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Pan Y, Yang T, Tong S, Yang J, Jia Y, Yang N, Zhang M. Spatial infiltration and redistribution of light crude oil in heterogeneous water-bearing soil layers under different hydrogeological processes. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:214. [PMID: 38286925 DOI: 10.1007/s10661-023-12218-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 12/02/2023] [Indexed: 01/31/2024]
Abstract
Two physical models were used to simulate the infiltration and redistribution process of light crude oil after leakage in a heterogeneous soil layer following water level variation and rainfall. Migration fronts and redistribution characteristics of oil during gravity seepage, water level variation, and rainfall were obtained using charge-coupled device (CCD) camera shooting and cyan-magenta-yellow‒black (CMYK)-based gray analysis, which were employed efficiently and at a low cost. Then, the influencing factors and migration mechanisms were examined. Finally, the soil water and oil contents were measured to verify the simulation results. The results are as follows: (1) the geologic lens and fine-coarse interface can intercept oil, resulting in a local highly contaminated area. (2) The crude oil infiltration path and velocity varied greatly with the different soil types and initial water contents. Within a certain range, the higher the initial water content is, the higher the lateral and vertical infiltration speeds. (3) The oil redistribution process was dominated by vertical infiltration under the condition of water level variation or rainfall, but oil-water displacement and the capillary pressure caused some oil to move horizontally near the geologic lens and fine-coarse interface. (4) Water level variation resulted in a synchronous rise or fall of the oil accumulation area, but rainfall caused it to move up. (5) Water level variation and rainfall imposed a certain influence on the periodic accumulation and release of crude oil in heterogeneous soil, especially in the presence of geologic lenses and lithologic interfaces.
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Affiliation(s)
- Yuying Pan
- School of Fishery, Zhejiang Ocean University, Zhoushan, China
- Key Laboratory of Marine Fishery Equipment and Technology of Zhejiang, Zhejiang Ocean University, Zhoushan, China
| | - Tingting Yang
- School of Fishery, Zhejiang Ocean University, Zhoushan, China
| | - Senwei Tong
- School of Fishery, Zhejiang Ocean University, Zhoushan, China
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Jinsheng Yang
- School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan, China
| | - Yonggang Jia
- Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao, China.
- Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
| | - Nanning Yang
- School of Fishery, Zhejiang Ocean University, Zhoushan, China
| | - Meng Zhang
- School of Fishery, Zhejiang Ocean University, Zhoushan, China
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Ibeto C, Onyekachi O, Aju E. Environmental and health risks assessment of n-alkanes and BTEX in Eze Iyi River at oil spill site in Isuikwuato, Abia State, Nigeria. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:717. [PMID: 37222847 DOI: 10.1007/s10661-023-11275-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 04/19/2023] [Indexed: 05/25/2023]
Abstract
The environmental and health risks of n-alkanes and benzene, toluene, ethylbenzene, and xylene (BTEX) in Eze-Iyi River at Isuikwuato oil spill site were evaluated. The water samples (60) were collected from upstream and downstream during the dry and rainy seasons. Concentrations of n-alkanes and BTEX were determined using a gas chromatograph coupled with a flame ionization detector. The percentage recovery of 87.3% and 92.0% was obtained for n-alkanes and BTEX in the water sample. The environmental risk analysis for n-alkanes and BTEX showed 80% of the water samples had a ratio greater than 1 indicating environmental risk in the area. Hydrocarbon source identification using biomarkers indicates that the n-alkane (nC16) dominant during the dry and rainy seasons was from anthropogenic/biogenic source, while nC14 and nC17 were from microbial and marine algae biogenic sources, respectively. The benzene levels in 100% (downstream) and 80% (upstream) of samples in the dry season and 40% (upstream) and 100% (downstream) of samples in the rainy season were above the WHO permissible limit of 0.01 mg/L for drinking water. The health risk index of n-alkanes during the dry season for children (upstream) was greater than 1 signifying adverse health risk. Therefore, consumption of water from the river should be discouraged and routine monitoring by regulatory authorities maintained to checkmate the build-up of BTEX and n-alkanes.
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Affiliation(s)
- Cynthia Ibeto
- Department of Pure and Industrial Chemistry, University of Nigeria Nsukka, Nsukka, Enugu State, Nigeria.
| | - Omeje Onyekachi
- Department of Pure and Industrial Chemistry, University of Nigeria Nsukka, Nsukka, Enugu State, Nigeria
| | - Esther Aju
- Department of Pure and Industrial Chemistry, University of Nigeria Nsukka, Nsukka, Enugu State, Nigeria
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Mineo S. Groundwater and soil contamination by LNAPL: State of the art and future challenges. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 874:162394. [PMID: 36858232 DOI: 10.1016/j.scitotenv.2023.162394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/05/2023] [Accepted: 02/18/2023] [Indexed: 06/18/2023]
Abstract
Contamination by Light Non-Aqueous Phase Liquids (LNAPL) represents a challenge due to the difficulties encountered in its underground assessment and recovery. The major risks arising from subsoil LNAPL accumulation face human health and environment, gaining a social relevance also in the frame of a continuously changing climate. This paper reports on a literature review about the underground contamination by LNAPL, with the aims of providing a categorization of the aspects involved in this topic, analyzing the current state of the art, underlying potential lacks and future perspectives. The review was focused on papers published in the 2012-2022 time-interval, in journals indexed in Scopus and WoS databases, by querying "LNAPL" within article title, abstract and/or key words. 245 papers were collected and classified according to three "key approaches" -namely laboratory activity, field based-data studies and mathematical simulations- and subordinate "key themes", so to allow summarizing and commenting the main aspects based on the application setting, content and scope. Results show that there is a wide experience on plume dynamics and evolution, detection and monitoring through direct and indirect surveys, oil recovery and natural attenuation processes. Few cues of innovations were found regarding both the use of new materials and/or specific field configuration for remediation, and the application of new techniques for plume detection. Some limitations were found in the common oversimplification of the polluted media in laboratory or mathematical models, where the contamination is set within homogeneous porous environments, and in the low number of studies focused on rock masses, where the discontinuous hydraulic behavior complicates the address and modeling of the issue. This paper represents a reference for a quick update on the addressed topic, along with a starting point to develop new ideas and cues for the advance in one of the greatest environmental banes of the current century.
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Affiliation(s)
- S Mineo
- University of Catania, Department of Biological, Geological and Environmental Sciences, Corso Italia 57, Catania 95123, Italy.
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Sun J, Wang X, Song Q, Li R, Xie J, Yang X, Cai L, Wang Z, Zhao C, Zhang X. Fingerprint characteristics of refined oils and their traceability in the groundwater environment. CHEMOSPHERE 2023; 333:138868. [PMID: 37160170 DOI: 10.1016/j.chemosphere.2023.138868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/03/2023] [Accepted: 05/05/2023] [Indexed: 05/11/2023]
Abstract
Chemical fingerprinting is essential for identifying the presence and responding to oil spills that frequently contaminate the groundwater environment of refineries. In this study, crude oil and oil products from the atmospheric and vacuum distillation units of a refinery were analyzed by gas chromatography-mass spectrometry (GC-MS) to evaluate their chemical variability before and after refinery. A series of experiments involving evaporation and soil column penetration were conducted to simulate refined oil spilling into groundwater and determine appropriate characteristic ratios (CRs) for principal component analysis (PCA) for oil source identification. The simulated study demonstrated that all products had bell-shaped n-alkane distributions, with dominant peaks that remained unchanged or shifted towards longer chain lengths compared to the source oil. Similarly, naphthalene and dibenzothiophene series remained the main PAH components like the source oil. Ten relatively stable CRs were selected for PCA to identify different oil products through the simulated experiments. The chosen CRs were then utilized to identify the sources for two groundwater oil spills recently occurred, one that occurred in an oil depot area, and another near a continuous catalytic reforming unit in a refinery. This study showed that the components with long-chain n-alkanes (n ≥ C18), pristane, phytane, and phenanthrene and dibenzothiophene series PAHs played an important role in the identification of refined oil products spilling into the groundwater environment. The selected CRs provide an effective tool for rapid and accurate identification of oil spills, especially for newly occurring spills in the groundwater environment, which can aid in developing appropriate response strategies.
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Affiliation(s)
- Juan Sun
- College of Chemistry and Chemical Engineering, China University of Petroleum East China, Qingdao, 266580, China; State Key Laboratory of Petroleum Pollution Control, Beijing, 102206, China.
| | - Xiaoyang Wang
- College of Chemistry and Chemical Engineering, China University of Petroleum East China, Qingdao, 266580, China
| | - Quanwei Song
- State Key Laboratory of Petroleum Pollution Control, Beijing, 102206, China; CNPC Safety and Environmental Protection Technology Research Institute, Beijing, 102206, China
| | - Ran Li
- College of Chemistry and Chemical Engineering, China University of Petroleum East China, Qingdao, 266580, China
| | - Jiacai Xie
- State Key Laboratory of Petroleum Pollution Control, Beijing, 102206, China; CNPC Safety and Environmental Protection Technology Research Institute, Beijing, 102206, China
| | - Xiaoqing Yang
- College of Chemistry and Chemical Engineering, China University of Petroleum East China, Qingdao, 266580, China
| | - Liuping Cai
- College of Chemistry and Chemical Engineering, China University of Petroleum East China, Qingdao, 266580, China
| | - Zihao Wang
- College of Chemistry and Chemical Engineering, China University of Petroleum East China, Qingdao, 266580, China
| | - Chaocheng Zhao
- College of Chemistry and Chemical Engineering, China University of Petroleum East China, Qingdao, 266580, China
| | - Xiuxia Zhang
- College of Chemistry and Chemical Engineering, China University of Petroleum East China, Qingdao, 266580, China
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Priyadarshini I, Chowdhury A, Rao A, Roy B, Chattopadhyay P. Assessment of bimetallic Zn/Fe 0 nanoparticles stabilized Tween-80 and rhamnolipid foams for the remediation of diesel contaminated clay soil. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 325:116596. [PMID: 36326527 DOI: 10.1016/j.jenvman.2022.116596] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 10/04/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Diesel contamination of soil due to oil spills, disposal of refinery waste, oil exploration constitutes a major environmental problem. This paper reports the remediation of diesel contaminated clay soil using Zn/Fe0 bimetallic nanoparticle stabilized Rhamnolipid (RMLP) and Tween-80 (TW-80) surfactant foams. Fe0, and Zn (x wt%)/Fe0 (x = 0.2, 2.0, and 10.0) bimetallic nanoparticles are synthesized by using sodium borohydride reduction method. The average particle size (from FESEM) is calculated to be 62, 57, 42 and 35 nm for the Fe0, Zn (0.2)/Fe0, Zn (2)/Fe0 and Zn (10)/Fe0 nanopowders, respectively. The highest foamability and foam stability of 109.6 and 108.5 mL, respectively are observed for the RMLP (12 mg/l) surfactant foam stabilized with 6 mg/l Zn (10)/Fe0 nanoparticles. The surface tension values reduce to the lowest value of 28.1 and 31.4 mN/m with the addition of 6 mg/l of Zn (10)/Fe0 powder in RMLP and TW-80 solutions of 12 mg/l, respectively. The maximum diesel removal efficiency of 83.8 and 59%, is achieved by RMLP (12 mg/l) foam stabilized by Zn (10)/Fe0 nanoparticles (6 mg/l) for the clay soil contaminated with 100 and 500 μl/g of diesel, respectively. The physicochemical properties of the nanoparticles are studied to explain the foam properties and the remediation behavior. These findings regarding the nanoparticle stabilized foams can offer a cost-effective environment friendly commercial solution for soil remediation in the future.
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Affiliation(s)
- Ipsita Priyadarshini
- Department of Chemical Engineering, Birla Institute of Technology and Science (BITS), Pilani Campus, VidyaVihar, Pilani 333031, Rajasthan, India
| | - Arjun Chowdhury
- Department of Chemical Engineering, Birla Institute of Technology and Science (BITS), Pilani Campus, VidyaVihar, Pilani 333031, Rajasthan, India
| | - Ankit Rao
- Center for Nano Science and Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Banasri Roy
- Department of Chemical Engineering, Birla Institute of Technology and Science (BITS), Pilani Campus, VidyaVihar, Pilani 333031, Rajasthan, India
| | - Pradipta Chattopadhyay
- Department of Chemical Engineering, Birla Institute of Technology and Science (BITS), Pilani Campus, VidyaVihar, Pilani 333031, Rajasthan, India.
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Utting N, Namsechi B, McMullen C, Brydie J, Ahad JME. Comparing simulated shallow subsurface spills of diluted bitumen and conventional crude oil. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 251:104099. [PMID: 36369109 DOI: 10.1016/j.jconhyd.2022.104099] [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: 05/13/2022] [Revised: 10/17/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Increased oil production in Canada has resulted in proposals to extend or develop new oil pipelines. Many of these proposals have been met by concerns from the public over potential environmental impacts related to construction and the potential for oil spills to negatively affect groundwater quality. Crude oil sourced from the Alberta oil sands represents a significant proportion of this increase in production. This crude oil is produced as bitumen, which is subsequently diluted with light hydrocarbons to lower viscosity to allow for pipeline transport producing diluted bitumen. In this study, we pumped water through tanks filled with sand to simulate groundwater flow. Tanks were injected with either conventional crude or diluted bitumen to simulate a crude oil spill from a pipeline rupture occurring below the water table representing a pipeline river crossing scenario. Water samples were collected from the downstream end of the tanks throughout the experiment period (∼two months). Compared to water quality guidelines, effluent waters from both conventional crude and diluted bitumen tanks contained elevated concentrations of dissolved organic compounds, particularly benzene, ethylbenzene, toluene and xylenes (BTEX). The effluent from each tank had similar concentrations of benzene, whereas discharge water from conventional crude tanks contained higher concentrations of ethylbenzene, toluene and xylenes. In both tanks, and as expected, the BTEX concentrations appeared to be proportional to those determined in their injected crude oils. The measured dissolved concentrations of benzene, ethylbenzene and toluene are lower than predicted which is attributed largely due to dilution along the flow path. In addition to organic constituents, effluent sampled from the diluted bitumen tank contained some metals (Co, Cr, Fe and V) which measured constituents of the oil.
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Affiliation(s)
- Nicholas Utting
- Natural Resources Canada, CanmetENERGY in Devon, 1 Oil Patch Dr, Devon, AB T9G 1A8, Canada.
| | - Behnam Namsechi
- Natural Resources Canada, CanmetENERGY in Devon, 1 Oil Patch Dr, Devon, AB T9G 1A8, Canada
| | - Craig McMullen
- Natural Resources Canada, CanmetENERGY in Devon, 1 Oil Patch Dr, Devon, AB T9G 1A8, Canada
| | - James Brydie
- Natural Resources Canada, CanmetENERGY in Devon, 1 Oil Patch Dr, Devon, AB T9G 1A8, Canada
| | - Jason M E Ahad
- Natural Resources Canada, Geological Survey of Canada, 490 rue de la Couronne, Québec, Québec G1K 9A9, Canada
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An J, Baek DJ, Hong J, Choi E, Kim I. Continuous VOCs Monitoring in Saturated and Unsaturated Zones Using Thermal Desorber and Gas Chromatography: System Development and Field Application. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19063400. [PMID: 35329092 PMCID: PMC8950982 DOI: 10.3390/ijerph19063400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 12/18/2022]
Abstract
Subsurface VOC monitoring has been mainly based on manual sampling, transport, and analysis, which would require a sufficient amount of samples to ensure data accuracy and reliability, and additional costs to ensure sample quality. Therefore, a continuous on-site monitoring system is desirable for accurate measurement and subsequent risk assessment. In this study, benzene, toluene, ethylbenzene, and xylene (BTEX) were continuously monitored by the system based on a thermal desorber (TD) and gas chromatography (GC) in an oil-contaminated site that consisted of saturated and unsaturated zones. For the saturated zone, fully automated groundwater sampling and purging processes were performed, and the gasified samples were applied to the TD–GC system. For the unsaturated zone, the gaseous sample in the site was directly applied to the TD–GC system. After verifying the accuracy and precision of the monitoring system, the continuous monitoring system was successfully operated for more than a month in the field. The monitoring system used in this study is applicable to other sites for continuous monitoring, thus providing a scientific background for advanced risk assessment and policy development.
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Affiliation(s)
- Jinsung An
- Department of Biological and Environmental Engineering, Semyung University, Jecheon-si 27136, Korea; (J.A.); (D.-J.B.)
| | - Dong-Jun Baek
- Department of Biological and Environmental Engineering, Semyung University, Jecheon-si 27136, Korea; (J.A.); (D.-J.B.)
| | - Jiseok Hong
- Department of Civil and Environmental Engineering, Hongik University, Seoul 04066, Korea; (J.H.); (E.C.)
| | - Eunsoo Choi
- Department of Civil and Environmental Engineering, Hongik University, Seoul 04066, Korea; (J.H.); (E.C.)
| | - Ijung Kim
- Department of Civil and Environmental Engineering, Hongik University, Seoul 04066, Korea; (J.H.); (E.C.)
- Correspondence: ; Tel.: +82-2-320-1688
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Wu J, Bian J, Wan H, Sun X, Li Y. Probabilistic human health-risk assessment and influencing factors of aromatic hydrocarbon in groundwater near urban industrial complexes in Northeast China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 800:149484. [PMID: 34392216 DOI: 10.1016/j.scitotenv.2021.149484] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 07/04/2021] [Accepted: 08/01/2021] [Indexed: 06/13/2023]
Abstract
Organic pollutants are common in the environment, very difficult to remove, and pose a serious threat to human health. Probabilistic risk assessment advances conservative single-point estimation and brings a new perspective to risk assessment. From 2009 to 2019, we monitored the distribution of major pollutants in an industrial park in Northeastern China. The result showed the maximum concentration of benzene reached 73,680 μg/L in 2009, benzo[a]pyrene reached 36.80 ng/L in 2016. These concentrations are significantly above the levels set by Chinese regulatory agencies. The single-factor index increases year by year, and pollutants gradually spread from the pollution leakage source to surrounding areas. A new method was used to quantify the human health risk from groundwater organic pollution accurately, based on the triangular fuzzy numbers coupled with the Monte Carlo simulation. The Monte Carlo simulation was used to simulate the triangular fuzzy numbers. This simplified the operation between the triangular fuzzy numbers and their function successfully and obtained the risk as a set of values. The results indicated that non-carcinogenic risk was negligible in all age groups (children, adolescents, and adults). Conversely, when it comes to carcinogenic risks, adults were about 50-270 times the tolerable level of risk due to long exposure years and wide skin contact areas. Oral ingestion played an essential role in total exposure (>90%) compared to dermal contact. Control of exposure duration and intake should be prioritized when making decisions to reduce risk uncertainty. Monte Carlo simulation-triangular fuzzy numbers can effectively reduce the risk of uncertainty and reflect the complex conditions of the groundwater environment for small amounts of data or inaccurate data.
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Affiliation(s)
- Juanjuan Wu
- Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Jilin University, Changchun 130021, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130021, PR China
| | - Jianmin Bian
- Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Jilin University, Changchun 130021, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130021, PR China.
| | - Hanli Wan
- Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Jilin University, Changchun 130021, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130021, PR China
| | - Xiaoqing Sun
- Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Jilin University, Changchun 130021, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130021, PR China
| | - Yanmei Li
- Department of Mine, Metallurgy and Geology Engineering, Engineering Division, Campus of Guanajuato, University of Guanajuato, Guanajuato C.P. 36020, Mexico
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Asejeje GI, Ipeaiyeda AR, Onianwa PC. Occurrence of BTEX from petroleum hydrocarbons in surface water, sediment, and biota from Ubeji Creek of Delta State, Nigeria. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:15361-15379. [PMID: 33231851 DOI: 10.1007/s11356-020-11196-y] [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: 04/06/2020] [Accepted: 10/09/2020] [Indexed: 06/11/2023]
Abstract
Petroleum exploration and production activities pose great threat worldwide in the marine environment with numerous occurrences of spills every year. Ubeji Creek in Nigeria suffers environmental pollution attributable to petroleum exploration. The hydrocarbons in petroleum encompass a large number of toxicants such as BTEX, which are frequently discharged into water bodies during spillage. In terms of scope, this study assessed for the first time BTEX levels in surface water, sediment, and biota of the Ubeji Creek. Environmental samples were collected at designated sampling locations along the Ubeji Creek quarterly for 2 years. Water quality was determined in situ, while BTEX levels in water, sediment, and biota were assessed in the laboratory using GC-FID. The physico-chemical characteristics of water were within the acceptable WHO limits with the exception of DO of 3.01 ± 0.25 mg/L. Organic pollution load could have contributed to the depression of DO level below the limit. BTEX of 5.57 ± 0.62 mg/kg in sediment samples was higher than the level in control sample. The BTEX levels in fish, shrimps, pawpaw fruit, pineapple tissue, bitter leaf, and cassava were 0.37 ± 0.05, 0.39 ± 0.01, 0.56 ± 0.02, 1.35 ± 0.04, 0.46 ± 0.06, and 0.22 ± 0.01 mg/kg, respectively. Accumulation of BTEX in this biota can affect their nutritive quality and consequently pose threat to humans who daily consume them.
