A dried sludge product resulting from the treatment process of domestic wastewater. The exact processes followed for the production of the dried sludge are: Preliminary + secondary treatment of the wastewater stream, thickening, dehydration and drying of the excess sludge.

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 March 2022-15 July 2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

As the test item is a dried sludge with no quantifiable markers (as per the COA provided), the visual observation is the approach adopted to determine the approximate solubility and no further testing is made.

GLP compliance:

yes

Type of method:

other: the visual observation is the approach adopted to determine the approximate solubility and no further testing is made.

Key result

Water solubility:

< 0.001 g/L

Conc. based on:

test mat. (dissolved fraction)

Temp.:

20 °C

pH:

>= 6.94 - <= 7.01

Remarks on result:

other: As the test item is a dried sludge with no quantifiable markers (as per the COA provided), the visual observation is the approach adopted to determine the approximate solubility and no further testing is made.

• Approximate Solubility of Test Item, in Double Distilled
  Water - Preliminary Test

Trial 1

Solvent	Repli-cation	Weight of Test Item Taken (g)	Final Volume of Double Distilled Water added (mL)	pH Observed	Final Visual Observations
Double distilled water	R1	0.1016	1000	6.97	The test item remained insoluble in 1000 mL of double distilled water.
	R2	0.1012	1000	6.94
	R3	0.1018	1000	6.96

 

 

 

Solvent	Repli-cation	Weight of Test Item Taken (g)	Final Volume of Double Distilled Water added (mL)	pH Observed	Final Visual Observations
Double distilled water	R1	0.00203	1000	7.01	The test item remained insoluble in 1000 mL of double distilled water.
	R2	0.00206	1000	6.99
	R3	0.00209	1000	6.97

 

 

 

 

TABLE 1.   Approximate Solubility of Test Item in Double Distilled Water - Preliminary Test (Continued)

Trial 2

Solvent	Repli-cation	Weight of Test Item Taken (g)	Final Volume of Double Distilled Water added (mL)	pH Observed	Final Visual Observations
Double distilled water	R1	0.001050	1000	6.94	The test item remained insoluble in 1000 mL of double distilled water.
	R2	0.001080	1000	7.01
	R3	0.001020	1000	6.96

 

 

Trial 3

Solvent	Repli-cation	Weight of Test Item Taken (g)	Final Volume of Double Distilled Water added (mL)	pH Observed	Final Visual Observations
Double distilled water	R1	0.001158	2000	6.99	The test item remained insoluble in 2000 mL of double distilled water.
	R2	0.001087	2000	6.95
	R3	0.001036	2000	6.98

 

 

Conclusions:

The preliminary test indicated that the test item, Dried Sludge from Domestic Wastewater remained insoluble in double distilled water. Based on the preliminary solubility testing trials made, the approximate solubility of the test item in double distilled water was visually observed to be <0.0005 g/L at room temperature. As the test item is a dried sludge with no quantifiable markers (as per the COA provided), the visual observation is the approach adopted to determine the approximate solubility and no further testing is made.

Executive summary:

The preliminary test indicated that the test item, Dried Sludge from Domestic Wastewater remained insoluble in double distilled water. Based on the preliminary solubility testing trials made, the approximate solubility of the test item in double distilled water was visually observed to be <0.0005 g/L at room temperature. As the test item is a dried sludge with no quantifiable markers (as per the COA provided), the visual observation is the approach adopted to determine the approximate solubility and no further testing is made.

Description of key information

OECD Guideline 105 (Water Solubility) 

Key value for chemical safety assessment

Water solubility:

0.001 g/L

at the temperature of:

20 °C