scholarly journals The Key Factors for the Fate and Transport of Petroleum Hydrocarbons in Soil With Related in/ex Situ Measurement Methods: An Overview

2021 ◽  
Vol 9 ◽  
Author(s):  
Liang Wang ◽  
Ying Cheng ◽  
Ravi Naidu ◽  
Mark Bowman
Keyword(s):  
Soil Properties ◽  
Petroleum Hydrocarbons ◽  
Water Status ◽  
Ex Situ ◽  
Contaminated Site ◽  
Key Factors ◽  
Transport Modelling ◽  
Soil Media ◽  
Site Characterisation

Once petroleum hydrocarbons (PHs) are released into the soil, the interaction between PHs and soil media is dependent not only upon the soil properties but also on the characteristics of PHs. In this study, the key factors influencing the interactions between PHs and soil media are discussed. The key factors include: 1) the characteristics of PHs, such as volatility and viscosity; and 2) soil properties, such as porosity, hydraulic properties and water status, and organic matter; and 3) atmospheric circumstances, such as humidity and temperature. These key factors can be measured either ex-situ using conventional laboratory methods, or in situ using portable or handheld instruments. This study overviews the current ex/in situ techniques for measuring the listed key factors for PH contaminated site assessments. It is a tendency to apply in situ methods for PH contaminated site characterisation. Furthermore, handheld/portable Fourier transform infrared spectroscopy (FTIR) instrument provides tremendous opportunities for in-field PH contaminated site assessment. This study also reviewed the non-destructive FTIR spectroscopy analysis coupling with handheld FTIR for in-field PH contaminated site characterisation, including determining the concentration of total PH, dominant PH fractions and soil key properties for PH transport modelling.

scholarly journals Soil Bioremediation: Overview of Technologies and Trends

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4664
Author(s):  
Israel Gonçalves Sales da Silva ◽  
Fabíola Carolina Gomes de Almeida ◽  
Nathália Maria Padilha da Rocha e Silva ◽  
Alessandro Alberto Casazza ◽  
Attilio Converti ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Petroleum Hydrocarbons ◽  
Ex Situ ◽  
Soil Bioremediation ◽  
Application Of Surfactants ◽  
Agricultural Pesticides ◽  
Advantages And Disadvantages ◽  
Microbiological Characteristics ◽  
Extent Of Damage

Petroleum hydrocarbons, heavy metals and agricultural pesticides have mutagenic, carcinogenic, immunotoxic and teratogenic effects and cause drastic changes in soil physicochemical and microbiological characteristics, thereby representing a serious danger to health and environment. Therefore, soil pollution urgently requires the application of a series of physicochemical and biological techniques and treatments to minimize the extent of damage. Among them, bioremediation has been shown to be an alternative that can offer an economically viable way to restore polluted areas. Due to the difficulty in choosing the best bioremediation technique for each type of pollutant and the paucity of literature on soil bioremediation enhanced by the use of specific additives, we reviewed the main in situ and ex situ methods, their current properties and applications. The first section discusses the characteristics of each class of pollutants in detail, while the second section presents current bioremediation technologies and their main uses, followed by a comparative analysis showing their respective advantages and disadvantages. Finally, we address the application of surfactants and biosurfactants as well as the main trends in the bioremediation of contaminated soils.

Diagnostic and resulting approaches to restore petroleum-contaminated soil in a Mexican tropical swamp

2000 ◽  
Vol 42 (5-6) ◽  
pp. 377-384 ◽  
Author(s):  
M. Gallegos Martínez ◽  
A. Gómez Santos ◽  
L. González Cruz ◽  
M.A. Montes de Oca García ◽  
L. Yáñez Trujillo ◽  
...  
Keyword(s):  
Petroleum Hydrocarbons ◽  
Total Petroleum Hydrocarbons ◽  
Microbial Consortia ◽  
Contaminated Site ◽  
Second Phase ◽  
Remote Sensors ◽  
Petroleum Contaminated Soil ◽  
Low Sensitivity ◽  
Oil Company

A multidisciplinary three-step methodology is being developed to diagnose the extent and type of petroleum pollutants and resulting technological approaches to restore a contaminated site. At first, the site was delimitated and its zones identified by using remote sensors. An area of 307 ha considered of major importance to the national Mexican oil company, Petróleos Mexicanos (PEMEX), was identified. 75% of total analyzed soil samples ranged between 10-50,000 ppm of total petroleum hydrocarbons (TPH) and 25% between 50,000 and 434,000 ppm. Aliphatic and asphaltene groups were predominant and technological alternatives were proposed. In a second phase the identification of native botanical and microbial capabilities to biodegrade pollutants was achieved. Three native botanical species were selected for greenhouse studies: Cyperus laxus showed low sensitivity to TPH resulting in higher seed germination efficiency and growth rate. Since microbial consortia isolated from C. laxus rhizosphere were able todegrade up to 70% of TPH in 30 days laboratory cultures, a phytoremediation-reforest alternative was finally proposed to PEMEX. In a third step, the construction of a pilot plant in situ is now in course wherein both treatability studies and reforest strategies are being developed.

scholarly journals Bioremediation of groundwater contaminated with petroleum hydrocarbons applied at a site in Belgrade (Serbia)

2020 ◽  
Vol 85 (8) ◽  
pp. 1067-1081
Author(s):  
Sandra Bulatovic ◽  
Nenad Maric ◽  
Tatjana Solevic-Knudsen ◽  
Jelena Avdalovic ◽  
Mila Ilic ◽  
...  
Keyword(s):  
Petroleum Hydrocarbons ◽  
Cost Effective ◽  
Subsequent Treatment ◽  
Limiting Factors ◽  
Contaminated Site ◽  
Microbiological Activity ◽  
A Site ◽  
Specialized Population ◽  
Remediation Process

