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Oden CP, Werth CJ, Notini L, Katz LE. Fate of pyrene on mineral surfaces during thermal remediation as a function of temperature. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:1181-1194. [PMID: 35766907 DOI: 10.1039/d2em00027j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
There is evidence that contaminants can transform at the elevated temperatures of thermal remediation; however, the contribution of redox active minerals to transformation has not been investigated. Three redox active minerals (i.e., birnessite (MnO2), magnetite (Fe3O4), and hematite (Fe2O3)) and one redox inactive mineral (Ottawa sand (SiO2)) were spiked with pyrene and thermally treated. Under dry, anoxic conditions, 100%, 75% ± 3%, 70% ± 15%, and 14% ± 28% of the initial pyrene mass was removed with birnessite, magnetite, hematite, and Ottawa sand, respectively, after treatment at 250 °C for 30 min. Under wet, oxic conditions, 92% ± 8%, 86% ± 12%, 79% ± 4%, and 42% ± 7% was removed for the same minerals, respectively, after treatment at only 150 °C for 30 min. Baseline studies with Ottawa sand resulted in volatilization alone of pyrene with no transformation observed. Increased pyrene loading was used to evaluate potential transformation pathways based on identified by-products, demonstrating that both oxidative and reductive pathways were operative depending on the conditions. Reaction products in the presence of redox active minerals indicate transformation was dominated by reduction via hydrogenation in dry experiments, and by oxidation via hydroxyl radicals in wet experiments. The latter was unexpected, because only low hydroxyl radical concentrations have been detected in mineral-water systems at ambient temperature. These results indicate that understanding dominant reaction pathways and products is advantageous for the design of efficient and safe thermally enhanced treatment systems.
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Affiliation(s)
- Cameron P Oden
- University of Texas at Austin, USA
- University of Colorado Boulder, USA.
| | | | - Luiza Notini
- University of Texas at Austin, USA
- ETH Zurich, Switzerland
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2
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Cheng P, Lin Z, Zhao X, Waigi MG, Vasilyeva GK, Gao Y. Enhanced transformation capability towards benzo(a)pyrene by Fe(III)-modified manganese oxides. JOURNAL OF HAZARDOUS MATERIALS 2022; 431:128637. [PMID: 35278963 DOI: 10.1016/j.jhazmat.2022.128637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/24/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
Manganese oxides (Mn oxides) are ubiquitous and may coexist with Fe(III) ions in soil environments. In this study, acid birnessite, alkaline birnessite, cryptomelane, pyrolusite, manganite, and their Fe(III)-modified analogues were synthesized and used for benzo(a)pyrene transformation. Fe-modified Mn oxides show a markedly enhanced transformation capability towards benzo(a)pyrene. Specifically, the benzo(a)pyrene transformation rate constants k for Bir-H, Bir-OH, Cry, Pyr, and Man were 0.49, 0.080, 0.0071, 0.0055, and 0.0022 h-1, respectively. After Fe(III) modification, the transformation rate constants were increased to 22, 2.7, 0.25, 0.0072 and 0.0098 h-1, respectively. Fe(III)-modified layered birnessites exhibited better activity than Fe(III)-modified tunnel Mn oxides, which was attributed to their high Fe(III) contents and abundant active free radicals. Fe(III) was found to accept electrons from benzo(a)pyrene, thereby accelerating the benzo(a)pyrene transformation. Moreover, modification with Fe(III) increased the surface adsorbed water and oxygen, and promoted the generation of active free radicals. Finally, the physicochemical and biochemical properties of transformation products showed the environmental benefits of this process. Overall, the results indicate that the occurrence of Fe(III) ions could promote the removal of PAHs in Mn oxides-rich soils, and this study provides a credible understanding of PAH fates in natural soils.
