A probabilistic model of decision making regarding the use of chemical dispersants to combat oil spills in the German Bight

Assessment of oil vertical diffusion in waters following an oil spill incident in an urban inland waterway

Accidental oil spills can have a serious impact on water bodies. While most current studies have focused on waves, few have examined water flows, which represent the most common hydrodynamic environment in urban inland waterways. In this study, 12 hydrodynamic conditions were constructed, and the oil vertical diffusion characteristics under hydrodynamic conditions were investigated by measuring oil concentration and oil droplet size distribution at different depths. The main findings include: (1) Oil concentration decays exponentially along the vertical direction, the related parameters follow power and quadratic functions in relation to mean flow velocity, respectively; (2) Oil droplet size distribution was influenced by hydrodynamic characteristics, mean flow velocity was significantly positively correlated with its distribution range; (3) Oil droplet size distribution patterns at different depths were similar, in line with the characteristics of Rosin-Rammler distribution. Based on experimental data, a set of models was constructed to describe and predict the vertical distribution of oil concentration and oil droplet size distribution under hydrodynamic conditions. This study not only reveals the characteristics of oil vertical diffusion under hydrodynamic conditions, but also provides a quantitative framework for understanding the relevant features, which is helpful for the response to the oil spill accident in urban inland waterways.

Effects of suspended particles and dispersants on marine oil snow formation of crude oil/diesel oil

Marine oil snow (MOS) potentially forms after an oil spill. To fully understand the mechanism of its formation, we investigated the effects of suspended particles (SP) and dispersants on MOS formation of crude oil and diesel oil by laboratory experiments. In the crude oil experiment, the SP concentration of 0.2 g L-1 was more suitable for crude oil MOS formation. The addition of dispersants significantly stimulated N and TV during MS/MOS formation of SP at 0.4 g L-1 and 0.8 g L-1 concentration (p < 0.05). Without SP, the dispersants also stimulated crude oil MOS formation. Furthermore, the concentration of SP had a significantly positive effect on the reduction of the total amount of N-alkanes (p < 0.05). In the diesel oil experiment, after adding dispersants to diesel oil, the maximum N, Dm, and TV values at a SP concentration of 0.2 g L-1 were significantly higher than those at 0.4 g L-1 and 0.8 g L-1 (p < 0.05). Besides, we found that dispersants stimulated MOS formation in diesel oil at a SP concentration of 0.2 g L-1. However, the dispersants had an inhibitory effect on diesel oil MOS formation without SP. Notably, the MOS formed by diesel oil appeared white, unlike the black MOS associated with crude oil. These findings are important for the environmental impact of oil spills and elevated SP concentrations.

Sustainability and capability-based assessment of marine oil spill response technologies using a decision support system under decomposed fuzzy set

Marine oil spills are a practically challenging environmental occurrence to remediate. The critical stage of managing marine oil spills is choosing an appropriate response technology. This research implements a novel sustainability and capability policy-oriented decision support system (DSS) and the decomposed fuzzy set-based ORESTE model. First, an integrated criteria system on the basis of the sustainability and capability aspects is employed by considering four social, environmental, economic, and capability dimensions. Second, the ORESTE model under the decomposed fuzzy environment is extended to deal with the uncertainty data, evaluate the conflicts between the candidate alternatives, and choose the optimal scenario. Seven technologies of bioremediation, solidifiers, dispersants, adsorbents, in situ burning, booms, and skimmers for remediating oil spills in the Persian Gulf, Iran, have been assessed. The assessment results indicate that the bioremediation technology is the optimal scenario for the oil spill-contaminated sites management and the suggested DSS is feasible and applicable.

Super-amphiphobic arabic gum-based coatings on textile for on-demand oily and dye wastewater treatment

Different membrane materials have broadly been constructed for oil-containing water separation, but most of preparation routes involve corrosive or toxic chemicals and especially many materials have only single superwetting property. Herein, a novel and eco-friendly cellulose-based textile membrane is developed by incorporating the composite coating consisting of arabic gum (AG), attapulgite (APT), and iron (Fe) onto cellulose textiles. The functionalized textile is superoleophobic underwater and superhydrophobic underoil. As a result, the textile prewetted with water or oil can be employed to separate light oil layer/water and heavy oil layer/water mixtures, respectively, and the separation efficiency to the two types of mixtures is larger than 98.3 %. Results also reveal that the decorated textile possesses superior stability and recyclability in purifying oily wastewater. More importantly, such coated textile is capable of filtrating water-soluble contaminants (dyes) from polluted water. Due to the versatility and environmental compatibility of product as well as the accessibility as agricultural and forestry product as raw materials, the advanced textiles may offer effective solutions to oily wastewater purification and water-soluble contaminant removal.