Due to their extensive use, petroleum hydrocarbons are among the most common groundwater contaminants. Compared to the traditional methods of physical pumping of contamination from the aquifer and subsequent treatment (i.e., pump and treat), bioremediation is an economically cost-effective technology. The aim of this remediation approach is to transform biologically contaminants, most often by microbiological activity, into non-toxic compounds. More precisely, it is an active remediation process that involves biostimulation (increase of aquifer oxygenation, addition of nutrients) and/or bioaugmentation (injection of a concentrated and specialized population of microorganisms). Using both biostimulation and bioaugmentation, enhanced in situ groundwater bioremediation was applied at a hydrocarbon-contaminated site in Belgrade. The bioremediation treatment, applied over twelve months, was highly efficient in reducing the concentrations of total petroleum hydrocarbon (TPH) to acceptable levels. The concentration of TPH in the piezometer P-5 was reduced by 98.55 %, in the piezometer P-6 by 98.30 % and in the piezometer P-7 by 98.09 %. These results provided strong evidence on the potential of this remediation approach to overcome site-limiting factors and enhance microbiological activity in order to reduce groundwater contamination.

Heavy Metal Pollution and its Management

2016 ◽  
pp. 27-50 ◽  
Author(s):  
Ashok K. Rathoure
Keyword(s):  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Ex Situ ◽  
Management Tool ◽  
Contaminated Site ◽  
Anthropogenic Activity ◽  
Toxic Heavy Metals ◽  
Metabolic Degradation

Environmental degradation has become a major societal issue thanks to uncontrolled anthropogenic activity, besides natural factors. Entry of toxic heavy metals and minerals in human system mainly through contaminated water, food and air, leads to overt and insidious health problems. Heavy metal pollution, a global concern today, can be managed by using bioremediation, an eco-friendly alternative. Bioremediation is one of the most promising technological approaches to the problem of hazardous waste. It is a technology for removing pollution from environment, restoring contaminated site and preventing future pollution. Bioremediation can be performed in situ or ex situ. Microorganisms directly degrade contaminants rather than merely transferring them from one medium to another, employ metabolic degradation pathways and can be used in situ to minimize disturbance of the cleanup site. Hence, microorganisms can be effective, economical and non-disruptive tools for eliminating hazardous chemicals. Its advantage generally outweigh the disadvantage, therefore may be used as management tool.

Heavy Metal Pollution and its Management

2020 ◽  
pp. 1013-1036 ◽  
Author(s):  
Ashok K. Rathoure
Keyword(s):  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Ex Situ ◽  
Management Tool ◽  
Contaminated Site ◽  
Anthropogenic Activity ◽  
Toxic Heavy Metals ◽  
Metabolic Degradation

Environmental degradation has become a major societal issue thanks to uncontrolled anthropogenic activity, besides natural factors. Entry of toxic heavy metals and minerals in human system mainly through contaminated water, food and air, leads to overt and insidious health problems. Heavy metal pollution, a global concern today, can be managed by using bioremediation, an eco-friendly alternative. Bioremediation is one of the most promising technological approaches to the problem of hazardous waste. It is a technology for removing pollution from environment, restoring contaminated site and preventing future pollution. Bioremediation can be performed in situ or ex situ. Microorganisms directly degrade contaminants rather than merely transferring them from one medium to another, employ metabolic degradation pathways and can be used in situ to minimize disturbance of the cleanup site. Hence, microorganisms can be effective, economical and non-disruptive tools for eliminating hazardous chemicals. Its advantage generally outweigh the disadvantage, therefore may be used as management tool.

scholarly journals DISOLVED OXYGEN PERFORMANCE IN DEGRADATION OF TOTAL PETROLEUM HYDROCARBONS BY EX SITE ACTIVATED SLUDGE

Konversi ◽  
2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Abubakar Tuhuloula
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Petroleum Hydrocarbons ◽  
Gravimetric Method ◽  
Degradation Process ◽  
Ex Situ ◽  
Total Petroleum Hydrocarbons ◽  
Contaminated Site ◽  
Nutrient Injection ◽  
Biological Methods

Contamination of soil by the activities of exploration, production and disposal of oil waste into the environment causes serious damage to the environmental ecosystem, the target of processing by the activated sludge as a model for remediation of petroleum contaminated site. Optimization of oxygen supply becomes special attention in aerobic bioprocess for optimizing the growth of microorganisms to degrade total petroleum hydrocarbons. Thus, the study was focused on determining the performance of dissolved oxygen in degradation of total petroleum hydrocarbons by ex situ activated sludge. The research used biological methods (bioremediation), with the ratio of contaminated soil to water was 20:80%(w/v) and a soil size 40/50 mesh.  The degradation process was carried out with 15% and 20% (v/v) activated sludge put into the bioreactor slurry with a capacity of 4 liters and stirring was 90 rpm at a temperature of 30oC as well as aeration and nutrient injection into the bioreactor. TPH analysis was measured by the gravimetric method. The results obtained showed that the performance of dissolved oxygen increased well in the bioreactor slurry at 15% (v/v) and 20% (v/v) activated sludge concentrations was 3.31–8.57 mg/L and 3.5–8.21 mg/L respectively, which had an impact on the level of TPH degradation, namely from 18,000 µg/g to 2870 µg/g and 18,000 µg/g to 1970 µg/g during the 49 days remediation period. In general, activated sludge shows good performance throughout the remediation period.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

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