Effectiveness of mechanical recovery for large offshore oil spills

Stereo-complex polylactide composite aerogel for crude oil adsorption

Adsorption materials are a cost-effective and simple method for oil spill remediation, but their efficiency is limited by high crude oil viscosity. Additionally, non-degradable materials pose another risk of secondary pollution, such as microplastic debris. Here, an environmentally-friendly stereo-complex polylactide composite (SCC) aerogel were developed via water-assisted thermally induced phase separation. The SCC with 3 wt% carbon nanotubes had a hierarchical structure of micro/nanoscale pores and high content of stereo-complex crystallites (35.7 %). Along with the excellent water repellency (water contact angle: 157°), SCC aerogel was 2.7 times as resistant to hydrolysis than poly(l-lactide) aerogel (Ph = 13, 37 °C). Additionally, a maximum absorption capacity of 41.2 g g-1 and over 97 % oil/water separation efficiency after 10 cycles were obtained in low viscosity conditions; while in high viscosity conditions, it displayed excellent photothermal performance, reaching a surface temperature of 85 °C under 1 sunlight, reducing crude oil absorption time from 42 min to 60 s (97.6 %-time savings). Moreover, it facilitated continuous crude oil spill recovery under sunlight with an adsorption rate of 3.3 × 104 kg m-3 h-1. The SCC aerogel presents a potential route for utilizing solar energy in crude oil adsorption applications without additional environmental burden.

Hydrophobic organogel sorbent and its coated porous substrates for efficient oil/water emulsion separation and effective spilled oil remediation

Frequent offshore oil leakage accidents and large quantities of oily-wastewater produced in industry and daily life bring huge challenges to global water purification. The adaptability and stability of organogels as adsorbent materials have shown wide application prospects in the field of oil-water separation. Herein, the organogels displayed stable hydrophobic/lipophilic properties with high absorption ability (1200 wt./wt%), efficient sorption of multiple emulsions (>99.0%), and good reusability. More importantly, the organogels were successfully assembled with 2D/3D substrates to achieve excellent sorption capacity (102.5 g/g) and recycling performance (50 cycles). The gel-carbon black assembled on MS (GCB-MS) sorbent with excellent photothermal conversion performance, and can rapidly heat the surface to 70.4 °C under 1.0 sunlight radiation (1.0 kW/m2) and achieved an ultra-high sorption capacity of about 103 g/g for viscous crude oil. Meanwhile, the GCB-MS was combined with a pump to build continuous oil spill cleaning equipment to achieve a super-fast cleanup rate of 6.83 g/min. The developed hydrophobic organogels had been expanded unprecedentedly to realize the comprehensive treatment of oily-wastewater in complex environments, including layered oils, emulsions, and viscous crude oil spill, which provided an effective path for the comprehensive treatment of oily wastewater in complex environments.

Simultaneous immobilization enhances synergistic interactions and crude oil removal of bacterial consortium

Oil spillage has serious adverse effects on marine environments. The degradation of crude oil by microorganisms may be an effective and sustainable approach. In this study, the removal of crude oil from seawater by immobilized bacterial consortium was performed and the enhancement of crude oil degradation efficiency by varying immobilization methods and inoculum volume ratio was examined. The nonpathogenic and heavy metal-tolerant bacterial consortium of Sphingobium naphthae MO2-4 and Priestia aryabhattai TL01-2 was immobilized by biofilm formation on aquaporousgels. The simultaneous immobilization of strains MO2-4 and TL01-2 showed better crude oil removal efficiency than independent immobilization, which indicated positive interactions among consortium members in the mixed-culture immobilized systems. Moreover, the immobilized consortium at a 2:1 (MO2-4:TL01-2) inoculum volume ratio showed the best crude oil removal capacity. The immobilized consortium removed 77% of 2000 mg L-1 crude oil in seawater over 7 days. The immobilized consortium maintained crude oil removal efficacy in semicontinuous experiments. In addition, the immobilized consortium was used to remediate seawater contaminated with 1000 mg L-1 crude oil in a 20 L wave tank. After 28 days, the crude oil degradation efficiency of immobilized consortium was approximately 70%, and crude oil degradation through natural attenuation was not observed. Moreover, the genomic features of strains MO2-4 and TL01-2 are reported. Genomic analyses of both strains confirmed the presence of many genes involved in hydrocarbon degradation, heavy metal resistance, biosurfactant synthesis, and biofilm formation, supporting the biodegradation results and characterizing strain properties. The results of this work introduce the potential benefit of simultaneous immobilization of bacterial consortia to improve efficiency of crude oil biodegradation and has motivated further investigations into large-scale remediation of crude oil-contaminated seawater.

