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In response to oil spills, it is imperative to develop efficient and eco-friendly sorbent materials. Oil remediation techniques are limited, prompting researchers to look into using nanotechnology for oil cleanup. Therefore, magnetic Fe3O4 composite nanoparticles (MNPs) were synthesized by the chemical co-precipitation method. The MNPs were then coated with activated carbon (AC) layer, followed by soybean oil/stearic acid surface decoration. The morphology and surface properties of the material were characterized using a scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), and contact angle (CA) analyses. The results showed an excellent amphiphilicity with water CA of 0° and oil CA of nearly 0°. In terms of applicability for oil recovery operations, the fabricated nanocomposite revealed sorption capacities greater than 6.5 g/g for a range of oils. In addition, the sorbent can be reused at least five times with advantageous characteristics for selective oil recovery on surface waters owning to its intense super-paramagnetic properties. Considering our results, we suggest that there is a practical application for magnetic AC nanomaterials in spilled oil response.

Water contamination is an environmental burden for the next generations, calling for advanced methods such as adsorption to remove pollutants. For instance, unwanted biowaste and invasive plants can be converted into biosorbents for environmental remediation. This would partly solve the negative effects of invasive plants, estimated at 120 billion dollars in the USA. Here we review the distribution, impact, and use of invasive plants for water treatment, with emphasis on the preparation of biosorbents and removal of pollutants such as cadmium, lead, copper, zinc, nickel, mercury, chromate, synthetic dyes, and fossil fuels. Those biosorbents can remove 90–99% heavy metals from aqueous solutions. High adsorption capacities of 476.190 mg/g for synthetic dyes and 211 g/g for diesel oils have been observed. We also discuss the regeneration of these biosorbents. [ABSTRACT FROM AUTHOR]

Polyacrylonitrile (PAN) is a popular polymer that can be made into membranes using various techniques, such as electrospinning and phase inversion. Electrospinning is a novel technique that produces nonwoven nanofiber-based membranes with highly tunable properties. In this research, electrospun PAN nanofiber membranes with various concentrations (10, 12, and 14% PAN/dimethylformamide (DMF)) were prepared and compared to PAN cast membranes prepared by the phase inversion technique. All of the prepared membranes were tested for oil removal in a cross-flow filtration system. A comparison between these membranes’ surface morphology, topography, wettability, and porosity was presented and analyzed. The results showed that increasing the concentration of the PAN precursor solution increases surface roughness, hydrophilicity, and porosity and, consequently, enhances the membrane performance. However, the PAN cast membranes showed a lower water flux when the precursor solution concentration increased. In general, the electrospun PAN membranes performed better in terms of water flux and oil rejection than the cast PAN membranes. The electrospun 14% PAN/DMF membrane gave a water flux of 250 LMH and a rejection of 97% compared to the cast 14% PAN/DMF membrane, which showed a water flux of 117 LMH and 94% oil rejection. This is mainly because the nanofibrous membrane showed higher porosity, higher hydrophilicity, and higher surface roughness compared to the cast PAN membranes at the same polymer concentration. The porosity of the electrospun PAN membrane was 96%, while it was 58% for the cast 14% PAN/DMF membrane.

The more humans need to develop, the more waste will be generated from by-products of an industry's operational processes. One of the most waste in produce, namely wastewater contaminated by oil. Oil waste not only pollutes aquatic ecosystems but the impact of waste oil itself can be very dangerous for human health. Therefore, it is necessary to process wastewater contaminated with this oil. On the one hand, the development of innovation also makes the methods of processing contaminated waste more varied. Therefore, there is a need for a study to determine which wastewater treatment processes are effective, especially for wastewater that contains oil. This is the background for writing the journal "Treatment Strategies for Reducing Oil Contaminants in Wastewater". The research methodology of this journal itself uses a qualitative method with a literature review approach. So that the results obtained from the comparison of the efficiency of several processing methods such as membrane technology, electrocoagulation, adsorption, and combination. But even so, it still needs to be reworked related to the cost efficiency of each processing method.

The present study investigated the effect of nutrient composition and pH on the lipopeptide production by Bacillus subtilis GY19. The maximum lipopeptide production (2.2 g/l) was achieved when the strain was grown in productive medium containing glycerol (4 g/l) and palm oil (0.75%, v/v) as substrates, sodium nitrate (0.5%, w/v) as nitrogen source, and glucose (1 g/l) and beef extract (0.5 g/l) as co-substrates with pH 7.5. In addition, the lipopeptide of B. subtilis GY19 could be applied for removal of slideway oil covered on metallic surface. Taguchi method was employed to evaluate the factors affecting the cleaning process. The results indicated that the presence of high levels of crude lipopeptide concentration positively affected surface washing efficacy. Further removal of slideway oil from the washing water could be achieved by the addition of immobilized oil-degrading bacterium, Acinetobacter sp. R2. The presence of lipopeptide increased the removal efficiency of slideway oil from 70% to 82% and did not show toxic effect on bacterial cells. This study shows promising ability of the lipopeptide from B. subtilis GY19 as a cleaning agent for oil-contaminated surface. In addition, it could subsequently enhance biodegradation of residual oil in the washing water. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a byproduct of the crude oil industry, oily water is a major environmental concern. In this study, a novel methodology that used low-frequency ultrasound (US) for the removal of oil from the production of oily water was proposed. A continuous phase was prepared by dissolving NaCl (18 g·L−1), CaCl2 (6 g·L−1), and MgCl2 (3 g·L−1) in water. Synthetic oil-in-water emulsion was without adding artificial emulsifiers (oil contents: 495–687 mg·dm−3) with median droplet size distributions of approximately 10 µm was prepared using a Brazilian heavy crude oil (API gravity of 11.9). Experiments were performed using ultrasonic baths operating at 35, 45, and 130 kHz at 60 °C in the presence of glass Raschig rings without any addition of chemical demulsifiers. Other materials were also evaluated: PVC; PTFE; Polypropylene; steel; and copper. For the synthetic oil-in-water emulsion with 495 mg·dm−3 oil, in the presence of glass Raschig rings, an oil removal efficiency of approximately 76.4% (35 kHz, 20 min) was achieved. Higher removal efficiencies were obtained for synthetic oil-in-water with 495 mg·dm−3 oil than for those with 687 mg·dm−3 oil (50.1%, 130 kHz, 20 min). Although typically used for emulsification, these findings reveal that low-frequency US association of glass Raschig rings is also a promising technology for treating the produced water to remove oil. [ABSTRACT FROM AUTHOR]