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Affiliation(s)
- Pengfei Cheng
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhipeng Lin
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Xuqiang Zhao
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Michael Gatheru Waigi
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Galina K Vasilyeva
- Institute of Physicochemical and Biological Problems in Soil Science, RAS, Pushchino, Moscow Region 142290, Russia
| | - Yanzheng Gao
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
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González Henao S, Karanauskas V, Drummond SM, Dewitt LR, Maloney CM, Mulu C, Weber JM, Barge LM, Videau P, Gaylor MO. Planetary Minerals Catalyze Conversion of a Polycyclic Aromatic Hydrocarbon to a Prebiotic Quinone: Implications for Origins of Life. ASTROBIOLOGY 2022; 22:197-209. [PMID: 35100015 DOI: 10.1089/ast.2021.0024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in astrochemical environments and are disbursed into planetary environments via meteorites and extraterrestrial infall where they may interact with mineral phases to produce quinones important for origins of life. In this study, we assessed the potential of the phyllosilicates montmorillonite (MONT) and kaolinite (KAO), and the enhanced Mojave Mars Simulant (MMS) to convert the PAH anthracene (ANTH) to the biologically important 9,10-anthraquinone (ANTHQ). All studied mineral substrates mediate conversion over the temperature range assessed (25-500°C). Apparent rate curves for conversion were sigmoidal for MONT and KAO, but quadratic for MMS. Conversion efficiency maxima for ANTHQ were 3.06% ± 0.42%, 1.15% ± 0.13%, and 0.56% ± 0.039% for MONT, KAO, and MMS, respectively. We hypothesized that differential substrate binding and compound loss account for the apparent conversion kinetics observed. Apparent loss rate curves for ANTH and ANTHQ were exponential for all substrates, suggesting a pathway for wide distribution of both compounds in warmer prebiotic environments. These findings improve upon our previously reported ANTHQ conversion efficiency on MONT and provide support for a plausible scenario in which PAH-mineral interactions could have produced prebiotically relevant quinones in early Earth environments.
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Affiliation(s)
| | | | - Samuel M Drummond
- Department of Chemistry, Dakota State University, Madison, South Dakota, USA
| | - Lillian R Dewitt
- Department of Chemistry, Dakota State University, Madison, South Dakota, USA
| | | | - Christina Mulu
- Department of Chemistry, Dakota State University, Madison, South Dakota, USA
| | - Jessica M Weber
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Laura M Barge
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Patrick Videau
- Department of Biology, Southern Oregon University, Ashland, Oregon, USA
| | - Michael O Gaylor
- Department of Chemistry, Dakota State University, Madison, South Dakota, USA
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4
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Tong Y, Wang X, Sun Z, Gao J. Two transformation pathways of Acetaminophen with Fe 3+ saturated clay particles in dark or light. CHEMOSPHERE 2021; 278:130399. [PMID: 33838409 DOI: 10.1016/j.chemosphere.2021.130399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/07/2021] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
Acetaminophen (AP) has been frequently detected in different environments due to its wide usage as a common analgesic and antipyretic pharmaceutical. Excess residual of AP in the environment may cause biological risk. However, information about its environmental behaviors was limited, especially the interactions with clay minerals. In this study, AP transformation mediated by Fe3+ saturated clay particles was systematically investigated. The results showed 47.6 ± 1.1% or 78.9 ± 0.5% of AP was removed in the presence of Fe3+-montmorillonite respectively in dark or under simulated sunlight irradiation after 10 h. The hypothesized mechanism was that exchangeable ferric ions can either obtain electron from AP to form AP radical, or produce •OH under light, which can further react with AP. In dark condition, AP radicals could cross-couple with each other to form dimers, while oxidation products were also detected under light irradiation due to •OH attacking. Moreover, higher concentration of dissolved oxygen (DO) facilitated Fe3+ regeneration on clay surfaces and more reactive Fe species distributed in lower pH, which could significantly enhance the removal of AP both in dark and light. Results of this study revealed that clay minerals played important roles in the abiotic transformation of AP either in dark or under light irradiation, and oligomerization other than mineralization were the dominant processes.
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Affiliation(s)
- Yunping Tong
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xinghao Wang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China
| | - Zhaoyue Sun
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Juan Gao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China.
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Ni Z, Zhang C, Wang Z, Zhao S, Fan X, Jia H. Performance and potential mechanism of transformation of polycyclic aromatic hydrocarbons (PAHs) on various iron oxides. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123993. [PMID: 33265030 DOI: 10.1016/j.jhazmat.2020.123993] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/20/2020] [Accepted: 09/12/2020] [Indexed: 06/12/2023]
Abstract
The abiotic transformation of polycyclic aromatic hydrocarbons (PAHs) is significantly impacted by soil components, especially inorganic redox species like iron oxides. In this study, the catalytic activities of three types of iron oxides in PAHs degradation without light irradiation were evaluated using a combination of experimental techniques. The results showed that α-Fe2O3 possessed the highest transformation rate for anthracene (ANT), with a reaction rate constant (Kobs) up to 0.28 d-1, followed by Fe3O4 (Kobs = 0.06 d-1) and α-FeOOH (Kobs = 0.06 d-1). X-ray photoelectron spectroscopy (XPS) characterization suggested that α-Fe2O3 had the highest oxygen vacancy concentration, which was conducive to the adsorption of O2 by α-Fe2O3, providing sufficient adsorbed oxygen species. Oxygen vacancy contributed to the exposure of Fe(III), and accordingly, more active sites were created that were responsible for ANT degradation. According to these results, two possible pathways for the degradation of PAHs on iron oxides can be concluded: (1) direct oxidation by Fe(III) and (2) oxidation by the O2•- generated onto oxygen vacancies. This study provides significant insights into the environmental fate of PAHs on iron oxides, and raises the possibility that iron oxides may be used as catalytic materials in the remediation PAHs-contaminated soil.