Melt-blown fiber felt for efficient all-weather recovery of viscous oil spills by Joule heating and photothermal effect

Adsorbents play a vital role in responding to marine oil spills, yet effectively cleaning up viscous oil spills remains a technical challenge. Herein, we present a superhydrophobic oil-adsorbing felt prepared using melt-blown technology and functionally enhanced with a photoelectric composite CNT/PANI coating for effectively cleaning up high-viscosity oil spills. By virtue of its superior solar/Joule heating ability and thermally conductive fiber network, p-CNT/PANI@PP notably reduced crude oil viscosity and enhanced the oil diffusion coefficient within pores. Leveraging primarily solar heating and supplemented by Joule heating, p-CNT/PANI@PP demonstrates an impressive in-situ adsorption rate of up to 560 g/h for ultra-high-viscosity crude oil (c.a. 138000 mPa·s), alongside an adsorption capacity of 15.57 g/g. This measure enables efficient viscosity reduction and continuous day-and-night recovery of viscous crude oil, addressing the challenges posed by seasonal fluctuations in seawater temperature and adverse weather conditions. Moreover, a conveyorized collector integrated with an oil-adsorbing felt realizes continuous recovery of viscous oil spills with speed control to tackle varying thicknesses of oil film. Given the top-down material design, superior functionality, and applicability to applications, this work provides a comprehensive and feasible solution to catastrophic large-area viscous oil spills.

Combined oil spill modelling and shoreline sensitivity analysis for contingency planning in the Irish Sea

Offshore oil spills often result in severe environmental and socio-economic consequences. This work focuses on a busy, yet poorly studied part of NW Europe, the Irish Sea, to assess the impact of future oil spills on the nearby coast. By integrating numerical models and shoreline sensitivity analyses for two confined areas, Liverpool Bay and Milford Haven, this work acknowledges wind direction and speed as principal controls on the movement of oil under winter/storm conditions and in shallow waters. Ocean currents play a secondary role, but are significant in deeper waters and in low-wind summer conditions. The temporal elements used in the modelling thus stress that when the spill occurs is just as important as where. As a corollary, the fate of spilled oil is determined in this work for distinct scenarios and types. Response strategies are recommended to minimise the impact of future spills on coastal populations.

Superhydrophobic polyurethane sponge for efficient water-oil emulsion separation and rapid solar-assisted highly viscous crude oil adsorption and recovery

Rapid and efficient cleaning of oily wastewater and high viscosity crude oil spills is still a global challenge. Conventional three-dimensional porous adsorbents are ineffective for oil-water separation in harsh environment and are restricted to the low fluidity of high viscosity crude oil at room temperature. Increasing temperature can enormously improve the fluidity of viscous crude oil. Herein, the polydimethylsiloxane (PDMS) /carbon black (CB) -modified polyurethane sponge (PU) were prepared by a simple one-step dip-coating method. PDMS/CB@PU (PCPU) exhibits high adsorption capacity to various oils and organic liquid (28.5-68.7 g/g), strong mechanical properties (500 cycles at 50%), outstanding reusability (100 cycles of adsorption and desorption) and excellent environmental stability due to the special PDMS/CB coating. The maximum surface temperature of PCPU sponge can reach 84.7 ℃ under 1 sunlight irradiation. Therefore, the PCPU sponge can rapidly heat and enhance the fluidity of viscous crude oil, significantly speeding up the viscous oil recovery process with the maximum adsorption capacity of 44.7 g/g. In addition, the PCPU sponge can also combine with the vacuum pump to realize the continuous and rapid repair of viscous oil spills from the seawater surface. In consideration of its simple preparation, cost-effectiveness and high oil absorption ability, this solar-assisted self-heating adsorbent provides a new direction for large-scale cleanup and recycling of viscous crude oil spill on the seawater surface.

