1
|
Sun X, Zhao L, Hai J, Liang X, Chen D, Liu J, Kang P. Mechanisms and extended kinetic model of thermal desorption in organic-contaminated soil. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 361:121169. [PMID: 38815425 DOI: 10.1016/j.jenvman.2024.121169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/30/2024] [Accepted: 05/10/2024] [Indexed: 06/01/2024]
Abstract
Thermal desorption is a preferred technology for site remediation due to its various advantages. To ensure the effective removal of different pollutants in practical applications, it is necessary to understand the kinetic behaviors and removal mechanisms of pollutants in thermal desorption process. This paper explored the thermal desorption processes of five organic pollutants (nitrobenzene, naphthalene, n-dodecane, 1-nitronaphthalene, and phenanthrene) at 50-350 °C in two different subsoils with 6-18% moisture content. The results suggested that the thermal desorption process was well-fitted by the exponential decay model (R2 = 0.972-0.999) and could be divided into two distinct stages. The first stage was relatively fast and highly influenced by soil moisture, while the second stage showed a slower desorption rate due to the constraints imposed by the soil texture and structure. The influence of soil moisture on thermal desorption depended on the octanol/water partition coefficient (KOW) of pollutants. Pollutants with log KOW values lower than the critical value exhibited enhanced thermal desorption, while those with log KOW values higher than the critical value were inhibited. The critical value of log KOW might be between 3.33 and 4.46. Changes in soil texture and structure caused by heating promoted thermal desorption, especially for naphthalene, 1-nitronaphthalene and phenanthrene. The differences in texture and structure between the two soils diminished as the temperature increased. Finally, an extended kinetic model under changing temperature conditions was derived, and the simulation results for the two subsoils were very close to the actual thermogravimetric results, with the differences ranging from -1.28% to 0.94% and from -0.67% to 1.35%, respectively. These findings propose new insights into the influencing mechanisms of soil moisture and structure on the thermal desorption of organic pollutants. The extended kinetic model can provide reference for future kinetic research and guide practical site remediation.
Collapse
Affiliation(s)
- Ximing Sun
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, China; Tianjin Engineering Center for Technology of Protection and Function Construction of Ecological Critical Zone, Tianjin, 300350, China
| | - Lin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, China; Tianjin Engineering Center for Technology of Protection and Function Construction of Ecological Critical Zone, Tianjin, 300350, China.
| | - Ju Hai
- State Environmental Protection Engineering Center (Tianjin) for Hazardous Waste Disposal, Tianjin, 300280, China; Guohuan Hazardous Waste Disposal Engineering Technology (Tianjin) Co., Ltd., Tianjin, 300280, China
| | - Xianwei Liang
- State Environmental Protection Engineering Center (Tianjin) for Hazardous Waste Disposal, Tianjin, 300280, China; Guohuan Hazardous Waste Disposal Engineering Technology (Tianjin) Co., Ltd., Tianjin, 300280, China
| | - Daying Chen
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, China; Tianjin Engineering Center for Technology of Protection and Function Construction of Ecological Critical Zone, Tianjin, 300350, China
| | - Jiashu Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, China; Tianjin Engineering Center for Technology of Protection and Function Construction of Ecological Critical Zone, Tianjin, 300350, China
| | - Peisong Kang
- State Environmental Protection Engineering Center (Tianjin) for Hazardous Waste Disposal, Tianjin, 300280, China; Guohuan Hazardous Waste Disposal Engineering Technology (Tianjin) Co., Ltd., Tianjin, 300280, China.
| |
Collapse
|
2
|
Xue Q, Jiao Z, Pan W, Liu X, Fu J, Zhang A. Multiscale computational simulation of pollutant behavior at water interfaces. WATER RESEARCH 2024; 250:121043. [PMID: 38154340 DOI: 10.1016/j.watres.2023.121043] [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: 07/30/2023] [Revised: 12/12/2023] [Accepted: 12/18/2023] [Indexed: 12/30/2023]
Abstract
The investigation of pollutant behavior at water interfaces is critical to understand pollution in aquatic systems. Computational methods allow us to overcome the limitations of experimental analysis, delivering valuable insights into the chemical mechanisms and structural characteristics of pollutant behavior at interfaces across a range of scales, from microscopic to mesoscopic. Quantum mechanics, all-atom molecular dynamics simulations, coarse-grained molecular dynamics simulations, and dissipative particle dynamics simulations represent diverse molecular interaction calculation methods that can effectively model pollutant behavior at environmental interfaces from atomic to mesoscopic scales. These methods provide a rich variety of information on pollutant interactions with water surfaces. This review synthesizes the advancements in applying typical computational methods to the formation, adsorption, binding, and catalytic conversion of pollutants at water interfaces. By drawing on recent advancements, we critically examine the current challenges and offer our perspective on future directions. This review seeks to advance our understanding of computational techniques for elucidating pollutant behavior at water interfaces, a critical aspect of water research.
Collapse
Affiliation(s)
- Qiao Xue
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhiyue Jiao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenxiao Pan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xian Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jianjie Fu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China.
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China.
| |
Collapse
|
3
|
Chen Z, Wang Y, Hu L. Thermal desorption mechanism of n-dodecane on unsaturated clay: Experimental study and molecular dynamics simulation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 323:121228. [PMID: 36773689 DOI: 10.1016/j.envpol.2023.121228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/13/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
Thermal desorption technology can effectively remediate fuels-contaminated clayey soil. However, the microscopic mechanism for the contaminant desorption on clay is still unclear, especially with the existence of water on clay surfaces. In this study, a combination method including TGA experiments, multi-phase and multi-component kinetic models, and MD simulation was proposed to reveal the thermal desorption mechanism of n-dodecane in unsaturated clay. Results showed that the thermal desorption behavior of the free nonaqueous phase liquid (NAPL) and the adsorbed phase of n-dodecane or water could be identified by the multi-phase and multi-component kinetic models based on the desorption process rate obtained by thermogravimetric analysis (TGA) experiments. The activation energy of the NAPL phase (49-69.9 kJ/mol) was lower than the adsorbed phase (90 kJ/mol). The activation energy of the NAPL phase had the same linear relationship with its mass on kaolinite and montmorillonite, while adsorbed phase only existed on the kaolinite surface. MD simulation showed that water demonstrated competitive adsorption with n-dodecane on montmorillonite surfaces and prevented the formation of the adsorbed phase while having little influence on the n-dodecane adsorption on kaolinite surface, which agrees well with the kinetic analysis of the TGA experiments. With the combination of macroscopic experimental analysis and microscopic molecular simulation, it can be concluded that the mass of the NAPL phase limited the desorption behavior, while the interaction between the clay mineral surface and n-dodecane was the key factor that dominated the thermal desorption behavior of the adsorbed phase. The presented results provide new insight into the desorption mechanism of hydrocarbon on clay minerals, which is of significance for the design of thermal desorption remediation.
Collapse
Affiliation(s)
- Zhixin Chen
- State Key Laboratory of Hydro-Science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing, China
| | - Yijie Wang
- State Key Laboratory of Hydro-Science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing, China
| | - Liming Hu
- State Key Laboratory of Hydro-Science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing, China.
| |
Collapse
|
4
|
Meng J, Zhang R, Chen H, Lyu Y. Molecular model construction and study of surfactant wetting of carbon black. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2022.134381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|