Oil Spills In Marine Environment Research Articles

Current dynamics to detect the spread of oil spills in coastal waters

Abstract Surface flow dynamics modelling is an important aspect of monitoring and detecting oil spills in marine environments, especially coastal waters. The model can predict the spatiotemporal distribution of oil spills in waters before remote sensing technologies such as radar and synthetic aperture radar (SAR) detect the oil spill distribution range. The purpose of this study is to model two-dimensional (2D) surface flow to predict the extent of oil spills, especially in shallow water or coastal areas. The accuracy of this ocean current distribution model was then verified using the case of an oil spill in East Aceh waters based on the results of the detection of synthetic aperture Interference images from the Sentinel-2B satellite Radar (InSAR) Technology from August 1st to September 20th, 2021. The results show that when the fluid dynamics used is residual flow, the oil distribution trajectory moves partly to the north and partly to the south toward the coast of the leak location. However, when mean current is applied, the distribution expands to the south toward the coast. Based on the state of the wind distribution when the oil spill occurred, it shows the same direction as the residual current model, but the influence of the wind is greater than the residual current. So, it can be concluded that oil spills in the waters of East Aceh are more influenced by a combination of mean currents and surface wind direction. These results were validated by the results obtained from satellite images. Therefore, the satellite image validation results indicate that mean flow provide a more accurate indication of oil spill distribution than the average flow in South Aceh waters.

Oil Spill Classification Using an Autoencoder and Hyperspectral Technology

Hyperspectral technology has been playing a leading role in monitoring oil spills in marine environments, which is an issue of international concern. In the case of monitoring oil spills in local areas, hyperspectral technology of small dimensions is the ideal solution. This research explores the use of encoded hyperspectral signatures to develop automated classifiers capable of discriminating between polluted and clean water and distinguishing between various types of oil. The overall objective is to leverage these classifiers to be able to improve the performance of conventional systems that rely solely on hyperspectral imagery. The acquisition of the hyperspectral signatures of water and hydrocarbons was carried out with a spectroradiometer. The range of the spectroradiometer used in this study covers the ranges between [350–1000] (visible near-infrared) and [1000–2500] (short-wavelength infrared). This gives detailed information regarding the targets of interest. Different neural autoencoders (AEs) have been developed to reduce inputs into different dimensions, from 1 to 15. Each of these encoded sets was used to train decision tree (DT) classifiers. The results are very promising, as they show that the AE models encoded data with correlation coefficients above 0.95. The classifiers trained with the different sets provide accuracies close to 1.

Oil Spill Cleanup Employing Surface Modified Magnetite Nanoparticles Using Two New Polyamines

Oil spills in marine environments are a serious environmental concern and using low-cost materials for oil spill cleanup is an emerging subject. In recent years, surface-modified magnetite nanoparticles (MNPs) have shown promising properties for oil spill cleanup due to their high performance, low cost, magnetic properties, and reusability. This study aims to modify the surface of magnetite nanoparticles (MNPs) using two new polyamines and employ them for oil spill remediation. First, tetraethylene glycol (TEG) was converted to the corresponding alkyl halide (AH). Next, two polyamines were synthesized via the alkylation of diamines, 1,11-undecanediamine (UD) and 1,5-pentanediamine (PD), yielding the corresponding AH-UD and AH-PD polyamines. Finally, AH-UD and AH-PD were applied to MNPs’ surface modification, yielding the corresponding surface-modified MNPs, AU-MNPs, and AP-MNPs. The performance of AU-MNPs and AP-MNPs for oil spill uptake (OSU%) was investigated using various MNPs-to-oil ratios at different contact times. Furthermore, the reusability of AU-MNPs and AP-MNPs was also investigated over four cycles. The results indicated that the OSU values of AU-MNPs and AP-MNPs were affected by MNPs’ ratios and contact time, where their OSU increased as their ratios and contact time increased. In addition, AU-MNPs showed a higher OSU than AP-MNPs, which could be ascribed to the longer alkyl chain in the polyamine (AH-UA) used for their surface modification compared to AP-MNPs. Furthermore, AU-MNPs and AP-MNPs reusability results exhibited effective OSU in four cycles with a relative decline with an increasing number of cycles.