Special wettable Azadirachta indica leaves like microarchitecture mesh filtration membrane produced by galvanic replacement reaction for layered oil/water separation

The oil/water separation has received significant attention due to its critical environmental impact. The special wettable surfaces are highly desired to deal with the oil/water mixtures. This work demonstrates a simple two-step method to develop a superhydrophobic Azadirachta indica leaves like Ag-decorated electrochemically copper-coated stainless-steel mesh (SH-AIL-Ag-EC-Cu-Mesh) for efficient separation of oil/water mixtures. In the first step, the electrodeposition of the copper took place on the mesh surface at a suitable applied potential. In the second step, the galvanic replacement reaction between the Ag⁺ and electrodeposited Cu produced the fascinating superhydrophobic Ag leaves on the mesh surface. The SH-AIL-Ag-EC-Cu-Mesh was thoroughly characterized by the X-ray photoelectron spectroscopy (XPS), Energy Dispersive X-Ray Spectroscopy (EDX), elemental mapping, surface wettability analysis, and the contact analyzer. The morphological analysis has shown the unique leafy structures of the reduced Ag on the surface of the mesh. The XPS analysis has confirmed that most of the Ag present on the surface is in zerovalent form. The combination of the electrodeposition and the displacement reaction between the copper and the silver turned the surface superhydrophobic, and the water contact angle was significantly improved from 115° to 158°. The designed SH-AIL-Ag-EC-Cu-Mesh has shown excellent selectivity for oil in oil/water mixtures with a separation efficiency of 99.1% with an exceptionally high flux of 8963 L m^-2h^-1. The SH-AIL-Ag-EC-Cu-Mesh has shown excellent reusability, and after 15 cycles of separation, no significant decrease in the oil/water separation efficiency was observed.

Risk assessment of marine oil spills using dynamic Bayesian network analyses

Oil spills are serious threats to the marine ecosystem. Especially when an oil spill is faced with extreme weather, the consequences might be more severe. Until now, no such researches focus on the risk of these extreme scenarios. This paper proposes a novel dynamic assessment method to quantify the risk of oil spills in extreme winds based on dynamic Bayesian networks (DBNs). The physical models of advection, spreading, evaporation, and dispersion are transformed into DBNs, and the vulnerability model is established according to coastline types and socio-economic resources. By integrating all the sub-models, the overall DBN to quantify the dynamic risk of oil spills occurring in extreme winds is obtained. The proposed method is demonstrated by the Laizhou Bay. The developed model is validated by a three-axiom-based approach. Temporal and spatial dynamics of risk caused by oil spills in potential locations could be calculated. Based on the developed DBN, the risk of the Laizhou Bay coast caused by oil spills in annual extreme wind speeds corresponding to different mean recurrence intervals is studied. In addition, the effects of the occurrence time of annual extreme winds are also researched.

Phytic acid and graphene oxide functionalized sponge with special-wettability and electronegativity for oil-in-water emulsion separation in single-step

Developing an emulsion separation material with one-step in-situ purifying capability and improved security in applications, especially for subsequent scale-up, is valuable but remains a challenge. Herein, the amphiphilic sponge (PA@RGO@MS) was prepared via impregnation and in-situ growth of the negatively charged hydrophilic phytic acid (PA) and the hydrophobic reduced graphene oxide (RGO) on the surface of the melamine sponge (MS) and applied in emulsion purification. The mechanics, wettability, absorption performance of the PA@RGO@MS were analyzed to identify its potential for stable demulsification. Results show that the PA@RGO@MS could purify emulsions (turbidity removal rate = 99.7%; TOC removal rate = 94.14%) in-situ in one step by simple shock absorption, profited from the hydrophilic and demulsification capability of PA, oil absorption of RGO, and wide reaction and storage space of MS. Targeting the emulsion with distinct properties (density, viscosity, and concentration) of the oil phase, the PA@RGO@MS could efficiently enable the purification. Meanwhile, the powerful flame-retardant granted from PA ensures the safe shipment and storage of sponges. The favorable cyclability (turbidity removal rate > 98.5% and TOC removal rate > 89.5% after 10 cycles) and diversified operating modes enhance the practical value of the PA@RGO@MS.

