Disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalenesulphonate

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:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental result using OECD test guidelines.

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

Biodegradation study was conducted according to OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test) for evaluating the percentage biodegradability of test chemical.

GLP compliance:

no

Oxygen conditions:

not specified

Inoculum or test system:

other: Mixed inoculum

Details on inoculum:

Mixed Inoculum Preparation:Polyseed were used for this study. 1 polyseed capsule was added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 10E7 to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism.

Duration of test (contact time):

28 d

Initial conc.:

4 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: OECD mineral medium was used for the study
- Test temperature: 20°C
- Continuous darkness: Yes
- Other: The water used in this study is deionized water.

TEST SYSTEM
- Culturing apparatus: The apparatus used in this study is BOD bottles; with glass stoppers (125 ml), BOD incubator & oxygen electrode and meter.

CONTROL AND BLANK SYSTEM
- Inoculum blank: it contains only test inoculum
- Procedure control: contains reference compound and inoculum

Reference substance:

other: Sodium Benzoate

Parameter:

% degradation (O2 consumption)

Value:

82.14

Sampling time:

28 d

Remarks on result:

other: Other details not known

Details on results:

The oxygen consumed by the test systems was corrected for oxygen consumption occurring in the blank test systems.The BOD Values (mgO2/mg) and percent biodegradation results for each test system arereported in Tables 2 and 3, respectively. The BOD28 value of test chemical was observed to be 1.15 mgO2/mg. ThOD was determined by calculation as 1.4 mgO2/mg. % Degradation was calculated using the values of BOD and ThOD for test item and was determined to be 82.14% at 20 ± 1°C. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 78.31%. Degradation of Sodium Benzoate exceeds 45.18 % on 7 days & 59.03 % on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid.

Results with reference substance:

The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 78.31%. Degradation of Sodium Benzoate exceeds 45.18 % on 7 days & 59.03 % on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid.

TABLE 1: D.O Values (mg/L)

No. of Days	Inoculum Blank (Control)	Test Suspension	Procedure Control (Reference Item)
0	7.1	7	7.1
7	6.7	4.7	3.7
14	6.5	3.4	2.6
21	6.2	1.8	1.1
28	5.9	1.2	0.7

TABLE 2: BOD Values (mg O2/mg)

 

No. of Days	Test Suspension	Procedure Control (Reference Item)
0	0	0
7	0.45	0.75
14	0.75	0.98
21	1.07	1.27
28	1.15	1.3

 

TABLE 3: PERCENT BIODEGRDATION RESULTS

No. of Days	Test Suspension	Procedure Control (Reference Item)
0	0%	0%
7	32.14%	45.18%
14	53.57%	59.03%
21	76.42%	76.5%
28	82.14%	78.31%

 

Table 4: BOD28, THOD AND % BIODEGRADATION VALUES

 

Method details	BOD28(mgO2/mg)	ThOD (mgO2/mg)	%Biodegradation
Test Item	1.15	1.4	82.14
Reference Item	1.3	1.66	78.31

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test chemical undergoes 82.14% biodegradation after 28 days in the test condition. Thus, the test item was considered to be readily biodegradable in nature.

Executive summary:

28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. 1 polyseed capsule were added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 10E7 to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 78.31%. Degradation of Sodium Benzoate exceeds 45.18 % on 7 days & 59.03 % on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.15 mgO2/mg. ThOD was calculated as 1.4 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 82.14%. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature.

Description of key information

A 28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical Disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalene sulphonate (CAS No. 3567-69-9). The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. 1 polyseed capsule were added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 10E7 to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 78.31%. Degradation of Sodium Benzoate exceeds 45.18 % on 7 days & 59.03 % on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.15 mgO2/mg. ThOD was calculated as 1.4 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 82.14%. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature.

 

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Biodegradation in water:

Various experimental studies for the target compound Disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalene sulphonate (CAS No. 3567-69-9) were reviewed for the biodegradation end point which are summarized as below:

 

 

A 28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical Disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalene sulphonate (CAS No. 3567-69-9). The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. 1 polyseed capsule were added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 10E7 to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 78.31%. Degradation of Sodium Benzoate exceeds 45.18 % on 7 days & 59.03 % on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.15 mgO2/mg. ThOD was calculated as 1.4 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 82.14%. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature.