The preparation of antifouling and superhydrophobic polyurethane sponge by grafting Econea to diisocyanate monomer for durable continuous oil/water separation and cleanup of oil spills

The oil-absorbent sponge is effective in the prevention and cleanup of offshore oil spills. However, biofouling in marine environments will significantly reduce its oil absorption capacity. Herein, a novel type of antifouling and superhydrophobic polyurethane (PU) sponge was successfully prepared via grafting Econea (antifouling agent) to diisocyanate monomer and hydrophobic modification of PDMS (Polydimethylsiloxane) and SiO2. The prepared PDMS-SiO2@PU-Econea sponge shows not only super-hydrophobicity with a WCA of 154.5° but also excellent antifouling properties with more than 99% of inhibition to Escherichia coli after immersed in artificial seawater (salinity ≈35‰) for 50 days. It can absorb 133.9 times of trichloromethane than its own weight and still maintain 98.5% of absorption after 50 cycles. In addition, the PDMS-SiO2@PU-Econea sponge exhibits excellent continuous oil–water separation performance. The separation fluxes of n-hexane and dichloromethane are 151.0 and 136.3 L·h−1·g−1, respectively, and the oil–water separation efficiency is up to 99.9%, it can absorb 50 times of crude oil than its own weight in 75 s. Therefore, the antifouling and superhydrophobic PDMS-SiO2@PU-Econea sponge is a promising and applicable oil absorbent sponge for long-term oil/water separation and cleanup of oil spills in marine environment.

Mesoscale evaluation of oil submerging and floating processes during marine oil spill response: Effects of dispersant on submerging stability and the associated mechanism

The migration of oil spills in marine environment is still not clear, especially the key processes of submerging and floating, which is an important concern for effective disposal of oil spills. In mesoscale wave tank (32 m × 0.8 m × 2 m), this study has evaluated the characteristics of oil submergence based on oil concentration and oil droplet size. The concept of effective submergence is put forward for the first time, utilized to analyze the effects of dispersant on submerging stability and associated mechanisms. The results indicate dispersants increase submerged oil concentration and promote homogeneous distribution and vertical penetration. Of concern is that dispersants increase the proportion of small oil droplets (2.5–70 µm), prolonging the residence time of oil droplets in water by delaying the floating process. Dispersants sharply reduce oil droplets size (VMD<44 µm) thus decreasing the coalescence probability. These contribute to better submerging stability. By contrast, the submerged oil, formed as oil patches, oil streamers, and large oil droplets (VMD>170 µm) when without dispersant, will float and reattach to oil slicks more quickly due to their large volume. These findings help to clarify spilled oil behaviors and provide a new idea for the research on oil submergence.

Durable hydrophobic Enteromorpha design for controlling oil spills in marine environment prepared by organosilane modification for efficient oil-water separation

Hydrophobic and oleophilic materials are attractive candidates for efficient oil collection due to their excellent oil-water separation. However, the most of currently reported oil adsorption materials are limited resources or require complicated preparation steps, which causes high energy consumption and not be practical for large-scale application. Herein, we report a facile strategy to modify the wettability of Enteromorpha from hydrophilic to hydrophobic, which not only greatly reduces energy consumption but also shows the outstanding capacity for oil-water separation with the maximum adsorption capacities is 11.4 g/g and the contact angle reaches 137°. The successful modification of the Enteromorpha is achieved by grafting n-octyltriethoxysilane on the surface of the pristine Enteromorpha. The hydrophobic and superoleophilic Enteromorpha guarantee adequate voids in the fibrous bundles only for oil adsorption and the oil floating on the seawater is removed by the formation of hydrogen bonding between oil and modified Enteromorpha. By optimizing test, the optimal adsorption conditions are adsorption time of 60 min, oil-water ratio of 1:10 and pH of 7. Our reported hydrophobic organosilane modified Enteromorpha will open a new avenue to control marine oil pollution and suppress the damage of Enteromorpha to the marine ecology system.

