Copper(2+), bis[N-[amino(imino-.kappa.N)methyl]urea-.kappa.O]-, nitrate (1:2)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Translation of a japanese report (2012-06-01) GLP certificate not translated in the report

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

other: mixture of non-adapted sludge

Details on inoculum:

- Source of inoculum/activated sludge: Sludge sampling was carried out at 10 locations in Japan (samples were from surface water and surface soil of rivers, lakes, and inland sea; or return sludges from sewage plants)
- Storage length: Not defined exactly
- Sampling period: December 2010; initiation date of use: January 5, 2011.
- Pretreatment: the activated sludge was cultivated for 19 hours after the synthetic sewage was added before its used
- Concentration of sludge: 3400 mg/L of suspended solid (February 7, 2011)
- Initial cell/biomass concentration: Not avalaible

2.65 mL was added to each test vessel concerned, so that the concentration of the suspended solid reached 30 mg/L.

Duration of test (contact time):

ca. 0 - ca. 28 d

Initial conc.:

ca. 100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

DOC removal

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

Detection of N-guanylurea; nitric acid ion, water-soluble copper and water-insoluble copper

Details on study design:

TEST CONDITIONS
- Composition of medium: basal culture medium (3 mL of each solution A, B, C and D (described in JIS K 0102-2010 section 21) and make up to 1 L with purified water
- Additional substrate: None
- Solubilising agent (type and concentration if used): None
- Test temperature: 25 +/- 1°C
- pH: 7.0 (basal culture medium)
- pH adjusted (basal culture medium): yes
- Aeration of dilution water: No information in the report
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes
- Other: each test soution was stirred by a stirrer
- Test vessel: volume 300 mL

TEST SYSTEM
- Culturing apparatus: closed system oxygen consumption measuring apparatus
- Number of culture flasks/concentration:
- Test solution to 100 mg/L (water + test item): 1 vessel
- Test solution to 100 mg/L (sludge + test item): 3 vessels
- Test solution to 100 mg/L (sludge + aniline): 1 vessel
- Control blank: 1 vessel
- Abiotic sterile control: None
- Toxicity control: None
- Method used to create aerobic conditions: Not available
- Measuring equipment: temperature controlled bath (containing a measuring unit) AI-0001 (Asahi Techneion Co., Ltd.); Data sampler OM7000A (Ohkura Electric Co., Ltd.)
- Details of trap for CO2 if used: soda lime No.1 (Wako Pure Chemical Industries, Ltd.)


SAMPLING
- Sampling frequency: continuous measurement (BOD) by a closed system oxygen consumption measuring apparatus
- Sampling method: /
- Sample storage before analysis: /
- Other: /


STATISTICAL METHODS: None

Reference substance:

aniline

Remarks:

100 mg/L (CAS number: 62-53-3; supplier: Wako Pure Chemical Industries Ltd., lot number: EPL1617)

Preliminary study:

A preliminary test showed that the test item was hydrolyzed rapidly in water.
Hydrolysis study of test item:
Results of the percentage detection of N-guanylurea (purified water + test item (100 mg/L of CuGun)):
0 hour: 1% of N-guanylurea
0.5 hour: 57.5% of N-guanylurea
1 hour: 100.5% of N-guanylurea
2 hours: 101% of N-guanylurea
3 hours: 100.5% of N-guanylurea

Parameter:

% degradation (O2 consumption)

Remarks:

with a closed system oxygen consumption measuring apparatus

Value:

0

Sampling time:

28 d

Remarks on result:

other: continuous measurements

Parameter:

% degradation (DOC removal)

Value:

< 5

Sampling time:

28 d

Remarks on result:

other: Average percentage detection: 96%

Details on results:

Average percentage biodegradation by BOD after 28 d: 0% ( average percentage of degradation:- 5%. The value of control blank was subtracted from the values of the test solutions (sludge + test item)).
Average percentage detection of DOC after 28 d: 96%
Average percentage detection of N-guanylurea after 28 d: 97%
Average percentage detection of nitric acid ion after 28 d: 97%
Average percentage detection of water-soluble copper after 28 d: 0%
Average percentage detection of water-insoluble copper after 28 d: 105%

Results with reference substance:

% biodegradation BOD 28 d: 76% (7 d: 62%)
% biodegradation DOC 28 d: Not available

Calculation table for percentage biodegradation by BOD (CuGun: 100 mg/L; duration of cultivation: 28 days)

Vessels	7th day		14th day		21st day		28th day		Mean
	BOD (mg)	Deg. (%)	BOD (mg)	Deg. (%)	BOD (mg)	Deg. (%)	BOD (mg)	Deg. (%)	Deg. (%)
Sludge + aniline	57.9	62	71.9	75	75.7	76	75.7	76	-
Control blank	2.0	-	4.4	-	7.1	-	7.1	-	-
Sludge + test item	1.6	-1	3.2	-4	5.4	-5	5.4	-5	-5
Sludge + test item	1.5	-1	3.2	-4	5.4	-5	5.4	-5
Sludge + test item	1.7	-1	3.5	-3	5.7	-4	5.7	-4
Water + test item	0.0	-	0.1	-	1.2	-	1.2	-	-

Validity criteria fulfilled:

yes

Remarks:

Difference between extremes of replicate values of % biodegradation (by BOD): 1% (< 20%); % biodegradation of aniline by BOD: after 7 days 62% (>= 40%) and after 14 days 75% (>= 65%); BOD value of control blank (after 28 days): 7.1 mg (< 60 mg/L)

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Report conclusion:
Under the test conditions of this study, the test item: Copper Guanylurea nitrate, a salt formed from copper-N-guanylurea complex ion (cationic component) and nitric acid ion (anionic component) is rapidly hydrolyzed in water (transformation products: N-guanylurea, nitric acid ion and copper).
Copper in the test item was remained as a water-insoluble and inorganic form in the test solution .
Nitric acid ion contained as an anionic component in the test item was remained as a dissociated form in the test solution and although N-guanylurea, which is an organic component, was freed in the test solution, it was not biodegraded in this study.

Description of key information

Under the test conditions of this study, the test item: Copper Guanylurea nitrate, a salt formed from copper-N-guanylurea complex ion (cationic component) and nitric acid ion (anionic component) is rapidly hydrolyzed in water (transformation products: N-guanylurea, nitric acid ion and copper). 

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Copper in the test item was remained as a water-insoluble and inorganic form in the test solution . Nitric acid ion contained as an anionic component in the test item was remained as a dissociated form in the test solution and although N-guanylurea, which is an organic component, was freed in the test solution, it was not biodegraded in this study.