Dispersants as an oil spill clean-up technique in the marine environment: A review

Oil is a major source of energy in the industrial world. Exploitation of oil and rigging activities, transportation via sea, and many other mechanical failures lead to oil spills into the marine environment. In view of these, the suitability and effectiveness of oil spill response methods have always been a topical discussion worldwide. It has become necessary, now than ever, for existing spill response methods used to remove oil from the environment to be improved upon and more importantly, develop new response materials that are sustainable and environmentally friendly. There exist surfactants in nature that are non-toxic and biodegradable, which can be explored to produce potential dispersants to help remove oil safely from the surface of marine water. This review comprises of the works and resourceful materials produced by various researchers and agencies in the field of oil spill response, placing emphasis on the use of dispersants in the marine environment.

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Smart dispersants have the potential to minimize dispersant wastage.

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Biodegradable dispersants may bring a closure to discussions on toxicity.

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Bio-based formulations have the potential to replace chemical based dispersants.

Recent Developments and Advancements in Graphene-Based Technologies for Oil Spill Cleanup and Oil-Water Separation Processes

The vast demand for petroleum industry products led to the increased production of oily wastewaters and has led to many possible separation technologies. In addition to production-related oily wastewater, direct oil spills are associated with detrimental effects on the local ecosystems. Accordingly, this review paper aims to tackle the oil spill cleanup issue as well as water separation by providing a wide range of graphene-based technologies. These include graphene-based membranes; graphene sponges; graphene-decorated meshes; graphene hydrogels; graphene aerogels; graphene foam; and graphene-coated cotton. Sponges and aerogels modified by graphene and reduced graphene oxide demonstrated effective oil water separation owing to their superhydrophobic/superoleophilic properties. In addition, oil particles are intercepted while allowing water molecules to penetrate the graphene-oxide-coated metal meshes and membranes thanks to their superhydrophilic/underwater superoleophobic properties. Finally, we offer future perspectives on oil water separation that are hindering the advancements of such technologies and their large-scale applications.

One-pot room-temperature synthesis of covalent organic framework-coated superhydrophobic sponges for highly efficient oil-water separation

Frequent oil-spill accidents not only cause serious and long-term damage to marine ecosystems, but also lead to a huge loss of valuable natural resources. To lighten the environmental pollution of oil spills as quickly as possible, an efficient and environment-friendly approach for oil-water separation is highly desirable. Herein, a facile one-pot room-temperature approach was developed for large-scale fabrication of covalent organic framework-coated superhydrophobic sponges (sponges@COFs). The as-prepared sponges@COFs possessed many superior properties, including superhydrophobicity with the water contact angle of approximately 154.3°, large specific surface area (153.059 m²/g), high porosity of the network structures, as well as good mechanical and chemical stability. Taking the aformentioned advantages together, the superhydrophobic sponges showed ultra-high adsorption capacity for oil and various organic solvents. In comparision with its own weight, the adsorption amount of the sponges@COFs for silicone oil was up to 150 times and for toluene was 125 times, respectively. Furthermore, the superhydrophobic sponges also showed fast and highly efficient oil-water separation, outstanding flame retardancy and recyclability. In addition, the sponges@COFs were successfully applied to the high-efficiency removal of oil suspension from industrial waste water, firmly confirming their application prospect in industrial wastewater treatment.

Decision support tools for oil spill response (OSR-DSTs): Approaches, challenges, and future research perspectives

Marine oil spills pose a significant threat to ocean and coastal ecosystems. In addition to costs incurred by response activities, an economic burden could be experienced by stakeholders dependent on coastal resources. Decision support tools for oil spill response (OSR-DSTs) have been playing an important role during oil spill response operations. This paper aims to provide an insight into the status of research on OSR-DSTs and identify future directions. Specifically, a systematic review is conducted including an examination of the advantages and limitations of currently applied and emerging decision support techniques for oil spill response. In response to elevated environmental concerns for protecting the polar ecosystem, the review includes a discussion on the use of OSR-DSTs in cold regions. Based on the analysis of information acquired, recommendations for future work on the development of OSR-DSTs to support the selection and implementation of spill response options are presented.