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Affiliation(s)
- Zheng Ni
- College of Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Chi Zhang
- College of Resources and Environment, Northwest A & F University, Yangling 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China
| | - Zhiqiang Wang
- College of Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Song Zhao
- College of Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Xiaoyun Fan
- Jinan University, School of Environment, Guangdong Province Key Lab Environment Pollution & Health, Guangzhou 510632, China.
| | - Hanzhong Jia
- College of Resources and Environment, Northwest A & F University, Yangling 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi 712100, China.
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6
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Jia H, Zhao S, Shi Y, Zhu K, Gao P, Zhu L. Mechanisms for light-driven evolution of environmentally persistent free radicals and photolytic degradation of PAHs on Fe(III)-montmorillonite surface. JOURNAL OF HAZARDOUS MATERIALS 2019; 362:92-98. [PMID: 30236946 DOI: 10.1016/j.jhazmat.2018.09.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 09/05/2018] [Accepted: 09/06/2018] [Indexed: 05/16/2023]
Abstract
Environmentally persistent free radicals (EPFRs) have been widely detected in superfund sites and atmospheric particles contaminated with organic contaminants, but the impacts of environmental factors such as light irradiation on the formation and evolution of EPFRs remain unclear. In the present study, in-situ irradiated Fourier transform infrared spectrometer and electron paramagnetic resonance were applied to probe the formation mechanisms of EPFRs during photo-transformation of polycyclic aromatic hydrocarbons (PAHs) on montmorillonite surface. EPFRs were only detected on Fe(III)-montmorillonite containing PAHs with relatively high electron-donating ability, such as anthracene (ANT), but not in the systems of Fe(III)-montmorillonite spiked with phenanthrene or Na(I)-montmorillonite. The 1/e lifetime of the EPFRs was much shorter under light irradiation (5.49 h) than in dark (30.3 h), suggesting that light irradiation facilitated the transformation of EPFRs. On the one hand, light irradiation promoted direct electron transfer from ANT to the mineral surface, accelerating the formation of PAHs-type radical cations. On the other hand, light irradiation induced the generation of reactive oxygen species, which facilitated the transformation from radical cations to oxygenic EPFRs, which finally led to ANT degradation. This work clarified the underlying mechanisms for EPFRs generation and evolution on clay minerals.
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Affiliation(s)
- Hanzhong Jia
- College of Resources and Environment, Key Laboratory of Plant Nutrition and The Agri-Environment in Northwest China, Ministry of Agriculture, Northwest A & F University, Yangling 712100, China
| | - Song Zhao
- College of Resources and Environment, Key Laboratory of Plant Nutrition and The Agri-Environment in Northwest China, Ministry of Agriculture, Northwest A & F University, Yangling 712100, China
| | - Yafang Shi
- College of Resources and Environment, Key Laboratory of Plant Nutrition and The Agri-Environment in Northwest China, Ministry of Agriculture, Northwest A & F University, Yangling 712100, China
| | - Kecheng Zhu
- College of Resources and Environment, Key Laboratory of Plant Nutrition and The Agri-Environment in Northwest China, Ministry of Agriculture, Northwest A & F University, Yangling 712100, China
| | - Pin Gao
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
| | - Lingyan Zhu
- College of Resources and Environment, Key Laboratory of Plant Nutrition and The Agri-Environment in Northwest China, Ministry of Agriculture, Northwest A & F University, Yangling 712100, China.
