Oil Pollution In Waters Research Articles

Study on the unique separation effect of emulsion in the stirring-induced turbulent flow field

Much attention has been gained to treat organic pollution dominated by oil pollutants in water with the frequent discharge of wastewater in industries. Liquid–liquid emulsion is a typical existence form of water and oil pollutants. The relative stable flow field is a necessary condition to separate the emulsion, while turbulence of the flow field is required for homogeneous mixing. For centuries, stirring-induced turbulent flow has been used for mixing, with a limited number of separation cases achieved by the stable part of the container at low Reynolds numbers (Re). In this study, the separation of liquid–liquid emulsions in a fully turbulent system for Reynolds number values above 10,000 was observed for the first time. Besides the turbulent flow influenced by the stirring speed, the additional dispersed phase, which was the same as the emulsified dispersed phase, played a critical role in the separation performance. The turbidity of oil-in-water emulsion could be decreased to less than 5 NTU (nephelometric turbidity unit) from 500 NTU under the optimal conditions in this study, with a separation efficiency of over 99%. This peculiar and wonderful characteristic of the turbulent flow and the study of the parameters and constraint conditions for separation may extend the application field of the turbulent flow field from conventional mixing to oil pollutants separation from water in environmental engineering.

Flash spinning polyethylene/Fe3O4 magnetic drive fibers for oil absorption underwater

Oil pollution in water has destructive effect on the ecological environment of water bodies. However, the treatments for oil pollution underwater in irregularly shaped and non-open environments face a challenge owing to the difficulty in driving oil absorption materials underwater. Herein, this work reports a facile strategy to prepare flash spinning magnetic polyethylene fibers (FSMPFs) for oil absorption application in irregularly shaped and non-open underwater environments. The as-prepared FSMPFs exhibit good oil absorption performance, of which the oil absorption in air and underwater is 76.70 g/g and 65.32 g/g, respectively, and the FSMPFs can maintain their oil absorption performance in environments with different salinities (1–5 %) and pH values (2–12). Also, the FSMPFs show good magnetic responsiveness and controllability when applied to oil–water separation underwater in irregularly shaped pipes, and the oil–water separation efficiency of FSMPFs for oil–water emulsion reaches 99.6 %. Besides, the FSMPFs have good mechanical properties and reusability, of which the tensile strength and elongation at break is 185.9 cN and 41.2 %, respectively, and oil absorption is 76.28 g/g (99.5 % of the initial value) after 10 cycles of absorption–desorption. The FSMPFs have great potential in practical applications for oil absorption under irregularly shaped and non-open environments.

Hydrophobic modified melamine sponge for highly effective remediation of crude oil in water and soil

Crude oil pollution in water and soil has resulted in considerable environmental damage. The utilization of hydrophobic and oleophilic sponge materials for the treatment of crude oil pollution has garnered significant interest, owing to their excellent selective adsorption performance. In this paper, superhydrophobic and superoleophilic sponges (SMF) are prepared by a simple silane hydrolysis-thermal curing method, which is low-cost, environmentally friendly, large-scale preparation, acid and alkali-resistant, and mechanically stable. They can be used for the remediation of oil pollutants in water and soil simultaneously, and show high efficiency, excellent stability, and biosafety. Under appropriate circumstances, SMF is capable of adsorbing up to 82.7 g/g of crude oil in water and eliminating over 70.0 % of crude oil in soil, while exhibiting exceptional recycling performance. Notably, this study introduces a novel technique that alters soil viscosity by controlling soil water content, in conjunction with SMF, for the removal of crude oil in soil. Consequently, SMF shows great promise for practical application in the remediation of oil pollutants in both water and soil.

