Oil-polluted Water Research Articles

Treatment of crude oil-polluted water using CoFe2O4-doped mango (Mangifera indica) seed shell composite

This study investigates the potential of cobalt ferrite-doped mango seed shell (CoFe2O4-MSS) as an innovative and eco-friendly approach for the treatment of crude oil-polluted water. CoFe2O4-MSS was synthesized by impregnating carbonized mango seed shell with cobalt ferrite nanoparticles through thermal precipitation. The study systematically evaluated the adsorption capacity, kinetics, and isotherm behavior of the developed material using standard equations. Experimental results demonstrate the effectiveness of the cobalt ferrite-doped mango seed shell in adsorbing crude oil components, with high removal efficiency of 98.3% at 80 °C after 50 min. The crystallite sizes of raw mango seed shell and CoFe2O4-MSS are 31.8 nm and 21.3 nm, respectively. The calculated adsorption capacity stood at 55.50 mg/g, the Brunauer–Emmett–Teller surface area of CoFe2O4-MSS was 1007.4m2/g with a porosity distribution of 1.685 η\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\eta$$\\end{document} while the volume and pore diameter are 3.104m3/g and 7.212 nm, respectively. FTIR analysis revealed the presence of aliphatic, aromatic, and silicon compounds. The isotherm data matched well with Langmuir isotherm model while kinetic data fitted well with Bhattacharya–Venkobachar model. The unique properties of cobalt ferrite, a magnetic and iron-based material, combined with the abundant and biodegradable nature of mango seed shells, make this composite an attractive adsorbent for removing crude oil contaminants. This research contributes to the development of sustainable and cost-effective solutions for addressing environmental challenges posed by crude oil pollution. Also, this research has contributed immensely to the sustainable development goals of the united nation (UN-SDG) regarding environmental protection.

Molecular Characterization and Tolerance Potential of Culturable Crude Oil-Degrading Microbes in Santa-Barbara River, Bayelsa State, Nigeria

There has been chronic contamination of the surrounding aquatic and terrestrial environments in the Niger Delta region of Nigeria due to the enormous activities of crude oil exploration. This study aimed to characterize and assess the crude oil tolerance potential of indigenous microbes from crude oil spills in Santa Barbara River, Bayelsa State, Nigeria, that could serve as potential consortia for bioremediation of the crude oil spills. Total crude oil hydrocarbon-utilizing bacteria count (THUBC) and total crude oil hydrocarbon-utilizing fungi count (THUFC) in the samples were determined with a culture-dependent spread plate technique. Bacterial and fungal isolates were characterised using standard phenotypic and 16S/Internal Transcribed Spacer region rRNA gene sequencing techniques, respectively. The tolerance of autochthonous bacterial isolates to different concentrations of crude oil was subsequently determined. THUBC and THUFC in crude oil-polluted water samples ranged from 1.88 log10 CFU/ml to 2.74 log10 CFU/ml and from 0.00 log10 CFU/ml to 1.70 log10 CFU/ml, respectively. Representative strains of Proteus mirabilis, Bacillus subtilis, Pseudomonas aeruginosa, Micrococcus luteus and Aspergillus flavus isolates obtained from crude oil-polluted water samples were deposited in the GenBank (NCBI) under accession numbers OQ969924, OQ969951, OQ969987, OQ970009 and OQ975908. Proteus mirabilis, Pseudomonas aeruginosa and Aspergillus flavus demonstrated the most significant tolerance to crude oil pollutants (minimum crude oil inhibitory concentrations (MIC) = 80%) followed by Bacillus subtilis and Micrococcus luteus (MIC= 40%). The findings from this study are pointers to the potential role of the microbial isolates as bioremediation consortia to remediate the polluted Santa Barbara River.

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.

Enhanced photocatalysis using metal-organic framework MIL-101(Fe) for crude oil degradation in oil-polluted water

Enhanced photocatalysis using metal-organic framework MIL-101(Fe) for crude oil degradation in oil-polluted water

Visible-Light-Active BiOI/TiO2 Heterojunction Photocatalysts for Remediation of Crude Oil-Contaminated Water.