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7
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Tao K, Zhao S, Gao P, Wang L, Jia H. Impacts of Pantoea agglomerans strain and cation-modified clay minerals on the adsorption and biodegradation of phenanthrene. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 161:237-244. [PMID: 29886310 DOI: 10.1016/j.ecoenv.2018.05.091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/26/2018] [Accepted: 05/29/2018] [Indexed: 06/08/2023]
Abstract
Interactions between microorganisms and minerals have the potential contribution to remove polycyclic aromatic hydrocarbons (PAHs) in model systems. In this study, phenanthrene (PHE) was used as a probe molecule to explore the potential adsorption and biotransformation processes in the presence of microorganisms and various reference clays, such as montmorillonite (M), kaolinite (K), and pyrophyllite (P). Equilibrium adsorption experiments and scanning electron microscopy (SEM) technique were used to investigate the sorption of Pantoea agglomerans strains on clay minerals saturated with cations (Na+ and Fe3+). The adsorption isotherms of PHE and Pantoea agglomerans strains on cation-modified clay minerals fitted to Langmuir equation, and their adsorbed amounts both followed the sequence: montmorillonite > kaolinite > pyrophyllite. For six types of cation-modified minerals, the behavior of PHE adsorbed and Pantoea agglomerans adhered onto mentioned minerals was in the order of Na(I)-M > Fe(Ⅲ)-M, Na(I)-K > Fe(Ⅲ)-K and Fe(Ⅲ)-P > Na(I)-P, respectively. The biodegradation results showed that cation-modified clay minerals could enhance the biodegradation of PHE, ascribing to their large specific surface area, and cation exchange capability, as well as the difference in zeta potential between minerals and Pantoea agglomerans strains. Comparison of biodegradation rates displayed that PHE was degraded the highest in the presence of Na-M (93.285%). In addition, the obtained results suggested that the adhesion of bacteria onto cation-exchanged clay minerals was beneficial to the biodegradation of PHE. Anthracen-9-ylmethanol and 3,4-dimethyl-2-(3-methylbutanoyl)benzoic acid were detected as the main intermediate compounds, which can be further biodegraded into small molecules. The overall results obtained in this study are of valuable significance for the understanding of the behavior of PHE in soil and associated environment.
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Affiliation(s)
- Kelin Tao
- College of Resources and Environment, Northwest A & F University, Yangling 712100, China; School of Geology and Mining Engineering, Xinjiang University, Urumqi 830046,China
| | - Song Zhao
- College of Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Pin Gao
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
| | - Lijin Wang
- School of Geology and Mining Engineering, Xinjiang University, Urumqi 830046,China
| | - Hanzhong Jia
- College of Resources and Environment, Northwest A & F University, Yangling 712100, China.
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8
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Juntunen HL, Leinen LJ, Pitts BK, O'Hanlon SM, Theiling BP, Barge LM, Videau P, Gaylor MO. Investigating the Kinetics of Montmorillonite Clay-Catalyzed Conversion of Anthracene to 9,10-Anthraquinone in the Context of Prebiotic Chemistry. ORIGINS LIFE EVOL B 2018; 48:321-330. [PMID: 30203410 DOI: 10.1007/s11084-018-9562-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 08/28/2018] [Indexed: 11/25/2022]
Abstract
Carbonaceous meteorites contributed polycyclic aromatic hydrocarbons (PAHs) to the organic inventory of the primordial Earth where they may have reacted on catalytic clay mineral surfaces to produce quinones capable of functioning as redox species in emergent biomolecular systems. To address the feasibility of this hypothesis, we assessed the kinetics of anthracene (1) conversion to 9,10-anthraquinone (2) in the presence of montmorillonite clay (MONT) over the temperature range 25 to 250 °C. Apparent rates of conversion were concentration independent and displayed a sigmoidal relationship with temperature, and conversion efficiencies ranged from 0.027 to 0.066%. Conversion was not detectable in the absence of MONT or a sufficiently high oxidation potential (in this case, molecular oxygen (O2)). These results suggest a scenario in which meteoritic 1 and MONT interactions could yield biologically important quinones in prebiotic planetary environments.
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Affiliation(s)
- Hope L Juntunen
- Department of Biology, Dakota State University, Madison, SD, 57042, USA
- Department of Chemistry, Dakota State University, Madison, SD, 57042, USA
| | - Lucas J Leinen
- Department of Chemistry, Dakota State University, Madison, SD, 57042, USA
| | - Briann K Pitts
- Department of Biology, Dakota State University, Madison, SD, 57042, USA
| | - Samantha M O'Hanlon
- School of Psychological Science, Oregon State University, Corvallis, OR, 97331, USA
| | | | - Laura M Barge
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Patrick Videau
- Department of Biology, Dakota State University, Madison, SD, 57042, USA.
- Department of Biology, Southern Oregon University, Ashland, OR, 97520, USA.
| | - Michael O Gaylor
- Department of Chemistry, Dakota State University, Madison, SD, 57042, USA.
