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Biodegradation in water

On the basis of the experimental studies of the test chemical and applying the weight of evidence approach, the percentage degradation of the test chemical can be expected to be ranges from 75 to 97.22%, respectively. Thus, based on this, it can be concluded that the test chemical is readily biodegradable in water.

Additional information

Biodegradation in water

Data available for the test chemical has been reviewed to determine the biodegradability in water. The studies are as mentioned below:

 

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 76.5%. Degradation of Sodium Benzoate exceeds 39.15% on 7 days & 70.48% 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 1.05 mgO2/mg. ThOD was calculated as 1.08 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 97.22%. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature,

 

In an another study, biodegradation experiment was conducted for 28-days using the Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test item. The study was performed using the same procedure as mentioned above. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was found to be 76.5%. Degradation of Sodium Benzoate exceeds 39.15% on 7 days & 70.48% on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD28 value of was observed to be 0.9 mgO2/mg. ThOD was calculated as 1.20 mgO /mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle Test was observed to be 75%. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature.

 

For the test chemical, additional 28-days Closed Bottle test following the OECD guideline 301 D was carried out for determining the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C using the same procedure as that mentioned above in the other experiments. 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.

 

On the basis of the experimental studies of the test chemical and applying the weight of evidence approach, the percentage degradation of the test chemical can be expected to be ranges from 75 to 97.22%, respectively. Thus, based on this, it can be concluded that the test chemical is readily biodegradable in water.