In this study, BiOI-sensitized TiO2 (BiOI/TiO2) nanocomposites with different levels of BiOI deposited via sequential ionic layer adsorption and reaction (SILAR) have been explored for the degradation of methyl orange, 4-chlorophenol (4-CP), and crude oil in water under visible (>400 nm) irradiation with excellent degradation performance. The reaction progress for methyl orange and 4-chlorophenol was monitored by a UV-vis spectrophotometer, and the degradation of the crude oil hydrocarbons was determined by GC-MS. The BiOI/TiO2 heterojunction improves separation of photogenerated charges, which enhances the degradation efficiency. Evaluation of the visible-light photocatalytic performance of the synthesized catalysts against methyl orange degradation confirmed that four SILAR cycles are the optimal deposition condition for the best degradation efficiency. The efficiency was further confirmed by degrading 4-CP and crude oil, achieving 38.30 and 85.62% degradation, respectively, compared with 0.0% (4-CP) and 70.56% (crude oil) achieved by TiO2. The efficiency of TiO2 in degrading crude oil was mainly due to adsorption along with photolysis. This study provides a simple and cost-effective alternative to traditional remediation methods requiring high energy consumption for remediation of crude oil-polluted water and refinery wastewater using visible-light photocatalysis along with adsorption.

Biomass-derived carbon nano-onions for the effective elimination of organic pollutants and oils from water.

Oil spillage and leakage of organic solvents have caused severe environmental and ecological damages. It is of great significance to develop a cost-efficient and green adsorbent material with high uptake efficiency to separate the oil-water mixture. In this work, biomass-derived CNOs were first time explored in the adsorption of organic pollutants and oils from water. Carbon nano-onions (CNOs) with hydrophobicity and oleophilicity were cost-effectively synthesized in an energy efficient flame pyrolysis process using flaxseed oil as a carbon source. The as-synthesized CNOs without any further surface modification have shown high adsorption efficiency in removing organic solvents and oils from the oil-water mixture. The CNOs could adsorb diverse organic solvents such as pyridine (36.81 mg g-1), dichloromethane (90.95 mg mg-1), aniline (76 mg mg-1), toluene (64 mg mg-1), chloroform (36.25 mg mg-1), methanol (49.25 mg mg-1), and ethanol (42.25 mg mg-1). The uptake capacity for petrol and diesel over CNOs was observed at 36.68 mg mg-1 and 58.1 mg mg-1, respectively. The adsorption of pyridine followed pseudo-second-order kinetics and Langmuir's isotherm model. Moreover, the adsorption efficiency of CNOs towards the remediation of pyridine was almost similar in real-water samples when tested in tap water, dam water, groundwater, and lake water. Similarly, the practical applicability for the separation of petrol and diesel was also verified in the real sample (sea water) and has been proven to be excellent. By simple evaporation, the recovered CNOs can be reused for more than 5 cycles. CNOs exhibit the promising potential to be used in practical applications for oil-polluted water treatment.

Characterization of polycyclic aromatic hydrocarbon (PAH) degrading bacteria and optimization of physicochemical conditions for the production of catechol 1, 2-dioxygenase

Biodegradation of recalcitrant polycyclic aromatic hydrocarbons (PAHs) is highly dependent on the activities of catabolic enzyme and the conditions for metabolism. The most significant studies on process optimization of conditions for catechol 1, 2 dioxygenase (C120) metabolism of PAHs used “one variable at a time” (OVAT) method, however, with its limitations. In this study, optimization of conditions for optimal C12O metabolism of PAH pollutants using the central composite design (CCD) of response surface methodology (RSM) was used. Enrichment technique using mineral salt medium (MSM) was used to isolate bacteria from oil-polluted water and soil milleu from Awoye community in Nigeria. Thereafter, the bacterial isolates were primarily screened through growth on mineral salt medium plates supplemented with (100 - 200) mM catechol and were subjected to secondary screening based on their initial catechol 1, 2-dioxygenase activity. Molecular tools were used to identify the isolate. Amongst the five (5) bacterial isolates acquired from primary screening, it was found that the cell free extract from isolate FEP B16a displayed the highest enzyme activity. Additionally, isolate FEP B16a was able to grow on MSM plate with 200 mM catechol. Based on CCD of RSM, the C12O produced from isolate FEP B16a had maximum activity at 35 ℃, pH 8.0, and 80μM of catechol. Molecular analysis confirmed it as a strain of Microbacterium hydrothermale FEP_B16a. This study concluded that CCD of RSM may be an efficient method to optimize C12O activity over the conventional approach of using single variable at a time.

