Material and Methods – biodegradability – SESAMULS® OW
Product tested
SESAMULS® OW [ Polyglyceryl-3 Cetyl Ether, Sesamum Indicum (Sesame) Seed Oil, Malic Acid]
Pre-Treatment
The carbon content of 68.5 % was determined by elemental analysis. The test item was used directly, in amounts according to its carbon content.
Positive Control
Aniline (Phenylamine, C6H5NH2, CAS-No. 62-53-3) was used as readily bio-degradable positive control. A stock solution containing 2127.8 mg/L in deionised water was prepared and its organic carbon content was measured with 1729.9 ppm, corresponding to an organic carbon content of the positive control of 81.3 %.
Test System
Specification
Activated sludge from a biologic sewage treatment plant was used. The chosen plant is treating mostly domestic sewage.
Source and Pre-Treatment
Source
The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, NW-Lachen-Speyerdorf.
Date of collection: 09. Jan 2015, batch no: 20150109.
Pre-Treatment
The sludge was filtrated, washed with tap water twice, then washed with and re-suspended in test medium. It was then aerated for ≥ 12 hours. The dry matter was determined with 4880 mg suspended solids/litre.
Chemicals
All chemicals used in the test were “analytical grade” or otherwise proved suitable.
Stock solutions
| Solution A | |||
| Potassium dihydrogenephosphate (KH2PO4) | 8.5 g | ||
|
Di-potassium hydrogenephosphate (K2HPO4) |
21.75 g | ||
|
Di-sodiumhydrogenephosphate dihydrate (Na2HPO4*2H2O) |
33.4 g | ||
|
Ammonia chloride (NH4Cl) |
0.5 g | ||
| H2O demin. Ad | 1000 mL | ||
|
The pH was adjusted to 7.4 ± 0.1. |
|||
| Solution B | |||
| Calcium chloride dihydrate (CaCl2*2H2O) | 36.4 g | ||
|
H2O demin. ad |
1000mL | ||
| Solution C | |||
|
Magnesium sulfate heptahydrate (MgSO4*7H2O) |
22.5 g | ||
|
H2O demin. ad |
1000 mL | ||
| Solution D | |||
|
Iron(III) chloride hexahydrate (FeCl3*6H2O) |
0.25 g | ||
|
Di-sodium-ethylendiamintetraacetate dihydrate (Na2EDTA*2H2O) |
0.4 g | ||
|
H2O demin. ad |
1000 mL | ||
Test Medium
The medium was freshly prepared.
Composition:
| Solution A | 10 mL |
| Solution B | 1 mL |
| Solution C | 1 mL |
| Solution D | 1 mL |
| H2O demin. ad | 1000 mL |
Sodium Hydroxide
NaOH, 0.25-m solution, used for trapping of emitted carbon dioxide.
NaOH, 1.5-m solution, used for scrubbing of purified air.
Mercury Chloride
HgCl2, used for poisoning of abiotic flasks
Barium hydroxide
Ba(OH)2 solution, used for checking the purified air (saturated solution ,1:3 diluted).
Hydrochloric Acid
HCl, 2-m solution, used for driving off dissolved CO2 on day 28.
Reference Items for Carbon Determination
Potassium hydrogenphthalate for TC, Na2CO3 and NaHCO3 for IC.
Test Vessels
All glassware was cleaned with the laboratory cleaning agent and then rinsed with tap water (thrice), diluted HCL (once), tap water (thrice) and deionised water (thrice).
2000 mL-SCHOTT-flasks were used as test vessels, 100 mL scrubber flasks as absorbent vessels.