Oily Water Research Articles

Experiments on thermal neutralization of marine oily waters

During the operation of the ship's power plant, the formation of oily waters is inevitable. Numerous methods and technologies used on ships do not always ensure the purification of oily waters to the amount of oil content regulated by national and international standards and requirements. In this regard, the development of a new type of installations that allow for the complete purification of oily waters from petroleum products, as well as to reduce their energy and weight and size indicators is relevant. The article presents the first results of experimental studies of the method of thermal neutralization of oily waters, consisting in their spraying in the gas outlet tract of a marine diesel engine, followed by evaporation of water and afterburning of petroleum products from the composition of oily waters with exhaust diesel gases. The research was carried out on a specially designed laboratory stand. The burner of the stand allows to obtain exhaust gases identical in composition and temperature to the exhaust gases in the flue of a marine diesel engine. A gas or liquid medium can be supplied to the flue through the nozzle. Within the framework of the described research period, the influence of the flow rate and composition of the medium supplied to the flue on the temperature at various points of the flue and the resulting composition of the exhaust gases were evaluated. The main task of this stage of the study is to determine the effect of the flow rate and composition of the medium supplied to the flue on the compliance of the gas parameters at the outlet of the installation with the standards for the content of harmful substances in the exhaust gases of marine diesel engines.

Investigation of synergistic effects incorporating esterified lignin and guar gum composite aerogel for sustained oil spill cleanup

The recently developed aerogel demonstrates a high capacity for pollutant absorption, making it an environmentally friendly option for oily water treatment. In an effort to reduce the adverse effects of the black liquor accumulation in the pulp industry, this study focused on utilizing the mentioned abundant bio-resource lignin, which can be applied to various high-value applications such as 3D porous materials for oil spill cleanup. Lignin, precipitated from the black liquor, was esterified using maleic anhydride as the esterifying reagent to enhance the hydrophobicity. Then, the composite aerogel fabricated from esterified lignin and guar gum (GG) was successfully prepared through the facile freeze-drying, using glutaraldehyde (GA) as the cross-linker. The resulting aerogel exhibited high porosity values exceeding 95%, low density (27.4 mg/cm3), and an impressive absorption capacity of 32.5 g/g for sunflower oil. These results demonstrate the potential of black liquor utilization as a bio-waste source of lignin and highlight the cost-effective guar gum-esterified lignin composite aerogel, which exhibits remarkable oil absorption capabilities and environmental sustainability promotion.

Superhydrophobic PCTFE-based microporous membrane for water/oil emulsion separation in various environments

The separation of oil from oily water is a critical endeavor owing to the escalating global oil pollution. Membrane separation technology has gained widespread adoption for oily water treatment. Inspired by the vertical segregation phenomenon in drying multi-component suspensions, this study proposed an evaporation-induced stratification coupled with sacrificial template method to prepare superhydrophobic polychlorotrifluoroethylene (PCTFE) membrane for fast gravity-driven oil/water separation. The precursor of PCTFE microporous membranes, PCTFE/fluoroelastomer/hydrophobic silica nanoparticles (PCTFE/FR/SiO2) composite films, were fabricated via a solvent-assisted method. Induced by solvent evaporation, the pre-fabricated composite films exhibited a stratified structure, where SiO2 nanoparticles enriched near the top surfaces, making it easily tailor the surficial wettability. For the matrix, PCTFE-rich domains and FR-rich domains intersected, forming a bicontinuous structure. After sacrificing FR, PCTFE porous membranes were obtained. Meanwhile, the PCTFE-based porous skeletons combining with surface enriched SiO2 nanoparticles constructed a multi-level roughness, thus achieving superhydrophobicity. The optimized membrane possessed an average pore size of ∼1.84 μm, a porosity of ∼60 %, and a WCA above 155°, owning excellent self-cleaning properties and efficient oil/water separation ability. The membrane exhibited remarkable capability in various oil/water mixtures, including emulsified water-in-oil. The separation flux and oil recovery purity for water-in-dichloromethane emulsion were up to 2843 ± 84 L/(m2·h) and 99.95 wt%, respectively. Furthermore, though being immersed into various organic solvents for 7 days or experiencing 15 separation cycles, the performances of the membranes hardly changed. Accordingly, this work provides a practical approach for tailoring surficial wettability and fabricating PCTFE-based membranes suitable for oil/water separation fields.

