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Li W, Qi Z, Xiong D, Wu Y, Wang W, Qi Y, Guo J. Formation and sedimentation of oil-mineral aggregates in the presence of chemical dispersant. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:1937-1944. [PMID: 37786335 DOI: 10.1039/d3em00327b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
The formation and sedimentation of oil-mineral aggregates (OMAs) is the major method to transport spilled oil to the seafloor. In this study, the formation and sedimentation experiments of OMA using montmorillonite and four crude oils were performed in a wave tank in the presence of chemical dispersant. Most of the formed OMAs were droplet OMAs, and single droplet OMA would aggregate into multiple ones under the action of the dispersant. The size of the oil droplets trapped in the OMA increased with time and was larger for the oil with higher viscosity. The sinking velocities of OMAs formed in this study were between 100-1200 μm s-1 and they were positively correlated with their diameter. The density of OMA was of the same order as that of the crude oil that formed them. An increase in the dispersant dosage could promote the formation of OMAs. The oil content in OMAs was higher for the denser oil in the presence of a dispersant. The maximum oil trapping efficiency of OMAs was 48.05%. This study provides fundamental data on the formation kinetics of OMAs.
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Affiliation(s)
- Wenxin Li
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian 116026, China.
| | - Zhixin Qi
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian 116026, China.
| | - Deqi Xiong
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian 116026, China.
| | - Yifei Wu
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian 116026, China.
| | - Wei Wang
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian 116026, China.
| | - Yajing Qi
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian 116026, China.
| | - Jian Guo
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian 116026, China.
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Yu X, Qi Z, Xiong D, An Y, Gao H, Yang M, Liu Z. Impact of mixing energy and dispersant dosage on oil dispersion and sedimentation with microplastics in the marine environment. MARINE POLLUTION BULLETIN 2023; 195:115542. [PMID: 37714077 DOI: 10.1016/j.marpolbul.2023.115542] [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: 06/14/2023] [Revised: 09/05/2023] [Accepted: 09/10/2023] [Indexed: 09/17/2023]
Abstract
Recently, the fate of spilled oil in the presence of microplastics (MPs) in the sea has attracted attention of researchers. Merey crude oil and polyethylene terephthalate (PET) were used as the experimental materials in this study. The effects of mixing energy and dispersant dosage on oil dispersion and sedimentation in the presence of MPs in the water column were investigated by laboratory experiments simulating actual sea conditions. The increase of mixing energy showed a promoting effect on oil dispersion. When the oscillation frequency increased from 140 rpm to 180 rpm, the oil dispersion efficiency (ODE) ranged from 2.1 %-3.7 % to 17.4 %-30.8 %, and the volumetric mean diameter (VMD) of the suspended oil droplets/MPs-oil agglomerates (MOA) decreased from 99.9-131.4 μm to 76.6-88.2 μm after 2 h oscillation. The application of chemical dispersant led to an increase in both the quantity and size of the formed sunken MPs-oil-dispersant agglomerates (MODA). At the dispersant-to-oil ratio (DOR) of 1:5, the ODE declined from 77.7 % to 62.6 % when the MPs concentration increased from 0 to 150 mg/L, while the oil sinking efficiency (OSE) rose from 3.4 % to 15.6 % when the MPs increased from 25 to 150 mg/L; the maximum size of the sunken MODA reached 13.0 mm, and the total volume of the MODA formed per unit volume oil reached 389.7 μL/mL oil at the MPs concentration of 150 mg/L. Meanwhile, the results showed that the presence of MPs inhibited the oil dispersion by increasing the oil-water interfacial tension. The outcomes of this work may provide assistance in predicting the transport of spilled oil and developing emergency measures.