Super-complex mixtures of aliphatic- and aromatic acids may be common degradation products after marine oil spills: A lab-study of microbial oil degradation in a warm, pre-exposed marine environment

When assessing oil spills in marine environments, focus has often been on describing degradation and removal of hydrocarbons. However, more and more attention is now given to the formation of mineral oil transformation products, and their potential toxicity and persistency in the environment. The aim of this study was to investigate the formation of dissolved acidic degradation products from crude oil in sea water from the Persian Gulf in a lab-experiment. A super-complex mixture of acidic degradation products was formed in the water phase and compound groups of aliphatic acids, monocyclic aromatic acids-, and polycyclic aromatic acids were identified. More specifically, alkylated PAHs were biodegraded to a high number of aromatic, carboxylic acids by hydroxylation of the alkyl side chains. These degradation products are more bioavailable than their parent compounds, and may therefore constitute a new group of contaminants that should be considered in oil spill assessments.

Hydrocarbonoclastic bacterial species growing on hexadecane: Implications for bioaugmentation in marine ecosystems

Limitationsof bioaugmentation strategies are an obstacle for damage mitigation caused by oil spills in marine environments. Cells added to the contaminated sites are quickly lost by low adherence to the contaminants, rendering ineffective. This study used two hydrocarbonoclastic species - Rhodococcus rhodochrous TRN7 and Nocardia farcinica TRH1 cells - growing in mineral medium containing hexadecane to evaluate cell distribution in a crude-oil contaminated marine water. Cell affinity to hydrophobic compounds was quantified using Microbial Adhesion to Hydrocarbons test and analysis of fatty acids profile was performed using the Microbial Identification System. Bioremediation simulations were set up and cell populations of both strains were quantified by Fluorescent in situ Hybridization. R. rhodochrous and N. farcinica reached up to 97% and 60% of adhesion to hexadecane, respectively. The carbon source had more influence on the fatty acid profiles of both strains than the microbial species. The presence of 45.24% of 13:0 anteiso on total fatty acids in R. rhodochrous and 12.35% of saturated fatty acids with less than 13 carbons atoms in N. farcinica, as well as the occurrence of fatty alcohols only in presence of hexadecane in both species, are indicators that fatty acid changes are involved in the adaptation of the cells to remain at the water/oil interface. Cell quantification after bioremediation simulations revealed an increase in the density of both species, suggesting that the bioremediation strategies resulted on the increase of hydrocarbonoclastic species and up to 27.9% of all prokaryotic microbial populations in the microcosms were composed of R. rhodochrous or N. farcinica. These findings show the potential of application of these two bacterial strains in bioaugmentation of hydrocarbon-contaminated marine ecosystems.R. rhodochrous TRN7 and N. farcinica TRH1 hydrocarbonoclastic strains modify the fatty acid profile and increases density, optimizing hydrocarbons biodegradation.

The interactions of oil droplets with filter feeders: A fluid mechanics approach

Filter feeding animals capture and lose oil droplets using cilia or ramified appendages. Here we demonstrate that copepod and barnacle appendages capture fish, canola and 1-decanol oil droplets up to 11μm without selectivity for size, chemistry, density, viscosity, or interfacial tension. Following capture, the droplets are ingested or lost via detachment. Capture and detachment did not differ between a barnacle appendage and stainless-steel wires of radii Rf=50 and 250μm. Key parameters to detachment include the ratio of oil droplet radius to fiber radius, and the Weber number. Smaller oil droplet size to fiber size ratio r=Ro∕Rf, required a higher We for detachment. These data plot as a curve that predicts whether a droplet will remain captured or detach and re-enter the fluid stream, based on the fluid, the droplet radius to fiber radius ratio, and the oil droplet properties. Significantly, this curve may be used to plan responses to oil spills in marine environments.