Production of Biosynthesized Silver Nanoparticles using Metarhizium anisopliae fungus for the Treatment of Petroleum Pollutants in Water

In this study, a silver nanoparticle (AgNPs) was created using a biological technique from an extract of the fungus Metarhizium anisopliae. The characteristics of the prepared AgNPs were identified by utilizing the optical, ultraviolet, and infrared absorbance spectroscopy. The shape, size, and charge distribution on the particles were determined by using scanning electron microscopy and zeta voltage analysis. The analysis of biological activity of the silver nanoparticles showed its effectiveness in treating pollutants, as confirmed by the reduction of higher than 93% weight of crude oil in contaminated water samples. The crude oil mass was effectively transformed into the gelatinous mass that lacks consistency and emulsification. The chemical analysis of NP-treated and untreated crude oil- contaminated water samples was performed using gas chromatography mass spectrometry (GC MASS). The results displayed the emergence of 55 graphic peaks, each of them indicating a chemical compound, in the control sample, while in the study sample, about 51 of these peaks disappeared and the area of the remaining 4 peaks was reduced. The silver nanoparticles' capability to maintain their effectiveness under cryogenic storage conditions for six months was tested and compared to that of the fungal isolation before the production of the silver nanoparticles. The results showed no significant changes in the shape, size, and efficiency of the silver nanoparticles in the treatment of oil pollutants in water. The results indicated the higher efficiency of the silver nanoparticles, as compared to chemicals, in treating petroleum pollutants as well as enhancing the solubility, emulsification, and degradation of hydrocarbons. In addition, the AgNPs are characterized by the availability of inexpensive, easy, fast to produce, and environmentally friendly production materials, as compared to the usage of chemical products that are highly toxic to aquatic organisms, expensive to produce, and highly accumulative in the ecosystem, i.e. environmentally unsafe.

3D-printed porous Al2O3 membrane coated with hydrophilic modified titanium dioxide particles for large-flux oil/water separation

ABSTRACT A viable material to address oil pollution in water is the super wetting surface, which is accessible to realise the separation of oil and water. According to Young’s equation, hydrophobic/oleophilic materials are theoretically simple to realise and have a wide range of applications. The hydrophobic/oleophilic membrane, however, has a poor separating effect on the mixture in which the oil has a lower density than water. Hence, to optimise the oil/water separation performance, hydrophilic modified titanium dioxide particles were introduced to a novel porous superhydrophilic/oleophobic substrate fabricated by 3D printing technology in this work. The contact angle of n-hexadecane on the membrane surface was about 130°, which was an oleophobic surface. The oil/water separation efficiency of the 0.7 mm thick oleophobic membrane was over 98% and the penetration flux was up to 11,191 L m−2 h−1, indicating that the membranes prepared in this work might be used in high-flux oil/water separation applications. This study provides an efficient, simple, and reliable method for preparing oil/water separation materials with 3D printing technology, and may have broader significance among the academic and industry communities.

Reduction of hydrocarbon pollutants by hyacinth plants ( Eichhornia crassipes).

Background: The application of phytoremediation by utilizing plants has been used to control oil pollution in waters. One of the plants that can act as a phytoremediator is the hyacinth because this plant can reduce various pollutants including petroleum hydrocarbons. This study aims to study the reduction ability of petroleum hydrocarbons at different concentrations including improving water quality. Methods: This study consisted of one treatment (petroleum hydrocarbon) consisting of five factors with three replicates. The treatments consisted of 10 ppm (E1), 30 ppm (E2), 50 ppm (E3), 70 ppm (E4), 90 ppm (E5), and (E0) without aquatic plants as controls. The treatments were observed daily and measured from the first day (D-1), the seventh day (D-7), and the 14 th day (D-14). The water quality in each treatment was also measured, such as water temperature, pH, and dissolved oxygen. Results: The results showed that the hyacinth plant was able to reduce hydrocarbon in terms of total petroleum hydrocarbon (TPH) by 79% while it was only between 17-27% naturally without the hyacinth. The reduction of TPH in the water was in line with the decrease of chlorophyll in the leaves of hyacinths, and it was followed by the increase of dissolved oxygen in the water media. Conclusions: In conclusion, hyacinths can reduce petroleum hydrocarbons and they can improve the water quality as well.

Magnetic biopolymers' nanocomposites from chitosan, lignin and phycosynthesized iron nanoparticles to remediate water from polluting oil

Targeting the remediation of oil pollution in water, the construction of super magnetic adsorbent nanocomposites (NCs) was achieved using the nanoparticles of chitosan (Cht), lignin (Lg) and phycosynthesized iron nanoparticles (Fe MNPs) using Gelidium amansii extract. The syntheses and conjugations of nanomaterials were authenticated via infrared spectral analysis and the structural physiognomies of them were appraised via electron microscopy and zeta analysis. The Lg NPs, Cht NPs, Fe MNPs and their composites (Lg/Cht MNCs) had mean particles' sizes of 42.3, 76.4, 14.2 and 108.3 nm, and were charged with - 32.7, + 41.2, + 28.4 and +37.5 mV, respectively. The magnetometer revealed the high magnetic properties of both Fe MNPs and Lg/Cht MNCs; the maximum swelling of Lg/Cht NPs (46.3 %), and Lg/Cht MNPs (33.8 %) was detected after 175 min. The diesel oil adsorption experiments with Lg/Cht MNPs, using batch adsorption practices, revealed the powerful potentiality of magnetic NCs to remove oil pollution in water; the maximum adsorption capacity (qt) was achieved with the conditions of pH = 7.5, adsorption period = 90 min and adsorbent dose = 200 mg/L. The magnetic Lg/Cht MNCs exhibited excellent recovery/reusability attributes for five adsorption cycles; the qt differences were negligible after the entire oil-adsorption cycles, with oil removal of >90 %. The innovative fabricated Lg/Cht MNCs could provide an effectual, sustainable and eco-friendly approach for the removal of pollutant oil in water resources.

Reduction of hydrocarbon pollutants by hyacinth plants (Eichhornia crassipes)

Background: The application of phytoremediation by utilizing plants has been used to control oil pollution in waters. One of the plants that can act as a phytoremediator is the hyacinth because this plant can reduce various pollutants including petroleum hydrocarbons. This study aims to study the reduction ability of petroleum hydrocarbons at different concentrations including improving water quality. Methods: This study consisted of one treatment (petroleum hydrocarbon) consisting of five factors with three replicates. The treatments consisted of 10 ppm (E1), 30 ppm (E2), 50 ppm (E3), 70 ppm (E4), 90 ppm (E5), and (E0) without aquatic plants as controls. The treatments were observed daily and measured from the first day (D-1), the seventh day (D-7), and the 14th day (D-14). The water quality in each treatment was also measured, such as water temperature, pH, and dissolved oxygen. Results: The results showed that the hyacinth plant was able to reduce hydrocarbon in terms of total petroleum hydrocarbon (TPH) by 79% while it was only between 17–27% naturally without the hyacinth. The reduction of TPH in the water was in line with the decrease of chlorophyll in the leaves of hyacinths, and it was followed by the increase of dissolved oxygen in the water media. Conclusions: In conclusion, hyacinths can reduce petroleum hydrocarbons and they can improve the water quality as well.

Preparation of superhydrophobic, green, and eco-friendly modified polylactic acid foams for separation oil from water

Developing a facile and green strategy to fabricate polymer foams with super hydrophobicity and eco-friendliness for large-scale oil-water separation remains a challenge. In this study, biocompatible polylactic acid polymer foam modified by nanochitosan and stearic acid was used to remove petroleum and organic contaminants in water. All three materials used to prepare and modify this foam are green and inexpensive. F4d foam (prepared by solvent displacement method) and F8d foam (prepared by freeze dryer) can selectively remove oil pollutants in water with a contact angle of 164.01° and 168.51°, respectively. The maximum absorption capacity of oil pollutants by F4d and F8d are related to chloroform with values of 32.7 g/g and 48.51 g/g, respectively. Also, the minimum absorption capacity is related to n-hexane with values of 24.83 g/g and 32.06 g/g. The absorption percentage range of F4d and F8d foams after 15 cycles of absorption-desorption for chloroform is 82.56 % and 87.81 %, respectively, and for n-hexane, is 77.28 % and 85.99 %, respectively. During the continuous water-oil pumping test, the efficiency of foam can be maintained for >15 h, which shows promising hope for large-scale oil pollution cleaning.

