NANOCOLOR BOD5-TT Test Kit Owner’s Manual
- June 15, 2024
- NANOCOLOR
Table of Contents
NANOCOLOR BOD5-TT Test Kit Owner’s Manual
Method
Tube test for determination of the biochemical oxygen demand in 5 days (BOD5)
in the presence of added nutrients according to
DIN EN 1899-1-H51. Additionally, a probable influence of nitrification
processes is inhibited by N-allylthiourea. The incubation of the samples is
carried out directly in test tubes. The determination of oxygen dissolved in
water is carried out after 5 days in accordance to the Winkler Method DIN EN
25813-G21 by photometric evaluation of iodine-color.
Contents of reagent set:
Box A: 22 test tubes BOD5-TT Box B: 1 bottle with 3 mL BOD5-TT R1
1 bottle with 3 mL BOD5-TT R2
1 bottle with 6 mL BOD5-TT R3
23 screw caps
Hazard warning:
Reagent R1 contains manganese(II) chloride 25 – 83 %, reagent R2 contains
sodium hydroxide solution 20 – 55 %, reagent R3 contains
sulfuric acid 51 – 80 %. H314 Causes severe skin burns and eye damage. P260,
P280, P301+330+331, P303+361+353, P304+340, P305+351+338, P501 Do not breathe
vapors. Wear protective gloves / eye protection. IF SWALLOWED: Rinse mouth. Do
NOT induce vomiting. IF ON SKIN (or hair): Take off immediately all
contaminated clothing. Rinse skin with water / shower. IF INHALED: Remove
person to fresh air and keep comfortable for breathing. IF IN EYES: Rinse
cautiously with water for several minutes. Remove contact lenses, if present
and easy to do. Continue rinsing. Dispose of contents / container to regulate
waste treatment. For further information ask for a safety data sheet.
Interferences:
Changes in pH value, accumulation of special microbial metabolites and
compounds, which are toxic to microorganisms (e.g. mycotoxines, free chlorine,
heavy metals) can cause a decrease of substrate metabolism and a reduction of
the oxygen consumption. Iron(II)salts, sulfur dioxide and sulfur hydrogen
consume oxygen and falsify the BOD5-results, meaning they cause false negative
results, also. If algae or nitrified microorganisms are present, increased
results could occur.
Sample preparation:
At the beginning, the sample is adjusted to room temperature. Then the pH
value is checked. The pH value of the sample should be
between pH 6 and 8, and has to be adjusted, if necessary. If, in this case, a
precipitate has been developed, the sample should be homogenized very well or
filtrated (membrane filtration kit, REF 916511). In case of samples containing
algae, filtration may also be necessary in order to avoid exaggerated results.
Remove free and / or bounded chlorine by addition of sodium sulfite.
Remark: Store the sample in a tightly closed bottle full to the brim at a
temperature of 0 – 4 °C immediately after taking the sample until carrying out
the analysis. Start the BOD5 determination as soon as possible or within 24
hours of taking the sample. Samples may also be frozen to keep longer.
Homogenize frozen samples after thawing and always use inoculating water for
BOD5 determination (see BOD5-TT Accessories Set, REF 916925).
Diluting water and inoculating water:
The manufacture and correct handling of diluting water for BOD5 determination
and inoculating water use is described in detail in the BOD5-TT-Accessories
Set (REF 916925). Please observe the specified data there.
**Determination of BOD5:
Requisite accessories:
**Requisite accessories: BOD5-TT-Accessories Set (REF 916925), graduated
cylinders 25 mL, piston pipette with tips, equipment for incubation with
thermostat for 20 ± 1 °C (e. g. water bath or incubator) or as an alternative
a dark room with a room
temperature of approx. 20 °C Important! Prior to testing, make sure to replace
the rubber stoppers of the test tubes with the grey screw caps provided!
Incubation of the filled test tubes and subsequent oxygen determination must
be performed with screw caps and not with rubber stoppers. The rubber stoppers
can be disposed of along with the household waste.
Step 1: Control (oxygen consumption of the diluting water)
At each day of analysis one control-test tube (diluting water without sample)
must be prepared, used as zero value for all test tubes containing sample
dilutions. Also when preparing whole test series, only one control-test tube
is necessary. Fill in a reaction vessel (BOD5-TT– Accessories Set, REF 916925)
20 mL aerated diluting water, close the vessel and shake strongly for 30 s to
enrich thecontrol solution with oxygen. Open one test tube with reagent
BOD5-TT R0 and fill to the brim with control solution without letting air
bubbles in. Close the test tube with control solution without letting air
bubbles in, label as “control” and incubate in a water bath or an incubator
for 5 days at 20 ± 1 °C in the dark.
Step 2: Sample dilutions
Depending on the expected BOD5 of a sample, the most suitable dilution in
accordance to the following table must be prepared in a
reaction vessel (BOD5-TT-Accessories Set, REF 916925). If there is no
experience regarding the expected BOD5 of a sample, at least
two, preferably three, different dilutions of this sample should be prepared
to assure accuracy of the determination. For more reliable results, we
recommend duplicate determinations
Expected BOD 5 [mg/L O2]| Dilution| Examples for typical
waters| Sample [mL]| Diluting water [mL]
---|---|---|---|---
< 5| –| R| 20| 0
4 – 12| 1 + 1| R, B| 10| 10
10 – 30| 1 + 4| R, B| 4| 16
20 – 60| 1 + 9| B| 2| 18
40 – 120| 1 + 19| C| 1| 19
100 – 300| 1 + 49| C, M| 0.4| 19.6
200 – 600| 1 + 99| C, M| 0.2| 19.8
400 – 1200| 1 + 199| M, I| 0.1| 19.9
800 – 2400| 1 + 399| I| 0.05| 19.95
1000 – 3000| 1 + 499| I| 0.04| 19.96
R: River water
M: Raw municipal sewage
B: Biologically suitable biomass from a sewage plant
C : Clarified biomass from a sewage plant or mildly polluted industrial
waste water
I: Heavily polluted industrial waste water
Fill in a reaction vessel (BOD5-TT-Accessories Set, REF 916925) sample and
aerated diluting water in accordance to the table
above.
Close the reaction vessel and shake strongly for 30 s to enrich the sample
dilution with oxygen.
Open one test tube with reagent BOD5-TT R0 and fill to the brim with sample dilution without letting air bubbles in.
Close the test tube with sample dilution without letting air bubbles in, label as “sample” and incubate in a water bath or an incubator for 5 days at 20 ± 1 °C in the dark.
Remark: The reaction vessels added to the BOD5-TT– Accessories Set can be used for all preparations of any water samples to be tested (control, sample dilutions). Before using for a new preparation, the vessels must be washed thoroughly by using tap water.
Step 3: Measurement of dissolved oxygen
After 5 days of incubation at 20 ± 1 °C in the dark, the concentration of dissolved oxygen must be determined in all incubated test tubes (control and sample dilutions).
Open test tube, add 2 drops BOD5-TT R1 and 2 drops BOD5-TT R2, close without air bubbles and shake. Wait 2 min.
Open test tube, add
5 drops BOD5-TT R3, close without air bubbles, shake to dissolve the flakes.
Clean outside of test tube and measure.
Measurement:
For NANOCOLOR ® photometers see manual, test 8-25.
Photometers of other manufacturers:
For other photometers check whether measurement of round glass tubes is
possible. Verify factor for each type of instrument by measuring standard
solutions. Analytical quality control: NANOCONTROL BOD5 (REF 92582)
References
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