Faveolate cell-engineered and multi-heterostructured flexible ceramic nanofibrous membranes with confined coalescent nanochannels enable sustainable oily water remediation

Oily wastewater, resulting from oil recovery, petrochemical industries, or accidents, poses a significant threat to the aquatic environment. Membrane separation technology can offer unprecedented opportunities for highly efficient water remediation but at the cost of poor permeability and serious oil fouling. Here, we report a faveolate nanofibrous membrane through the steric growth of bismuth oxybromide-bismuth oxyiodide nanoflakes on the TiO2/polypyrrole nanofibers. The spatially faveolate cells create highly covered confined spaces that efficiently capture and coalesce nanosized oil droplets, thus achieving substantial selectivity for micron porous membranes. The faveolate membranes are capable of efficiently separating various oil-in-water emulsions, particularly nanoscale surfactant-stabilized emulsions with a high permeation flux of 6075 L m-2h−1 and a good separation efficiency of 99.95 %. Moreover, the membranes with multi-heterostructure act as efficient photocatalysts, giving rise to visible light-induced sufficient fouling-tolerant property with nearly zero irreversible oil fouling. This study could provide a novel strategy for developing a new generation of membranes with high performance and long service lifetime for oily sewage remediation.

A novel poly (lactic-acid) and poly (butylene adipate-co-terephthalate) blend membrane modified with hesperidin for oily water emulsions separation

The oily wastewater produced by a variety of industrial operations presents a serious threat to both humans and the environment. Separation efficiency, good mechanical stability, high flux, and recyclability are critical parameters for a suitable oil-water separation membrane. In this study, a novel blend membrane of (poly (lactic acid)/poly (butylene adipate-co-terephthalate)) with hesperidin-NPs was synthesized by using the phase inversion technique to effectively separate oily-water emulsions. Herein, hesperidin (HSP) was harnessed for the first time as a green agent to optimize its content in the polymeric matrix. (FTIR) Fourier transform infrared spectroscopy, (FESEM) Field emission scanning electron microscopy, (CA) contact angle, mechanical tester, pore size and porosity were utilized to comprehensively characterize the manufactured (PLA/PBAT/HSP) membranes. The current work presents the proposed interaction mechanism between the contents of PLA/PBAT/HSP and the interaction mechanism of PLA/PBAT/HSP membrane with H2O molecules. The synthesized (PLA/PBAT/HSP) membrane manifested high wettability and has a 49° water contact angle and oleophobicity under a water contact angle of 146±2° for diesel oil. The PLA/PBAT membrane exhibited a homogeneous and symmetric spongy-like structure from top to bottom across its entire cross-section with very tiny active layer observed at the top surface of the membrane in FESEM images. Meanwhile, incorporating of 0.0125 wt% HSP into the casting solution has resulted in a significant change in the structural morphology. Furthermore, upon adding the HSP to the polymeric matrix, distinct changes in the structure were formed, which resulted in enhancing the mechanical features (tensile strength) of the membranes. Modified membrane with 0.025 wt% HSP displayed an optimal flux for pure water (220.5 L/m2.h1) and the modified membranes maintained a high rejection (more than 99%) against oil-water emulsions. Outcomes demonstrated that the improved permeation and separation characteristics of the (PLA/PBAT/HSP) membranes could present a potential option to treat applications that use oily wastewater.

