title: Effect of freeze-thawing cycles on soil aging behavior of individually spiked phenanthrene and pyrene at different concentrations.
abstract: This work was initiated to study the concentration effects on phenanthrene and pyrene extraction during process of aging in phaeozem and burozem with or without freeze-thawing cycles. 1, 10, and 100 μg g(-1) phenanthrene and pyrene contaminated soils were extracted by 10,000 mg L(-1) surfactant SDBS at various times. The extraction amount decreased with increasing contact time. Aging process could be divided into two stages: an initially rapid and then a slow sorption period. The amount extraction of 1 μg g(-1) pyrene in phaeozem was higher at the initial sorption stage. The time for 100 μg g(-1) phenanthrene and pyrene extraction efficiency to reach equilibrium in both soils were shorter than 1 and 10 μg g(-1). Changes in extraction efficiency rate caused by slow sorption were affected by contact time, physicochemical properties of soils and chemicals and the applied concentration of chemicals. For 1 and 10 μg g(-1) phenanthrene and pyrene contaminated soils, freeze-thawing cycle increased the extraction efficiency at the initial 1st and 8th days. The extraction efficiency with no freeze-thawing cycle was higher than that with freeze-thawing cycles at 30 and 120 days. A conceptual model was proposed to account for this process.
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhao
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
authors.forename: Peidong
authors.initials: P
authors.lastname: Tai
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Song
authors.forename: Lizhu
authors.initials: L
authors.lastname: Zhang
authors.forename: Peijun
authors.initials: P
authors.lastname: Li