Anthracene

Biodegradation in soil

Administrative data

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study based on accepted scientific principles, well documented, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Fate of PAH compounds in two soil types: influence of volatilization, abiotic loss and biological activity.

Author:

Park KS, Sims RC, Dupont RR, Doucette WJ, Matthews JE

Year:

1990

Bibliographic source:

Environ. Toxicol. Chem., 9, 187-195 (1990)

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

Principles of method if other than guideline:

Method: Static soil incubation test: Determination of volatilization and biodegradation in closed bottle tests / comparative study including various PAH (see below)

GLP compliance:

not specified

Test type:

laboratory

Test material

Test material information

Constituent 1

Reference substance name:

Anthracene

EC Number:

204-371-1

EC Name:

Anthracene

Cas Number:

120-12-7

Molecular formula:

C14H10

IUPAC Name:

anthracene

Details on test material:

- Name of test material (as cited in study report): anthracene
- Source: Aldrich Chemical Co.

Radiolabelling:

no

Study design

Oxygen conditions:

aerobic

Soil classification:

not specified

Soil properties

Soil properties 1

Soil no.:

#1

Soil type:

other: Kidman sandy loam

% Org. C:

0.5

pH:

7.9

CEC:

10.1 meq/100 g soil d.w.

Soil properties 2

Soil no.:

#2

Soil type:

other: McLaurin sandy loam

% Org. C:

1.1

pH:

4.8

CEC:

4.4 meq/100 g soil d.w.

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location: Kidman sandy loam(Calciaquoll, Utah) / McLaurin sandy loam (Paleudult, Mississippi)
- Sampling depth (cm): 0 - 0.15 cm
- Soil preparation: 2 mm sieved; air dried

PROPERTIES OF THE SOILS (in addition to defined fields)
- Moisture at 1/3 atm (%): 16.3 (Kidman) / 12.4 (McLaurin)
- Bulk density (g/cm3): no data
- microbial colonisation: 1# Kidman 6.7 x10^6 bacterial CF/g soil; 1.9 x10^4 fungal CF/g soil
2# Mc Laurin 6.7 x10^6 bacterial CF/g soil; 1.9 x10^4 fungal CF/g soil

Duration of test (contact time)

Duration of test (contact time) 1

Soil No.:

#1

Duration:

196 d

Duration of test (contact time) 2

Soil No.:

#2

Duration:

105 d

Initial test substance concentration

Initial test substance concentration 1

Soil No.:

#1

Initial conc.:

210 mg/kg soil d.w.

Based on:

test mat.

Initial test substance concentration 2

Soil No.:

#2

Initial conc.:

199 mg/kg soil d.w.

Based on:

test mat.

Parameter followed for biodegradation estimation:

test mat. analysis

Experimental conditions

Humidity:

16.3 other: -1/3 bar

Details on experimental conditions:

Static soil incubation test:

1. PRELIMINARY EXPERIMENTS:
VOLITILISATION TEST
- Soil condition: air dried, sieved
- Soil amount: 200 g dw per test, moistened
- Soil preincubation conditions: 1 week before start, 25 °C, moistened
- Moisture: >=60 % of water holding capacity (soil water matric potential: -33 J/kg)

VOLITILISATION procedure
- Test apparatus: 500 mL Erlenmeyer flask
- Soil amount: 200 g dw, moistened (loss of water checked and compensated for by daily weight control)
- Control conditions: 1. poisoned with 2 % HgCl2 to evaluate abiotic loss
2. soil only
- Test flask soil with single PAH
- Temperature: 25 °C
- Duration: 48 h
- Details of traps for CO2 and organic volatile: Tenax sorbent tube with methanol as carrier solvent
Purge rate: 200 mL/min
- Soil sampling: 20 g dw were withdrawn at 0, 8, 24, and 48 h and analysed for PAH by HPLC after methanol extraction.


