorine-free tap water, with shaking, and the wash-water should then be removed by re-centrifuging and discarding again.
skupna prostornina zmesi (ml)
The washing and centrifuging process should be repeated, if necessary.
koncentracije v zmesi
The dry mass of a known volume of the re-suspended sludge should be determined and the sludge concentrated by removing liquor or diluted further in chlorine-free tap water to obtain the required sludge solids concentration of 3 g/l.
preskusna suspenzija (mg/l)
The activated sludge should be continuously aerated (e.g. 2 l/minute) at the test temperature and, where possible used on day of collection.
aktivno blato
If this is not possible, the sludge should be fed daily with the synthetic sewage feed (50 ml synthetic sewage feed/l activated sludge) for two additional days.
(suspendirane trdne snovi) (mg/l)
The sludge is then used for the test and the results are accepted as valid, provided that no significant change in its activity, assessed by its endogenous heterotrophic and nitrification respiration rate, has occurred.
Preskus je treba izvesti z vsaj tremi koncentracijami preskusne kemikalije, na primer 10 mg/l, 100 mg/l in 1000 mg/l, s slepo kontrolo in po potrebi z vsaj tremi abiotskimi kontrolami z najvišjimi koncentracijami preskusne kemikalije (kot primer glej preglednico 1).
Difficulties can arise if foaming occurs during the incubation to the extent that the foam and the sludge solids carried on it, are expelled from the aeration vessels.
V idealnem primeru najnižja koncentracija ne bi smela imeti nikakršnega učinka na privzem kisika.
Occasionally, foaming may simply result from the presence of the synthetic sewage, but foaming should be anticipated if the test chemical is, or contains, a surfactant.
Izračunati je treba hitrosti porabe kisika in hitrost nitrifikacije, če je to smiselno;
Loss of sludge solids from the test mixtures will result in artificially lowered respiration rates that could mistakenly be interpreted as a result of inhibition.
nato je treba izračunati odstotek zaviranja.
In addition, aeration of surfactant solution concentrates the surfactant in the foam layer;
Odvisno od namena preskusa je mogoče tudi samo določiti strupenost mejne koncentracije, npr. 1000 mg/l.
loss of foam from the test system will lower the exposure concentrations.
Če pri tej koncentraciji ni nobenega statistično značilnega strupenega učinka, nadaljnje preskušanje pri višjih ali nižjih koncentracijah ni potrebno.
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.
Velja pripomniti, da je treba snovi, ki so slabo topne v vodi, zmesi, katerih sestavine imajo različno topnost v vodi, in adsorptivne snovi odtehtati neposredno v preskusne posode.
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.
V tem primeru je treba količino, rezervirano za založno raztopino preskusne snovi, nadomestiti z vodo za redčenje.
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).
Končni preskus
If antifoam agents are used, there should be no interaction with inoculum and/or test chemical.
Zaviranje celotnega privzema kisika
TEST PROCEDURE
Preskus je treba izvesti s serijo koncentracij, izpeljanih iz predhodnega preskusa.
The inhibition of three different oxygen uptakes may be determined, total, heterotrophic only and that due to nitrification.
Za pridobitev vrednosti NOEC in ECx (npr. EC50) se v večini primerov priporoča šest kontrolnih koncentracij in pet koncentracij tretiranih vzorcev v geometrijski vrsti s petimi ponovitvami.
Normally, the measurement of total oxygen uptake inhibition should be adequate.
Abiotske kontrole ni treba ponavljati, če v predhodnem preskusu ni bilo privzema kisika, če pa pride do znatnega privzema, je treba vključiti abiotske kontrole za vsako koncentracijo preskusne kemikalije.
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.
Občutljivost blata je treba preveriti z referenčno kemikalijo 3,5-diklorofenol.
The test should be performed at a temperature within the range 20 ± 2 °C.
Občutljivost blata je treba preveriti za vsako preskusno serijo, saj je znano, da se spreminja.
Test mixtures
V vseh primerih se za merjenje hitrosti privzema kisika v celici s kisikovo elektrodo vzorci iz preskusnih posod odvzamejo po 3 urah in, po potrebi, dodatnih 30 minutah.
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).
Iz zbranih podatkov se izračunajo specifične hitrosti dihanja kontrolnih in preskusnih zmesi;
The pH should be adjusted to 7,5 ± 0,5, if necessary;
odstotek zaviranja se nato izračuna na podlagi spodnje enačbe 7.
mixtures should be diluted with water and the inoculum added to obtain equal final volumes in the vessels and to begin the aeration.