Photocatalytic degradation of marine diesel oil spills using composite CuO/ZrO2 under visible light

Diesel oil spills in marine environments pose a severe threat to both aquatic and terrestrial ecosystems. Photocatalysis is an environment-friendly method for marine oil remediation; however, its practical usage is limited due to several issues. In this study, we demonstrate the enhanced efficacy of doped CuO/ZrO2 photocatalyst at degrading marine diesel in comparison to undoped ZrO2. The photocatalysts were prepared using co-precipitation method, and their physical and chemical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and ultraviolet-visible spectroscopy (UV-Vis). XRD analysis showed that the photocatalytic crystallite size of ZrO2 and CuO/ZrO2 was 28.80 nm and 40.32 nm, respectively. Both catalysts exhibited stable crystalline forms. UV-Vis analysis showed that doping of ZrO2 with CuO significantly reduced its band gap from 4.61 eV to 1.18 eV, thus enhancing the utilization of visible light. The effect of catalyst dosage, doping ratio, and initial diesel concentration on the degradation rate of diesel was investigated by performing single-factor experiments. The optimization experiment results showed that 96.96% of diesel could be degraded under visible light. This study laid an experimental foundation for expanding the practical applications of photocatalytic technology.

Time series evaluation of oil spill in marine environment: a case study in marine area of Cyprus

The eastern Levantine Sea is known as one of the illegal discharge regions of the world. Nevertheless, the coastal waters of Cyprus are famous for its crystal clear oligotrophic waters in spite of the fact that its exposure to high pollution pressure is due mainly to the intensive touristic and maritime activities. This study aimed to evaluate and understand the oil spill dynamics in the marine area surrounding Cyprus over a period of 18 months between January 2017 and June 2018. A practical method utilizing multiple products of satellite remote-sensing was used to detect and evaluate oil spill events in the study area. A total of 122 images were available for the study period. Results showed that average coverage per sampling days was 0.10%. A small portion of the study area, which is 0.05%, showed relatively intense oil spill detection. However, none of the region showed constant reoccurrence of oil spill detection. The analysis showed that the marine area has a low oil spill intensity. Additionally, intensity and reoccurrence of oil spill events are relatively higher in the main ports of Cyprus and the main routes of maritime traffic. It is concluded that continuous monitoring of oil spill detection in the marine areas will provide an important contribution to implement effective management plans by increasing understanding of impacts on marine ecosystem. It is also provide a baseline for detection and implementation of precautionary or recovery actions of any possible oil spill accident in high- or low-risk zones.

Optimization of Biodegradation of Long Chain n-Alkanes by Rhodococcus sp. Moj-3449 Using Response Surface Methodology

Oil spills and subsequent pollution of marine ecosystems are associated with oil exploitation. The ultimate fate of unrecoverable portion of spilled oil is biodegradation by microorganisms. Rhodococcus sp. Moj-3449 has proven ability of growth on aliphatic hydrocarbons. In this study Response Surface Methodology was employed to optimize the biodegradability of Moj-3449 by changing salinity, pH, temperature and n-C16 concentration. The duplicate experiments conducted were based on a 5-levels rotatable and orthogonal central composite design (CCD) done in 2 separate blocks. The effect of each factor and their interactions on the biodegradation of n-C16 revealed that the optimal conditions for the biodegradation are 0 % salinity at pH= 6.97, T=28°C and 52.98 % wt/V n-C16 concentration. Under these conditions, the maximum biodegraded amount was predicted at 45.52 % wt/V out of 52.98 % wt/V. The experimentally obtained biodegradation amount at the optimum condition was 44.27 ±0.07 % wt/V. The ability of the strain to effectively break down long-chain n-alkanes at concentration up to 55 % wt/V shows at that this strain is an outstanding candidate for industrial bioremediation of crude oil spills in marine environment.