Application of Three-Dimensional Fluorescence Spectroscopy in Smart Agriculture — Detection of Oil Pollutants in Water

Three-dimensional fluorescence spectroscopy is a fast, nondestructive analysis method with good selectivity and high precision, which provides a foundation for the development of the current smart agriculture system. In modern agriculture, where agricultural information is fully perceived, it is still very difficult to quickly and destructively detect the internal chemical composition of soil, crops and agricultural products. Accurate determination of oil pollutants in water by using three-dimensional fluorescence spectroscopy technology can provide a basis for crop irrigation and is of great significance for improving agricultural benefits. The fluorescence spectrum analysis method is adopted to distinguish three kinds of mineral oil-gasoline, kerosene and diesel. In order to make the distinguishment more intuitive and convenient, a new identification method for mineral oil is proposed. The three-dimensional fluorescence spectra of the experimental dimension are reduced into two-dimensional fluorescence spectra. The concrete operations are as follows: adopting the method of end-to-end data matrix to constitute a large Ex image, and then figuring out the envelope curve, processing and analyzing the envelope image. Four factors, such as the ranges of excitation wavelength when the relative fluorescence intensity is greater than 0.5, the optimal excitation wavelengths, their kurtosis coefficients and skewness coefficients, are to be selected as the distinguishing feature parameters of mineral oil, and thus different kinds of mineral oil can be distinguished directly according to the feature parameters. The experimental results show that the proposed method has a high resolution for different kinds of mineral oil. Accurate and fast spectral data analysis methods can make up for the deficiencies of other agricultural information perception methods, provide a basis for the application of smart agriculture in many aspects and have a positive significance for promoting the comprehensive intelligent development of agriculture.

Status of oil pollution in water and sediment from Shatt Al-Arab Estuary and North-West Arabian Gulf

In the present study, an attempt was made to study the levels of petroleum hydrocarbon residues in Water and Sediment samples collected from ten stations at the region of Shatt Al-Arab Estuary and North-West of the Arabian Gulf. The water and sediment samples were analyzed by utilizing the spectrofluorometry technique. The results of the present research obviously indicated a degree of oil pollution, however, still lower in magnitude when compared with status in some other regional sites. The obtained levels of petroleum hydrocarbons in water was ranged from (3.09 µg/l) at station 7 to (30.87 µg/l) at station 9 while in sediment ranged from (19.43 µg/g) dry weight at station 4 to (49.09 µg/g) dry weight at station 9. In order to give a better evaluation of the petroleum hydrocarbon levels in the sediments, the Total Organic Carbon (TOC) percentage and grain size analyses were done by granulometry technique on selected slips of the bulk sediments obtained for this purpose. The mean percent TOC estimations ranged from 0.1 at Station 4 to 1.34 at Station 9. The mean values obtained in this study indicated that the petroleum hydrocarbon levels in the sediment samples are lower than the levels in sediment samples obtained with similar methodology and analyses in some of the Gulf States and countries in close vicinity of the region. The major pollution sources may involve tanker and boat discharges and activities, municipal sewage and rural runoff from land. Also, discharges and effluents from oil refineries, electricity generating station and industrial activities into the Basrah city are obvious.

Components of Oil Pollution in Water and Bottom Sediments of the Northeastern Part of the Russian Black Sea Region

Components of Oil Pollution in Water and Bottom Sediments of the Northeastern Part of the Russian Black Sea Region

NiO-Ni foam supported Ag3PO4 for efficient photoelectrocatalytic degradation of oil pollutant in water

The treatment of oily wastewater has received significant attention because of its negative influence on environments. Despite various methods on oil removal were developed, photoeletrocatalysis (PEC) technique is considered to be a promising method. In this study, Ag3PO4@NiO-Ni foam photoelectrode was synthesized through the “hydrothermal-impregnation-calcination” three-steps to realize the PEC degradation of oil pollutants in water. The introduction of NiO-Ni foam provides simultaneous advantages of functioning as an electrode material and the synergistic photodegradation with Ag3PO4. The resulting Ag3PO4@NiO-Ni foam photoelectrode are characterized and utilized for the degradation of diesel and crude oil under PEC condition. Within two hours, the photoelectric removal of 1000 mg/L diesel can reach 88.7%. The influence of virous environmental factors, such as pH, temperature, inorganic cation and humic acid, on PEC degradation have been investigated. After 10 cycles, the removal of more than 70% can still be maintained. Finally, the possible PEC degradation mechanism was analyzed. This provides effective theoretical support for the treatment of actual oily wastewater.