Design of hydrophobic polyurethane–magnetite iron oxide-titanium dioxide nanocomposites for oil-water separation

Efficacious oil-water separation has become a global challenge owing to regular oil spillage accidents and escalating industrial oily wastewater. In this study, we synthesized titanium dioxide and magnetite iron oxide nanoparticles to use as a precursor for the production of the nanocomposites. Hydrophobic nanocomposites were fabricated using polyurethane, hematite and magnetite iron oxide nanoparticles, and titanium dioxide nanoparticles through a sol-gel process. The formation of the obtained nanocomposites was confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses. In addition, the thermogravimetric and differential thermogravimetric (TGA/DTG) and BET surface area results exhibited enhanced thermal stability of the optimized nanocomposite which displayed mesoporous type materials feature with high porosity. Furthermore, the obtained outcomes demonstrated that the distribution of nanoparticles into a polymer matrix had a significant impact on enhancing superhydrophobicity and the separation efficiency against sunflower oil. Seeing the water contact angle of the nanocomposite-coated filter paper was about 157° compared to 0° for the uncoated filter paper and endowed separation efficiency of almost 90% for 5 consecutive cycles. Thereby, these nanocomposites could be an ideal candidate for self-cleaning surfaces and oil-polluted water purification.

Fabrication of bio-inspired metal-based superhydrophilic and underwater superoleophobic porous materials by hydrothermal treatment and magnetron sputtering.

Oil-water separation using porous superhydrophilic materials is a promising method to circumvent the issue of oil-polluted water by separating water from oil-water mixtures. However, fabricating metal-based porous superhydrophilic materials with stable superhydrophilicity that can recover their strong hydrophilicity and have acceptable oil-water separation efficiency without complex external stimuli is still a challenge. Inspired by the anti-wetting behavior of broccoli buds, this study successfully fabricated metal-based superhydrophilic and underwater superoleophobic porous materials by hydrothermal treatment of stainless steel meshes (SSMs) combined with magnetron sputtering of metallic Ti and W. The process was then followed with annealing at 300 °C for 4 hours. The effects of coating materials, annealing temperature, and surface structure on the wetting behavior of the prepared meshes were studied and analyzed. The modified meshes exhibited unique broccoli-like microstructures coated with thin TiO2-x N x /WO3 films and showed superhydrophilicity with a 0° water contact angle (WCA) and underwater superoleophobicity with underwater oil contact angles (UOCAs) higher than 155°. They also maintained strong hydrophilicity for more than three weeks with WCAs of less than 13°. Besides, they could recover their initial superhydrophilicity with a 0° WCA after post-annealing at 80 °C for 30 minutes. Notably, the broccoli-like structures and the strong hydrophilic coatings contributed to a significant water flow rate (Q) of 3650 L m-2 h-1 and satisfactory oil-water separation efficiency of 98% for more than 15 separation cycles toward various oil-water mixtures. We believe that the presented method and fabricated material are promising and can be applied to induce hydrophilicity of various metallic materials for practical applications of oil-water separation, anti-fouling, microfluidic transport, and water harvesting.

Hydrocarbon biodegradation by Proteus and Serratia strains isolated from oil-polluted water in Bonny Community, Niger Delta, Nigeria

Two indigenous hydrocarbon utilizing bacteria strains, designated as TKZ and QGR were isolated in oil rich Niger Delta of Nigeria. Determination of the nucleotide sequence of the gene encoding 16S rRNA allowed TKZ and QGR to be identified as Proteus vulgaris and Serratia marcescens. Hydrocarbon degradation potential of the strains was confirmed on hydrocarbon mineral salts medium (1 %, v/v) at 37 °C. Assessment of oil degradation capability of the isolates was monitored using gas chromatographic analysis (GC). The ability of the strains to utilize benzene, diesel, kerosene, and naphthalene was also studied. The results show maximal increase in optical densities at 540 nm and total viable counts was proportional with decrease in pH of the culture media. Percentage degradation in the culture medium showed that the two isolates exhibited biodegradation efficiency above 90 % for kerosene. The two bacterial strains also possess a plasmid of about 9.1 kb size which is suspected to influence the bacterium’s hydrocarbon degradation potential.

High flux durability underwater superoleophobic mesh modified by poly (maleic acid mono-(2-(dimethylamino)-ethyl ester-co-hydroxyethyl acrylate) and nanosilica particles hybrid

It is difficult to separate oil-polluted water mixtures, which has been considered a global problem. In this study, a simple dip-coating process was used to produce a stainless-steel mesh coated with poly (malaic acid mono-(2-(dimethylamino)-ethyl ester-co-hydroxyethyl acrylate)-tetraethyl orthosilicate-silica (P(MDME-co-HEA)-TEOS-SiO2). The membrane’s shape, chemical composition, separation capabilities, and mechanical properties were carefully examined. The membrane was extremely hydrophilic and extremely oil-phobic underwater due to its rough surface structure and hydrophilic chemical composition. For petroleum ether/water mixture, the separation flux of the membrane reached 224,600 l·m−2·h−1, with a 99.96% separation efficiency. The coated mesh also presented outstanding anti-oil fouling performance. Moreover, it exhibited excellent mechanical resistance and chemical stability.