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Affiliation(s)
- Xinping Yu
- College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Zhixin Qi
- College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Deqi Xiong
- College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Yaya An
- College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Huan Gao
- College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Miao Yang
- College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Ziyue Liu
- College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian 116026, China
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Qi Z, Wang Z, Yu Y, Yu X, Sun R, Wang K, Xiong D. Formation of oil-particle aggregates in the presence of marine algae. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:1438-1448. [PMID: 37424387 DOI: 10.1039/d3em00092c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
After an oil spill, the formation of oil-particle aggregates (OPAs) is associated with the interaction between dispersed oil and marine particulate matter such as phytoplankton, bacteria and mineral particles. Until recently, the combined effect of minerals and marine algae in influencing oil dispersion and OPA formation has rarely been investigated in detail. In this paper, the impacts of a species of flagellate algae Heterosigma akashiwo on oil dispersion and aggregation with montmorillonite were investigated. This study has found that oil coalescence is inhibited due to the adhesion of algal cells on the droplet surface, causing fewer large droplets to be dispersed into the water column and small OPAs to form. Due to the role of biosurfactants in the algae and the inhibition of algae on the swelling of mineral particles, both the oil dispersion efficiency and oil sinking efficiency were improved, which reached 77.6% and 23.5%, respectively at an algal cell concentration (Ca) of 1.0 × 106 cells per mL and a mineral concentration of 300 mg L-1. The volumetric mean diameter of the OPAs decreased from 38.4 μm to 31.5 μm when Ca increased from 0 to 1.0 × 106 cells per mL. At higher turbulent energy, more oil tended to form larger OPAs. The findings may add knowledge about the fate and transport of spilled oil and provide fundamental data for oil spill migration modelling.
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Affiliation(s)
- Zhixin Qi
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Zhennan Wang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Yue Yu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
- National Maritime Environmental Monitoring Center, Dalian 116023, China
| | - Xinping Yu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Ruiyang Sun
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Kaiming Wang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Deqi Xiong
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
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Li W, Wang W, Qi Y, Qi Z, Xiong D. Combined effects of chemical dispersant and suspended minerals on the dispersion process of spilled oil. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 341:118110. [PMID: 37150165 DOI: 10.1016/j.jenvman.2023.118110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/25/2023] [Accepted: 05/04/2023] [Indexed: 05/09/2023]
Abstract
The dispersion process of spilled oil is an important concern for the effective disposal of oil spills. The dispersed oil concentration and oil droplets size distribution were studied through a wave tank test under the application of chemical dispersant and suspended minerals. The results indicated that dispersant and minerals increased the dispersed oil concentration and the effect of dispersant was more significant, and they had a synergistic effect on oil dispersion. When dispersant and minerals were applied together, the volume mean diameter of oil droplets decreased in the first 30 min, then increased and reached a maximum value at 90-120 min, and decreased again. Moreover, suspended minerals could inhibit the coalescence of oil droplets. This study can afford data support for oil spill emergency response that occurs in inshore or estuaries.
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Affiliation(s)
- Wenxin Li
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian, 116026, China
| | - Wei Wang
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian, 116026, China
| | - Yajing Qi
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian, 116026, China
| | - Zhixin Qi
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian, 116026, China.
| | - Deqi Xiong
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian, 116026, China.
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Dong R, Wan Z, Wang X, Bai Y, Bao M, Li H. The Role of Bacteria in the Formation and Migration of Oil-Particle Aggregates (OPAs) after Marine Oil Spills and the Associated Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:7018-7028. [PMID: 37083415 DOI: 10.1021/acs.est.3c00647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Oil spills interact with mineral particles to form oil-particle aggregates (OPAs), which promotes the oil's natural diffusion and biodegradation. We investigated the effect of bacteria on the formation and vertical migration of OPAs under different concentrations and types of particles and proposed and elucidated an oil-particle-bacteria coupling mechanism. The depth of particle penetration into oil droplets (13-17 μm) was more than twice that of the nonbacterial group. Oil that remained in the water column and deposited to the bottom decreased from 87% to 49% and increased from 14% to 15% at high/low concentration, respectively. Interestingly, the median droplet diameter showed a negative correlation (R2 = 0.83) and positive correlation (R2 = 0.60) at high/low concentration, respectively, with the relative penetration depth first proposed. We further demonstrated that bacteria increased the penetrating depth by a combination of reducing/increasing the interfacial tension, reducing the oil amount (C17-C38) in the OPAs, and increasing the particle width. These effects reduced the droplet size and ultimately changed the vertical migration of OPAs. Finally, we provided a simple assessment of the vertical distribution of OPAs in nearshore environments based on experimental data and suggested that the role of bacteria in increasing the depth of particles penetrating into the oil droplets should not be ignored. These findings will broaden the research perspective of marine oil spill migration.