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10
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Injectable cationic traps and sticky bacterial emulsifiers: A safe alliance during diesel bioremediation. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.126051] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Rajasekhar B, Nambi IM, Govindarajan SK. Human health risk assessment for exposure to BTEXN in an urban aquifer using deterministic and probabilistic methods: A case study of Chennai city, India. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114814. [PMID: 32505959 DOI: 10.1016/j.envpol.2020.114814] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/12/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
The aquifer in Tondiarpet, Chennai, had been severely contaminated with petroleum fuels due to an underground pipeline leakage. Groundwater samples were analyzed quarterly for priority pollutants such as benzene, toluene, ethylbenzene, xylenes, and naphthalene (BTEXN) using purge and trap gas chromatography and mass spectrometer from 2016 to 2018. The maximum concentrations of BTEXN in groundwater at the site were found to be greater than the permissible limits significantly. Among the five sampling locations (MW1, MW2, MW3, MW4, and MW5), mean BTEXN levels were found to be higher near MW2, confirming the source location of petroleum leakage. Human health risk assessment was carried out using deterministic and probabilistic methods for exposure to BTEXN by oral and dermal exposure pathways. Risk analysis indicated that mean cancer and non-cancer risks were many times higher than the allowable limits of 1E-06 and 1 respectively in all age groups (children, teens, and adults), implying the adverse health effects. Oral exposure is predominately contributing (60-80%) to the total health risk in comparison to the dermal exposure route. Variability and uncertainty were addressed using the Monte Carlo simulations and the resultant minimum, maximum, 5th, 95th, and mean percentile risks were predicted. Under the random exposure conditions to BTEXN, it was estimated that the risk would become unacceptable for >98.7% of the exposed population. Based on the sensitivity analysis, exposure duration, and ingestion rate are the crucial variables contributing significantly to the health risk. As part of the risk management, preliminary remediation goals for the study site were estimated, which require >99% removal of the BTEXN contamination for risk-free exposures. It is suggested that the residents of Tondiarpet shouldn't utilize the contaminated groundwater mainly for oral ingestion to lower the cancer incidence related to exposure to BTEXN.
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Affiliation(s)
- Bokam Rajasekhar
- Environmental and Water Resources Engineering, Department of Civil Engineering, Indian Institute of Technology Madras, 600036, India
| | - Indumathi M Nambi
- Environmental and Water Resources Engineering, Department of Civil Engineering, Indian Institute of Technology Madras, 600036, India.
| | - Suresh Kumar Govindarajan
- Reservoir Simulation Laboratory, Petroleum Engineering Programme, Department of Ocean Engineering, Indian Institute of Technology Madras, 600036, India
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Lamont K, Marangoni AG, Pensini E. 'Emulsion locks' for the containment of hydrocarbons during surfactant flushing. J Environ Sci (China) 2020; 90:98-109. [PMID: 32081345 DOI: 10.1016/j.jes.2019.11.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/28/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
Reversible double water in oil in water (W/O/W) emulsions were developed to contain subsurface hydrocarbon spills during their remediation using surfactant flushing. Double emulsions were prepared by emulsifying CaCl2 solutions in canola oil, and subsequently by emulsifying the W/O emulsions in aqueous sodium alginate solutions. The formation of double emulsions was confirmed with confocal and optical microscopy. The double emulsions reversed and gelled when mixed with the surfactants sodium dodecyl sulfate (SDS) and cocamidopropyl betaine (CPB). Gels can act as 'emulsion locks' to prevent spreading of the hydrocarbon plume from the areas treated with surfactant flushing, as shown in sand column tests. Shear rheology was used to quantify the viscoelastic moduli increase (gelation) upon mixing the double emulsion with SDS and CPB. SDS was more effective than CPB in gelling the double emulsions. CPB and SDS could adsorb at the interface between water and model hydrocarbons (toluene and motor oil), lowering the interfacial tension and rigidifying the interface (as shown with a Langmuir trough). Bottle tests and optical microscopy showed that SDS and CPB produced W/O and O/W emulsions, with either toluene or motor oil and water. The emulsification of motor oil and toluene in water with SDS and CPB facilitated their flow through sand columns and their recovery. Toluene recovery from sand columns was quantitated using Gas-Chromatography Mass-Spectroscopy (GC-MS). The data show that SDS and CPB can be used both for surfactant flushing and to trigger the gelation of 'emulsion locks'. Ethanol also gelled the emulsions at 100 mL/L.