Solvent-tolerant lignosulfonate-attapulgite/calcium carbonate coating on nylon filter mesh for oily water treatment

Due to the rapid increasing drainage of oily wastewater, robust and durable filtration materials with underwater superoleophobic coatings are highly desired. The existing underwater superoleophobic filter materials for oil/water separation are always subject to mechanical and chemical damages, causing the significant loss of superoleophobicity. Herein, a robust and tolerant nylon filter mesh (NFM) with underwater superoleophobicity was fabricated through simple layer-by-layer (LBL) assembly of lignosulfonate (LS), attapulgite (APT) nanorods, calcium ion, and carbonate on NFM. Compared with LS@CaCO3 assembly, the obtained LS-APT@CaCO3 assembly on NFM exhibits good micro/nano-structure, uniform distribution, and excellent underwater superoleophobicity (oil contact angle: > 156°). Moreover, after the fabricated mesh is subjected to the immersion in corrosive environments (acid, base, and salt aqueous solutions) and hot water as well as severe mechanical scratch, the oil contact angle are still higher than 147.5°, implying superb durability. More importantly, the as-obtained NFM is able to treat a variety of oil/pure water and oil/corrosive solution mixtures with separation efficiencies of over 98.2 %. Therefore, the as-prepared mesh has a huge application potential in oil-polluted water remediation due to the simple, facile, and eco-friendly preparation process.

Break oily water emulsion during petroleum enhancing production processes using green approach for the synthesis of SnCuO@FeO nanocomposite from microorganisms.

The aim of this work was to synthesize a green nanoparticle SnCuO@FeO nanocomposite core-shell to break oily water emulsions during petroleum-enhancing production processes as an alternative to chemical and physical processes. In this study, eight bacterial isolates (MHB1-MHB8) have been isolated from tree leaves, giant reeds, and soil samples. The investigation involved testing bacterial isolates for their ability to make FeO nanoparticles and choosing the best producers. The selected isolate (MHB5) was identified by amplification and sequencing of the 16S rRNA gene as Bacillus paramycoides strain OQ878685. MHB5 produced the FeO nanoparticles with the smallest particle size (78.7nm) using DLS. XRD, FTIR, and TEM were used to characterize the biosynthesized nanoparticles. The jar experiment used SnCuO@FeO with different ratios of Sn to CuO (1:1, 2:1, and 3:1) to study the effect of oil concentration, retention time, and temperature. The most effective performance was observed with a 1:1 ratio of Sn to CuO, achieving an 85% separation efficiency at a concentration of 5mg/L, for a duration of 5min, and at a temperature of 373K. Analysis using kinetic models indicates that the adsorption process can be accurately described by both the pseudo-first-order and pseudo-second-order models. This suggests that the adsorption mechanism likely involves a combination of film diffusion and intraparticle diffusion. Regarding the adsorption isotherm, the Langmuir model provides a strong fit for the data, while the D-R model indicates that physical interactions primarily govern the adsorption mechanism. Thermodynamic analysis reveals a ∆H value of 18.62kJ/mol, indicating an exothermic adsorption process. This suggests that the adsorption is a favorable process, as energy is released during the process. Finally, the synthesized green SnCuO@FeO nanocomposite has potential for use in advanced applications in the oil and gas industry to help the industry meet regulatory compliance, lower operation costs, reduce environmental impact, and enhance production efficiency.

The treatment of oily wastewater by thermo-responsive calcium alginate capsules immobilized Pseudomonas aeruginosa.

A microfluidic strategy of smart calcium alginate (CA) capsules is presented to immobilize Pseudomonas aeruginosa to treat oil slicks effectively. The capsule wall is embedded with poly (N-isopropyl acrylamide) sub-microspheres as thermo-responsive switches. CA capsules, with a diameter of 3.26 mm and a thin wall thickness about 12.8μm, have satisfying monodispersity, cavity structure, and dense surface structures. The capsules possess excellent encapsulation of bacteria, which are fixed in a restricted space and become more aggregated. It overcomes the disadvantages of a long fermentation production cycle, easy loss of bacteria, and susceptibility to shear effect. The smart CA capsules immobilized with bacteria treat model wastewater containing soybean oil or diesel and display favorable fermentation ability. The capsules can effectively treat oil slicks with high concentration, and it is an economical way for processing oily wastewater. PRACTITIONER POINTS: A thermo-responsive calcium alginate capsule was prepared by microfluidic strategy. Pseudomonas aeruginosa is environmentally friendly in treating oil slicks. The capsules, immobilized bacteria, treat oil slicks effectively. This study provides an economical way for processing different oily water.

Effects of thermal disposal of oil-water residues on operation heating plant boiler

Industrial zones are often the source of specifically polluted waters, depending on type of industry. These waters are usually not in the limits for outtake into public sewers and it is necessary to dispose them externally or build-up technologies for their pre-treatment. The article is about the real case of an industrial. A separate sewage network is built for oily water. Solid impurities are separated from the oily water and oily water is treated by evaporation technology. The evaporator produces two types of products - condensate and concentrate. Condensate is a water with high organic content, and it is necessary to purified it by a chemical treatment plant in next step. Evaporator technology remove from water the most of metal content and significantly decrease organic and water content in concentrate. Concentrate is oily stream with lower water content. Water content in concentrate decreased in next technology steps to ca. 40-50 %. The final product is certificated technological fuel, and its final elimination is in the heating plant fluidized bed boiler. The article is detailed focused on the influence of concentrate combustion. A local temperature increases around 10-15 °C extending across the combustion chamber was confirmed. There was also an increase in HF concentration in flue gas. CO concentrations were higher in the first moments of combustion, but the control system responded by increasing the combustion air supply, and CO concentrations were finally lower at the level of 3 mg·m-3. During combustion, there was no provable increase in concentrations of NOX or other substances, and the co-combustion did not have a significant effect on the operation of the boiler, so this way was evaluated like technically and economically effective.

Influence of the collecting vessel speed on the efficiency of the ship waste collection system

Off-vessel treatment of ship-generated waste is one of the ways to ensure environmental safety in ship operation. Sewage and oily waters generated on the vessel are transferred to coastal environmental protection facilities with the help of a collecting vessel. When considering such a way of ensuring the environmental safety of shipping, a number of issues arise related to the optimization of the operation of such a system. In this article, the influence of the average speed of the collecting vessel on the operation of the off-ship waste collection system is considered. To solve this problem, a numerical model of this system was developed, that combines elements of probabilistic and simulation modeling. There was found to be a negligible effect of the speed of the collecting vessel on the performance of this system. As a result of modeling the operation of the ship waste collection system through the collection vessel, it can be said that high speeds of the collecting vessel are not required in ship maintenance.

Experimental study of secondary oil droplet formation during coalescence process of oil Droplet-Gas bubble

Flotation is an efficient pretreatment technology for oily water. In this study, the coalescence processes of air bubbles and isooctane droplets with different size ratios, 1.0–2.2, were investigated using a high-speed imaging system. Two types of oil droplet-gas bubble interaction have been identified: full coalescence and partial coalescence. Through analysis of interfacial force at the liquid bridge, it has been observed that interfacial force at the oil droplet bridge affects the lateral contraction of the liquid bridge, which in turn affects the coalescence of oil droplets and gas bubbles. Through dimensional analysis, a phase diagram of dimensional parameter coalescence behavior has been constructed, and the critical line of partial coalescence and full coalescence has been determined. This work fills the void in the study of secondary oil droplet coalescence within the oil droplet-gas bubble coalescence in gas flotation, which is potentially applied for industrial air flotation system design and optimization.

Oily water treatment using particles of crushed dates seeds as a deep bed filtration material

There is a common consensus among petroleum companies that oily water produced from oil and gas wells creates a formidable challenge for humans, water, air, and soil owing to its hazardous content. Therefore, oily water treatment is an inevitable requirement in the development plans.This study reviewed the existing treatment methods for the treatment of oily water associated with oil production, emphasizing deep bed filtration. Furthermore, an experimental investigation of the suitability and efficiency of using crushed date seeds for oily water treatment was conducted. Moreover, the challenges affecting the optimal performance of treatment methods and recommendations for the future development of this technology were discussed.The results showed that the surface of crushed date seeds was highly oil-wet. As a filtration material, these seeds demonstrated almost 95% oil removal efficiency, indicating that the efficiency of crushed date seeds is comparable with that of the existing materials used in the industry, such as nutshell crushed particles. It is worth noting that date seeds are abundantly available, especially in the Arab regions, are cheap, and can be recycled as deep bed filtration media.