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Affiliation(s)
- Ranran Dong
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, People's Republic of China
- College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, People's Republic of China
| | - Zhifeng Wan
- School of Marine Sciences, Sun Yat-sen University/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, People's Republic of China
| | - Xinping Wang
- North China Sea Environmental Monitoring Center, State Oceanic Administration, Qingdao 266033, People's Republic of China
| | - Yan Bai
- School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, People's Republic of China
| | - Mutai Bao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, People's Republic of China
- College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, People's Republic of China
| | - Haoshuai Li
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, People's Republic of China
- College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, People's Republic of China
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Li W, Yu Y, Xiong D, Qi Z, Wang W, Qi Y. Effects of oil properties on the formation of oil-particle aggregates at the presence of chemical dispersant in baffled flask tests. JOURNAL OF HAZARDOUS MATERIALS 2022; 436:129227. [PMID: 35739747 DOI: 10.1016/j.jhazmat.2022.129227] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 05/13/2022] [Accepted: 05/22/2022] [Indexed: 06/15/2023]
Abstract
The formation of oil-particle aggregates (OPA) is the major sedimental pathway of spilled oil, which can bring great harm to both the benthic communities and marine environment. In this paper, effects of GM-2 chemical dispersant and oil properties on the formation of OPA was investigated by the EPA baffled flask test. The addition of dispersant can promote the formation of OPA from montmorillonite and five test oils obviously. With the increase of the dispersant dosage, the size of trapped oil in OPA increased and the density of OPA decreased. The dispersant can increase the kinematic viscosity of crude oil, and high viscosity of the oil is advantageous for the formation of OPA. The oil-seawater interfacial tension is reduced after the addition of dispersant, which makes oil dispersed into the water column easier. A kinematic equation of dispersed oil concentration attenuation was modified by introducing the oil property coefficient β. The modified empirical equation can calculate the mass of oil in sunken OPA in oil spill accidents.
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Affiliation(s)
- Wenxin Li
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian 116026, China
| | - Yue Yu
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian 116026, China
| | - Deqi Xiong
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian 116026, China.
| | - Zhixin Qi
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian 116026, China.
| | - Wei Wang
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian 116026, China
| | - Yajing Qi
- Dalian Maritime Univ, Coll Environm Sci & Engn, Dalian 116026, China
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Li W, Yu Y, Xiong D, Qi Z, Fu S, Yu X. Effects of chemical dispersant on the surface properties of kaolin and aggregation with spilled oil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:30496-30506. [PMID: 35000158 DOI: 10.1007/s11356-021-17746-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/21/2021] [Indexed: 06/14/2023]
Abstract
After oil spills occur, dispersed oil droplets can collide with suspended particles in the water column to form the oil-mineral aggregate (OMA) and settle to the seafloor. However, only a few studies have concerned the effect of chemical dispersant on this process. In this paper, the mechanism by which dispersant affects the surface properties of kaolin and the viscosity and oil-seawater interfacial tension (IFTow) of Roncador crude oil were separately investigated by small-scale tests. The results indicated that the presence of dispersant impairs the zeta potential and enhances the hydrophobicity of kaolin. The viscosity of Roncador crude oil rose slightly as the dosage of dispersant increased, while IFTow decreased significantly. Furthermore, the oil dispersion and OMA formation at different dispersant-to-oil ratio (DOR) were evaluated in a wave tank. When DOR was less than 1:40, the effect of dispersant on the dispersion of spilled oil was not obvious. With the increasing DOR, the effect became more pronounced, and the adhesion between oil droplets and kaolin was inhibited. The size ratio between oil droplets and particles is the significant factor for OMA formation. The closer the oil-mineral size ratio is to 1, the more difficultly the OMA forms.