Removal of Oil Pollution in water using hydrophobic silica

Nowadays the contamination in waters by oily substances turns out to be a problem of world-wide scope and although some methods of removal of oils in water exist; these present some limitations; therefore, this project proposes the use of hydrophobic silicas as absorbent materials for oily substances. Modified silicas (R-SiO2) were synthesized using the Stöber method, modifying the surface by co-condensation. Tetraethyl-orthosilicate (TEOS) and two surface modifiers were used as silica former: Methyl-trimethoxysilane (MeTEOS) and n-octyl-triethoxysilane (nOctyl-TEOS). The R-SiO2 were characterized by infrared spectroscopy identifying the modifying groups and their hydrophobicity was qualitatively evaluated according to the change in solubility in water. Finally, the removability of an automotive motor oil was evaluated by determining the amount of oil removed per gram of modified silica.

Highly efficient photocatalytic degradation of oil pollutants by oxygen deficient SnO2 quantum dots for water remediation

The oil spill pollution has become one of the most significant threats to the marine environment and coastal ecology. An efficient way is urgently expected to remove the oil pollutants at this last stage of the petroleum age. In this work, the oxygen vacancy-rich SnO2 quantum dots (QDs) are prepared in aqueous solution via a facile bottom-up self-assembly route. The QDs are applied to the photocatalytic degradation of oil pollutants in water. A high degradation efficiency of 91.9% for octane is obtained within 48 h under the ultraviolet–visible irradiation and the excellent performance is able to be maintained within a period of 90 days. The primary reactive radical is superoxide anion (O2•−) in the degradation process, where the oxygen supply is essential to the photocatalytic removal of oil pollutants. The optical characterizations conclude that the QDs have 16.7% of oxygen vacancies and a band gap of 4.2 eV. Based on these characteristics, a computational model is established for the first principle-based simulation, which reveals the electrical properties and demonstrates a deep energy level of oxygen vacancies at 1.4 eV below the conduction band. The proficient photocatalytic degradation efficiency is ascribed to the inherent oxygen vacancies, which build an internal Z-scheme mechanism for the electron transition. A novel strategy is therefore proposed that the deep energy levels in low dimensional semiconductors are beneficial to the enhancement of photocatalytic activity. The present oxygen vacancy-rich SnO2 QDs are prospective candidates for mass degradation of organic oil pollutants in water and they are of great significance to the development of semiconductor photocatalysts as well as the remediation of marine environment.

3D-printed controllable gradient pore superwetting structures for high temperature efficient oil-water separation

Superwetting surfaces have the potential to address oil pollution in water, through their ability to separate the two. However, it remains a great challenge to fabricate stable and efficient separation structures using conventional manufacturing techniques. Furthermore, the materials traditionally used for oil-water separation are not stable at high temperature. Therefore, there is a need to develop stable, customizable structures to improve the performance of oil-water separation devices. In recent years, 3D printing technology has developed rapidly, and breakthroughs have been made in the fabrication of complicated ceramic structures using this technology. Here, a ceramic material with a gradient pore structure and superhydrophobic/superoleophilic properties was prepared using 3D printing for high-efficiency oil-water separation. The gradient pore structure developed here can support a flux of up to 25434 L/m2h, which is nearly 40% higher than that an analogous structure with straight pores. At 200 °C, the oil-water separation performance was maintained at 97.4%. Furthermore, samples of the material exhibited outstanding mechanical properties, and chemical stability in a variety of harsh environments. This study provides an efficient, simple, and reliable method for manufacturing oil-water separation materials using 3D printing, and may have broader implications for both fundamental research and industrial applications.

Popped Rice Biochar and Superhydrophobic SiO2 / Popped Rice Biochar for Oil Adsorption

A novel biochar, whose precursor is popped rice, was produced to remove oil pollution in water. Popped rice biochar is characteristic with large pores. When popped rice was carbonized at 300 °C, its oil absorption capacity for paraffin oil is up to 10.88 ± 0.51 g/g, being much higher than that of the original popped rice (4.03 ± 0.39 g/g). In order to improve the oil-water separation property of popped rice biochar to absorb oil selectively, epoxy resin was used as a binder to make superhydrophobic SiO2 coated on the surface of popped rice biochar. The water contact angle of superhydrophobic SiO2 / popped rice biochar is 153 ± 0.9°, and it has good oil-absorption capacity with low water-absorption ratio. As the oil-absorption material is environmentally friendly, it will be a good select for the removal of oil pollution.