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Jia H, Zhao S, Shi Y, Zhu L, Wang C, Sharma VK. Transformation of Polycyclic Aromatic Hydrocarbons and Formation of Environmentally Persistent Free Radicals on Modified Montmorillonite: The Role of Surface Metal Ions and Polycyclic Aromatic Hydrocarbon Molecular Properties. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:5725-5733. [PMID: 29658709 DOI: 10.1021/acs.est.8b00425] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
This paper presents the transformation of PAHs (phenanthrene, anthracene, benzo[a]anthracene, pyrene, and benzo[a]pyrene) on montmorillonite clays that are modified by transition-metal ions [Fe(III), Cu(II), Ni(II), Co(II), or Zn(II)] at room temperature (∼23 °C). The decay of these PAHs follows first-order kinetics, and the dependence of the observed rate constants ( kobs, day-1) on the presence of metal ions follows the order Fe(III) > Cu(II) > Ni(II) > Co(II) > Zn(II). The values of kobs show reasonable linear relationships with the oxidation potentials of the PAHs and the redox potentials of the metal ions. Notably, transformation of these PAHs results in the formation of environmentally persistent free radicals (EPFRs), which are of major concern due to their adverse effects on human health. The potential energy surface (PES) calculations using density functional theory were performed to understand the trends in kobs and the plausible mechanisms for radical formation from the PAHs on modified clays. The yields and stability of these EPFRs from anthracene and benzo[a]pyrene on clay surfaces varies with both the parent PAH and the metal ion. The results demonstrated the potential role of metals in the formation and fate of PAH-induced EPFR at co-contaminated sites.
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Affiliation(s)
- Hanzhong Jia
- Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment , Northwest A&F University , Yangling 712100 , China
- Xinjiang Technical Institute of Physics & Chemistry , Chinese Academy of Sciences , Urumqi 830011 , China
| | - Song Zhao
- Xinjiang Technical Institute of Physics & Chemistry , Chinese Academy of Sciences , Urumqi 830011 , China
| | - Yafang Shi
- Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment , Northwest A&F University , Yangling 712100 , China
| | - Lingyan Zhu
- Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment , Northwest A&F University , Yangling 712100 , China
| | - Chuanyi Wang
- Xinjiang Technical Institute of Physics & Chemistry , Chinese Academy of Sciences , Urumqi 830011 , China
| | - Virender K Sharma
- Program for the Environment and Sustainability, Department of Occupational and Environmental Health, School of Public Health , Texas A&M University , College Station , Texas 77843 , United States
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Pardo F, Santos A, Romero A. Fate of iron and polycyclic aromatic hydrocarbons during the remediation of a contaminated soil using iron-activated persulfate: A column study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 566-567:480-488. [PMID: 27235898 DOI: 10.1016/j.scitotenv.2016.04.197] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 04/24/2016] [Accepted: 04/29/2016] [Indexed: 06/05/2023]
Abstract
Remediation of contaminated soils under flow-through conditions is an issue of great interest since it provides a better approach to real case applications than batch experiments. In this work, a column filled with soil, artificially spiked and aged for three months with Phenanthrene (PHE), Anthracene (ANT), Pyrene (PYR) and Benzo(a)pyrene (BaP), was treated for 25days with persulfate (PS) activated by Fe(3+) and nanoparticles of zerovalent iron (nZVI). Effects of type of iron fed into the column (Fe(3+) or nZVI) and nZVI concentration were studied. PS inlet concentration was 0.2mmolcm(-3) and residence time in the column was close to 1.72days. Iron, PS and polycyclic aromatic hydrocarbons (PAHs) concentration, as well as pH, were monitored during treatment. Concentration profiles of iron and PAHs were observed along the column, with higher iron concentrations and higher PAHs removal efficiencies in the closest sections to the column entrance. BaP and ANT were completely depleted regardless the conditions used, but PHE and PYR showed higher resistance to oxidation, achieving near a 90% removal in the closest sections to the injection source in all runs, but decreasing significantly with column length. Besides, natural degradation of ANT resulted in the formation 9.10-anthraquinone (ATQ), an oxy-PAH which showed higher resistance than PHE and PYR. Although higher PAHs removal efficiencies were achieved when nZVI was used as activator, only a moderate improvement was noticed when the highest concentration of nZVI was used as a consequence of radical scavenging by an excess of Fe(2+). Finally, a kinetic model based on runs performed in batch, from a previous work, was able to predict the experimental average concentrations of PAHs in the column when Fe(3+) was used as activator.
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Affiliation(s)
- F Pardo
- Department of Chemical Engineering, Universidad Complutense de Madrid, Av. Complutense s/n, 28040 Madrid, Spain
| | - A Santos
- Department of Chemical Engineering, Universidad Complutense de Madrid, Av. Complutense s/n, 28040 Madrid, Spain.
| | - A Romero
- Department of Chemical Engineering, Universidad Complutense de Madrid, Av. Complutense s/n, 28040 Madrid, Spain
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