2. EXPERIMENTAL DESIGN: MAIN TEST
- Soil preincubation conditions: 1 week before start, 25 °C, moistened
- Moisture: >=60 % of water holding capacity (soil water matric potential: -33 J/kg)
- Soil condition: air dried, sieved
- Soil (g/replicate): 40 g dw
- Control conditions: 1 per time point, poisoned with 2 % HgCl2 to evaluate abiotic loss
- No. of replication controls: 3 per time point
- No. of replication treatments: 3 per time point
- Test apparatus (Type/material/volume): 500 mL Erlenmeyer flask, covered with polyethylene film
- Details of traps for CO2: none
- If no traps were used, is the system: open

Test material application
- Volume of test solution used/treatment: no data, dissolved in dichloromathane
- Is the co-solvent evaporated: yes

Experimental conditions (in addition to defined fields)
- Moisture maintenance method: weight control
- Continuous darkness: Yes

3. OXYGEN CONDITIONS
- Methods used to create the an/aerobic conditions: open system

4. SAMPLING DETAILS
- Sampling intervals: Kidman soil 0, 42, 84, 140, and 196 d
McLaurin soil 0, 35, 70, 105
- Sampling method for soil samples: one flask per time interval

Results and discussion

Half-life / dissipation time of parent compound

Half-life / dissipation time of parent compound 1

Soil No.:

#1

DT50:

134 d

Type:

not specified

Remarks on result:

other: average with CI 106 - 182 d

Half-life / dissipation time of parent compound 2

Soil No.:

#2

DT50:

50 d

Type:

not specified

Remarks on result:

other: average with CI 42 - 61

Transformation products:

no

Evaporation of parent compound:

yes

Volatile metabolites:

no

Residues:

yes

Details on results:

Statistical analysis indicated that abiotic degradation was significant for 2- and 3-ring compounds.
The losses were statistically insignificant for the those PAH that contained greater than 3 rings.
Cumulative volatile mass (Park et al. 1990, p. 192)
for naphthalene approx. 30 % from both soils after 48 h,
for 1-methylnaphthalene approx. 15 % (Kidman loam) and approx. 27 % (McLaurin loam) after 48 h,
for all remaining PAH <0.1 % or undetectable from both soils.

Any other information on results incl. tables

BIODEGRADATION

The estimated amounts of biologically degraded PAHs were:

= mass added – (volatilised mass + abiotic loss of mass + mass of soil residue)

	Half-lives of biodegradation [days] in brackets: 95-% Confidence Intervals
	Kilman sandy loam	McLaurin sandy loam
Naphthalene	2.1 [1.7-2.7]	2.2 [1.7-3.4]
1-Methylnaphthalene	1.7 [1.4-2.1]	2.2 [1.6-3.2]
Anthracene	134 [106-182]	50 [42-61]
Phenanthrene	16 [13-18]	35 [27-53]
Fluoranthene	377 [277-578]	268 [173-630]
Pyrene	260 [193-408]	199 [131-408]
Chrysene	371 [289-533]	387 [257-866]
Benz[a]anthracene	261 [210-347]	162 [217]
7,12-Dimethyl-benz[a]anthracene	20 [18-24]	28 [21-41]
Benzo[b]fluoranthene	294 [231-385]	211 [169-277]
Benzo(a)pyrene	309 [239-462	229 [178-315
Dibenz[a,h]anthracene	361 [267-533]]	420 [267-990]
Dibenzo[a,i]pyrene	361 [277-533]	232 [178-330]
Indeno[1,2,3-c,d]-pyrene 193-39-5	288 [224-408]	289 [224-408]

The disappearance of the parent compounds was similar in both soils. The biological degradation of the 2-ring compounds was very rapid, and of 3-ring compounds, too, in particular of phenanthrene which exhibited a more extensive removal than anthracene. 4- and 5-ring PAH were more resistant with half-lives of 100 to 400 days. An exception was 7,12-dimethylbenzanthracene with an average half-life of 24 days.