2D Nano-Mica Sheets Assembled Membranes for High-Efficiency Oil/Water Separation.

Oil-polluted water has become one of the most important environmental concerns nowadays due to the increasing industrial oily wastewater and frequent oil spill accidents. Herein, a novel two-dimensional (2D) nano-mica sheets assembled composite membrane with underwater super-oleophobic properties was developed for effective oil/water separation. A 2D nano-mica sheet was synthesized by a facile solvent-assisted ultrasonic exfoliation and then the obtained 2D nano-mica sheets were co-deposited with dopamine on polyvinylidene fluoride substrate to prepare nano-mica composite membranes (NCM). The NCM is hydrophilic in air and super-oleophobic underwater (the water contact angle in the air is 37.6°, and the oil contact angle in water is 151.4°). Furthermore, the prepared NCM provided outstanding stability in different acid–base environments (pH = 1–11). Noteworthily, the oil removal rate is higher than 99.5% as the sodium dodecyl sulfate SDS-stabilized oil (soya-bean oil, mineral oil and pump oil) -in-water emulsions. Meanwhile, the NCM showed excellent reusability, as the oil removal efficiency kept at 99.0% after ten soya-bean oil-in-water or mineral oil-in-water emulsion filtration cycles. The present work paved a new way for developing a low-cost and environmentally friendly strategy for oily wastewater treatment and developed a high-increment utilization application field for natural minerals.

Effective separation of petroleum oil-water mixtures via flexible and re-usable hydrophobic soot-coated melamine sponge

Superhydrophobic materials like carbon-coated sponges have been attracting attention due to their wide applicability in several industries. One of the main applications of such materials is the efficient removal of various water pollutants such as oil by adsorption. Herein, a flexible, porous, and hydrophilic melamine sponge was coated by superhydrophobic soot that was produced by incomplete combustion of the propane-butane mixture. Characterization of the soot and the sponge was performed via several methods such as spectroscopy, microscopy, and thermogravimetry. The product was tested in the petroleum oil removal process. The superhydrophobic sponge repelled water well and at the same time perfectly sorbed oil products. The wetting edge angle of soot coated sponge was found between 145 and 150°. The sponge showed an excellent adsorption capacity of 24 g oil/g for the selective separation of oil from water. The entrapped oil was released simply by squeezing the sponge for cyclic use and about 95.5 wt% of the oil was adsorbed and the soot-coated sponge still maintained this capacity after 19 cycles. Hence, this novel soot-coated hydrophobic sponge is considered a promising candidate for oil-polluted water treatment.

Batch sorption of vegetable oil from simulated oil-polluted water onto Populus nigra leaf waste

Batch sorption of vegetable oil from simulated oil-polluted water onto Populus nigra leaf waste

Concentrations of polycyclic aromatic hydrocarbons (PAHs) in the African catfish (Clarias gariepinus) juveniles exposed to crude oil contaminated water

The concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) were investigated in the African catfish (Clarias gariepinus) juveniles exposed to crude oil using gas chromatography coupled with mass spectrometry. A total of 180 juvenile catfish of weight ranging from 7.5-8.3g (7.993 ±0.98g) and length 9.3-10.1cm (9.7 ± 0.72cm) were exposed to crude oil of varying concentrations 0.0% - 1.0% (labelled TA-TF, respectively) of crude oil for 480 h. The highest temperature value (25.25 °C) was recorded in the TF, while the highest level of dissolved oxygen was recorded in the TA (6.0 mg/l). pH values ranged from neutral (7.0) in the control to slightly alkaline (7.4 – 8.0) in the various treatment media. Significantly different (P<0.05) concentrations of PAHs were obtained with the highest level of PAHs (10.754 µg/kg) in fish from TF. The overall results showed that crude oil in the aquatic environment has negative effects on fish fauna. Fishes in oil-polluted water can accumulate PAHs in their flesh and organs; therefore, it is not advisable to consume fish from such a contaminated environment due to the high health risk associated. Regular investigation of oil-producing areas for environmental contaminants and prompt remediation of polluted areas by the authority are recommended.