Chemical enhanced oil recovery (cEOR) is a process that involves the injection of chemicals (like polymers) to improve oil recovery. These processes generate a lot of produced water (PW) that needs to be treated properly for final disposal in the environment. This work has the goal to evaluate the influence of the injection biopolymer guar gum on PW treatment, as well the oil removal efficiency (ORE) of a flocculant system composed by the bioflocculant chitosan and sodium dodecyl benzene sulfonate (SDBS). The flocculation-flotation experiments were planned and carried out based on a design of experiments (central composite rotatable design – CCRD). It was possible to find out that guar gum concentration did not impact oil removal efficiency in a statistically significant way. But chitosan and SDBS concentrations were statistically significant, achieving better ORE when chitosan concentration is between 50 and 100 ppm and SDBS concentration is higher than 200 ppm, achieving a maximum of 86% of ORE at concentrations of 75 ppm and 250 ppm, respectively. The findings of this study can help for better understanding of how nonionic injection biopolymers impact on PW treatment and to propose the use of chitosan as a flocculant along with SDBS to enhance PW treatment. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Inappropriate disposal of Produced Water is one of the causes of degradation of the environment in the Niger-Delta. The effect on farmlands and aquatic life has been disastrous and this disposal continues because of lack of treatment equipment or inability to maintain treatment equipment. This work has developed a method for produced water treatment focusing on oil and salt removal. A small scale produced water treatment system was fabricated. The system’s processes were based on thermal energy; thermal phase separation was used for oil removal and humidification-dehumidification was used for salt removal. The water obtained at the various process stages was tested to ascertain the oil content and salinity. Results obtained showed that oil levels in the produced water dropped from 3034.28mg/l to 380.58mg/ after phase separation which is significant but not meeting the Department of Petroleum Resources (DPR) requirement. However, after the humidification – dehumidification process, it was reduced to 4.02mg/l which meets the DPR requirement of 10mg/l. The salinity also reduced from 887.50mg/l to 35mg/l, this meets DPR acceptable limits for land disposal of 600mg/l. [ABSTRACT FROM AUTHOR]

Abstract The objective of this study is to optimise the flotation process that separates crude oil and water from anionic polymer (GLP-100) via response surface methodology. Hence, a model was developed to describe the efficiency of oil removal under the influence of GLP-100 concentration, gas flowrate, and duration of flotation. Confirmatory experiments were performed to validate the model at a randomly selected point which was at 450 ppm of polymer concentration. At this point, the optimum values of the flotation parameters were recorded: 3 L/min of gas flowrate and 6 min of flotation time with 99% efficiency. The predicted values seemed to match the actual value with standard deviation 0.252%. The outcomes prove that this model can be used to optimise the flotation process in the presence of GLP-100 polymer.

We report the synthesis of reduced graphene oxide (rGO)-α-Fe2O3 nanocomposite and its application to remove and recover dissolved oil from a high-salinity oil–water emulsion in batch and column/breakthrough setups. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and nitrogen adsorption characterized the synthesized nanocomposite’s structure, morphology, and surface properties. Both batch and continuous breakthrough adsorption studies were investigated. The effect of the adsorption parameters on the adsorption capacity and removal efficiency was analyzed. The rGO-Fe2O3 nanocomposite (rGO-Fe2O3-NC) demonstrated a superior adsorption capacity, both when measured experimentally (1213 mg/g) and predicted using the Freundlich isotherm (1301 mg/g). The adsorption process followed pseudo-second-order kinetic, and the rGO-Fe2O3-NC exhibited a very rapid removal, with more than 60% of oil being removed within 10 min. Breakthrough confirmed the exceptional removal capacities with good regeneration and cycling ability under a short contact time. Moreover, the adsorption capacity was enhanced with an emulsion salinity of up to 100,000 ppm, confirming the suitability for high-salinity wastewater.

This work describes synthesis of poly (sulfur/soya bean oil) composite material by co-polymerization of elemental sulfur and soya bean oil at 180 °C. The poly (sulfur/soya bean oil) (PSSBO) composite material was characterized by FTIR, XRD and SEM, BET, and TGA analysis. The surface area was found to be 4.063 m2 per g. The XRD analysis revealed that sulfur also existed as S8 in the polymer matrix also and therefore all the peaks of native elemental S8 were also found in the sample PSSBO (1:1). The SEM analysis indicated multilayered even surface. The PSSBO (1:1) composite was employed in batch mode experiments for the removal of oil from O/W emulsions, prepared in the range of 50 to 400 mg L−1 from Soya bean oil and distilled water. The adsorption data, obtained at 298 K, were interpreted in terms of various isotherm models. Based on the regression values, the order of fitness of these models was Langmuir > Freundlich > Temkin. The maximum oil sorption capacity was found to be 14285.71 mg per g dry polymer. The adsorbent was re-generated by washing with minimum quantity of ethanol and employed in five successive cycles for de-emulsification of water. A hydrophobic–hydrophobic interactions based mechanism was proposed to explain oil uptake by adsorbent PSSBO (1:1) composite. Considering zinc-based zeolitic imidazolate framework (ZIF-8) as a model adsorbent, it was found that Qo value of PSSBO (1:1) was almost three times greater than ZIF-8 and production cost of PSSBO (1:1) was almost 450 times less than ZIF-8. [ABSTRACT FROM AUTHOR]