Toxic effect of oil spill on the growth of Ulva pertusa by stable isotope analysis

The oil spills occur frequently during the offshore oil exploration and transportation, resulting in the destruction of the marine environment. After an oil spill, petroleum can stay in the sea for a long time and pose a toxic effect on marine organism. Under the action of the waves, oil continues to diffuse, flows to the intertidal zone of the coast, where it accumulates. Ulva pertusa Kjellman (Ulvales, Chlorophyta) is the marine green algae and is widely distributed and easy to breed in the intertidal zone. The study investigated the growth rates, chlorophyll-a, and carbon and nitrogen stable isotopes of U. pertusa under the stress of the water accommodated fraction (WAF) for two kinds of oils (0# diesel oil and Russian crude oil). The results showed that the growth rate and chlorophyll-a initially increased and then decreased under the stress of WAF. High concentration of WAF posed the obviously inhibitory effect on algae; and oil spill also causes the distinct fraction of carbon and nitrogen stable isotopes of U. pertusa, especially for carbon stable isotope. The change trends of bulk carbon and nitrogen isotopes were similar to those of growth rates of U. pertusa. Therefore, the application of stable isotope techniques can quickly evaluate the toxic effects of petroleum on algae and can be used as a new method to evaluate the toxicity of the oil spill in marine environment.

Sorption and removal of crude oil spills from seawater using peat-derived biochar: An optimization study

Bio-based sorbents are preferred over chemical-based methods for the clean-up of crude oil spills in marine environments because bio-based sorbents are more environmentally friendly. This study evaluates the use of peat-derived biochar (PB) as a bio-sorbent for the sorption and removal of crude oil spills from synthetic seawater. Experiments were designed to determine the effect of four operating factors (PB/crude oil contact time, PB dosage, oil dosage, and temperature) on two performance indicators (crude oil sorption capacity of PB, S, and oil removal efficiency, R%). Regression models containing linear, quadratic, and two-way interaction terms were developed to predict S and R% from the four factors. Response surface methodology (RSM) was employed to identify the optimum conditions for the sorption and removal of crude oil from seawater. The performance indicators were predicted with a high degree of accuracy, i.e. with coefficient of determination (R2) values exceeding 90%. The optimum values of S and R% were estimated to be 32.5 g of crude oil/g of sorbent and 91.2% respectively. These optimum values were attained after 70 min of PB/crude oil contact time and at a temperature of 45 °C. The spent sorbent maintained its performance after three cycles of regeneration and reuse, suggesting that the material is reusable.

Removal of crude oil from highly contaminated natural surfaces with corexit dispersants

Dispersants are used to reduce the impact of oil spills in marine environment. Experiments were conducted with natural materials which were contaminated by direct application of fresh Louisiana crude oil. The natural materials evaluated included sea sand (South Beach in Miami, Florida), red mangrove leaves (Rhizophora mangle), and sea shells (Donax variabili). Salt water at two different salinities (17 and 34 ppt) was used with two types of Corexit dispersant solutions (9500A and 9527A) in concentrations ranging from 100 to 3500 mg/L. Washing of the contaminated samples was conducted by a three-step mixing procedure (salt water only, then with the addition of the dispersant solution to the salt water, and salt water) to simulate oil-saltwater-dispersant interactions. In general, increasing dispersant concentration increased the percentage of oil dispersed into the aqueous phase up to dispersant solutions containing 400 mg/L for Corexit 9500A and 300 mg/L Corexit 9527A. Increasing the dispersant concentration above these levels also decreased the dispersion of oil from the surfaces. At very high concentrations of dispersant solutions (above 1500 mg/L), the percentage of oil dispersed into the solution from the contaminated surfaces was about one half what was observed at 400 mg/L with Corexit 9500A and 300 mg/L Corexit 9527A. Although dispersants were most effective for removing the fresh Louisiana crude oil from sand particles and dispersing into the solution due to large surface area of the particles per unit weight; the residual oil remaining on the sand particles was relatively high in comparison to mangrove leaves and sea shells due to clustering of sand particle with oil. There was some oil penetration into the porous structure of the sea shells (at the microscopic level) which could not be removed.

Metagenomic and metatranscriptomic responses of natural oil degrading bacteria in the presence of dispersants.

Oil biodegradation has been extensively studied in the wake of the deepwater horizon spill, but the application of dispersant to oil spills in marine environments remains controversial. Here, we report metagenomic (MG) and metatranscriptomic (MT) data mining from microcosm experiments investigating the oil degrading potential of Canadian west and east coasts to estimate the gene abundance and activity of oil degrading bacteria in the presence of dispersant. We found that the addition of dispersant to crude oil mainly favours the abundance of Thalassolituus in the summer and Oleispira in the winter, two key natural oil degrading bacteria. We found a high abundance of genes related not only to n-alkane and aromatics degradation but also associated with transporters, two-component systems, bacterial motility, secretion systems and bacterial chemotaxis.

Characteristic Assessment of Diesel-degrading Bacteria Immobilized on Natural Organic Carriers in Marine Environment: the Degradation Activity and Nutrient

Oil spill has led to severe environmental and ecological problems. Due to the harsh environmental conditions, the bioremediation technology is not successfully used to remedy the oil spill in marine environment. In this study, immobilization technology was used to immobilize bacteria on natural organic carriers (i.e., wood chips and maize straw). The higher surface area of in wood chips leads to larger biomass density (0.0242 gVSS/g) than that of maize straw of 0.0097 gVSS/g carrier. Compared with biodegradation efficiency of free bacteria (44.79%), the immobilized bacteria on wood chips and maize straw reached to 73.39% and 52.28%, respectively. The high biological activity of the immobilized bacteria can be also explained by nutrients, such as TN (total nitrogen) and TP (total phosphorus), released from wood chips and maize straw, which was 8.83 mg/g and 5.53 mg/g, 0.0624 mg/g and 0.0099 mg/g, respectively.

Facile sorbent from esterified cellulosic sago waste for engine oil removal in marine environment

This article reports on the utilization of chemically modified cellulosic sago (MCS) from sago bark as a highly potential material for remediating oil spills in marine environment. MCS was prepared via incorporation of hydroxyl-rich cellulosic sago bark (CS) with fatty acid derivative. The sorption capacity, hydrophobicity, and lipophilicity of MCS and CS were evaluated. MCS exhibited higher total pore volume (0.012 cm3/g) and high hydrophobicity (60%) compared to CS. The oil spills adsorption studies was compared in batch system both in deionized water and seawater. MCS showed higher oil sorption capacity in deionized water after 60 min (MCS 3.0 g/g, CS 2.4 g/g). The maximum oil sorption capacity of MCS in dynamic seawater system was 5.7 g/g which was higher than CS (5.0 g/g). The results suggested that MCS is a potential low-cost natural sorbent which work best in the removal of oil spilled from dynamic seawater environment than deionized water.

Analysis of Two Oil Spills in the Southern Brazilian Shelf, in the Years of 2012 and 2014

Numerical models have been widely used to simulate and predict the behavior and transport of oil spills in marine environments. Their behavior is governed by physical, chemical and biological processes which are related to the hydrocarbon properties, hydrodynamic and weather conditions, and other environmental variables. The transport and interactions of oil particles were evaluated in simulations reproducing two oil spills recorded in the northern part of the Southern Brazilian Shelf (SBS). The numerical simulations were performed using the ECOS (Easy Coupling Oil System) model coupled to the three-dimensional hydrodynamic module TELEMAC3D. The hydrodynamic model provides the variables needed by oil spill model to calculate and infer the properties and behavior of the oil slick. The results indicate that the local wind forcing is the most important factor in determining the oil fate, followed by the intensities and directions of coastal currents. Regarding the events, in 2012 the oil reached the coast after 10 hours of the leak while in 2014 it was transported towards the ocean. The simulation strategy used in this article did not prove to be appropriate for estimates of the oil risk in the region, due to the distinct susceptibility responses between the events simulated.

Pollution Due to Oil Spills in Marine Environment And Control Measures

Pollution Due to Oil Spills in Marine Environment And Control Measures