reaction mass of copper sulfate and deta to Reaction products of 2,2'-iminodi(ethylamine) and copper sulphate (1:1)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Version / remarks:

1981

Deviations:

no

GLP compliance:

not specified

Specific details on test material used for the study:

Diethylenetriamine was obtained from Delamine B.V., Delzijl, The Netherlands.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Secondary activated sludge and settled sewage were collected from activated sludge plants treating predominantly domestic sewage.

- Preparation of inoculum for exposure:
Inocula from the wastewater purification plants were preconditioned to reduce the endogenous respiration rates. To this end, the sludge (200 mg dry wt/L) was aerated for a period of 7 days.
- Concentration of sludge:
The sludge was diluted to a concentration of 2 mg dw/l in the bottles.

Duration of test (contact time):

21 d

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
Test conditions according to OECD301D guideline.
- Composition of medium:
Ammonium chloride was omitted from the medium to prevent nitrification.
Triplicate control (mineral medium + inoculum) and test (minieral medium + inoculum + test substance) bottles were incubated at 22 ± 2 °C.

TEST SYSTEM
According to OECD301D guideline.
- Culturing apparatus:
- Number of culture flasks/concentration: 3
- Measuring equipment:
The dissolved oxygen concentrations in the closed bottles were periodically determined electrochemically using an oxugen electrode (WTW Trioxmatic EO200) and meter (WTW OXI 530).
The suspended solid concentrations were determined by filtering a sample over a preweighted 8 micrometer Schleicher and Schüll filter. This filter was dried for 1.5 hours at 104°C and weighted after cooling in an exsiccator. Suspended solid concentrations were calculated by subtracting the weighted filters.
Chemical oxygen demand was determined using the method of Jirka and Carter 1975.

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

9 d

Parameter:

% degradation (O2 consumption)

Value:

87

Sampling time:

21 d

Details on results:

Biodegradation of DETA did not start before day 12 in a closed-bottle test inoculated with unacclimated sludge. Subsequently, biodegradation up to 87% took place within 3 weeks.
Test was terminated after 21 days.

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

The ready biodegradability of DETA was determined using activated sludge in a closed-bottle test (OECD 301D). Although biodegradation started slowly (no biodegradation after 10 days), DETA was found to biodegrade significantly within 3 weeks (87% biodegradation).

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is inorganic

Justification for type of information:

Copper is inorganic and therefore does not biodegrade.

Description of key information

The reaction product of copper sulfate and DETA is inorganic - it contains copper - and therefore was considered not biodegradable.

The constituent DETA, however, is known to biodegrade (Van Ginkel 1995).

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater