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The application of hollow fiber membranes is one of the excellent processes to treat oily wastewater and wetland water. Treating oily wastewater and wetland water is a significant challenge and reported expensive. These wastes generally come from due the expansion of massive industries and human activities these days. This review discusses the critical ways of membrane hollow fiber application in treating oily wastewater as well as wetland water. It is also reported in literature that there is mostly organic contaminant accommodated in oily wastewater and wetland water. Due to that, the application of hollow fiber is the best way as a removal organic contaminant in oily wastewater as well as wetland water. Apart from that, the conventional and advanced methods are also well explained within this review followed by detail treatments, application, and performance of this hollow fiber membrane application. To achieve the best completed outcome of pollutants removal, several applications relate to other processes before contacting to hollow fiber membranes. The integration between conventional and advanced membrane technology in oily wastewater and wetland treatment is also well explained. The important factors in the fabrication and application of hollow fiber membrane depend on membrane materials and filtration processes. It means that the selection between membrane materials and final processes to choose are depending on the urgency, source of pollutants, and intended use. [ABSTRACT FROM AUTHOR]

Copyright of Railway Standard Design is the property of Railway Standard Design 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.)

Moving bed bioreactor is a promising technology for removing a wide range of contaminants from both municipal and industrial wastewater. For process optimization, it is crucial to have a detailed design of a reactor involving the development of a model that can predict the outcome of the operation. The present study attempts to develop a simplistic mathematical model for substrate removal in biofilms considering Fick’s Law of diffusion to illustrate the simultaneous substrate transport and its utilization within the biofilm and the microbial kinetics as explained by Monod’s theory. The mathematical solution is derived using second order differential equation with relevant boundary conditions. To investigate the applicability of the model for substrates with moderate biodegradability, experimental studies are conducted using synthetic oily wastewater, where oil and grease (O&G) primarily contribute to chemical oxygen demand (COD). The ease of practical implications of the model without any sophisticated software and tools would make it an economically viable option for process design in MBBR in treatment plants. The model is developed using FORTRAN language, implying that the same can be developed in other advanced languages. Furthermore, the model is experimentally validated at different hydraulic retention times, initial O&G concentration and biofilm density using the data obtained from laboratory-scale studies of an MBBR treating synthetic oily wastewater. The results indicate that a maximum relative error of 7.14% occurs with respect to the data obtained from the experimental analysis, implying the applicability of the model for treating moderately degradable pollutants in MBBR. Moreover, the performance precision of the model is carried out based on Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and Coefficient of Determination (R2), where the respective values of 0.005, 0.004 and 0.97 suggest the accuracy of the model. Discussion regarding the limitations and subsequent areas for future research clearly highlights the potential for further development of process design model for MBBR treating wastewater with moderate biodegradability.Highlights: A simplistic mathematical model is derived for substrate utilization in MBBR The model is based on Monod’s kinetics and Fick’s second law of diffusion It predicts effluent substrate concentration, biofilm thickness and substrate flux Model can be executed in any language including FORTRAN to get relevant parameters Experimental validation shows results within 10% deviation of model predicted data [ABSTRACT FROM AUTHOR]

Introduction. The accumulation of oily wastewater in the environment is becoming an increasing threat to the ecosystem and human health. The modification of ultrafiltration PVDF membrane was investigated in order to create a hydrophilic layer on its surface, to improve performance and increase antifouling properties in the purification of oil-water emulsions.Materials and methods. PVDF hollow-fibre capillary membranes with 0.1 μm diameter pores were used. The membranes were subjected to two-step modification, which included treatment with tannic acid and subsequent oxidation with potassium permanganate in various buffer solutions. Motor oil, kerosene, distilled water and sodium dodecyl sulfate were used to create model water-in-oil emulsions. All oil-water emulsion separation experiments were performed while maintaining a constant filtration pressure of 1 bar on a prepared filter cell, in dead-end mode. The prepared model solutions were made with sodium dodecyl sulfate and contained the pollutant motor oil or kerosene. The filtrate after the membrane was sampled to determine the permeability and separation efficiency of the solutions. Surface modification had a positive effect on the retention efficiency of petroleum products. In the case of motor oil emulsion separation, the efficiency reached 99 %, and the content of oil products in all filtrate samples was below 0.4 mg/l. In the case of separation of kerosene emulsion there was observed a slight decrease in the efficiency of purification up to 95 %, the content of oil products was below 1.15 mg/l.Results. The results obtained showed a significant increase in throughput and separation efficiency. The specific membrane performance increased up to 143 % for motor oil separation and up to 67 % for kerosene separation.Conclusions. The modified membranes showed high petroleum product removal efficiency, up to 99 % for motor oil and up to 98 % for kerosene, also had high flux recovery rate (FRR) up to 91 %. The results obtained may be promising for scaling up.

Three-dimensional (3D) porous absorbents have attracted significant attention in the oily wastewater treatment technology due to their high porosity and elasticity. Given their amphiphilic surface, they have a propensity to simultaneously absorb water and oil, which restricts their range of applications. In this study, a reduced graphene oxide and titanium dioxide nanocomposite (rGO/TiO2) was used to fabricate an ultrahydrophobic melamine sponge (MS) through interfacial modification using a solution immersion technique. To further modify it, polydimethylsiloxane (PDMS) was grafted onto its surface to establish stronger covalent bonds with the composite. The water contact angle of the sponge (rGO/TiO2/PDMS/MS) was 164.2°, which satisfies the condition for ultrahydrophobicity. The evidence of its water repellency was demonstrated by the Cassie–Baxter theory and the lotus leaf effect. As a result of the increased density of rGO/TiO2/PDMS/MS, it recorded an initial capacity that was 2 g/g lower than the raw MS for crude oil absorption. The raw MS retained 53% of its initial absorption capacity after 20 cycles of absorption, while rGO/TiO2/PDMS/MS retained 97%, suggesting good recyclability. Excellent oil and organic solvent recovery (90%–96%) was demonstrated by rGO/TiO2/PDMS/MS in oil–water combinations. In a continuous separation system, it achieved a remarkable separation efficiency of 2.4 × 106 L/(m3·h), and in turbulent emulsion separation, it achieved a demulsification efficiency of 90%–91%. This study provides a practical substitute for massive oil spill cleaning.

AbstractThe widespread use of polymer flooding has resulted in a large number of produced liquids consisting of crude oil emulsions and oily wastewater. Efficient flocculants are required to treat these produced liquids till the oily wastewater satisfies the requirements for reinjection formation in order to maintain the regular manufacturing process. In this work, an unsaturated polyether macromonomer (PEP-30) was prepared by ring-opening polymerization using isobutenol as a starting material. Subsequently, a novel flocculant (PMAP) was obtained by copolymerization of dimethylamino propylmethacrylamide (DMAPMA) and PEP-30. For the produced liquids with different crude oil emulsion content, the oil removal rate of PMAP at a dosage of 150 mg/L was more than 75%, and the oil removal rate and versatility were better than those of conventional cationic flocculants. Furthermore, the findings of the flocculation mechanism investigation demonstrated that PMAP had a low interfacial elastic modulus and a large interfacial adsorption mass. Specifically, the optical tweezers were used to detect the interaction force between oil droplets. PMAP effectively strengthened the attraction between oil droplets, extending their duration in contact during flocculation and promoting their coalescence. [ABSTRACT FROM AUTHOR]

The study illustrated here aims on an organic solvent tolerant lipase from Staphylococcus capitis (SCL). The gene part, encoding the mature lipase, was cloned and sequenced. The concluded polypeptide sequence, equivalent to the protein, consist of 388 amino acid residues with a molecular mass of about 45 kDa. A structure-based alignment of the SCL amino acid sequence shows high identities with those many staphylococcal lipases. From this alignment of sequences, the catalytic triad (Ser 117, Asp 308 and His 347) of SCL could be identified. The mature part of the SCL was expressed in Escherichia coli and the recombinant lipase (r-SCL) was purified to homogeneity. The purified r-SCL presented a quite interesting stability at low temperatures (< 30 °C) and the enzyme was found to be highly stable in polar organic solvent and at a pH ranging from 3 to 12. After that, we have demonstrated that the recombinant enzyme may be implicated in the biodegradability of oily wastewater from effluents of fast-food restaurants; the maximum conversion yield into fatty acids obtained at 30 °C, was 65%. [ABSTRACT FROM AUTHOR]

While the petroleum industry plays a significant role in the global economy, it also produces a considerable amount of oily wastewater, posing environmental challenges. Petroleum wastewater contains diverse pollutants, including phenol, sulfide, ammonia, petroleum hydrocarbons, mercaptans, oil, and grease. Therefore, petroleum wastewater and oil-water emulsions are considered two of the main environmental pollutants. Various methods like gravity separation, sand filtration, chemical treatment, membrane filtration, biological treatment, advanced oxidation processes, and electrochemical treatment are employed to treat petroleum wastewater. Among the methods used to treat these contaminants, polymeric ultrafiltration membranes have attracted significant attention for reasons such as high separation efficiency, cost-effectiveness, and process simplicity. This research presents the results of experimental studies on treating petroleum wastewater using the ultrafiltration process. For the experiments, a handmade modified polysulfone membrane was used as the ultrafiltration membrane, and a sample of sour water produced from Mozdouran layer wells was used as the feed. The effect of operational conditions, including the applied pressure difference across the membrane and the feed temperature, on the permeate flux and pollutant removal efficiency, was investigated. The results indicate that increasing the effective pressure difference and temperature increases the permeate flux. At a constant temperature of 25 °C, increasing the pressure from 3 to 5 bar results in an increase in COD and turbidity removal by 29% to 40% and 55.31% to 74.41%, respectively, while the removal efficiency of electrical conductivity and TDS decreases from 29.45% to 21.3% and from 28.2% to 22.3%, respectively. Additionally, the removal efficiency of H2S decreases from 86% to 55%. [ABSTRACT FROM AUTHOR]

One of the most dangerous organic compounds to the environment is gasoline emulsions, discharged without prior treatment by most oil refining industries. This study focuses on the modification of bentonite clays by acid and thermal activation to maximize their adsorption capacity for treating refinery wastewater. The surface properties and porous structure of the adsorbents were investigated with the use of BET, SEM, FTIR, XRD, XRF, EDX, and MAP methods. Based on the results of BET analysis, the surface area of the raw bentonite (RB) and activated bentonite (AB) was (17.57, 69.72) m2 /g. The four independent variables, namely the initial gasoline concentration (200–1000 mg/L), solution pH (3−9), contact time (30–120 min), and adsorbent dosage (ranging from 0.05 to 0.15 g/L). According to the results, the maximal adsorption capacity (74.6.38, 138 mg/g) by RB and AB was achieved using the following optimized conditions: initial COD gasoline concentration of 1000 mg/L, pH= 6 for RB and pH= 3 for AB, contact time 120 min, and adsorbent dosage 0.15 g for RB and AB. Additionally, the kinetic and equilibrium studies demonstrated that the present adsorption process's kinetics and equilibrium behavior were adequately represented by the pseudo second-order kinetic model and the Langmuir isotherm. The data by Langmuir isotherm showed that the maximum adsorption capacity for RB and AB was equal to 83 and 140.84 mg/g, respectively. Furthermore, thermodynamic studies demonstrated that the present adsorption procedures were both spontaneous and endothermic. The mechanism of gasoline adsorption onto RB and AB was effectively investigated with the assistance of characterization techniques. The current study demonstrates that RB and AB can be utilized as adsorbents for the elimination of gasoline with high efficiency. [ABSTRACT FROM AUTHOR]

In the present study, oily wastewater generated during car washing was separated using ultrafiltration (UF). Wastewater was collected from the settling tank of two manual car washes. In addition to pollutants removed from cars, such wastewater contains surfactants, the impact of which on the process of ultrafiltration has been analyzed. For this purpose, the application of commercial UF polyethersulfone (PES) membranes (10 and 100 kDa) and polyvinylidene fluoride (PVDF) tubular membranes (100 kDa) was comprehensively examined. Almost 100% removal of oil contaminants was achieved; however, intensive fouling was noticed. The membrane morphology and deposit composition were studied using a scanning electron microscope coupled with energy dispersion spectrometry. The fouling phenomenon was reduced by washing the membranes with an alkaline cleaning agent (pH = 11.5), which is used in car washes to remove insects. The filtration/membrane washing cycle was repeated many times to achieve stable operation of the membrane modules. The UF process was carried out for 120–140 h, and the separation efficiency was analyzed based on the rejection of dextrans, COD, BOD, total N and P, turbidity, and anionic surfactants. It has been found that cyclic repeated washing did not deteriorate the membrane's performance, and a permeate with a turbidity of 0.12–0.35 NTU was obtained. Thus, cleaning agents used for washing cars can also be used for membrane cleaning. [ABSTRACT FROM AUTHOR]

Copyright of Technology of Water Treatment is the property of Technology of Water Treatment 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.)

Electrochemical wastewater treatment technologies are increasingly being used in practice, and the combination of electrocoagulation with advanced oxidation processes has been shown to increase treatment efficiency. The treatment of oily wastewater produces electrocoagulated metal sludge (EMS). In this work, the possibility of using different ratios of EMS produced during oily wastewater treatment was investigated. EMS was dried conventionally in an oven at 105 °C and used as a partial substitute for clay in the manufacture of laboratory bricks. The main research objectives of this study were to examine the possibility and justification of introducing EMS in brick production. The results show that an increase in the proportion of EMS in the manufacturing of bricks leads to a deterioration in the quality of the bricks. Bricks with an addition of 1 wt% and 5 wt% EMS showed the best properties. The loss on ignition (LOI), compressive strength, boiling water absorption and initial water absorption were determined at 5.7%; 49 N/mm2, 16%, 14 g/min/200 cm2, 15% for modified bricks with 1 wt% EMS and 6.3%, 48 N/mm2, 20%, 15 g/min/200 cm2 for modified brick with 5 wt%. [ABSTRACT FROM AUTHOR]

Oily wastewater is one of the most hazardous contaminants that can hurt the ecosystem. There is an urgent need to adopt an efficient, eco-friendly, and low-cost material to replace the old traditional treatment methods of oily wastewater that were very expensive in addition to their relatively low efficiency. Eucalyptus bark is considered one of the materials that are rarely used in this field, although it has the characteristics that qualify it to be a distinguished and promising one. The optimum conditions of using Eucalyptus globulus Labill. (Blue gum) bark in the removal of oil from prepared aqueous solutions were concluded before applying in the treatment of real oily industrial wastewater from New Borg El-Arab City, Egypt. The sequential optimization adsorption results were as follows: initial oil concentration, 500 mg/l; adsorbent dosage, 0.5 g/l; pH, 3; exposure time, 45 min; temperature, 20 °C; and shaking rate, 300 rpm. The pretreatment of biomass with H3PO4 proved it to be superior in the oil removal process where the efficacy reached 450.69 mg/g, while the unmodified form came second where the adsorption efficacy reached 395.86 mg/g, after that the NaOH-modified form came third by efficacy reached 315.85 mg/g. The results of SEM elucidated this order of efficacy according to the porosity of the bark surface. FTIR analysis indicated that OH, carboxylic C = O, and carboxylic C-O groups are the contributing groups in the oil adsorption process for the three forms of Eucalyptus bark. The reusability of Eucalyptus bark using n-hexane for one cycle reached 96.34, 97.13, and 95.83% for unmodified, H-modified, and OH-modified forms, respectively, and for five cycles reached 56.29, 58.01, and 55.81% for unmodified, H-modified, and OH-modified forms, respectively. The application of Eucalyptus bark in the H-form in the treatment of real oily wastewater was achieved by efficacy ranging between 91.46 and 96.23% which proves the excellence of Eucalyptus bark in the treatment of oily wastewater. [ABSTRACT FROM AUTHOR]

Oil-contaminated water from oil and gas exploration remains the industry’s primary waste stream. The common method of using chemical coagulation/flocculation followed by air flotation has drawbacks such as generating non-biodegradable and toxic sludge and high operational costs. This study presents an eco-friendly alternative utilizing chitosan and beach sand to remove emulsified oil from water. Chitosan acts as a biodegradable flocculant, while beach sand aids in high-density floc formation and accelerates settling velocity. This approach achieved up to 94 % oil removal efficiency and reduced settling time from 90 to 15 min by using 100 mg/L chitosan and 500 mg/L beach sand with a particle size distribution of 50–100 μm. Shorter settling time reduces capital expenditure compared to conventional methods. Additionally, using natural materials like chitosan and beach sand minimizes toxic sludge generation. This eco-friendly approach offers a promising alternative to conventional methods for treating oily wastewater.

The low energy consumption and efficient treatment of oily wastewater using microbubble flotation technology is a current research hotspot. A low-energy microbubble jet flotation system for treating oily wastewater was established using an effervescent atomizer as a microbubble generator. The effects of air-liquid mass flow ratio(ALR) and working pressure (p) on the size distribution characteristics of microbubbles and de-oiling capacity were discussed, and the energy consumption of effervescent atomizer was analyzed. The experimental results showed that a large number of microbubbles could be generated by using the effervescent atomizer to organize submerged jet, the number of microbubbles with diameters less than 150 μm accounted for more than 55%, and the number of microbubbles with diameters less than 600 μm accounted for more than 98%. The number of microbubbles increased first and then decreased with the increase of ALR, and the optimum ALR was 0.15. When p was 0.2 MPa and ALR was 0.15, the Sauter mean diameter of microbubbles could be as low as 238 μm, the oil concentration in wastewater was 29.73 mg/L, the power consumed by the microbubble jet flotation was only 6.53×10-4 kW·h per kilogram of wastewater , which was more than 35% lower than dissolved air flotation.

With the increasing moisture content of oil and gas in the main block and the further development of unconventional oil and gas resources，the amount of wastewater associated with oil and gas exploitation is increasing. Due to the continuous evolution of oil and gas extraction technology，wastewater quality exhibits characteristics of high oil content and strong emulsification stability，high suspended solids content and reduced suspended solids density. The removal of emulsified oil，dispersed oil and light suspended solids has become a key step in the treatment of oily wastewater. In this paper，the principles and influencing factors of coagulation and air flotation for oil removal were summarized. The research status of coagulation and air flotation systems were reviewed，including research progress on the generation of air flotation bubbles，the structure of air flotation tanks，and the coupling process of air flotation. On this basis，combining the swirl field with the eddy current field，and strengthening the degumming and coalescence separation efficiency of the composite functional pharmaceutical system in the eddy current field was proposed. The development and application of the coagulation air flotation reaction system integrating oxidation，degumming，flocculation，air flotation and separation would be the development trend of oil and gas field wastewater treatment in the future.

Effluent wastewater from industrial processes needs to be properly treated before being discharged into the environment. Conventional procedures for handling this wastewater can be problematic due to the presence of toxic elements, time constraints, and complexity. However, a new electrochemical procedure has been developed as an effective method for remediation. In a recent study, refinery wastewater was successfully treated using an electrochemical technique combined with ultrasonic irradiation and photocatalysis. The study found that electrocoagulation, which uses cheap and recyclable metal electrodes, was a simple, efficient, practical, and cost-effective way to handle refinery wastewater. Various parameters were investigated, including electrode metals, operating time, applied voltage, pH, inter-electrode gap, and temperature. The aim was to determine the optimal configuration for pollutant removal. The study also focused on the synergistic effects of combining electrocoagulation and photocatalysis to improve the efficiency of contaminant removal in oily wastewater. By integrating these two treatment technologies, the researchers aimed to enhance pollutant removal rates, energy efficiency, and overall system performance. The research provided valuable insights into the feasibility, optimization parameters, and applicability of the electrocoagulation-photocatalysis process for remediating organic contaminants in oily wastewater industrial effluents. The results showed that electrocoagulation, especially when combined with ultrasonic irradiation and TiO2 photocatalysis, was highly effective in pollutant removal within a short timeframe. These findings support the implementation of this procedure for remediating most industrial wastewater.In conclusion, the study contributes to the development of more effective and sustainable water treatment strategies. The electrocoagulation-photocatalysis process shows promise in addressing the remediation of organic contaminants in oily wastewater from industrial processes.

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

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute 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.)

Effluent wastewater from industrial processes needs to be properly treated before being discharged into the environment. Conventional procedures for handling this wastewater can be problematic due to the presence of toxic elements, time constraints, and complexity. However, a new electrochemical procedure has been developed as an effective method for remediation. In a recent study, refinery wastewater was successfully treated using an electrochemical technique combined with ultrasonic irradiation and photocatalysis. The study found that electrocoagulation, which uses cheap and recyclable metal electrodes, was a simple, efficient, practical, and cost-effective way to handle refinery wastewater. Various parameters were investigated, including electrode metals, operating time, applied voltage, pH, inter-electrode gap, and temperature. The aim was to determine the optimal configuration for pollutant removal. The study also focused on the synergistic effects of combining electrocoagulation and photocatalysis to improve the efficiency of contaminant removal in oily wastewater. By integrating these two treatment technologies, the researchers aimed to enhance pollutant removal rates, energy efficiency, and overall system performance. The research provided valuable insights into the feasibility, optimization parameters, and applicability of the electrocoagulation-photocatalysis process for remediating organic contaminants in oily wastewater industrial effluents. The results showed that electrocoagulation, especially when combined with ultrasonic irradiation and TiO2 photocatalysis, was highly effective in pollutant removal within a short timeframe. These findings support the implementation of this procedure for remediating most industrial wastewater.In conclusion, the study contributes to the development of more effective and sustainable water treatment strategies. The electrocoagulation-photocatalysis process shows promise in addressing the remediation of organic contaminants in oily wastewater from industrial processes. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute 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.)

Oily wastewater has been causing serious water environment pollution and greatly affecting the safety of drinking water. Compared with superwettable oil‐water separation membrane technology, solar‐driven evaporators based on specific wettability can effectively remove not only oil but also ions, dyes, and other substances from wastewater. We report a longitudinally cut, porous, and wood‐based evaporator that exhibits superhydrophilic and underwater superoleophobic properties. By collaborating hydrophilic and oleophobic wettability, high porosity and the structural anisotropy of wood, the solar evaporators effectively remove different oils from oily emulsions. Separation efficiency of surfactant‐containing crude oil‐in‐water, peanut oil‐in‐water, silicone oil‐in‐water, diesel oil‐in‐water, and n‐dodecane‐in‐water emulsions can reach up to 99.57%, 99.1%, 99.86%, 99.75%, and 99.28%, respectively. The rate of evaporation increased by 1.83 times to 1.63 kg m−2 h−1 compared with the radially‐cut wood‐based evaporator. Meanwhile, it is also capable of purifying heavy metal ions, dyes, and acid‐base solution. This easily prepared and accessible solar evaporator provides a viable idea for obtaining pure water from oily wastewater treatment. [ABSTRACT FROM AUTHOR]

Copyright of Energy Chemical Industry is the property of Energy Chemical Industry 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.)

Oily wastewater from ocean oil spills endangers marine ecosystems and human health. Therefore, developing an effective and sustainable solution for separating oil-water mixtures is urgent. Interfacial solar photothermal evaporation is a promising approach for the complete separation of two-phase mixtures using only solar energy. Herein, we report a carbonized wood-based absorber with Janus structure of comprising a hydrophobic top-layer and an oleophobic bottom-layer for simultaneous solar-driven oil-water separation and electricity generation. Under sunlight irradiation, the rapid evaporation of seawater will induce a separation of oil-water mixtures, and cause a high salt concentration region underlying the interface, while the bottom "bulk water" maintains in a low salt concentration, thus forming a salinity gradient. Electricity can be generated by salinity gradient power. Therefore, oil-water separation efficiency of > 99% and derived extra electricity power of ∼0.1 W/m2 is achieved under solar radiation, demonstrating the feasibility of oil-water separation and electricity production synchronously directly using solar energy. This work provides a green and cost-effective path for the separation of oil-water mixtures. [ABSTRACT FROM AUTHOR]

This comprehensive study looks at how operational conditions affect the performance of a novel seven-channel titania ceramic ultrafiltration membrane for the treatment of produced water. A full factorial design experiment (23) was conducted to study the effect of the cross-flow operating factors on the membrane permeate flux decline and the overall permeate volume. Eleven experimental runs were performed for three important process operating variables: transmembrane pressure (TMP), crossflow velocity (CFV), and filtration time (FT). Steady final membrane fluxes and permeate volumes were recorded for each experimental run. Under the optimized conditions (1.5 bar, 1 m/s, and 2 h), the membrane performance index demonstrated an oil rejection rate of 99%, a flux of 297 L/m2·h (LMH), a 38% overall initial flux decline, and a total permeate volume of 8.14 L. The regression models used for the steady-state membrane permeate flux decline and overall permeate volume led to the highest goodness of fit to the experimental data with a correlation coefficient of 0.999. A Multiple Linear Regression method and an Artificial Neural Network approach were also employed to model the experimental membrane permeate flux decline and analyze the impact of the operating conditions on membrane performance. The predictions of the Gaussian regression and the Levenberg–Marquardt backpropagation method were validated with a determination coefficient of 99% and a Mean Square Error of 0.07.

A significant waste (e.g., high oil content and pollutants such as heavy metals, dyes, and microbial contaminants) in water is generated during crude oil extraction and industrial processes, which poses environmental challenges. This study explores the potential of Ag@Fe3O4 nanocomposite (NC) biosynthesized using the aqueous leaf extract of Laurus nobilis for the treatment of oily wastewater. The NC was characterized using ultraviolet–visible (UV–Vis) spectrophotometry, Scanning Electron Microscopy (SEM), Fourier Transformed Infrared (FTIR) and X-Ray Diffraction (XRD) spectroscopies. The crystalline structure of the NC was determined to be face-centered cubic with an average size of 42 nm. Ag@Fe3O4 NC exhibited significant degradation (96.8%, 90.1%, and 93.8%) of Rose Bengal (RB), Methylene Blue (MB), and Toluidine Blue (TB), respectively, through a reduction reaction lasting 120 min at a dye concentration of 10 mg/L. The observed reaction kinetics followed a pseudo-first-order model, with rate constants (k-values) of 0.0284 min−1, 0.0189 min−1, and 0.0212 min−1 for RB, MB, and TB, respectively. The fast degradation rate can be attributed to the low band gap (1.9 eV) of Ag@Fe3O4 NC. The NC elicited an impressive effectiveness (99–100%, 98.0%, and 91.8% within 30 min) in removing, under sunlight irradiation, several heavy metals, total petroleum hydrocarbons (TPH), and total suspended solids (TSS) from the oily water samples. Furthermore, Ag@Fe3O4 NC displayed potent antibacterial properties and a good biocompatibility. These findings contribute to the development of efficient and cost-effective methods for wastewater treatment and environmental remediation. [ABSTRACT FROM AUTHOR]

A low-cost ceramic membrane was evaluated, on a bench scale, in the oil/water emulsion separation process. The ceramic membrane was produced by dry uniaxial compaction and characterized by XRD, porosity and permeation measurements. The membrane contains a composition of 95.00% clay, 5.00% corn starch and a sintering temperature of 650 °C. The initial emulsion concentrations were 500, 800 and 1000 mg/L, pressure 0.5, 1.0, 1.5, 2.0, 2.5 bar, 25 °C. The oil/water emulsion separation efficiency, permeate flux were measured at different transmembrane pressures and oil-in-water concentrations in oil emulsion, the results showed that 99.91% oil-in-water emulsion separation efficiency was maintained for a range of pressures. transmembrane and oil concentration. The highest permeate flow rate and separation efficiency (%) was 452 L/m².h and 99.91%, respectively at 2 bar using oil-in-water emulsions. However, the water flux decreased with the reduction of the transmembrane pressure, increase of the oil concentration and with the use of the membrane. The use of low-cost ceramic membranes was very promising, since it is a membrane produced with alternative raw material of natural origin, using low sintering temperature and cost-effectiveness, disfavoring ceramic membranes produced from metallic oxides, which are relatively expensive, requiring a large amount of energy in production. [ABSTRACT FROM AUTHOR]

The treatment of cooking oil wastewater is an urgent issue need to be solved. We aimed to screen for efficient oil-degrading bacteria and develop a new microbial agent for degrading waste cooking oil in oily wastewater. Three extremely effective oil-degrading bacteria, known as YZQ-1, YZQ-3, and YZQ-4, were found by the enrichment and acclimation of samples from various sources and separation using oil degradation plates. The 16S rRNA sequencing analysis and phylogenetic tree construction showed that the three strains were Bacillus tropicus, Pseudomonas multiresinivorans, and Raoultella terrigena. Under optimal degradation conditions, the maximal degradation rates were 67.30 ± 3.69%, 89.65 ± 1.08%, and 79.60 ± 5.30%, respectively, for YZQ-1, YZQ-3, and YZQ-4. Lipase activity was highest for YZQ-3, reaching 94.82 ± 12.89 U/L. The best bacterial alliance was obtained by adding equal numbers of microbial cells from the three strains. Moreover, when this bacterial alliance was applied to oily wastewater, the degradation rate of waste cooking oil was 61.13 ± 7.30% (3.67% ± 2.13% in the control group), and COD removal was 62.4% ± 5.65% (55.60% ± 0.71% in the control group) in 72 h. Microbial community analysis results showed YZQ-1 and YZQ-3 were adaptable to wastewater and could coexist with local bacteria, whereas YZQ-4 could not survive in wastewater. Therefore, the combination of YZQ-1 and YZQ-3 can efficiently degrade oil and shows great potential for oily wastewater treatment. [ABSTRACT FROM AUTHOR]

Oily wastewater poses a significant environmental concern as it has adverse effects on both ecosystems and human health. The development of highly efficient and robust antifouling membranes for oily emulsion is in great demand to prevent these serious issues in oil/water emulsion filtration. Moreover, fouling was inevitable when dealing with membrane separation. In order to overcome the addressed matters, this paper reported sprayed hydrophilic surface coating using commercialized levodopa (L -DOPA). The coated solution was mixed with 3-amino-propyltriethoxysilane in various ratios to obtain a smooth coated layer. Based on the results, the highest pure water flux and rejection efficiency of 586.51 ± 23.95 L/m2‧h and 98.22% was achieved in this study, respectively. The abundant hydroxyl and carboxyl functional groups on the membrane surface from L -DOPA benefit the membrane in many ways, especially the membrane wetting properties. The water and oil contact angles of the coated membrane increased by approximately 75% and 85%, respectively. The fouling behaviors are influenced by the presence of the coated layer, resulting in the attainment of 90% fouling resistance ratio (FRR). This is mostly due to the reduction in adherence of oil droplets on the membrane surface, hence enhancing the effectiveness of the anti-oil fouling membrane. Additionally, this provides excellent properties of the membrane to be applied in oily wastewater treatment. [Display omitted] • The MMM was coated using a solution of L -DOPA/APTES at the optimal ratio. • The presence of L -DOPA improved membrane hydrophilicity and oleophobicity. • Spray coated layer concealed rough surface of the nanocomposite membrane. • Spray coated membrane are effective in separating oil emulsions and minimizing oil fouling. [ABSTRACT FROM AUTHOR]

In this study, oily wastewater (OW) from soybean oil processing plant was subjected to iron electrocoagulation (Fe-EC) to evaluate the method's effectiveness at chemical oxygen demand (COD) removal. Experiments were conducted in a batch-operated electrochemical cell with a pair of cylindrical iron electrodes, placed 3 cm apart and connected in a monopolar configuration. The effects of operating parameters, initial pH (4, 7, and 9) and applied current (0.1, 0.2, and 0.4 A) were studied, and the statistical significance of the parameters and their interaction were assessed using ANOVA. The results showed that an initial pH of 9 and current of 0.4 A favoured the highest COD removals (91.76% and 91.31%, respectively) from OW, and both parameters were statistically significant to COD removal based on a linear regression model without interaction. The findings of this study have demonstrated that Fe-EC is technically capable of removing over 85% of COD from OW produced from soybean oil processing and the technique can be used as an alternative treatment method for high COD wastewater. Further work is required to assess the technique's economic feasibility within the Jamaican context. [ABSTRACT FROM AUTHOR]

In this work, novel sandwich-type asymmetric ceramic microfiltration membranes with a sea urchin-like mullite whisker skeleton were prepared one step. Their structural properties and oil-water separation performance were investigated. The results show that after sintering at 1400 °C, the prepared membrane possesses good hydrophilic, underwater oleophobic, and anti-fouling properties. During the continuous separation of a 300 mg/L oil-in-water emulsion, a maximum stable flux of 267 L·m−2·h−1 was achieved without membrane cleaning. After chemical cleaning and simple physical cleaning, the membranes recovered to a steady flux of 397 L·m−2·h−1 and 305 L·m−2·h−1, respectively, and maintained a 95% oil rejection. The good underwater oleophobicity and selective permeability brought about by the flat-lying whiskers on the top surface, coupled with the efficient water channels between the sea urchin-like structures inside the membrane, are considered to be the main reasons for its improved separation characteristics over conventional low-cost ceramic membranes. [ABSTRACT FROM AUTHOR]

Most industries depend mainly on oil and oil-based processes, which resulted in producing large volumes of oily wastewater. One of the most common methods used for the treatment of oily contaminated water is filtration by modified surfaces. In this research g-C3N4 nanostructured material was prepared via thermal condensation method. The samples were characterized by advanced techniques such as XRD, XPS, FTIR scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectrophotometry (EDX). The result showed that g-C3N4 were crystallized in tri-s-triazine phases and their mean crystalline sizes of these nanostructures were 12.17 nm. The high-magnification microscopy images show that the morphology of g-C3N4 was nanosheet. A stainless-steel mesh was modified and coated with the prepared g-C3N4 nanostructured materials to be used for the separation of oil and water mixture. Due to the hydro-phobic nature of the modified meshes, oil drops spread over the mesh surface and the water drops form spherical shapes. The most efficient coating among all the modified meshes was g-C3N4, which was functionalized using silane moiety. The separation efficiency of this coated mesh reached 74.87% and it resulted in fast separation. This mesh can separate different types of oil from the oil/water mixture, such as toluene, mineral oil, 2-ethyl-1-hexanol, and n-pentane with good efficiency. Separation was repeated up to 40 times using the same mesh, and the separation efficiency was measured each time. [ABSTRACT FROM AUTHOR]

Abstract Membrane filtration exhibit operational limitations such as biofouling, which leads to concentration polarization and reduces permeability and selectivity, despite advantages such as low operating cost, high selectivity, and permeability. In recent years, the antibacterial properties of silver nanoparticles (AgNPs) have been investigated for improving membrane processes; however, the fouling phenomena in presence of AgNPs in the membrane matrix have not been fully discussed. Herein, the antifouling properties of a poly (acrylonitrile-styrene) copolymer incorporated with AgNPs were studied in a microfiltration membrane process. The Creighton method was used to synthesize AgNPs, and the effects of AgNPs on the porosity, morphology, pore size, mechanical strength, permeability, and selectivity of the membranes were investigated. Moreover, to investigate the biofouling of the obtained membranes, microfiltration of industrial oily wastewater was performed at constant pressure over three cycles. Using AgNPs in the membrane matrix resulted in enhanced antifouling properties of the copolymer membrane, which is related to the structure of the AgNPs in the casting solution, as proven by SAXS analysis. The results show that the CFU% for Staphylococcus aureus and E.coli reach 2% and 6%, respectively. Finally, the Derjaguin–Landau–Verwey–Overbeek (DLVO) thermodynamic model was applied to study the antifouling mechanism, correctly predict the separation behavior in the membrane, and design, simulate, and optimize the separation processes in the membrane separation plantsa. The DLVO model could predict the separation behavior in the synthesized membranes, and the poly(acrylonitrile-styrene) copolymer membranes containing AgNPs were proven have promising industrial wastewater treatment applications.

In the present study, oily wastewater generated during car washing was separated using ultrafiltration (UF). Wastewater was collected from the settling tank of two manual car washes. In addition to pollutants removed from cars, such wastewater contains surfactants, the impact of which on the process of ultrafiltration has been analyzed. For this purpose, the application of commercial UF polyethersulfone (PES) membranes (10 and 100 kDa) and polyvinylidene fluoride (PVDF) tubular membranes (100 kDa) was comprehensively examined. Almost 100% removal of oil contaminants was achieved; however, intensive fouling was noticed. The membrane morphology and deposit composition were studied using a scanning electron microscope coupled with energy dispersion spectrometry. The fouling phenomenon was reduced by washing the membranes with an alkaline cleaning agent (pH = 11.5), which is used in car washes to remove insects. The filtration/membrane washing cycle was repeated many times to achieve stable operation of the membrane modules. The UF process was carried out for 120–140 h, and the separation efficiency was analyzed based on the rejection of dextrans, COD, BOD, total N and P, turbidity, and anionic surfactants. It has been found that cyclic repeated washing did not deteriorate the membrane’s performance, and a permeate with a turbidity of 0.12–0.35 NTU was obtained. Thus, cleaning agents used for washing cars can also be used for membrane cleaning.

Abstract The water pollution problem caused by large‐scale industrial activity is becoming increasingly serious, which not only poses a major threat to the ecosystem and human health but also seriously impedes the green and sustainable development of modern society. It is urgent to efficiently purify stubborn wastewater containing oils and other pollutants to eliminate their harm to human and environment. Therefore, it is desirable to develop multifunctional materials that can simultaneously remove oil and various pollutants or microorganisms by filtration or absorption methods to meet the practical demand for highly effective purification of wastewater with complex components. This paper summarizes the latest research progress on the “oil removal” and “water removal” materials capable of purifying complex oily wastewater and their applications in adsorption, photocatalytic degradation, antibacterial, magnetic recovery, and others. The producing routes of multifunctional materials by constructing variable wettability surfaces and introducing functional components were summarized, and the mechanism of multifunctional materials in removing oil and various pollutants was discussed. On the basis of summarizing the types, compositions, and conventional separation technologies of oil‐bearing wastewater, the preparation methods and applications of the widely concerned convertible materials with complex wettability are also introduced, and the challenges and future development trends of efficient multifunctional oil–water separation and pollutant purification materials are proposed. It is expected to provide a reference for the development of more high‐performance multifunctional purification materials.

Oily wastewater presents a significant challenge that requires attention from the scientific community to not only treat it but also transform it into a valuable resource. Membrane-based separation techniques offer several advantages for treating oily wastewater, particularly in terms of ease of operation and lower energy requirements. The present research was aimed to develop polymeric-inorganic composite mixed matrix membranes (MMMs) for the treatment of surfactant stabilized oil-in-water (O/W) emulsions. These composite MMMs were fabricated using a non-solvent induced phase separation (NIPS) method, with polyvinyl alcohol (PVA)/glutaraldehyde (GA) serving as the matrix polymer and silicon carbide (SiC) nanoparticles incorporated into the matrix on a Nylon support. The concentrations of PVA (4, 10, and 12 wt%) and SiC nanoparticles (0, 0.1, 0.5, 1, 5, and 10 wt% relative to PVA) were varied for fabricating MMMs. In addition, other factors such as crosslinking times (10, 30, 60, and 240 min), and method of phase inversion (dry and wet) were also studied to yield the best-performing MMMs for O/W separation. The SiC content in the MMMs was found to have a significant impact on the physical characteristics of the membranes, such as surface morphology and porosity, which ultimately influenced the membrane performance. Hence, out of the six membranes tested for O/W separation, the M0.5 membrane containing 0.5 wt% SiC demonstrated high rejection (85 %) of total organic carbon (TOC) and a flux of 569.3 LMH when utilizing 100 ppm diesel O/W emulsion as the feed at 4 bar. This study underscores the potential of SiC MMMs for water treatment applications, while also emphasizing the need for further research to optimize their performance and resistance to fouling.

This study explains the mechanical design of a mixer with a focus on the fluid forces generated by the fluid continuum in the mixing reactor on the impellers. The research demonstrates that the forces are caused by transient asymmetries in fluid flow that act on the mixing impeller. The mixer shaft and gear reducer receive these dynamic loads from the impeller blades. A general equation for the fluid force behavior can be developed. The research also stresses on the significance of the mechanical interaction of the mixing process with the mixing vessel and impeller. Four parameters were measured; impeller speed for coagulation and flocculation, mixing time for coagulation, and flocculation. The experimental results in the final section will explain that impellers with four blades provide higher oil removal than impellers with two blades in oily wastewater treatment.

In this research, single and multi-bed adsorption columns for oily wastewater treatment were investigated both experimentally and numerically. For this purpose, two mineral adsorbents, namely natural zeolite and calcined bentonite, were used. The adsorbent characteristics were analyzed by XRD, BET, and SEM. Adsorption isotherm and single fixed-bed adsorption column performance for both adsorbents were experimentally assessed at different concentrations. In addition, single- and multi-fixed-bed column applicability with two different configurations, series and parallel connections, were simulated. The experimental results showed that Freundlich and Langmuir isotherms had the best performance to describe the adsorption of calcined bentonite and natural zeolite, respectively. Moreover, natural zeolite has better performance for oily wastewater treatment than calcined bentonite. The maximum capacity of calcined bentonite and natural zeolite was obtained at 3.06 mg/g and 5.37 mg/g, respectively. The simulation results indicated that the maximum separation yields of single fixed-bed, multi-fixed-bed with series connections, and multi-fixed-bed with parallel connections were 39.3%, 99.98% and 74.58%, respectively. Adsorbent mass optimization indicated that the required adsorbent mass decreased by 33.1% when four beds were presented in an operation instead of a single bed. This research recommends a promising application of natural zeolite as an economic adsorbent in multi-bed adsorbers for oily wastewater treatment.

BACKGROUND: Photocatalysts with Z‐type heterojunction structures for organic pollutant removal are prospective in environmental advanced oxidation processes. Introducing single metal atom to the heterojunction can further improve the synergistic activity of photocatalysts, so we doped Co single metal atom in g‐C3N4/Bi2WO6 Z‐type heterojunction. RESULTS: For this aim, a simple calcination and hydrothermal method was used to dope single atom Co on top of the Z‐type 10 wt% g‐C3N4/Bi2WO6 heterojunctions which we had tested previously. The optimal Co doping was determined at 0.2 wt% Co/10 wt% g‐C3N4‐Bi2WO6, that it most efficiently degraded (100 mg/L) RhB under visible light irradiation (99.7% in 30 min, kinetic rate constant 0.182 min −1). This single‐atom doped catalysts (Co/g‐C3N4/Bi2WO6) should be most favorably used in treating practical wastewater in EC (electro‐chemical)‐MFC (microbial fuel cell) system. Its remarkable performance was recorded (96% COD removal and 92.8% TOC removal). CONCLUSION: The reactive oxidizing species include h+, 1O2, ·O2−, e−, and OH, they act together leading to the rapid degradation of pollutants. The developed Co‐doped ternary catalyst has promising application prospects in pollution control in real world wastewater treatment. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study aims to improve polycarbonate (PC) membrane properties by incorporation of various amounts of polydopamine-modified titanium oxide (TiO2-PDA) nanoparticles (0.5–1.5 wt%). Neat PC and composite membranes fabricated were evaluated by a submerged membrane system for the removal of oily wastewater. The results observed from Fourier transform infrared spectroscopy and X-ray diffraction analysis demonstrated PDA immobilization on the surfaces of TiO2 nanoparticles. Moreover, the PC nanocomposite membranes fabricated were characterized using thermogravimetric analysis (TGA), field emission scanning electron microscopy, atomic force microscopy, contact angle, porosity measurement, mechanical analysis and pure water flux. TGA analyses indicated that the degradation temperature of neat PC membrane was increased influenced by the incorporation of TiO2-PDA nanoparticles in the polymer matrix. The addition of TiO2-PDA nanoparticles led to increase in hydrophilicity and porosity of neat PC membranes. Incorporation of TiO2-PDA nanoparticles resulted in forming large pores and macrovoids on the surface and cross-section of the composite membranes. The tensile strength was lessened up to 43% by adding 1.5 wt% TiO2-PDA nanoparticles. Among the samples, PC/TiO2-PDA-1 nanocomposite membranes revealed higher FRR (76.3%) and lower IFR (23%) with a total organic carbon content of 62.6 mgL−1. [ABSTRACT FROM AUTHOR]

The methanol-to-olefins (MTO) process is regarded as a crucial approach for ensuring the sustainable growth of China's chemical industry. However, the fine catalyst particles and insoluble organics in the water system poses a serious threat to the stability of the MTO process. A novel horizontal swirl regeneration micro-channel separation (HSRMS) method for purifying the MTO reaction wastewater was developed in this study. On-site experiments were conducted using a device with a capacity of 1 t/h to investigate the separation and regeneration effects under various parameters and to verify the feasibility of this method through a long-term observation. The results showed that this method could effectively remove the fine solids and insoluble organics in the reaction wastewater, and the device operated stably with fluctuations in both the quality and quantity of wastewater for 24 consecutive days. The suspended solids in the effluent was maintained below 5 mg/L, and the average removal efficiency for insoluble organics exceeded 75%. Furthermore, the excellent regeneration performance was achieved, with solid particles and oil in the media reduced to less than 0.2% after regeneration. This method could ensure long-term stable operation of the water system and outperform other commonly used reaction wastewater treatment methods in terms of investment, maintenance cost, freshwater supplementation, and energy consumption. [Display omitted] [ABSTRACT FROM AUTHOR]