In an attempt to develop the methodologies used for oil spill clean-up, polyurethane sponge was modified by deposition of NiFe2O4 nanoparticles on the surface of the original polyurethane sponge under ultrasonic treatment. The fabrication process was facile and low-cost. The as-prepared magnetic sponge exhibited remarkable features including great porosity, high oil adsorption capacity, hydrophobicity, and reusability. In addition, the magnetic property of the modified sponge facilitated the process of oil-water separation. Indeed, the hydrophobicity of the modified sponge contributed to the adsorption of different types of oil and organic solvent on the sponge surface. The modified sponge exhibited the same characteristic peaks as those of the NiFe2O4 magnetic nanoparticles, ascertaining the formation of the crystalline nickel ferrite nanoparticles. The XRD and FTIR results proved the formation of the composite. FESEM images of the nanocomposite showed a highly porous mulberry-like structure with a rough skeleton. More importantly, the oil and water contact angle measurements proved the hydrophobicity of the modified sponge. [ABSTRACT FROM AUTHOR]

In an attempt to develop the methodologies used for oil spill clean-up, polyurethane sponge was modified by deposition of NiFe2O4 nanoparticles on the surface of the original polyurethane sponge under ultrasonic treatment. The fabrication process was facile and low-cost. The as-prepared magnetic sponge exhibited remarkable features including great porosity, high oil adsorption capacity, hydrophobicity, and reusability. In addition, the magnetic property of the modified sponge facilitated the process of oil-water separation. Indeed, the hydrophobicity of the modified sponge contributed to the adsorption of different types of oil and organic solvent on the sponge surface. The modified sponge exhibited the same characteristic peaks as those of the NiFe2O4 magnetic nanoparticles, ascertaining the formation of the crystalline nickel ferrite nanoparticles. The XRD and FTIR results proved the formation of the composite. FESEM images of the nanocomposite showed a highly porous mulberry-like structure with a rough skeleton. More importantly, the oil and water contact angle measurements proved the hydrophobicity of the modified sponge. [ABSTRACT FROM AUTHOR]

The purpose of this research was to develop chitosan beads as an oil adsorbent in household grease traps. The results showed that chitosan beads, synthesized from 3% w/v chitosan flakes in 5% v/v acetic acid and formed the beads in 2.0 M NaOH, provided the best characteristics. The white colored beads were slightly hard with maximum average weight and maximum diameter of 0.0925±0.0101 g and 0.67±0.06 cm. respectively. SEM images revealed that the beads had spherical shapes and homogenously distributed pores. The maximum adsorption capacity was 1667.93±39.61 mg/g (83.40±1.98%) at the optimum adsorbent dosage of 10 g/l, initial oil concentration 20 g/l, pH 5 and 303 K with 25 min of contact time. The adsorption was fitted to the Langmuir adsorption isotherm. Our results indicated that the adsorption was monolayer and chemisorption, and Cm increased with increasing temperature. The kinetic study was correlated with the pseudo-second order, and the intraparticle diffusion was the rate controlling step. The adsorption of oil in the household grease trap showed a significant decrease in Fat, Oil & Grease (FOG), Biochemical Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) (p < 0.05), while the pH did not change. Also, oil removal in real wastewater was lower than synthetic oil-in-water due to the competition for the biding sites between oil and other compositions presented in wastewater and the formation of stable micelle droplets by the surfactant. Nevertheless, the values of oil concentration in the household wastewater were lower than the standard limit of domestic discharge in Thailand, whereas the values in the treated wastewater from a noodle shop were over the standard value. [ABSTRACT FROM AUTHOR]

This work explored the use of ozonation and photoperoxidation before the microfiltration process to reduce fouling. Produced water was synthesized with salt, viscosifier, and surfactant. The additives influence on membrane fouling was evaluated. Photoperoxidation process led to an overall better performance than ozonation in terms of oil removal and fouling reduction. The maximum oil removal efficiency was 86%, obtained for emulsions with salt after 2 h of treatment (COD: H2O2 ratio 1:1, UV dose of 965 J/m2). The inclusion of chemical additives impaired the oxidative power of hydroxyl radicals leading to a moderate oil removal; however, they were still able to reduce membrane fouling, mainly in oil/water emulsions with viscosifier. Higher salt concentration promoted fouling resistance and also benefited the permeate quality. Cross-flow microfiltration process integrated with photoperoxidation was able to improve the permeate flux from 84 to 182 L/m2.h after 3 h of exposure to UV radiation, resulting in a permeate with less than 10 mg/L of oil content. [ABSTRACT FROM AUTHOR]

During the oil production process, oily waste water is coproduced at a rate several times that of oil. This water is known as produced water. Treatment levels and technologies are selected based on disposal method or reutilization objectives, environmental impacts, economics, and other such factors. For the treatment of produced water, the treatment system equipped with nitrogen microbubble flotation in conjunction with anthracite filtration and activated carbon adsorption was designed and examined. Polymer flooding is being used as an enhanced oil recovery (EOR) method in Oman. The quality of polymer flood produced water (PFPW) is different from produced water (PW) without polymer, it was clarified that aluminum sulfate (AS) is more effective than poly-aluminum chloride (PAC) as a flocculant. Based on the examination results, a 50 m3/day capacity pilot plant was designed, fabricated, and utilized to conduct produced water treatment trials, good oil removal was confirmed in all tests. It was also confirmed that this accompanied water treatment water could be used as irrigation water for agriculture by performing necessary higher order treatment. As a result, it was considered that the development as a new water source in the Middle East, where water resources are scarce, could be expected. [ABSTRACT FROM AUTHOR]

Silicone oil (SO) is a commonly used tamponading agent in retinal detachment surgeries. Inadvertent anterior migration of SO and complete anterior chamber (AC) oil fill in an aphakic or pseudophakic eye is occasionally encountered. This can cause secondary glaucoma with very high intraocular pressure and pain. In this scenario, an urgent silicone oil removal (SOR) is warranted. Since SO is buoyant, in the supine position, it tends to rise anteriorly. Hence, removal of SO trapped in the AC will invariably lead to further migration of oil from the posterior segment into the AC to replace the volume removed. Simultaneous replacement of AC volume is necessary to prevent this. We describe a modified technique of partial SOR that employs air to prevent recurrent migration of SO into AC.