Razlikovanje med zaviranjem heterotrofnega dihanja in nitrifikacijo
Reference mixtures
Z uporabo posebnega zaviralca nitrifikacije, ATU, je mogoča neposredna ocena zaviralnih učinkov preskusnih kemikalij na heterotrofno oksidacijo, z odštetjem hitrosti privzema kisika v prisotnosti ATU od celotne hitrosti privzema (brez prisotnosti ATU) pa je mogoče izračunati učinke na hitrost nitrifikacije.
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.
Treba je pripraviti dve seriji reakcijskih zmesi v skladu z načrti preskusov za vrednost ECx ali NOEC, opisano v odstavku 41, dodatno pa mora biti vsaki zmesi ene serije pri končni koncentraciji 11,6 mg/l dodana ATU, ki dokazano popolnoma zavira nitrifikacijo v blatu s koncentracijami suspendiranih trdnih snovi do 3000 mg/l (4).
Blank controls
Po obdobju izpostavljenosti je treba izmeriti hitrosti privzema kisika;
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.
te neposredne vrednosti predstavljajo le heterotrofno dihanje, razlika med njimi in ustreznimi hitrostmi celotnega dihanja pa predstavlja nitrifikacijo.
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.
Nato se izračunajo različne stopnje zaviranja.
Blank controls contain an equal volume of activated sludge and synthetic medium but not test or reference chemical.
Meritve
They should be diluted with water to the same volume as the test and reference mixtures.
Po obdobju(-ih) izpostavljenosti je treba vzorec iz prve prezračevalne posode prenesti v celico s kisikovo elektrodo (slika 1 v Dodatku 2) in takoj izmeriti koncentracijo raztopljenega kisika.
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.
Če je na voljo sistem z več elektrodami, je mogoče meritve izvesti sočasno.
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.
Mešanje (s prekritim magnetom) je nujno pri isti hitrosti kot takrat, ko se elektroda umerja; s tem se zagotovi, da se sonda na spreminjajoče se koncentracije kisika odziva z minimalno zamudo in da so omogočene redne in ponovljive meritve kisika v merilni posodi.
General procedure and measurements
Navadno zadošča sistem s samodejno mešalno sondo, ki ga imajo nekatere kisikove elektrode.
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.
Med meritvami je treba celico splakniti z vodo.
Stirring the cultures is also necessary to maintain sludge flocs in suspension.
Namesto tega se za polnjenje BPK-steklenice (slika 2 v Dodatku 3), opremljene z magnetnim mešalom, lahko uporabi vzorec.
The incubation is considered to begin with the initial contact of the activated sludge inoculum with the other constituents of the final mixture.
Nato je treba v vrat steklenice vstaviti kisikovo sondo s prilagoditvijo v obliki obojke in zagnati magnetno mešalo.
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.
V obeh primerih je treba nenehno meriti koncentracijo raztopljenega kisika in jo določeno obdobje, običajno 5– 10 minut ali dokler koncentracija kisika ne pade pod 2 mg/l, beležiti.
The manner in which the incubations begin also depends on the capacity of the equipment used to measure oxygen consumption rates.
Elektrodo je treba odstraniti, zmes vrniti v prezračevalno posodo, če pa so nujne meritve po daljšem obdobju izpostavljenosti, je treba nadaljevati s prezračevanjem in mešanjem.
For example, if it comprises a single oxygen probe, the measurements are made individually.
Preverjanje koncentracije preskusne kemikalije
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.
Pri nekaterih namenih je morda nujno merjenje koncentracije preskusne kemikalije v preskusnih posodah.
Each incubation should be started in turn, at conveniently timed intervals of e.g. 10 to 15 minutes.
Če se uporabljajo založne raztopine:
Alternatively, the measuring system may comprise multiple probes that facilitate multiple simultaneous measurements;
snovi, ki so slabo topne v vodi,
in this case, inoculum may be added at the same time to appropriate groups of vessels.
zmesi s sestavinami, ki imajo različne topnosti v vodi, ali
The oxygen consumption should be measured after 3 hours of exposure.
je treba opozoriti, da raztopljeni del ni znan in da tudi ni znana prava koncentracija preskusne kemikalije, ki je prenesena v preskusne posode.
Additional 30-minute exposure measurements should be performed as appropriate and previously described in paragraph 5.