Novel Magnetically Driven Superhydrophobic Sponges Coated with Asphaltene/Kaolin Nanoparticles for Effective Oil Spill Cleanup

Fast and effective cleanup of oil spills remains a global challenge. A modified commercial sponge with superhydrophobicity, strong absorption capacity, outstanding magnetic response, and fire resistance were fabricated by a facile and inexpensive route of dip-coated melamine sponge carbonization. The low-cost petroleum asphaltene and kaolin nanoparticles were used as the dip-coating reagent. High absorption capacity of the fabricated sponges allowed rapid and continuous removal of oil contaminants. Taking advantage of the good refractory property, the sponges can be used in burning conditions and directly reused after burning out of the absorbed oil. Reusability tests showed that the modified sponges still maintained high absorption capacity (>85%) after six regeneration and reuse cycles. These characteristics make the fabricated sponge a promising aid to promote effective in situ burning cleanup of oil spills, contributing as a magnetic oil collector and a fire-resistant flexible boom. An example usage scenario of the sponges applied to in situ burning cleanup of oil spills is described.

The fingerprint stability of the biomarker hopanes and steranes in soot emissions from in-situ burning of oil

The behavior of emissions is an important concern of in-situ burning (ISB) of spilled oils. In particular, the heavy soot originated from ISB can negatively impact the atmospheric environment. To track the behavior of ISB soot, the conservative biomarkers, such as hopanes and steranes, can be potentially used. In this study, the stability of chemical fingerprints of hopanes and steranes in the ISB soot were investigated based on the burning of two different types of oils, including one ultra-light condensate (i.e., surrogate Sanchi condensate) and one heavy oil. The results indicate that the chromatographic patterns and diagnostic ratios of hopanes and steranes in the ISB soot emissions almost remain identical to their corresponding source oils, proving the various oil source identification of ISB soot can be realized. This work attempts to provide novel insights into the application of biomarkers in the management of ISB emissions.

Solar-assisted self-heating Ti3C2Tx-decorated wood aerogel for adsorption and recovery of highly viscous crude oil

Frequent oil-spill accidents have posed serious threats to ecosystem balance and the efficiency of resources use. Hydrophobic adsorbents that can adsorb and recover oil without causing secondary pollution are ideal candidates for the remediation of oil contamination in water. However, these composites are inefficient for crude oil-spills cleanup because crude oil has low liquidity of at room temperature. Increasing the temperature can effectively enhance the flowability of crude oil. To achieve efficient crude-oil heating and removal in situ, wood aerogels were immersed in Ti₃C₂T_x suspensions and then coated with polydimethylsiloxane (PDMS) to obtain a solar-heated adsorbent (PT-WA). The prepared PT-WA exhibits super-hydrophobicity (water contact angle: 154° ± 2°), mechanical robustness (withstanding 20 loading-unloading cycles under 50% strain without structural damage), strong solar absorption, and favorable photothermal-conversion capability (rising to ~85 °C within 90 s under 1.5 sun). Owing to these advantages, PT-WA is an effective adsorbent for crude oil cleanup. In addition, a 'self-heating crude oil collector' was assembled for the fast adsorption and restoration of crude oil from the water surface. This solar-assisted self-heating sorbent offers a competitive platform for the cleanup and recycling of viscous crude oil spills.

Optimisation Methodology for Skimmer Device Selection for Removal of the Marine Oil Pollution

This paper emphasised the importance of proper handling and selection of specialised skimmer equipment for accidental pollution with oils. The research was motivated by the lack of similar papers that offer an extensive and recent literature analysis related to the use of skimmers, with the ultimate aim to present the methodology for proper selection of appropriate pollution equipment. Knowledge on the equipment characteristics such as capacity, selectivity, speed, and pump power of the skimmer is essential for efficient and fast collection of spills. The study aimed to calculate the oil collection rate of an individual skimmer device with different pumps. The classification of skimmers, pumps, and collecting tanks was made according to their main features. The results showed the correlation between pump capacity and the skimmers. Due to the complexity of mechanical equipment and various devices, it was crucial to identify and connect the skimmer with the proper pump. For these reasons, the authors proposed a model which determines the optimal combination for thirteen skimmers and eleven pumps. The model can help shorten the time of collecting oil from the sea surface and provide a more efficient and smoother response in the events of accidental marine pollution.

Oil at sea-how much is too much?

The anthropogenic share of marine oil discharge is much larger than previously thought.