Microemulsion cleaning method has been proved to be an effective way to clean oily sludge with low interfacial tension and high solubilizing ability for non-miscible liquids. In this paper, the percentage range of the microemulsion in the formulation was obtained by studying phase behavior of the microemulsion. The response surface method was used to model and optimize the microemulsion to obtain the best formulation: n-BuOH content at 9.89%, NaCl content at 2.24% and AES/APG ratio at 3.75, and the oil removal rate reached 97.28%. Meanwhile, the cleaning conditions of oil sludge were also optimized by the response surface method and the optimal cleaning parameters were determined as liquid-solid ratio at 4.2, stirring rate at 157 r·min−1, and stirring time at 38 min. In addition, some experiments were carried out to confirm the simulation results, affording the oil removal rate of 98.79%. SEM and FTIR confirmed that the oil on the sludge can be removed by microemulsion. [ABSTRACT FROM AUTHOR]

As a common pretreatment process for coal chemical wastewater, the conventional one-stage coagulation process has the problem of poor removal of small size oil, which will inhibit the subsequent biological treatment. Measures to improve oil removal efficiency based on the development of new coagulants and the addition of composite processes are common in the literature, but two-stage coagulation to improve coagulation efficiency has not been reported to date. Here, we optimized coagulation parameters and compared the oil removal efficiency of two-stage coagulation and one-stage coagulation. Under the same total dosage of coagulant (PAC), the optimum removal of oil in two-stage coagulation was achieved 90% which increased by 11% compared to one-stage process. P10 and P 1 μm were proposed to evaluate the oil removing effect of two-stage coagulation. In addition, SEM scanning was used to conduct flocs analysis and two-stage coagulation process simulation, revealing the principle of the excellent oil removal performance of two-stage coagulation. Finally, coagulant in filter residue was recovered by acidification method and the recovered coagulant was used again in the two-stage coagulation process of coal chemical wastewater. These results suggest that two-stage coagulation is a cost-effective alternative oil removal technique with high energy efficiency and environmental benign. This research may offer helpful insights to develop an advanced oil removal process. [ABSTRACT FROM AUTHOR]

Dual functional membranes that can simultaneously remove water-insoluble oil and degrade water-soluble dyes have received considerable attention. Nevertheless, there remain arduous challenges due to the critical restriction of slow degradation rate and the heavy dependence on external stimuli like light, electricity or heat. Herein, we report a superwetting and rapidly catalytic β-MnO 2 mesh prepared by one-step hydrothermal method. In activation of peroxymonosulfate (PMS), this β-MnO 2 mesh can expeditiously degrade dyes without any external stimuli and simultaneously remove oils. The removal efficiencies were all > 99% and the filtrates were proved eco-friendly through leaching test and toxic experiment. Furthermore, a mechanism on the excellent catalytic ability of β-MnO 2 mesh was proposed, i.e. H+ was immobilized in 1 × 1 tunnel of β-MnO 2 , which made the mesh surface a positive zeta potential and attract more negative sulfate radicals, as a result inducing an improved degradation efficiency. Therefore, we anticipate this bifunctional and ingenious β-MnO 2 mesh can contribute a lot to prompt and mild sewage purifications. [ABSTRACT FROM AUTHOR]

Using magnetic nanoparticles for contaminant removal has received considerable attention for their unique properties. The novelty of this study lies in the integration of electrocoagulation with magnetite nanoparticles for the treatment of oily wastewater, where these processes have been used individually in previous studies. Such combination and enhancement will reduce the requirements for time, power, and cost to reach the allowable limits of oil content. The used commercial magnetite was characterized by XRD, FT-IR, and SEM. Moreover, the experiments were conducted in a batch electrocoagulator with aluminum and iron plates as anode and cathode, respectively. Four parameters were studied, namely pH, current density, time, and magnetite dosage. The results verified that the current density required to obtain 90% oil removal efficiency for the 275-ppm initial oil concentration decreased from 25 to 15 mA/cm2 after the addition of 0.93 mg/L magnetite to the electrocoagulation process and time decreased from 30 to 10 min, which is an indication of the enhancement of nanoparticles in the electrocoagulation process. Furthermore, the minimum oil content reached by the electrocoagulation + magnetite process was 8.9-ppm at the optimum current density of (20 mA/cm2), while electrocoagulation process provided 22.2-ppm final oil content at the same operating conditions. The adsorption kinetics could be well described by pseudo-second-order model. The Langmuir isotherm model showed a better fit with experimental data compared with Freundlich isotherm model. The treated oily wastewater by the electrocoagulation + magnetite process was found to be feasible for reusing in other processes or reinjection in the oil fields. [ABSTRACT FROM AUTHOR]

Microalgae have received considerable attention in recent years due to their significant potential in contaminants removal from wastewater and can be used as a sustainable feedstock for biofuel production. However, existing researches on microalgae are mainly focused on inorganic nutrients (i.e., nitrogen and phosphorus) removal, while oil as one of the major pollutant classes has been lack of study. Therefore, the present work was aimed to use microalgae to remove oil in wastewater and for simultaneous lipid production. In this study, variables such as ozone flowrate, oil concentration, amount of microalgae seeds and cultivation pH value were introduced to optimize the oil removal efficiency and lipid yield. The optimized parameters that resulted the highest oil removal percentage (41.56%) were as follows: 0.4 L/min of ozone flowrate, 3 mL/L of oil concentration, 200 mL/L of microalgae seeds and cultivation pH value of 3 to 5. Under this condition, the lipid content embedded within the microalgae cells was 41.5% and mainly consisted of unsaturated fatty acids. The present results affirmed the capability of microalgae to remove oil from wastewater and could produce higher lipid yield from the metabolized oil. [ABSTRACT FROM AUTHOR]

In this paper, novel flower-like hollow MoS2 microspheres (FHMs) were synthesized by a hydrothermal method using MF microspheres as template. The FHMs were hydrophobically modified and utilized as porous fillers to fabricate FHMs/acrylic resin composites through suspension polymerization. The oil-absorption tests revealed that the composite with 4 wt% FHMs had a high oil-absorption capacity, which might be due to the synergistic absorption effect of organic and inorganic components. Their high absorption capacity, rapid absorption rate, and excellent reusability make them attractive options as absorbents for practical oil/water separation. [ABSTRACT FROM AUTHOR]

With the frequent occurrence of oil spill accidents and the continuous discharge of oily water during oil production and transportation, effective oil removal from environmental water by adsorption still faces severe challenges. Here, a novel absorbent hydroxofluorographene-coated melamine foam, namely G(OH)F@MF, with high affinity to oils was fabricated via stepwise assembly. The G(OH)F@MF absorbent achieved effective removal of various oils within 1 min with relatively high adsorption capacities for petrol (89.34 g/g), lubricating oil (89.60 g/g), and peanut oil (104.79 g/g). Furthermore, it could be regenerated by simply squeezing and reused for more than 10 times with an adsorption capacity exceeding 37.12 g/g. In addition, the results indicated that the G(OH)F@MF absorbent was suitable for oil cleanup at a wide range of pH values (4–12) and temperatures (5–45 °C). The adsorption performance of the material was stable in the presence of natural organic matter and even in different water environments. This study can provide a novel sorbent and method for the green, rapid, recyclable, and stable removal of oils from environmental water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sodium alginate hydrogels were grown in situ on the graphite felt surface. • A novel self-floating solar evaporator was synthesized. • The synchronization of clean water production and environmental remediation. At present, the shortage of drinking water caused by environmental pollution hinders social development. The advent of solar interface evaporation systems provides an effective solution for clean water production. However, the issue of residual pollutants has not been adequately addressed. In this paper, we introduce BiOBr into the floating layer, which not only increases the roughness to achieve superhydrophobic performance but also photodegrades soluble pollutants. Additionally, to overcome the poor water supply capacity of carbon felt, we propose the use of a sodium alginate hydrogel, which reduces the evaporation enthalpy to 1690 J/g and increases the steam flux to 1.99 kg m−2 h−1 under 1 sun irradiation. It is hoped that the design strategies presented in this paper will provide a reference for optimizing solar evaporation systems and enhancing environmental purification. [ABSTRACT FROM AUTHOR]

Industrial oil was collected using hydrophobic silica powders. Silica nanopowder was modified with octadecyltriethoxysilane (OTS) using spray pyrolysis reactor continuously. Besides nanoparticles, mesoporous silica powder synthesized using Pluronic P104 was adopted as another oil adsorbents. Spherical macroporous or meso-macroporous silica particles were prepared by self-assembly for the removal of oil. The effects of the amount of powder on the oil adsorption were studied and compared with the results of various silica powders. The meso-macroporous silica particles were found to be the most efficient, indicating that both specific surface area and porosity played crucial role.

As an efficient, eco-friendly and economical Pickering emulsifiers, magnet-responsive oil-degrading bacteria is fabricated and used for encapsulation and removal of oil from water. Besides effective oil-water separation, magnetic bacteria shows ability in further harmless conversion of oil when the separated oil as contaminants could not be back to use. Effective removal of oil pollutants from the surface of water is important in oil-polluted environments. Since living microorganisms can be used as particle-stabilizers for oil emulsification, magnet-responsive oil-degrading bacteria (M-Bacteria) are expected to integrate three intriguing properties, such as Pickering emulsification, magnet-responsiveness and bioactivity. Hence, by acting as an efficient Pickering emulsifier to encapsulate oil pollutants, it should be possible to eliminate oil from water under the application of an external magnetic field. Oil-degrading bacteria, Brevibacillus parabrev , were successfully coated with a shell of magnetic Fe 3 O 4 nanoparticles using polycations. The morphology and physicochemical characteristics of M-Bacteria were characterized by various techniques. A systematic study on Pickering emulsification of M-Bacteria and the removal of five types of oils were performed. Specific adsorption of M-Bacteria at the oil droplet surface was observed through optical, fluorescence, and scanning electronic microscopy images. The biodegradation process of oil was monitored using gas chromatography. Eco-friendly M-Bacteria not only acts as an effective particle emulsifier to realize encapsulation and magnetic separation of oil contaminants but also shows a strong ability for further conversion of oil. This is the first report of oil removal via Pickering emulsification of living bacterial cells, which shows the potential of bacterial cells as functional colloidal materials in treating oily wastewater. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Normal University (Natural Science Edition) / Huanan Shifan Daxue Xuebao (Ziran Kexue Ban) is the property of Journal of South China Normal University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effect of the plasma modification of mixed leaf litter on the mechanism of oil removal from water surface was studied. It was found that that the sorption isotherm of a plasma-modified mixed leaf litter is described with high reliability by the Langmuir, Freundlich, and Dubinin–Radushkevich equations. A kinetic study revealed a diffusion-kinetic sorption mode, and the calculated Gibbs energy it allowed a conclusion that the process of oil adsorption by a plasma-modified leaf litter involves no chemisorption. The modification of the proposed material in a plasma flow of the litter forms charged particles on the surface, thereby ensuring specific adsorption and the presence of electrostatic (Coulomb) forces that causing orientational and inductive interactions. [ABSTRACT FROM AUTHOR]

This paper presents a novel hydrophobic material based 9-octadecenoic acid grafted graphene (POG) for oil/water separation. Graphene derived from graphite was modified with 9-octadecenoic acid to obtain 9-octadecenoic acid grafted graphene (OG). Then, emulsion polymerization of styrene was performed on OG to produce polystyrene branches on 9-octadecenoic acid grafted graphene (POG). Synthesized POG composites were then characterized by using various tools. The separation performance of the composites was evaluated by using an emulsion of organic compounds such as heptane with dye-colored water. Three different composites were prepared by varying the amount of 9-octadecenoic acid grafted graphene used as follows: POG 25 , POG 50 , and POG 75. The results showed that the higher the ratio of the 9-octadecenoic acid grafted graphene, the higher the oil uptake efficacy of the material and the faster the rate of the adsorption. The material was regenerated and its performance was tested again. The adsorption rate was constant for the next several cycles. Thus, this material has the potential to be utilized to clean up oil spills or to remove oil contaminants from water for cleaner production of produced water. • Polystyrene branched 9-octadecenoic acid grafted graphene is reported. • It showed excellent performance for the removal of oil from water. • The material showed recyclability with constant adsorption rate for several cycles. [ABSTRACT FROM AUTHOR]

FE-SEM micrographs showing the ENMs before and after hot press process. • Modification of PES electrospun membrane by improving mechanical properties. • Hydrophobic membrane becomes superhydrophilic with enhanced wettability behaviour. • Iron oxide provides control over membrane pore size, porosity and wettability. • Electrospun PES/Fe 3 O 4 membrane is prepared by hot pressing technique. • Hot pressed PES/Fe 3 O 4 membrane is used for oil removal with high efficiency. This paper reports the synthesis and characterization of novel ultrafiltration (UF) electrospun nanofibrous membranes (ENMs) incorporated with iron oxide (Fe 3 O 4) nanoparticles (NPs) for effective oily solution treatment. Three strategies were employed to improve the physiochemical properties of the resultant ENMs. Firstly, n -methyl-pyrrolidinone (NMP) was added to dimethylformamide (DMF) wherein the solvent stimulated fusion of the inter-fiber junctions was enhanced. Secondly, Fe 3 O 4 NPs were introduced into the ENMs to improve their hydrophilicity and anti-fouling resistance against oil molecules. Thirdly, hot pressed technique was adopted to strengthen the electrospun mat, avoiding delamination of the ENMs layer during liquid filtration processes. The findings indicated that the developed Fe 3 O 4 NPs incorporated ENMs exhibited outstanding oil elimination (94.01%) and excellent water flux recovery (79.50%) when tested with synthetic oil solution (12,000 ppm). Water productivity of over 3200 L/m2 h was achieved without forfeiting the rate of oil removal under gravity. Extraordinarily low flux declination disclosed by the proposed ENMs was attributed to their tailored surface resistance mediated oil anti-fouling character. The enhanced mechanical and oil anti-fouling traits of the prepared ENMs were established to be potential for the treatment of diverse oily effluents (especially emulsions of oil–water) in the industries. [ABSTRACT FROM AUTHOR]

The purpose of this study is to fabricate porous polyurethane membranes that maintain oil absorption performance even when the surface is contaminated. The segmented polyurethane (SPU) films were prepared by the solvent casting method and the porous SPU membranes were prepared by electrospinning. A superhydrophobic methylsilicone network was formed both on the hydroxylated SPU (SPU−OH) film and membrane surfaces by condensation with methyltrichlorosilane. The morphological changes to the methylsilicone-network-coated SPU (SPU−OH−Si) were observed by field emission scanning electron microscopy. The changes in the chemical components on the surface by the introduction of the methylsilicone network were confirmed by attenuated total reflection Fourier transform infrared spectroscopy, and the type of wettability of the surface was confirmed to be superhydrophobicity and superoleophilicity on the SPU−OH−Si film or membrane by contact angle measurements. The self-cleaning performances of the prepared surfaces were confirmed using methylene blue, Oil Red O, and SiC adsorption tests. As a result, the SPU−OH−Si surface displayed excellent self-cleaning properties, as well as oil removal performance, in contaminated water. Furthermore, the oil absorption property was preserved even when the membrane was pre-contaminated with SiC particles. [ABSTRACT FROM AUTHOR]

We report lipase‐based nanomotors that are capable of enhanced Brownian motion over long periods of time in triglyceride solution and of degrading triglyceride droplets that mimic "blood lipids". We achieved about 40 min of enhanced diffusion of lipase‐modified mesoporous silica nanoparticles (MSNPs) through a biocatalytic reaction between lipase and its corresponding water‐soluble oil substrate (triacetin) as fuel, which resulted in an enhanced diffusion coefficient (ca. 50 % increase) at low triacetin concentration (<10 mm). Lipase not only serves as the power engine but also as a highly efficient cleaner for the triglyceride droplets (e.g. tributyrin) in PBS solution, which could yield potential biomedical applications, for example, for dealing with diseases related to the accumulation of triglycerides, or for environmental remediation, for example, for the degradation of oil spills. [ABSTRACT FROM AUTHOR]