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Affiliation(s)
- Wenxin Li
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian, 116026, China
| | - Yue Yu
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian, 116026, China
| | - Deqi Xiong
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian, 116026, China.
| | - Zhixin Qi
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian, 116026, China
| | - Sinan Fu
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian, 116026, China
| | - Xinping Yu
- Coll Environm Sci & Engn, Dalian Maritime Univ, Dalian, 116026, China
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Yu Y, Qi Z, Xiong D, Li W, Yu X, Sun R. Experimental investigations on the vertical distribution and properties of oil-mineral aggregates (OMAs) formed by different clay minerals. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 311:114844. [PMID: 35276564 DOI: 10.1016/j.jenvman.2022.114844] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
After oil spills, the floating oil may interact with suspended minerals to form the oil-mineral aggregates (OMAs) in turbulent environments. In this work, a flume was used in conjunction with a settling device to investigate the vertical distribution and properties of OMAs formed by different clay minerals. The density and size of OMAs depend on the density and surface properties of the constituent particles, which also affect the vertical distribution of dispersed oil. Density of oil-montmorillonite aggregates increased from 1165 to 1897 kg/m3 within 6 h test. Among the four minerals, montmorillonite displayed the highest affinity with dispersed oil and the most significant modification of oil-water interfacial tension. Oil dispersion efficiency was significantly greater and reached 39.3% in the presence of montmorillonite at 300 mg/L compared with the control group (17.6%). Particle concentration is the most important factor for the capture of oil and participation of particles during the OMA formation, while the zeta potential and hydrophobicity have nonsignificant effect on the two processes. Cation exchange capacity has a moderate effect on the sunken oil formation, which is also the second main factor governing the particle participation. Particle size plays a second leading role in governing the sunken oil formation but with a minor contribution of the particle participation.
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Affiliation(s)
- Yue Yu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Zhixin Qi
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China.
| | - Deqi Xiong
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China.
| | - Wenxin Li
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Xinping Yu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Ruiyang Sun
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
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Hollanda LR, Santos SBF, Faustino JGAA, Dotto GL, Foletto EL, Chiavone-Filho O. Oil field-produced water treatment: characterization, photochemical systems, and combined processes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:52744-52763. [PMID: 34467489 DOI: 10.1007/s11356-021-16222-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Produced water, a mixture of inorganic and organic components, comprises the largest effluent stream from oil and gas activities. The removal of contaminants from this wastewater is receiving special attention of the researchers since most of them are persistent and difficult to remove with simple techniques. Several technologies from conventional to advanced oxidation processes have been employed to treat produced water. However, the achievement of greater efficiency may be conditioned to a combination of different wastewater treatment techniques. Hereupon, the present paper discusses three important aspects regarding produced water treatment: analytical methods used for characterization, relevant aspects regarding photochemical systems used for advanced oxidation processes, and combined techniques for treating oil field wastewaters. Analytical methods employed for the quantification of the main species contained in produced water are presented for a proper characterization. Photochemical aspects of the reaction systems such as operating conditions, types of irradiation sources, and technical details of reactors are also addressed. Finally, research papers concerning combined treatment techniques are discussed focusing on the essential contributions. Thus, this manuscript aims to assist in the development of novel techniques and the improvement of produced water treatment to obtain a high-quality treated effluent and reduce environmental impacts.
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Affiliation(s)
- Luana Rabelo Hollanda
- Department of Chemical Engineering, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil
| | | | | | - Guilherme Luiz Dotto
- Department of Chemical Engineering, Federal University of Santa Maria, Santa Maria, 97105-900, Brazil.
| | - Edson Luiz Foletto
- Department of Chemical Engineering, Federal University of Santa Maria, Santa Maria, 97105-900, Brazil
| | - Osvaldo Chiavone-Filho
- Department of Chemical Engineering, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil
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