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Affiliation(s)
- Kristine Lamont
- University of Guelph, School of Engineering, 50 Stone Road East, Guelph ON, N1G 2W1, Canada
| | - Alejandro G Marangoni
- University of Guelph, Food Science Department, 50 Stone Road East, Guelph ON, N1G 2W1, Canada
| | - Erica Pensini
- University of Guelph, School of Engineering, 50 Stone Road East, Guelph ON, N1G 2W1, Canada.
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Biosca B, Arévalo-Lomas L, Barrio-Parra F, Díaz-Curiel J. Application and limitations of time domain-induced polarization tomography for the detection of hydrocarbon pollutants in soils with electro-metallic components: a case study. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:115. [PMID: 31940086 DOI: 10.1007/s10661-020-8073-0] [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: 09/19/2019] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
Nowadays, the growing concern about the environmental problems affecting the subsoil has focussed efforts on the detection and characterization of contaminated sites through geophysical prospecting methods. In the present study, a case of a contaminated site by hydrocarbons and their study by means of time domain-induced polarization tomography is presented. The response in chargeability of porous media due to this kind of pollutant allows its delimitation using this method. However, one of the limitations for the application of this technique is the presence of lithologies that contain electro-metallic salts. These salts can produce anomalies of chargeability and mask those due to nonaqueous phase liquids. The studies were conducted in an area contaminated by fuel leaks from supply tanks within a train maintenance facility. Those leaks occurred while the tanks were in use, but since their dismantling, the leak stopped. The geology of the area presented strong heterogeneities and the access was limited by train tracks. In order to locate and characterize the contaminant plume, measurements of resistivity and chargeability were carried out. A grid of monitoring wells in this area was also available from which information about free-phase pollutants was obtained, and a new drilling was carried out to verify an unexpected anomaly. The results obtained show that the location of the plume by the geophysical techniques employed can lead to ambiguity, as an anomaly that does not correspond to contaminated areas appeared but to the presence of clays rich in electro-metallic components such as Mg, Fe, Mn and Al.
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Affiliation(s)
- Bárbara Biosca
- Department of Energy and Fuels Systems, School of Mines and Energy, Universidad Politécnica de Madrid, C/ Ríos Rosas 21, 28003, Madrid, Spain
| | - Lucía Arévalo-Lomas
- Department of Geological and Mining Engineering, School of Mines and Energy, Universidad Politécnica de Madrid, C/ Ríos Rosas 21, 28003, Madrid, Spain
| | - Fernando Barrio-Parra
- Department of Energy and Fuels Systems, School of Mines and Energy, Universidad Politécnica de Madrid, C/ Ríos Rosas 21, 28003, Madrid, Spain
| | - Jesús Díaz-Curiel
- Department of Geological and Mining Engineering, School of Mines and Energy, Universidad Politécnica de Madrid, C/ Ríos Rosas 21, 28003, Madrid, Spain.