Aluminum hot-rolled waste emulsion (AWE) which possessed the properties of high oil content, chemical oxygen demand (COD) and organic pollutants became difficult to treat and demulsify in a traditional way. In the light of the common inorganic demulsifier poly aluminum silicate chloride (PASC), a novel demulsifier epichlorohydrin amine cationic polymer (FP-1) made by our laboratory was added to achieve the effect of complete demulsification. The treatment of AWE was optimized by dint of employing the response surface method and Box–Behnken design to determine the optimal conditions of PASC dose, FP-1 dose and pH. The experimental results which were consistent with the polynomial model predictions demonstrated that oil and COD removal efficiencies of 97.1% and 91.5%, could be achieved by dint of utilizing 1.45 g L–1 PASC, 2.22 g L–1 FP-1 and pH 5.14 at 328 K for 50 min. The demulsification process was studied by morphology analysis, infrared spectrum analysis and zeta potential analysis. [ABSTRACT FROM AUTHOR]

Highlights • The synthesis methods of iron oxide nanoparticles are reviewed. • Desirable characteristics of the magnetic sorbents for oil removal are crucial for the design of magnetic sorbents. • Magnetic oil sorbents could be synthesized by different materials and methods. • The removal efficiencies of the magnetic sorbents can reach up to 100%. Abstract Oil pollution has posed a great threat to marine ecosystems and human health. In recent years, many studies have focused on the functionalization of magnetic iron oxide nanoparticles to obtain efficient adsorbents for oil removal from water. This review focuses on recent studies on magnetic materials based on iron oxide nanoparticles and their applications as oil sorbents. The main techniques used to obtain iron oxide nanoparticles are also discussed. The aim of this literature review is to obtain a better understanding of the materials that could be used to obtain efficient oil adsorbents with magnetic iron oxide nanoparticles and suitable synthesis strategies by encapsulating iron oxides with organic or inorganic coatings or embedding them in a matrix/support. Another purpose is to identify the desirable characteristics of magnetic materials required for high oil removal efficiency. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Bead-free and uniform PIM-2 fibers were produced by electrospinning. • Self-standing electrospun PIM-2 fibrous membranes show high surface area. • Fibrous membranes demonstrate significantly high hydrophobicity with a water contact angle of 155 ± 6°. • Fibrous membranes of PIM-2 were employed in effective organic/oil removal. • PIM-2 fibrous membranes show high organic and oil uptake. Abstract Polymers of intrinsic microporosity (PIMs) are increasingly recognized as a potential membrane material for adsorption and separation applications due to their permanent porosity and solution processability. PIM-2 can be produced using commercially available 5,5′,6,6′-Tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobisindane and decafluorobiphenyl monomers in the powder form. It possesses considerable amount of fluorine in the polymer backbone and this feature could provide significant hydrophobicity to polymer. This research aims to investigate the fabrication of self-standing PIM-2 fibrous membranes by electrospinning method to introduce a useful material for adsorption applications. Electrospinning was performed using tetrachloroethane as a solvent and bead-free, uniform fibers were produced as confirmed by SEM imaging. Average fiber diameter was calculated as 5.5 ± 1.5 μm for a self-standing fibrous membrane of PIM-2. Structural characterization was conducted using FT-IR, NMR and XPS spectroscopies showing the purity of pristine powder and fibrous membrane of PIM-2. Thermal stability of PIM-2 fibrous membrane was investigated using TGA and it shows no discernible weight loss below 450 °C. The porosity of fibrous membrane was investigated by N 2 adsorption/desorption measurements that indicates significant microporosity with ∼600 m2 g−1 BET surface area. In addition, the hydrophobicity of PIM-2 was tested by water contact angle measurements, showing 155 ± 6° WCA, indicating superhydrophobicity owing to rough surface and high fluorine content. Consequently, the combination of straightforward synthesis, solution processability, high thermal stability, high surface area, and superhydrophobicity makes PIM-2 a promising candidate for adsorption applications. Therefore, it was successfully employed in organic and oil adsorption. Fibrous membranes of PIM-2 has shown up to 2200 ± 100% and 1900 ± 100% weight gain after in contact with silicon oil and DMSO respectively. In addition, dense membrane of PIM-2 was prepared by solvent casting method and the uptake ability was compared with fibrous membrane showing that fibrous form is more convenient for liquid adsorption applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cyclodextrin-based polymers responsive to ultraviolet light were synthesized by the atom transfer radical polymerization. • Assemblies of the polymer and nanoparticles in aqueous solutions were triggered by the pH & light stimulations. • Adsorption mechanism of the polymer and nanoparticles was investigated via the adsorption experiment and molecular dynamics simulation. • Dual stimulation allowed the polymer and nanoparticles to enhance viscous oil removal and control dye release. Responsive Pickering emulsions are an excellent platform to control the interfacial properties of oil–water systems. However, the removal of viscous crude oil from oily waste by external stimuli is still a challenge. Here, a dual-stimuli supramolecular assembly of the polymer and silica particles (PS) was designed to achieve desirable control of oil–water interfaces for viscous oil removal and controlled molecular release. The β-cyclodextrin-based polymer was fabricated through the atom transfer radical polymerization (ATRP) method for the host molecules responsive to UV light and amine-modified silica particles for the guest molecules responsive to pH. Utilizing their responsive properties, the PS system was demonstrated in this study to significantly enhance the oil washing efficiency (from 18.3% to 74.2%). Moreover, as the acidic condition was replaced by CO 2 injection, it was further enhanced from 74.2% to 88.5%, which is beneficial to greener remediation and production. The responsive PS assembly was also applied for dye release with a slower or faster release of methyl red by tuning the stimuli (pH & UV light). The molecular mechanism was revealed via the molecular dynamics (MD) simulation, which articulates the interaction and motion of the PS system under various stimulations. More importantly, this novel assembly of the cyclodextrin-based polymer and amine-modified silica particles affords a simple and efficient route to enhance the removal of viscous oil waste and precisely control the molecular release. The findings of the molecular self-assembly in this work offer unique opportunities to integrate functional polymers and particles into the liquid–liquid interface, opening an avenue for applications in Pickering emulsions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A sodium alginate hydrogel was successfully grown on the aerogel surface. • The designed solar steam device had the self-floating characteristic. • Bismuth molybdate was introduced into the floating layer to degrade dyes. It is a challenge to construct devices for producing clean and purified water. In this paper, devices assembled using an aerogel-hydrogel composite and a floating layer were used to produce clean water while purifying water sources. A low-surface-tension polymer and bismuth molybdate were loaded to the surface of a carrier through co-deposition. The contact angle of the constructed superhydrophobic fabric, canvas and felt was 162°, 159° and 160° respectively. Even under the external force of deformation, the beads still quickly left the surface, showing a low adhesion effect. The purification efficiency of the assembled self-floating solar steam generator was 99.82 % and 99.48 % for rhodamine B (Rh B) and methyl orange (MO) respectively, whose mechanical stability and salt suppression capacity were demonstrated through stress–strain curves and photothermal experiments with a high saline concentration (10 wt% NaCl). Through the introduction of bismuth molybdate in the floating layer, not only the roughness increased, but the properties of photodegradation performance were also achieved. Through an active substrate capture test and a band structure analysis, the h+ played a decisive role in the degradation process. The valence and conduction band position of the catalyst were 2.28 eV and −0.35 eV, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • A superhydrophobic Bi/BiOCl photocatalyst was synthesized. • The floating layer with photodegradation performance was constructed. • The PMDA-TAPA COF photothermal layer expands the application range of the solar evaporator. Solar interface heating evaporators are widely used and have been able to obtain clean water vapor from sewage. However, the soluble contaminants remaining in the original solution were not removed, and the floating organic pollutants affect the steam production rate. In this paper, the superhydrophobic Bi/BiOCl with low surface tension is synthesized and loaded to the felt to construct the floating layer of the photothermal device. The floating layer collaborated with the filter paper hydrophilic layer and the Pyromellitic dianhydride-Tris (4-aminophenyl) amine covalent organic framework (PMDA-TAPA COF) photothermal layer to treat the sewage containing dissolved pollutants, achieving an interfacial evaporation rate of 1.47 kg⋅m−2⋅h−1. Importantly, the floating layer not only has a contact angle of 161°, which can selectively adsorb the organic solvents floating on the water surface, but also can degrade the pollutants dissolved in the water under the light and solving the problems that hinder device applications. The valence band and conduction band potentials of superhydrophobic Bi/BiOCl are at 3.065 eV and −0.435 eV, respectively, which produce h+ and O 2 – under light to degrade dissolved pollutants in water. The introduction of novel superhydrophobic Bi/BiOCl photocatalyst in the floating layer provides a reference for solving the problem of pollutant residues. [ABSTRACT FROM AUTHOR]

