Effect of ageing on benzo[a]pyrene extractability in contrasting soils.
Changes in benzo[a]pyrene (B[a]P) extractability over 160 days ageing in four contrasting soils varying in organic matter content and clay mineralogy were investigated using dichloromethane: acetone 1:1 (DCM/Ace), 60 mM hydroxypropyl-β-cyclodextrin (HPCD) solution, 1-butanol (BuOH) and Milli-Q water. The B[a]P extractability by the four methods decreased with ageing and a first-order exponential model could be used to describe the kinetics of release. Correlation of the kinetic rate constant with major soil properties showed a significant effect of clay and sand contents and pore volume fraction (<6 nm) on sequestration of the desorbable fraction (by HPCD) and the water-extractable fraction. Analysis of (14)C-B[a]P in soils after ageing showed a limited loss of B[a]P via degradation. Fractionation of B[a]P pools associated with the soil matrix was analysed according to extractability of B[a]P by the different extraction methods. A summary of the different fractions is proposed for the illustration of the effect of ageing on different B[a]P-bound fractions in soils. This study provides a better understanding of the B[a]P ageing process associated with different fractions and also emphasises the extraction capacity of the different methods employed.
CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095, Australia.
Luchun
L
Duan
CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095, Australia. Electronic address: Ravi.Naidu@newcastle.edu.au.
Ravi
R
Naidu
CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095, Australia.
Yanju
Y
Liu
CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095, Australia.
Thavamani
T
Palanisami
CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095, Australia.
Zhaomin
Z
Dong
CERAR-Centre for Environmental Risk Assessment and Remediation and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Building X, University of South Australia, Mawson Lakes, SA 5095, Australia.
Megharaj
M
Mallavarapu
Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom.
Kirk T
KT
Semple
D000538:Aluminum Silicates / Q000737:chemistry; D001315:Australia; D001564:Benzo(a)pyrene / Q000032:analysis* / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods*; D000077215:Clay; D004784:Environmental Monitoring; D008962:Models, Theoretical; D012822:Silicon Dioxide / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D013997:Time Factors
D000538:Aluminum Silicates; D012987:Soil; D012989:Soil Pollutants; D001564:Benzo(a)pyrene; D012822:Silicon Dioxide; D000077215:Clay
Ageing; B[a]P; Extractability; Fractionation; Model