Diammonium dihydroxybis[lactato(2-)-O1,O2]titanate(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

Study period:

17.10.2018 - 19.12.2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes

Specific details on test material used for the study:

Batch manufactured & supplied by : Dorf Ketal Chemicals India Private Limited
Plot no. 2, Block-F, Sector -12N,
Adani ports & SEZ, Taluka – Mundra,
District-Kutch, Gujarat-370421

Test Item : Tyzor LA

CAS No. : 65104-06-5

Chemical name (IUPAC) : diammonium dihydroxybis[lactato(2-)-O1.O2]titanate(2-)

Physical appearance : Clear to slightly hazy, colorless to light yellow liquid

Titanium in product as TiO2 : 13.71 %

Lot No. : 334-300149/000160

Molecular formula : C6H10O8Ti 2(NH4)

Molecular weight : 294

Manufactured date : April 2018

Expiry date : March 2020

Recommended storage condition : Ambient (+15 to +25 °C)

pH of Solution : 8.3

Specific gravity : 1.215

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

The inoculum was a secondary effluent, collected from a treatment plant receiving predominantly domestic sewage. This effluent was used as test system as it is recommended in the guideline. A fresh sample of secondary effluent was collected from the treatment plant and was kept aerobic during transport.

This effluent was allowed to settle for one hour, decanted and the decanted effluent was used in the test.

Source of the Inoculum

Sewage Treatment Plant
Eurofins Advinus Limited
Bengaluru – 560 058
India

Determination of Bacterial Population in the Inoculum

The bacterial population in the inoculum was determined as colony forming units (CFU/mL) by diluting the inoculum to an appropriate dilution and then plating on nutrient agar plates.

Preconditioning of the Inoculum

The decanted effluent was preconditioned by aerating for 5 days at 22 to 24C.

Duration of test (contact time):

28 d

Initial conc.:

0.5 other: mg/mL

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (CO2 evolution)

Value:

32.85

St. dev.:

0.424

Sampling time:

28 d

Details on results:

8.1 Test Item Solubility
The test item formed a suspension in mineral medium at 620 mg/L.
8.2 Bacterial Population in the Inoculum
The bacterial population in the inoculum was 6.0 x 107 CFU/L.
8.3 Production of Carbon-dioxide during the Treatment Period
The carbon dioxide production during the treatment period is given in Table 1. pH of the test solutions at the end of the test is given in Table 2.

The mean carbon dioxide produced from the inoculum blank (Flask No. 3 and 4) on days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment was 13.81, 10.51, 12.71, 14.25, 11.77, 13.31, 14.08, 12.21, 8.97 and 0 mg, respectively. The total carbon dioxide produced from the inoculum blank for throughout the test period was 43.33 mg/L.

The cumulative carbon dioxide produced from the test item was 11.82, 19.79, 33.37, 35.95, 43.10, 45.63, 46.84, 48.82, 54.48 and 54.48 mg in Flask 1 on days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment, respectively. Similarly, in Flask 2 it was 8.63, 17.04, 35.79, 43.21, 49.48, 48.93, 48.27, 50.80, 55.47 and 55.47 mg on days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment, respectively.

The cumulative carbon dioxide produced from the reference item (Flask No. 5) was 15.01, 41.13, 68.90, 93.59, 119.99, 132.64, 141.77, 146.50, 150.84 and 150.84 mg, on days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment, respectively.

The cumulative carbon dioxide produced from the toxicity control (Flask No. 6) was 9.40, 27.71, 36.56, 41.34, 49.81, 51.13, 53.33, 58.83, 60.75 and 60.75 mg, on days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment, respectively.

The pH of the test solutions at the end of the test was 7.61, 7.62, 7.67, 7.66, 7.79 and 7.71 in Flask 1, 2, 3, 4, 5 and 6 respectively.
8.4 Percent Degradation
The percent degradation of the test item, reference item and toxicity control is presented in Table 3 and Figure 1.

The percent degradation of the test item was 32.55% and 33.15% in Flask No. 1 and 2, respectively, at the end of the test. The mean per cent degradation of the test item was 32.85% at the end of the test while, the percent degradation of the reference item was 90.13% and the toxicity control was 36.30% at the end of the test.

Based on the results, it was concluded that the test item, Tyzor LA is biodegradable but not readily biodegradable as 32.85% mean degradation was achieved at the end of test which is less than 60% pass level in a 10-day window period within the 28-day period of the test.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Based on the results, it was concluded that the test item, Tyzor LA is biodegradable but not readily biodegradable as 32.85% mean degradation was achieved at the end of the test which is less than 60% pass level in a 10-day window period within the 28-day period of the test.

Executive summary:

The ready biodegradability of Tyzor LA was tested using the CO₂Evolution Test. The test item was added to two test vessels at a concentration of 62 mg/L (equivalent to 15.2 mg of Total Organic Carbon/L). Two control treatments containing only the inoculum, one reference item treatment and one toxicity control treatment containing the test item and the reference item were also tested. All the treatments were added with an equal volume of inoculum which was collected from a secondary effluent treatment plant receiving predominantly domestic sewage.

 

Treatment mixtures were aerated for 29 days with carbon dioxide (CO₂) free air. The CO₂released was trapped in a series of bottles containing barium hydroxide, which were connected to the outlet of each test vessel. The residual barium hydroxide was measured on Days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the initiation of the test.

 

The mean per cent degradation of test item was 32.85% at the end of the test while, the percent degradation of reference item was 90.13% and the toxicity control was 36.30% at the end of the test.

 

The test fulfilled all the validity criteria.

 

Based on the results, it was concluded that the test item, Tyzor LA is biodegradable but not readily biodegradable as 32.85% mean degradation was achieved at the end of test which is less than 60% pass level in a 10-day window period within the 28-day period of the test.

Description of key information

Based on the results, it was concluded that the test item, Tyzor LA is biodegradable but not readily biodegradable as 32.85% mean degradation was achieved at the end of the test which is less than 60% pass level in a 10-day window period within the 28-day period of the test.  

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater