title: Transformation of anthracene on various cation-modified clay minerals.
abstract: In this study, anthracene was employed as a probe to explore the potential catalytic effect of clay minerals in soil environment. Clay minerals saturated with various exchangeable cations were tested. The rate of anthracene transformation follows the order: Fe-smectite >> Cu-smectite > Al-smectite ≈ Ca-smectite ≈ Mg-smectite ≈ Na-smectite. This suggests that transition-metal ions such as Fe(III) play an important role in anthracene transformation. Among Fe(III)-saturated clays, Fe(III)-smectite exhibits the highest catalytic activity followed by Fe(III)-illite, Fe(III)-pyrophyllite, and Fe(III)-kaolinite, which is in agreement with the interlayer Fe(III) content. Moreover, effects by two common environmental factors, pH and relative humidity (RH), were evaluated. With an increase in pH or RH, the rate of anthracene transformation decreases rapidly at first and then is leveled off. GC-MS analysis identifies that the final product of anthracene transformation is 9,10-anthraquinone, a more bioavailable molecule compared to anthracene. The transformation process mainly involves cation-π bonding, electron transfer leading to cation radical, and further oxidation by chemisorbed O2. The present work provides valuable insights into the abiotic transformation and the fate of PAHs in the soil environment and the development of contaminated land remediation technologies.
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi, 830011, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Hanzhong
authors.initials: H
authors.lastname: Jia
authors.forename: Xiyou
authors.initials: X
authors.lastname: Li
authors.forename: Chuanyi
authors.initials: C
authors.lastname: Wang
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D000873:Anthracenes / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D000077215:Clay; D004785:Environmental Pollutants / Q000737:chemistry*; D006813:Humidity; D010084:Oxidation-Reduction; D013499:Surface Properties
chemical_list: D000538:Aluminum Silicates; D000873:Anthracenes; D002412:Cations; D004785:Environmental Pollutants; C034020:anthracene; D000077215:Clay