N-(carboxymethyl)-N-(phosphonomethyl)glycine

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: sewage treatment simulation testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment.

Justification for data waiving:

other:

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Biodegradation potential of the environmental isolations were conducted for degrading microorganisms using samples obtained from soils, sludges and waters. Enrichments for microorganisms capable of degradation were performed using sequencing batch reactors (SBRs), immobilized bacteria columns and anaerobic incubations.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

N-(carboxymethyl)-N-(phosphonomethyl)glycine

EC Number:

227-824-5

EC Name:

N-(carboxymethyl)-N-(phosphonomethyl)glycine

Cas Number:

5994-61-6

Molecular formula:

C5H10NO7P

IUPAC Name:

2-[(carboxymethyl)(phosphonomethyl)amino]acetic acid

Details on test material:

- Name of test material (as cited in study report): N-phosphonomethyliminodiacetic acid
- Substance type: Pure active substance
- Analytical purity: 97.5-98.0 %


Radiolabeled material 1
- Radiochemical purity (if radiolabelling): 14C-Carboxymethyl labeled GI
- Specific activity (if radiolabelling): 19.0 mCi/mM
- Radiochemical impurity: Iminodiacetic acid (IDA)
- Purity: > 99 %

Radiolabeled material 2
- Radiochemical purity (if radiolabelling): 14CPhosphonomethyl-Iabeled GI
- Specific activity (if radiolabelling): 8.27 mCi/mM
- Radiochemical impurity: Iminodiacetic acid (IDA)
- Purity: > 96 %

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Radiolabelling:

yes

Study design

Oxygen conditions:

aerobic/anaerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Details on source and properties of surface water:

- Details on collection (e.g. location, sampling depth, contamination history, procedure): Sediment plus overlying water from the Cape Fear River

Details on source and properties of sediment:

- Details on collection (e.g. location, sampling depth, contamination history, procedure):
Five samples were obtained in or around the Luling site: Sediments from the decant and polishing ponds, soil adjacent to a processing unit, sludge from the aerobic digester and sediment plus overlying water from the Mississippi River.
Four environments were sampled in or around the Fayetteville site: sludges from a SBR and second stage digester, soil surrounding a processing unit, and sediment plus overlying water from the Cape Fear River.

Details on inoculum:

Composition of the Sequencing Batch Reactors:
- 10 g polishing pond sediment, 5 g Mississippi River sediment, 5 g processing unit soil, 240 mL decant pond sludge and 840 mL digester sludge

Duration of test (contact time):

25 d

Initial test substance concentration

Initial conc.:

1.6 g/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

test mat. analysis

other: Test material degrading activity

Details on study design:

Please refer " Any other information on materials and methods incl.table" section

Reference substance

Reference substance:

not specified

Results and discussion

Test performance:

No data

% Degradation

% Degradation 1

% Degr.:

> 99

Parameter:

test mat. analysis

Sampling time:

5 d

Remarks on result:

other: In bacterial isolates at 1000 mg/L

% Degradation 2

% Degr.:

> 99

Parameter:

other: Degrading activity

Sampling time:

10 h

Remarks on result:

other: In immobilized bacteria column (influent concentration of 500 mg/L)

Transformation products:

yes

Identity of transformation products

No.:

#1

Reference

Reference substance name:

Unnamed

IUPAC name:

AMPA

Identifier:

common name

Identity:

AMPA

Details on transformation products:

No data

Evaporation of parent compound:

not measured

Volatile metabolites:

not measured

Residues:

not measured

Details on results:

TEST CONDITIONS
- Aerobicity (or anaerobicity), moisture, temperature and other experimental conditions maintained throughout the study: Yes

Results with reference substance:

None

Any other information on results incl. tables

Glyphosate intermediate degrading activity (GI-DA) was established in a SBR. The cycle time required to degrade up to 1.6 g/L glyphosate intermediate (GI) was reduced from 21 to less than 3 d.

Table 1. GI biodegradation by bacterial isolates and SBR sludges in GI minimal media

Inoculum Isolate #	% GI removal
1	4.7
2	99.9
3	1.8
4	0.0
5	99.9
6	0.0
7	0.0
8	99.9
Mixed liquor- SBR A	18.2
Mixed liquor- SBR B	31.9

 

Applicant's summary and conclusion

Validity criteria

Validity criteria fulfilled:

no

Conclusions:

Under the test conditions, the test material is readily biodegradable

Executive summary:

A study was conducted to assess the biodegradation potential of the test material for degrading microorganisms using samples obtained from soils, sludges and waters.

 

Enrichments for microorganisms capable of degradation were performed using sequencing batch reactors (SBRs) immobilized bacteria columns, and anaerobic incubations. A microbial population was established which was capable of degrading test material. Test material degrading activity (GI-DA) was determined by HPLC analysis and confirmed by radiolabeled studies.

 

The cycle time required to degrade up to 1.6 g/L test material in SBRs was reduced from 21 to <3 d. Test material removal was >99% at an influent concentration of 500 mg/L and a hydraulic retention time of <10 h. In shake flask assays, microbial isolates removed 1000 mg/L test material in less than 5 d demonstrating the biodegradation of test material.

 

Under the test conditions, the test material is readily biodegradable.