Za opis izpostavljenosti je nujna analitična ocena koncentracij preskusne kemikalije v preskusnih posodah.
Nitrification potential of sludge
Zaradi poenostavitve je treba analitično oceno izvesti pred dodajanjem inokuluma.
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.
Ker bodo v preskusne posode preneseni le raztopljeni deli, bodo izmerjene koncentracije morda zelo nizke.
The mixtures should be aerated and incubated at 20 °C ± 2 °C for 3 hours.
Da se izognemo časovno potratnim in dragim analizam, je preskusno kemikalijo priporočljivo samo odtehtati neposredno v preskusne posode in se za poznejše izračune zanesti na prvotno tehtano nominalno koncentracijo.
Then the rates of oxygen uptake should be measured and the rate of oxygen uptake due to nitrification calculated.
Razlikovanje med raztopljenimi, neraztopljenimi in adsorbiranimi deli preskusne kemikalije ni potrebno, ker se vsi ti deli prav tako pojavljajo v resničnih pogojih v čistilni napravi za odpadne vode in se lahko spreminjajo glede na sestavo odplak.
Test designs
Cilj te metode je realistična ocena neinhibitorne koncentracije in ni primerna za podrobno raziskovanje tega, kateri deli prispevajo k zaviranju organizmov v aktivnem blatu.
Range-finding test
Izračun hitrosti privzema kisika
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.
Hitrosti privzema kisika je treba izračunati iz srednje vrednosti izmerjenih vrednosti, npr. iz linearnega dela krivulj koncentracije kisika v odvisnosti od časa, s čimer se omeji izračune na koncentracije kisika med 2,0 mg/l in 7,0 mg/l, saj lahko višje in nižje koncentracije vplivajo na hitrosti porabe.
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.
Odklonu v razpone koncentracije pod ali nad temi vrednostmi se občasno ni mogoče izogniti in je nujen, na primer, kadar je dihanje močno zadušeno in zato zelo počasno ali pa, če določeno aktivno blato diha zelo hitro.
Examples of mixtures for the preliminary test
To je sprejemljivo, če so podaljšani deli krivulje privzema ravni in se njihovi nakloni ob prehodu meje 2,0 mg/l ali 7,0 mg/l O2 ne spreminjajo.
Reagent
Vsi ukrivljeni deli krivulje kažejo, da se sistem za merjenje stabilizira ali pa, da se hitrost privzema spreminja in se je ne sme uporabiti pri izračunu hitrosti dihanja.
Original Concentration
Hitrost privzema kisika mora biti izražena v miligramih na liter na uro (mg/lh) ali v miligramih na gram suhega blata na uro (mg/gh).
Test chemical stock solution
Hitrost porabe kisika, R, v mg/lh je mogoče izračunati ali interpolirati iz linearnega dela krivulje zabeleženega upada kisika v skladu z enačbo 1:
10 g/l
koncentracija kisika na začetku izbranega dela linearne faze (mg/l),
Synthetic medium stock solution
koncentracija kisika na koncu izbranega dela linearne faze (mg/l),
See paragraph 16
časovni razmik med tema dvema meritvama (min.).
Activated sludge stock suspension
Specifična hitrost dihanja (Rs) je izražena kot količina kisika, porabljenega na gram suhe teže blata na uro (mg/gh) v skladu z enačbo 2:
3 g/l of suspended solids
Rs = R/SS
Components of mixtures
pri čemer je SS koncentracija suspendiranih trdnih snovi v preskusni zmesi (g/l).
Dosing into test vessels [3]
Različni kazalniki R, ki jih je mogoče kombinirati, so:
Test chemical stock solution (ml)
S specifična hitrost,
(paragraphs 19 to 21)
T hitrost celotnega dihanja,
Synthetic sewage feed stock solution (ml)
N hitrost zaradi nitrifikacijskega dihanja,
(paragraph 16)
H hitrost zaradi heterotrofnega dihanja,
Activated sludge suspension (ml)
A hitrost zaradi abiotskih procesov,
(paragraphs 26 to 29)
B hitrost, ki temelji na slepih poskusih (srednja vrednost).
(paragraph 15)
Izračun hitrosti privzema kisika zaradi nitrifikacije
Total volume of mixtures (ml)
Razmerje med celotnim dihanjem (RT), nitrifikacijskim dihanjem (RN) in heterotrofnim dihanjem (RH) je podano z enačbo 3:
Concentrations in the mixture
izmerjena hitrost privzema kisika slepe kontrole (brez ATU; FB) (mg/lh),
Test suspension (mg/l)
izmerjena hitrost privzema kisika slepe kontrole z dodano ATU (FN) (mg/lh).