Solar-assisted high-efficient cleanup of viscous crude oil spill using an ink-modified plant fiber sponge

Rapid and efficient clean-up of viscous crude oil spills is still a global challenge due to its high viscous and poor flowability at room temperature. The hydrophobic/oleophilic absorbents with three-dimensional porous structure have been considered as a promising candidate to handle oil spills. However, they still have limited application in recovering the high viscous oil. Inspired by the viscosity of crude oil depended on the temperature, a solar-heated ink modified plant fiber sponge (PFS@GC) is fabricated via a simple and environmentally friendly physical foaming strategy combined with in-situ ink coating treatment. After wrapping by the polydimethylsiloxane (PDMS), the modified PFS@GC (PFS@GC@PDMS) exhibits excellent compressibility, high hydrophobic (141° in water contact angle), solar absorption (> 96.0%), and oil absorptive capacity (12.0-27.8 g/g). Benefiting from the favorable mechanical property and photothermal conversion capacity, PFS@GC@PDMS is demonstrated as a high-performance absorbent for crude oil clean-up and recovery. In addition, PFS@GC@PDMS can also be applied in a continuous absorption system for uninterrupted recovering of oil spills on the water surface. The proposed solar-heated absorbent design provides a new opportunity for exploring biomass in addressing large-scale oil spill disasters.

Hierarchical Optimization of Oil Spill Response Vessels in Cases of Accidental Pollution of Bays and Coves

Ships pollute bays and coves with oils daily. Although the number of major pollution events is decreasing, accidents still occur and are likely to occur in the future. Most often, pollution arises from spills of non-persistent oil in bays, mainly during the summer season. A prompt response is key to oil collection success in semi-enclosed waters. In order to ensure that oil does not reach the mainland and endanger a potentially crucial economic resource of a country, it is vital to collect it in minimal time. Furthermore, it is also essential to send response ships that minimize the cost. In practice, there may be several optimal combinations of response ships to be sent. When the response cost is considered, obtaining all possible optimal solutions (a complete Pareto front) is vital because the shortest collection time does not necessarily mean the lowest costs. For these reasons, two general optimization models are considered. The first model gives the minimum response time to collect oil from the sea’s surface, while the second model gives the minimum response cost of ships participating in the clean-up operation. The supplied pseudo-codes allow for all optimal solutions to be found.

Environmental Impacts and Challenges Associated with Oil Spills on Shorelines

Oil spills are of great concern because they impose a threat to the marine ecosystem, including shorelines. As oil spilled at sea is transported to the shoreline, and after its arrival, its behavior and physicochemical characteristics change because of natural weathering phenomena. Additionally, the fate of the oil depends on shoreline type, tidal energy, and environmental conditions. This paper critically overviews the vulnerability of shorelines to oil spill impact and the implication of seasonal variations with the natural attenuation of oil. A comprehensive review of various monitoring techniques, including GIS tools and remote sensing, is discussed for tracking, and mapping oil spills. A comparison of various remote sensors shows that laser fluorosensors can detect oil on various types of substrates, including snow and ice. Moreover, current methods to prevent oil from reaching the shoreline, including physical booms, sorbents, and dispersants, are examined. The advantages and limitations of various physical, chemical, and biological treatment methods and their application suitability for different shore types are discussed. The paper highlights some of the challenges faced while managing oil spills, including viewpoints on the lack of monitoring data, the need for integrated decision-making systems, and the development of rapid response strategies to optimize the protection of shorelines from oil spills.

Superhydrophobic starch-based adsorbent with honeycomb coral-like surface fabricated via facile immersion process for removing oil from water

The development of novel superhydrophobic adsorbents is highly demanded for tackling frequent oil spill accidents. Porous starch-based materials have been proven to possess good oil absorption performance, but their superhydrophobicity has not yet been reported, thus limiting their application in oil spill cleanup. Herein, a superhydrophobic starch-based adsorbent (MSC) was fabricated through the facile immersion process of starch cryogel (SC) into toluene solution of methyltrichlorosilane (MTS). Low-surface-energy and honeycomb coral-like micro/nanostructures, which contribute to high water contact angle (>151.0°) and low sliding angle (<15.0°), were provided simultaneously to SC by the hydrolysis-condensation reaction of MTS. MSC exhibited excellent water repellent, self-cleaning, and anti-fouling properties, as well as passable mechanical and chemical durability. The reasonable oil adsorption performance and selective wettability toward oil and water allowed this absorbent to be applied for heavy oil removal underwater and oil slick cleaning from the water surface. It is expected that the facile strategy provided by this work will accelerate the application of superhydrophobic starch-based materials in oil contamination removal and other industrial activities.