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Lamont K, Pensini E, Marangoni AG. Gelation on demand using switchable double emulsions: A potential strategy for the in situ immobilization of organic contaminants. J Colloid Interface Sci 2019; 562:470-482. [PMID: 31785939 DOI: 10.1016/j.jcis.2019.11.090] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 11/06/2019] [Accepted: 11/20/2019] [Indexed: 12/31/2022]
Abstract
Switchable double emulsions (water in oil in water, W/O/W) are proposed for the in situ immobilization of subsurface organic contaminants such as toluene, hexane or benzene. Primary W/O emulsions were prepared by emulsifying 250 mL of 0.36 M CaCl2 aqueous solutions in 1 L of canola oil (with 12.5 g/L of ethylcellulose, EC, and 2.5 g/L of calcium stearate). In the primary W/O emulsion the water droplets in oil were ≈8 μm, as observed using an optical and a confocal microscope. EC and calcium stearate adsorbed at the oil water interface (as demonstrated by interfacial tension measurements), forming films which stabilized the W/O emulsions (as verified with bottle tests). Experiments conducted using a Langmuir trough suggest that EC and calcium stearate films did not desorb from the oil-water interface upon compression. Crumpling tests and optical microscopy observations indicate that EC and calcium stearate films were skin-like, and buckled when deformed. To obtain double W/O/W emulsions the primary emulsions were emulsified in a 0.75 wt% solution of sodium alginate, with 2 mL/L of Tween 20 and 10 g/L of NaCl. The formation of W/O/W emulsions was verified through optical microscopy and confocal microscopy observations. In the absence of the contaminants the double emulsions were stable, as observed by resting them on the bench over three days and agitating them with a multi-action wrist shaker for 30 min. Also, they had low shear elastic (G' = 2.67 ± 0.58 Pa) and viscous (G″ = 1.69 ± 0.24 Pa) moduli, which should facilitate their transport through geological media (e.g. soil) to polluted areas. Upon mixing with toluene, hexane or benzene at concentrations ranging from 5% to 17%, the double emulsions were destabilized. Emulsion destabilization caused the release of CaCl2, which crosslinked sodium alginate and formed gels in which the contaminants were incorporated. The gelation rate and the magnitude of the viscoelastic moduli depended on the contaminant type and concentration, and on the mixing time. Gelation occurred fastest with the highest toluene concentrations tested (9% to 17%), but the highest elastic moduli were measured with 9% toluene concentrations for the longest mixing times tested (90 s). Gelation occurred slowest with hexane, likely due to the poor solubility of EC in hexane. Because of their ability to gel exclusively in contaminant proximity, the double emulsions studied offer a potential strategy to control the migration of plumes of contaminants such as toluene, hexane or benzene.
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Affiliation(s)
- Kristine Lamont
- University of Guelph, School of Engineering, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Erica Pensini
- University of Guelph, School of Engineering, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.
| | - Alejandro G Marangoni
- University of Guelph, Food Science Department, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
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Rajasekhar B, Nambi IM, Govindarajan SK. Human health risk assessment of ground water contaminated with petroleum PAHs using Monte Carlo simulations: A case study of an Indian metropolitan city. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 205:183-191. [PMID: 28985597 DOI: 10.1016/j.jenvman.2017.09.078] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 09/09/2017] [Accepted: 09/28/2017] [Indexed: 06/07/2023]
Abstract
Underground pipelines are frequently used to transport petroleum fuels, through industrial as well as residential zones. Chennai is one of the four largest metropolitan cities of India. The region of interest in this study is located in the northern part of the Chennai. Ground water of this area was contaminated with polyaromatic hydrocarbons (PAHs) from the leaking oil storage tanks and pipe lines. Health risk assessment was conducted for exposure to PAHs in the ground water using incremental life time cancer risk (ILCR) models coupled with benzo[a]pyrene toxic equivalent method. The exposure pathways considered in this study were direct water ingestion and dermal contact under residential scenario. Exposure input parameters were transformed to statistical parameters using lognormal/uniform distributions and resultant probabilities of cancer risk were estimated by performing Monte Carlo simulations. Preliminary remediation goals were predicted using the combination of the cancer risk models of all the exposure routes with the consideration of high-safety risk of 1-in-1 million. Results showed that the cancer risk is predominantly contributed (greater than 98%) by dermal exposure than the oral in both adults and children. The total ILCR is found to be greater than a low safety risk of 1-in-10,000 with higher probability percentages (>90%). The 95th percentile values of the risk were presented in order to address the need for remediation. Appropriate remedial and treatment methods for the subject site were proposed. The results of the study will be useful for the regulatory boards and policy makers in India in understanding the actual impact of the contamination on receptors, setting up final remediation goals and deciding on a specific remedial method.
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Affiliation(s)
- Bokam Rajasekhar
- Environmental and Water Resources Engineering Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.
| | - Indumathi M Nambi
- Environmental and Water Resources Engineering Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.
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