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Environmental fate & pathways

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Description of key information

Biodegradation in water:

Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound   sodium naphthalene-1-sulfonate (CAS no.  130- 14 -3 ) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical  sodium naphthalene-1-sulfonate is expected to be not readily biodegradable.

Biodegradation in water and Sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3). If released in to the environment, 21.6% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of sodium naphthalene-1-sulfonate in water is estimated to be 15 days (360 hrs). The half-life (15 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low whereas the half-life period of sodium naphthalene-1-sulfonate in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.133%), indicates that sodium naphthalene-1-sulfonate is not persistent in sediment.

Biodegradation in Soil:

The half-life period of sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 77.3% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of sodium naphthalene-1-sulfonate in soil is estimated to be 30 days (720 hrs). Based on this half-life value of sodium naphthalene-1-sulfonate, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Additional information

Biodegradation in water:

Predicted data study for target chemical sodium naphthalene-1-sulfonate(CAS no.  130- 14 -3) and experimental studies for its structurally similar read across chemical have been conducted and their results are summarized below for biodegradation in water endpoint.

 

In first study the Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound Sodium naphthalene-1-sulfonate (CAS no.  130- 14 -3) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical Sodium naphthalene-1-sulfonate is expected to be not readily biodegradable.

 

Next study was experimental study reviewed from journal Water research (1976) in this study a batch test in an open system was conducted for 5 days for evaluating the biodegradability of test chemical. Adapted activated sludge was used as a test inoculum obtained from a sewage plant is cultivated in a 1000ml volumetric cylinder. The mixture is aerated with pressure air. Every day 200 ml of the mixture is driven off so that the sludge age is 5 days. After driving off the 200ml of the mixture aeration is interrupted, and after sedimentationca.600 ml of the liquid phase is driven off. The residue (200 ml of the thickened activated sludge) is diluted with tap water to the volume ofca.800 ml and 600 mg/l of starch or glucose, 600 mg/l of peptone, 25 ml of a phosphate buffer pH 7.2, and the solution of the tested compound are added. Then the mixture in the cylinder is made up to 1000ml with tap water and aerated for 23 h (the recirculation ratio is 0-25). After this period the procedure is repeated. Test chemical conc. used for the study was 200 mg/l based on COD. To 1000-1500ml of the biological medium such amount of the solution of the substance tested is added that the initial COD is 200 mg/l. Then such an amount of the adapted activated sludge, washed and thickened by sedimentation, is dosed tothe medium that the concentration of the dry matter is 100 mg/l. Simultaneously, a blank test is prepared. The beaker was placed in a dark room with a roughly 3 constant temperature of 20±3°C on an electromagnetic stirrer and a pH of 7.2 for 120 hrs. The initial value of COD or organic carbon of the liquid phase was determined. Samples were filtered or centrifuged before analysis, are taken at suitable intervals. The decrease of the tested substance in the liquid phase is evaluated by determining COD or organic carbon. The results are compared with those of a blank test and standard compound decomposition. With the degree of degradation also the average specific rate of degradation is determined, expressed in terms of mg COD (or organic carbon) removed by a gramme of dry matter of the activated sludge per hour. The percentage degradation of test chemical was determined to be 0% degradation by COD parameter in 5 days. Thus, based on percentage degradation, test substance was considered to be not readily biodegradable in nature.

 

Another experimental study was reviewed from journal The Science of the Total Environment (1995) in this Biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test substance by bacteria as a test inoculum. Seeding bacteria was used as a test inoculum. The seeding bacteria had been cultured in a continuous anaerobic bioreactor at 37 + 1°C. Synthetic sewage, composed of glucose, peptone and corn steap liquor (carbon ratio = 1:1:2), is supplied into the reactor (3.0 g-C/l, 8.0 g-CS./.d). In this culture, > 95% acidic decomposition and > 90% methanogenic decomposition are achieved. A standard test and low conc. tests using 50 ml vials (total capacity: 68 ml) was employed. Ten test vials were prepared under the same conditions, and they were set in a water bath at 37°C ± 0.5”C. The original solution was added to the test inoculum and organic medium in oxygen-free water. At the starting time and after every week, two vials were opened simultaneously, and the concentration of organic compound was analyzed. The concentration of organic compound was determined by dissolved organic carbon (DOC) in the standard test and by chromatography in low conc. test. Biodegradation ratio is determined by analysing the decrease of DOC in the standard test. The percentage degradation of the test compound was determined to be < 30% degradation by DOC removal, chromatography in 28 days by using standard test and low conc. test. Thus, based on the percentage degradation, the test chemical was considered to be not readily biodegradable in nature.

 

Next both the studies are also experimental studies reviewed from authoritative database (J check, 2018)

 

In first study the biodegradation experiment was conducted for 14 days for evaluating the percentage biodegradability of test substance. Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance was determined to be 0 and < 0% by BOD, O2 consumption, TOC removal, test mat. analysis and UV-Vis parameter in 14 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

 

In another study the Biodegradation experiment was conducted for 14 days for evaluating the percentage biodegradability of test substance. The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)). Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance was determined to be 3.8, 0.7, 0 and 5.8% by BOD, TOC removal, UV-VIs and HPLC parameter in 14 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

 

By considering all the studies mentioned above it can be concluded that test chemical sodium naphthalene-1-sulfonate (CAS no.  130- 14 -3) is not readily biodegradable in nature.

Biodegradation in water and Sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3). If released in to the environment, 21.6% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of sodium naphthalene-1-sulfonate in water is estimated to be 15 days (360 hrs). The half-life (15 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low whereas the half-life period of sodium naphthalene-1-sulfonate in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.133%), indicates that sodium naphthalene-1-sulfonate is not persistent in sediment.

Biodegradation in Soil:

The half-life period of sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 77.3% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of sodium naphthalene-1-sulfonate in soil is estimated to be 30 days (720 hrs). Based on this half-life value of sodium naphthalene-1-sulfonate, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.