OBTAINING SORBENTS FOR COLLECTING OIL AND OIL PRODUCTS ON THE WATER SURFACE

The main patterns of purification of oily waters using sorption materials based on vegetable and man–made raw materials (sunflower husk, rice husk, polystyrene foam and rice husk) have been established, determining the possibility of effective use of their carbonates in the processes of water purification from petroleum products. It has been established that materials based on carbonates of sunflower husks and rice husks are characterized by the process of absorption of oil and petroleum products by the entire volume. As a result of the conducted research, an optimal carbon-polystyrene sorbent was obtained (21 % rice husk, 79 % expanded polystyrene), which has a high oil capacity in terms of the amount of oil collected at 0 о C. A technological system for local wastewater treatment of petrochemical industries using sorption materials obtained during thermochemical disposal of waste of plant origin has been developed.

In-situ ionized construction of PVDF/sodium polyacrylate-grafted-PVDF blend ultrafiltration membrane with stable anti-oil-fouling ability for efficient oil-in-water emulsion separation

Traditional polymeric membranes usually suffer from serious oil fouling and quick decline of water flux when separating oil-in-water emulsions. In this work, we report the fabrication of the sodium polyacrylate (PAAS) blended polyvinylidene fluoride (PVDF) ultrafiltration membrane which behaves hydrophilicity, underwater low-oil-adhesive superoleophobicity and outstanding anti-oil-fouling ability even for viscous crude oil. The blend membrane was fabricated via a two-step method, including the nonsolvent-induced phase inversion of PVDF/polyacrylic acid-grafted-PVDF (PVDF/PAA-g-PVDF) blend membrane and the subsequent in-situ ionization of PAA into PAAS. The two-step method improves the affinity between the strong hydrophilic additive PAAS and the hydrophobic polymer matrix PVDF, thus endowing the blend membrane with long-term stable superwetting property for 1,100 days. The PVDF/PAAS-g-PVDF blend membrane can efficiently separate multiple emulsifier-stabilized oil-in-water emulsions with ultrahigh separation efficiency of 99.97% (the residual oil content in the filtrate is lower than 3 ppm after one-step separation) and high water flux of 350 L m-2 h-1 bar-1. The blend membrane also shows good cycling performance, and can be easily cleaned by water washing during several separation cycles of the crude oil-in-water emulsion. This work inspires a feasible route of fabricating stable anti-oil-fouling membranes for separation of emulsified oily water.

Long-Lasting Filtration of Oily Water by Anti-Fouling Underwater Oleophobic Sand Particles

Long-Lasting Filtration of Oily Water by Anti-Fouling Underwater Oleophobic Sand Particles

Resourceful and harmless treatment of the steam-assisted gravity drainage produced fluid

The steam-assisted gravity drainage (SAGD) process is an effective technology for heavy crude oil extraction. SAGD produced fluid (including oil, water, and sludge) that has strong stability and difficult separation characteristics. It is very necessary to thoroughly separate SAGD produced fluid, as it can lead to environmental pollution and resource waste. In this study, a combined process of thermochemical treatment and electrocoagulation was proposed to deal with SAGD produced fluid. The influence of such parameters as type and structure of surfactants, temperature, stirring rate, and current density were examined on the separation efficiency of SAGD produced fluid. The results indicated that the oil recovery rate was 99%, with the oil and suspended solids content (4.4 and 0.58 mg/L, respectively) in the water meeting the reinjection standard (oil content <15 mg/L, suspended solids <3 mg/L) and the oil content in the sludge (1 wt%) attained the solid waste disposal standard (<2 wt%). The combined separation process of SAGD produced fluid allowed the obtaining of qualified oil, sludge, and water, with oily sludge and waste water simultaneously eliminated. Therefore, this process achieved oil and water resource utilization, as well as harmless sludge treatment, which would achieve great economic benefits and application prospects in the oil field.

A study on the efficient separation of oily water using mullite whiskers membrane through combined filtration and electrofiltration.

