1,3,5,7-Tetraazatricyclo[3.3.1.13,7]decane, mononitrate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: public available literature (non GLP)

Data source

Reference

Reference Type:

publication

Title:

Biodegradation of formaldehyde and its derivated in industial watewater with methylotrophic yeast Hansenula polymorpha and with the yeast-bioaugmented activated sludge

Author:

Kaszycki, P.; Koloczek, H.

Year:

2002

Bibliographic source:

Biodegradation 13 : 91-99, 2002

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

Deviations:

not applicable

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Methenamine

EC Number:

202-905-8

EC Name:

Methenamine

Cas Number:

100-97-0

Molecular formula:

C6H12N4

IUPAC Name:

1,3,5,7-tetraazatricyclo[3.3.1.1~3,7~]decane

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
1) pH 7.8

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, adapted

Details on inoculum:

The study included several independent activated sludge samples collected at aeration chambers of biological wastewater treatment stations of different chemical plants. As an additional reference in yeast integration experiments, the activated sludge from a typical municipal household wastewater treatment
station was also used. The activated sludge was applied in experiments within two weeks after collection.
The sludge was stored at 4 ◦C and upon experiment, it was reactivated by placing 50–100 ml suspension in a 250 ml flask and by aerobically cultivating in a rotary shaker for 48 h at room temperature. Both themorphology and biological condition of each activated sludge sample were monitored by microscopic observations. In biodegradation studies, the sludge was preadapted to formaldehyde in a manner similar to methylotrophic yeast cultures. Integration of the activated sludge with H. polymorpha was performed by adding the appropriate number of yeast cells to 20–50 ml of the sludge suspension and by cultivating the mixture under aerobic conditions for 24 hours at 25 ◦C. In model experiments, a synthetic wastewater solution contained ammonium nitrogen, chloride and inorganic phosphorus at concentrations: 200 mg/l (NH4)2SO4, 300 mg/l KCl, and 30 mg/l H3PO4 as well as a trace amount (0.0025%) of yeast extract to provide the cell cultures with a minimum amount of microelements, vitamins, and other factors. A defined concentration of a particular xenobiotic was added to the medium as a sole carbon source.

Duration of test (contact time):

48 h

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

1 675 mg/L

Based on:

other: Methenamine in 2350 mg/l of bound and anbound formaldehyd (mainly methenamine) in wastewater experiments

Initial test substance concentration 2

Initial conc.:

1 600 mg/L

Based on:

other: pure methenamine

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

1) Measurement of methenamin in wastewater

2) Measurement of pure methenamine

Reference substance

Reference substance:

not specified

Results and discussion

Preliminary study:

no data

Test performance:

A good test performance was documented.

% Degradation

% Degradation 1

Parameter:

% degradation (test mat. analysis)

Value:

9

Sampling time:

48 h

Remarks on result:

other: Wastewater, pH 8.1

% Degradation 2

Parameter:

% degradation (test mat. analysis)

Value:

74

Sampling time:

48 h

Remarks on result:

other: Wastewater, pH 4.5

% Degradation 3

Parameter:

% degradation (test mat. analysis)

Value:

44

Sampling time:

48 h

Remarks on result:

other: Wastewater, pH 5.3

Details on results:

1) Wastewater:
Very poor degradation with H. polymorpha at high ph values of 8.1. At lower pH (4.5) a degradation of 74% was observed.
2) Pure methenamine:
In a model system at pH 5.3, H. polymorpha dens culture (at about 10(exp 7) cells/mL) was able to biodegrade methenamineat initial concentrations up to 1600 mg/L to about 44%.

BOD5 / COD results

Results with reference substance:

No reference substance

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

Methenamine is biodegradable in wastewater at low pH conditions.

Executive summary:

Methylotrophic yeast Hansenula polymorpha were shown to cooperate with activated sludge from biological wastewater treatment stations, enhancing substantially its potential to biodegrade formaldehyde in industrial wastewater. After integrationwith yeast cells themodified sludge retained its original structure and activity whereas its resistance to elevated formaldehyde concentrations was significantly improved. The applicability of the yeast in the utilization of formaldehyde derivatives, as exemplified by urotropine and trioxane, was also investigated. The treatment of urotropine-containing wastewater with methylotrophic yeast was found to be effective at acidic conditions (pH below 5.5). Trioxanewas not degraded due to the stability of an ether bond whichmade the molecule recalcitrant to oxidation via methylotrophic pathway reactions. It is concluded that the yeast species may be applied to treat wastewater containing formaldehyde and some of its derivatives as either monocultures or as an integrated, specialized element of the activated sludge biocenosis.

Results:

1) Wastewater: Very poor degradation with H. polymorpha at high ph values of 8.1. At lower pH (4.5) a degradation of 74% was observed.

2) Pure methenamine: In a model system at pH 5.3, H. polymorpha dens culture (at about 10(exp 7) cells/mL) was able to biodegrade methenamine at initial concentrations up to 1600 mg/L to about 44%.

Methenamine can be regarded biodegradable in wastewater at low pH conditions.