An efficient strategy was developed for the rapid separation and enrichment of bafilomycin A1 (baf A1) from a crude extract of the marine microorganism Streptomyces lohii fermentation. This strategy comprises liquid−liquid extraction (LLE) with a three-phase solvent system (n-hexane–ethyl acetate–acetonitrile–water = 7:3:5:5, v/v/v/v) followed by separation using high-speed counter-current chromatography (HSCCC). The results showed that a 480.2-mg fraction of baf A1-enriched extract in the middle phase of the three-phase solvent system was prepared from 4.9 g of crude extract after two consecutive one-step operations. Over 99% of soybean oil, the main hydrophobic waste in the crude extract, and the majority of hydrophilic impurities were distributed in the upper and lower phase, respectively. HSCCC was used with a two-phase solvent system composed of n-hexane–acetonitrile–water (15:8:12, v/v/v) to isolate and purify baf A1 from the middle phase fraction, which yielded 77.4 mg of baf A1 with > 95% purity within 90 min. The overall recovery of baf A1 in the process was determined to be 95.7%. The use of a three-phase solvent system represents a novel strategy for the simultaneous removal of hydrophobic oil and hydrophilic impurities from a microbial fermentation extract.

The current situation with the problems associated with the removal of oil from wastewaters by membranes is being explored. Many types of membranes have been investigated—organic polymers, inorganic or ceramic species and hybrids of the two. Polymeric membranes can be designed to facilitate the passage of oil, but the more successful approach is with hydrophilic types that encourage the passage of water. Ceramic membranes have an advantage here as they are less often irreversibly fouled and give a higher recovery of oil, with a lower flux decline. Furthermore, they can be cleaned up by a simple heating procedure. More attention should be given to understanding the mechanism of fouling so that operating conditions can be optimised to further reduce fouling and further decrease the flux decline, as well as assisting in the design of antifouling membranes. Another obstacle to ceramic membrane use is the high cost of manufacture. Cheaper starting materials such as clays have been surveyed.

The offshore and deep-sea marine environment provides many ecosystem services (i.e., benefits to humans), for example: climate regulation, exploitable resources, processes that enable life on Earth, and waste removal. Unfortunately, the remote nature of this environment makes it difficult to estimate the values of these services. One service in particular, waste removal, was examined in the context of the Deepwater Horizon oil spill. Nearly 5 million barrels of oil were released into the offshore Gulf of Mexico, and 14 billion dollars were spent removing about 25% of the oil spilled. Using values for oil spill cleanup efforts, which included capping the wellhead and collecting oil, surface combustion, and surface skimming, it was calculated that waste removal, i.e., natural removal of spilled oil, saved BP over $35 billion. This large amount demonstrates the costs of offshore disasters, the importance of the offshore environment to humans, as well as the large monetary values associated with ecosystem services provided.