This study explores the efficacy of a ceramic membrane combining filtration, electrofiltration, and backwashing for oily water treatment. A secondary mullite membrane was synthesized, showcasing high permeate flux (534 LMH), biaxial flexural strength (75.21 MPa), and cost-effectiveness. Operational parameters, set at 2 bar pressure and 0.727 m s-1 cross-flow velocity, were optimized for desirable permeate flux and oil removal rates. Critical electric field intensity (E crit) ranged from 50 to 55 V, guiding optimal voltage selection for electrofiltration. Electrokinetic phenomena, such as electrophoresis and electroosmosis, addressed fouling issues. Higher salt concentrations exacerbated fouling and reduced electric field efficiency. Energy analysis revealed potential savings, dropping from 3.88 kW h m3 without voltage to 2.71 kW h m3 at 65 V for salt-free solutions. However, higher salt concentrations increased fouling, elevating energy consumption. These findings affirm the value of affordable ceramic membranes for oily water treatment, stressing the need for parameter optimization to enhance performance and energy efficiency.

Bilge and Oily Water Treatment During Operation of Vessel

Bilge and Oily Water Treatment During Operation of Vessel

Omniphobic melamine sponge for interfacial solar desalination of saturated water with anti-fouling performance

Interfacial solar desalination has shown great potential to address the global freshwater scarcity attributing to the advantages of high energy conversion efficiency, environmental friendly, cost effective and so on. However, accompanied by rapid vapor generation in the interfacial region, salt simultaneously crystallizes on the surface of photothermal materials, especially in highly concentrated brine, which would seriously affect the efficiency and long-term stability due to the blocking of vapor escaping channels as well as decreasing of solar absorption. In addition, organic substances in seawater may also pollute the absorbers during evaporation. Here, we demonstrate an omniphobic-hydrophilic melamine sponge based janus photothermal absorber by taking advantage of the 1H,1H,2H,2H-perfluorooctyltrichlorosilane modification, providing the upper layer both hydrophobic and oleophobic features, resulting in salt resistance and anti-fouling performance, respectively. Even with saturated NaCl solution as input, no salt accumulation was observed on the light absorbing surface during 8 h continuous evaporation. Moreover, the absorber exhibits excellent anti-fouling properties in oily water. Our strategy provides an avenue for the development of multifunctional solar absorbers aiming to sustainable treatment of highly concentrated brine and oil-bearing water.

Amino-functionalization of tungsten oxide nanoparticles for stable decoration in the active layer of alumina-supported inorganic-organic hybrid membrane with super-wettable and photocatalytic self-cleaning surfaces for crude oil-in-water emulsion separation

The ceramic membrane was hybridized with an amino-functionalized inorganic metal oxide and organic polymer to achieve the optimal oil and water surface wettability and photo-catalytic self-cleaning capability. The resulting membrane was used for the treatment of crude oil-contaminated wastewater under cross-flow filtration mode. The fundamental functional material, tungsten oxide nanoparticles (NH2-WO3 NPs) modified by aminopropyl triethoxysilane (APTES) was created and coated on the alumina ceramic support surface via interfacial polymerization, in which the material covalently cross-links on the membrane's active layer in the presence of terephthaloyl chloride (TPC) as a cross-linker and piperazine (PIP) as an external amine. Achieving a unique combination of oil and water surface wettability- superhydrophilicity (0° water-in-air contact angle) and underwater super-oleophobicity (160.25° under-water oil contact angle) was the key to creating the water-permeating NH2-WO3/PA@alumina ceramic membrane. The second advantageous feature of the membrane is its capacity for self-cleaning, which results from WO3 NP's innate photocatalytic activity that has been further enhanced by amino functionalization. A water permeate flux of up to 250 L m−2 h−1 and an oil/water separation efficiency of nearly 100 % were attained for an oil concentration of 50 ppm of crude oil-in-water emulsion when NH2-WO3/PA@alumina ceramic membrane was employed as a separation medium in a cross-flow filtration system for the separation of crude oil-in-water emulsion. Furthermore, the permeate flux decreased to ∼25 % of its initial flux after using NH2-WO3/PA@alumina ceramic for approximately 210 min. This was caused by organic pollutants in the oily water clogging the membrane pores. The permeate flux was recovered by exposing the membrane to UV light for photo-catalytic self-cleaning. Due to its water-passing nature, this membrane has high efficiency. Additionally, because the self-cleaning add-on removes the need for chemical cleaning, it is environmentally friendly.