Oil-polluted water purification via the carbon-nanotubes-doped organohydrogel platform

Oil-polluted water purification via the carbon-nanotubes-doped organohydrogel platform

Operational parameters optimization for remediation of crude oil-polluted water in floating treatment wetlands using response surface methodology

The application of floating treatment wetlands (FTWs) is an innovative nature-based solution for the remediation of polluted water. The rational improvement of water treatment via FTWs is typically based on multifactorial experiments which are labor-intensive and time-consuming. Here, we used the response surface methodology (RSM) for the optimization of FTW’s operational parameters for the remediation of water polluted by crude oil. The central composite design (CCD) of RSM was used to generate the experimental layout for testing the effect of the variables hydrocarbon, nutrient, and surfactant concentrations, aeration, and retention time on the hydrocarbon removal in 50 different FTW test systems planted with the common reed, Phragmites australis. The results from these FTW were used to formulate a mathematical model in which the computational data strongly correlated with the experimental results. The operational parameters were further optimized via modeling prediction plus experimental validation in test FTW systems. In the FTW with optimized parameters, there was a 95% attenuation of the hydrocarbon concentration, which was very close to the 98% attenuation predicted by the model. The cost-effectiveness ratio showed a reduction of the treatment cost up to $0.048/liter of wastewater. The approach showed that RSM is a useful strategy for designing FTW experiments and optimizing operational parameters.

Development and Validation of a Design Tool for an Improved Pitot-Tube Jet-Pump Allowing Continuous Fluid-Fluid Separation

Abstract A pitot-tube jet-pump (PTJ pump) has been considerably modified and extended in order to continuously separate and transport liquids of different densities. As a first application, an oil–water mixture is considered in this work. The modified PTJ pump could be used as a primary separator for oil-polluted water (e.g., around off-shore platforms, after oil spills from ships), while additionally being able to transport the resulting fluid to further heaters, exchangers, centrifuges, distillation columns, etc., without necessitating additional machinery. The performance behavior of the separating PTJ pump (abbreviated SPP in what follows) has been first investigated with computational fluid dynamics (CFD), and then validated by comparison with experimental data acquired on a small-scale prototype. Based on these observations, a design tool has been developed to (i) predict performance and (ii) support proper device scaling. This tool is based on dimensionless parameters that are already employed for classical turbomachinery, similar to the Cordier chart. However, since the SPP works at an extremely low specific speed, its operating points lie outside the standard Cordier chart. To verify the accuracy of the design tool, a scale-up test has been conducted and validated by CFD, delivering a good agreement. A separation efficiency better than 99% has been obtained in the experiments for suitable operation conditions, while the numerical scale-up test reveals a head of 15.1 m and an oil content below 0.2% in the purified water at the high-pressure outlet.

Superhydrophobic nanohybrid sponges for separation of oil/ water mixtures

The industrial revolution has led to different types of environmental pollution, including frequent leakage of crude oil to marine waters and the contamination of wastewater with immiscible or emulsified oils and organic liquids from various industrial residues. Hence, developing multifunctional materials for oil/water separation is a field of high significance for the remediation of oil-polluted water. Recently, advanced superwetting materials have been employed for oily wastewater treatment. This review summarizes the recent development in fabricating superhydrophobic/superoleophilic nanohybrid polyurethane, melamine, and cellulose sponges for oil/water separation. The use of organic and/or inorganic nanohybrid materials opens the horizon for designing a diverse and wide range of superhydrophobic sponges due to the synergistic effect between the surface roughness and chemical composition. The discussion is organized based on different classes of low surface energy materials including thermoplastics, thermosets, elastomers, fluorinated polymers, conductive polymers, organosilanes, long alkyl chain compounds, and hydrophobic carbon-based materials. Recent examples for the separation of both immiscible and emulsified oil/water mixtures are presented, with a focus on fabrication strategies, separation efficiency, recyclability, mechanical performance, and durability. Currently, most studies did not focus on the mechanical/chemical stability of the fabricated sponges, and hence, future research directions shall address the fabrication of robust and long-term durable superhydrophobic sponges with proper guidelines. Similarly, more research focus is required to design superhydrophobic sponges for the separation of emulsified oil/water mixtures and heavy crude oil samples. Superhydrophobic sponges can be employed for treatment of oily wastewater, emulsion separation, and cleanup of crude oil spills.

Hydrocarbon Biodegradation by Proteus and Serratia Strains Isolated from Oil-Polluted Water in Bonny Community, Niger Delta, Nigeria

Hydrocarbon Biodegradation by Proteus and Serratia Strains Isolated from Oil-Polluted Water in Bonny Community, Niger Delta, Nigeria