 

 

Another, biodegradation test was conducted to study the degradability of chemical Acid red 14 (CAS no 3567 -69 -9). The biodegradation of dye Acid red 14 was studied with fluidized bed reactor with pumice as the support material. Mixed anaerobic cultures with mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS) concentrations of 72.776.8 and26.03 71.37 g/l, respectively, was obtained from the anaerobic sludge digesters of the Ankara wastewater treatment plant. The feed contained methanol, glucose and yeast extract as well as basal medium (BM) during the start-up period.Basal medium contained all the necessary micro- and macro-nutrients for an optimum anaerobic microbial growth During the start-up period the COD loading was gradually raised by increasing the feed rate while keeping the influent COD constant at around5000 mg/ l. The yeast extract concentration in the feed was 20 mg/l and the remaining COD was supplied by methanol and glucose at different ratios. The effect of operational conditions such as organic loading rate (OLR), hydraulic retention time (HRT), influent glucose concentration as the co-substrate, etc. was investigated to achieve the maximum color removal efficiency in the reactor. Results indicated that anaerobic treatment of textile wastewater studied was possible with the supplementation of an external carbon source in the form of glucose (about 2 g/l). The % color removal was found to be 86% in 24 hrs. of hydraulic retention time. Hence, the chemical Acid red 14 was found to be readily biodegradable with 86% color removal of product in 24-hrs of time.

 

Further, the biodegradation test was conducted to study the degradability of chemical carmoisine (CAS no 3567 -69 -9). This study aims to study the bioconversion potential of commonly available Saccharomyces cerevisiae for the two textile dyes of Carmoisine and Reactive Black 5. Reaction mixtures for biotransformation of dyes included 50 mg/l Carmoisine or 25 mg/l Reactive Black 5 and 1% dried harvested cells of S. cerevisiae (bread’s yeast) were tested. Harvested cells of S. cerevisiae were investigated in the reaction mixtures to study the ability for biotransformation of carmoisine. The biotransformation of chemical carmoisine was found to be 85% within 24-hrs of sampling time. The chemical carmoisine was found to be readily biodegradable with 85% biotransformation of product in 24-hrs of time.

 

The aerobic biodegradation test was conducted to study the degradability of chemical Acid red 14 (CAS no 3567 -69 -9). The effect of ozonation on the degradation process of azo dyes CI Acid Red14, has been studied in the semi batch rector and parameters such as pH, Color, Absorbance(at maximum wavelength, λmax ), COD, TOC, BOD5 were monitored during process at 0,20,40,60,80 min time interval.

Relatively high dye concentrations of 1000 mgl-1 for AR14 aqueous solutions were prepared in double distilled water in order to investigate the effect of ozonation on color, COD, TOC, biodegradability and effect of aerobic biodegradation on ozonated dye solutions. Rector was filled with 500 ml dye solution, prepared in BOD dilution water and flow of oxygen to ozone generator was set to 0.5 l min-1. To prepare microbial seed acclimatized to ozonated compounds, for first 10 days domestic wastewater (volume 400ml) was aerated with 50 ml fresh domestic wastewater replaced each day after 30 min settling of biomass, to ensure rapid biomass growth. From 11 th day onwards 25% of influent to the reactor was replaced by corresponding 30 min ozonated compound. This proportion was increased to 50%, 75% and 100% at interval of 5 days. For 100 % proportion of compound feed solutions were prepared with BOD dilution water to maintain required nutrient for biomass growth. Two similar aerobic reactors were also run for at least one month for biodegradability study of model compounds Acid red 14. For aerobic biodegradation, dye solutions were ozonated for 20, 40, 60 and 80 min separately. Ten aerobic reactors were operated simultaneously (five for each AR14 and CR). Each reactor fed with 100 ml ozonated feed and 5 ml of acclimatized seed of the appropriate type and aeration started. Reactors were maintained at average retention time of 2.5 days, i.e., 40 ml of effluent was extracted and 40 ml of feed added each day. Reactors were operated at these final influent COD concentrations for more than 40 days and steady-state COD removal in each reactor recorded. BOD, COD and TOC values BOD5 data reveal that partial ozonation of all selected dyes increases the biodegradability of the dye solutions. The chemical Acid red 14 was found to be readily biodegradable with 76% COD removal and 91% for TOC removal in 80 min.

 

As per the CLP classification, the test material Acid red 14 is likely to be classified as readily biodegradable.