Activated sludge
To razmerje velja za vrednosti slepih kontrol (RNB, RTB, RHB), abiotskih kontrol (RNA, RTA, RHA) in preskusov s preskusnimi kemikalijami (RNS, RTS, RHS) (mg/gh).
(suspended solids) (mg/l)
Specifične hitrosti dihanja se izračunajo iz enačb:
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).
RHS = RH/SS
Ideally the lowest concentration should have no effect on oxygen consumption.
Če je vrednost RN v predhodnem preskusu zanemarljiva (npr. < 5 % RT v slepih kontrolah), je mogoče predpostaviti, da je heterotrofni privzem kisika enak celotnemu privzemu in da ni prišlo do nitrifikacije.
The rates of oxygen uptake and the rate of nitrification, if relevant, should be calculated;
Če bi morali preskusi upoštevati učinke na heterotrofne in nitrifikacijske mikroorganizme, bi bil potreben alternativni vir aktivnega blata.
then the percentage inhibition should be calculated.
Dokončni preskus se izvede, če so na voljo dokazi o zadušenih hitrostih privzema kisika pri drugih koncentracijah preskusne kemikalije.
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.
Izračun odstotka zaviranja
If no statistically significant toxic effect occurs at this concentration, further testing at higher or lower concentrations is not necessary.
Odstotek zaviranja, IT, celotne porabe kisika pri vsaki koncentraciji preskusne kemikalije je podan z enačbo 7:
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.
Podobno je odstotek zaviranja heterotrofnega privzema kisika, IH, pri vsaki koncentraciji preskusne kemikalije podan z enačbo 8:
In this case, the volume reserved for the test substance stock solution should be replaced with dilution water.
Zaviranje privzema kisika zaradi nitrifikacije, IN, je pri vsaki koncentraciji podano z enačbo 9:
Definitive test
Odstotek zaviranja privzema kisika je treba izrisati v odvisnosti od logaritma koncentracije preskusne kemikalije (krivulja zaviranja, glej sliko 3 v Dodatku 4).
Inhibition of total oxygen uptake
Krivulje zaviranja se izrišejo za vsako 3-urno obdobje prezračevanja ali dodatno po 30 minutah.
The test should be carried out using a range of concentrations deduced from the preliminary test.
Koncentracijo preskusne kemikalije, ki zavira privzem kisika za 50 % (EC50), je treba iz krivulje izračunati ali pridobiti z interpolacijo.
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.
Če so na voljo primerni podatki, je mogoče izračunati ali z interpolacijo pridobiti 95-odstotne meje zaupanja vrednosti EC50, naklon krivulje in primerne vrednosti, ki označujejo začetek območja zaviranja (na primer, EC10 ali EC20) in konec območja zaviranja (na primer, EC80 ali EC90).
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.
Treba je opozoriti, da je z vidika variabilnosti, ki jo je mogoče pogosto opaziti pri rezultatih, v mnogih primerih dovolj dodatno izraziti rezultate po velikosti:
The sensitivity of the sludge should be checked using the reference chemical 3,5-dichlorophenol.
od 1 mg/l do 10 mg/l,
The sludge sensitivity should be checked for each test series, since the sensitivity is known to fluctuate.
od 10 mg/l do 100 mg/l,
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.
> 100 mg/l.
From the data collected, the specific respiration rates of the control and test mixtures are calculated;
Razlaga rezultatov
the percentage inhibition is then calculated from equation 7, below.
Vrednosti ECx, vključno z njihovimi pripadajočimi zgornjimi in spodnjimi 95-odstotnimi mejami zaupanja za parameter, se izračunajo z ustreznimi statističnimi metodami (npr. z analizo probit, logistično ali Weibullovo funkcijo, prilagojeno metodo Spearman-Karber ali enostavno interpolacijo (11)).
Differentiation between inhibition of heterotrophic respiration and nitrification
ECx se pridobi tako, da se v postavljeno enačbo vstavi vrednost, ki ustreza x % sredine kontrole.
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.
Za izračun vrednosti EC50 ali katere koli druge vrednosti ECx je treba srednjo vrednost glede na tretirano skupino (x) analizirati z regresijsko analizo.