A 3D printed centrifugal microfluidic platform for spilled oil enrichment and detection based on solid phase extraction (SPE)

Portable devices for real time monitoring of oil pollution in coastal water can be very useful in environmental protections. This is particularly true after the disastrous BP oil spill in Gulf of Mexico and huge amount of residual oil drifted to the costal water system. Fluorescence detection method is one of the most popular method adopted to determine the existence and concentration of the oil in water. When polycyclic aromatic hydrocarbons (PAHs) in crude oil is excited by ultra-violet (UV) light, fluorescent light with wavelengths from 400 nm to 650 nm is emitted. To realize the detection of trace oil pollution in water, solid phase extraction (SPE) is widely used to enrich the PAHs in the sample for enhanced detection sensitivity. However, conventional methods to enrich and detect PAHs usually need to be conducted in the lab because professional equipment are required and the operations are complicated and time consuming. This paper reports a novel centrifugal microfluidic platform for automatically detecting trace oil pollution in test sample. Mechanical valves were used to control the flow of the reagents and water sample in the device. The prototype of the proposed system was fabricated using 3D printing technology and tested with 10 ppm standard oil-water mixing sample. Different stationary sorbents were tested and compared. The experimental results had proved that the detection sensitivity of the water-oil mixture sample can be significantly enhanced after it was enriched using the centrifugal microfluidic platform. The study has proved the functionality of the 3D printed centrifugal microfluidic platform and demonstrated it can potentially be used as a portable, real time, in-situ detection for oil detection device.

Novel sandwiched composite electro-spun mats based on polyacrylonitrile and polyvinyl butyral for fast oil–water separation

In recent years, the issue on oil pollution in water has drawn continuous attention of researchers. Wastewater containing oil is generated in various industrial technologies, such as petrochemical, leather, textile, food, steel, and metal-finishing industries. Thus, oil sorbents are very commonly used during oil spills cleanup operation for their cost-effectiveness and affordability. In the present work, a novel sandwiched composite electro-spun nanofibrous mat (SCEM) was generated by electro-spinning technique. This sandwiched composite electro-spun mat was fabricated by sandwiching the chitosan-incorporated polyvinyl butyral nanofiber mat between two layers of polyacrylonitrile electro-spun mats. Surface morphology of the generated multilayer nanofibrous mat was observed by the static water contact angle measurement, SEM and FTIR analyses. SCEM was modified by alcoholysis reaction to increase the hydrophobicity and oleophilicity properties by enhancing the surface roughness. After fabrication and modification processes, oil-absorption capacities of single mats, SCEM, and modified mat designated as M-SCEM were investigated and calculated in terms of weight gains. Mats with sandwich structure exhibited excellent absorption capacities up to 100–140 times their own weight for motor oil. The obtained results suggest that these characteristics make spun bond nanofibrous mat a promising oil sorbent material for efficient oily water remediation.

Bubble-Propelled Hierarchical Porous Micromotors from Evolved Double Emulsions

Bubble-propelled micromotors with well-engineered hierarchical porous structures are developed by a simple and flexible strategy for efficient water decontamination. Controllably and spontaneously evolved double emulsions from microfluidics are used as templates for continuous fabrication of the micromotors in one-step. The micromotors possess interconnected hierarchical porous structures with two well-aligned microscale pores incorporated in nanoporous matrix. The opening hole of one microscale pore at the bottom of micromotor is decorated with Fe3O4@Ag nanoparticles to decompose H2O2 for bubble-propelled motion. Due to their hydrophobic and magnetic hierarchical porous matrix, the micromotors can be used for capture of oil pollutants in water, and then easy recovery by using a magnetic field. Moreover, the micromotors can be flexibly functionalized by simply incorporating functional nanoparticles into the hierarchical porous structures for efficient water decontamination. This is demonstrated by modifyi...