Oil Wastewater Treatment Research Articles

Robust multifunctional rGO/MXene@PPS fibrous membrane for harsh environmental applications

Efficient cleanup of crude oil spills and wastewater treatment in harsh conditions remains a big challenge due to the absent of robust membrane materials. Herein, a kind of reduced graphene oxide and MXene (Ti3C2Tx) decorated PPS fibrous membrane with super chemical-resistance for all-weather cleanup of crude oil via Joule heat and solar-driven heat performance was reported. With the assist of the Joule heat and photothermal effect, the crude oil adsorption rate of composite membrane improved by more than 97 %. More importantly, the robust membrane still remained excellent oil/water separation performance even under strong acid and alkali conditions. Meanwhile, the gravity driven oil (dichloromethane)/water separation flux of composite membrane reached 11,502 L m-2h−1 with a separation efficiency up to 99.98 %. Moreover, the composite membrane could realize solar-driven evaporation for seawater desalination due to its great photothermal properties, the evaporation rate could be up to 1.235 kg m-2h−1 under one sun. The composite membrane also exhibited great electrical conductivity and EMI shielding performance for radiation protection with efficiency of 61.9 dB. This robust multifunctional fibrous membrane design offers a progressive approach for the efficient cleanup of viscous crude oil spills, oil/water separation, solar desalination and EMI shielding under harsh environments.

Circulating flow hybrid ultrasonic and electrochemical process for the treatment of mineral oil wastewaters

This paper examines the removal of mineral oil from oily wastewater by a hybrid ultrasonic and electrochemical circulating flow process. The Box-Behnken design was used to study the effects of number of cycles, current density, flow rate and the presence of ultrasound on the efficiency of mineral oil removal and process optimization. A reduced cubic regression model with estimated coefficients was developed to describe the mineral oil removal rate. The experimental results show that this novel hybrid system can effectively reduce mineral oil by 94.3 % under the optimal conditions of 14.130 cycles, current density of 53.07 A/m2 and a flow rate of 0.234 L/s. The experimental observations agreed well with the modelled values, and the model was verified experimentally. Under the optimal conditions, the electrical energy consumption was 10.04 kWh/m3 and the average operational costs were 2.04 EUR/m3.

Fabrication of a Novel (PVDF/MWCNT/Polypyrrole) Antifouling High Flux Ultrafiltration Membrane for Crude Oil Wastewater Treatment

The present work deals with the fabrication of novel poly(vinylidene fluoride) (PVDF)/Multi-wall Carbon Nanotubes (MWCNT)/Polypyrrole (PPy) ultrafiltration membrane by phase inversion technique for the removal of crude oil from refinery wastewater. In situ polymerization of pyrrole with different concentrations of MWCNT ranging from 0.025 wt.% to 0.3 wt.% in PVDF prepared solutions. Measurement of permeability, porosity, contact angle, tensile strength, zeta potential, rejection studies and morphological characterization by scanning electron microscopy (SEM) were conducted. The results showed that membrane with (0.05% MWCNT) concentration had the highest permeability flux (850 LMH/bar), about 17 folds improvement of permeability compared to pristine PVDF membrane. Moreover, membrane rejection of crude oil reached about 99.9%. The excellent performance of this nanocomposite membrane suggests that novel PVDF modification with polypyrrole had a considerable effect on permeability with high potential for use in the treatment of oily wastewater in the refinery industry.

Recent advances of biosurfactant for waste and pollution bioremediation: Substitutions of petroleum-based surfactants

Biosurfactant is one of the emerging compounds in the industrial sector that behaves similarly with their synthetic counterparts, as they can reduce surface and interfacial tension between two fluids. Their unique properties also enable biosurfactant molecules to be able to clump together to form micelles that can capture targeted molecules within a solution. Biosurfactants are compared with synthetic surfactants on various applications for which the results shows that biosurfactants are fully capable of replacing synthetic surfactants in applications including enhanced oil recovery and wastewater treatment applications. Biosurfactants are able to be used in different applications as well since they are less toxic than synthetic surfactants. These applications include bioremediation on oil spills in the marine environment and bioremediation for contaminated soil and water, as well as a different approach on the pharmaceutical applications. The future of biosurfactants in the pharmaceutical industry and petroleum industry as well as challenges faced for implementing biosurfactants into large-scale applications are also discussed at the end of this review.

Optimization of mobile oil and gas produced water treatment unit deployment logistics to achieve economic feasibility

• Techno-economic assessment of on-site produced water desalination . • The concept of capacity factor is applied to desalination where demand is variable. • Systems level optimization of mobile desalination module deployment. • Multi-objective optimization considering economics and water reclamation . Development of unconventional oil and gas wells has resulted in large volumes of wastewater that require careful handling to minimize environmental risks. Common practice is to truck the wastewater from well sites to Environmental Protection Agency Class II underground injection control wells. Recently, on-site wastewater treatment followed by surface water discharge for downstream reuse has emerged as being viable. This work applies the concept of capacity factor to on-site oil and gas wastewater treatment. By accounting for intermittent wastewater treatment demands at individual well sites, the attributes of optimal on-site packaged treatment unit deployment logistics for oil and gas wastewater management are determined. The attributes considered are packaged unit capacity, deployment length, and the number of units deployed. This work explores different deployment logistics in Weld County, Colorado, United States to determine a set of Pareto optimal logistics from a techno-economic and environmental perspective. Ultimately, there exists a Pareto frontier because the marginal cost of water treatment increases as reuse increases beyond a critical threshold, in Weld County where the cost of business as usual operation (injection) is constant at $7.68 per m 3 produced. Generally, optimal deployment logistics, when accounting for capacity factor, utilize packaged wastewater treatment units sized at 100 m 3 per day capacity with deployment location reevaluated monthly. This article focuses on the importance of capacity factors at on-site treatment units and presents limitations of the study and the opportunity for the application of the presented methods to other case studies through utilization of the open-source model produced in this work.

Mitigating membrane wetting in the treatment of unconventional oil and gas wastewater by membrane distillation: A comparison of pretreatment with omniphobic membrane

The treatment of unconventional oil and gas (UOG) wastewater by membrane distillation (MD) is a promising alternative to disposal via deep-well injection for UOG wastewater management. However, MD has been constrained by membrane pore wetting, which could be induced by surfactants that are commonly used in hydraulic fracturing fluids. Herein, we investigated and compared two strategies, namely pretreatment via coagulation-adsorption and the use of omniphobic membranes, for wetting mitigation in MD treatment of UOG wastewater from the Denver-Julesburg Basin, Colorado. Both strategies were able to mitigate membrane wetting, but pretreatment exhibited better treatment efficiency than the use of omniphobic membranes that was subject to significant membrane fouling. Membrane characterization using scanning electron microscopy, energy dispersive X-ray spectroscopy, and attenuated total reflectance-Fourier transform infrared spectroscopy demonstrated the effective reduction of membrane fouling and scaling after pretreatment. Further, ultrahigh pressure liquid chromatography (UHPLC) coupled with quadrupole time-of-flight mass spectrometry (LC/QToF/MS) was performed to investigate the efficacy of pretreatment in removing surfactants. Pretreatment was found to be highly efficient at removing polyethylene glycol (PEG) and polypropylene glycol (PPG) surfactant classes, which were likely responsible for membrane wetting. Our findings suggest that pretreatment could have comparable or even better effectiveness than omniphobic membranes for improving MD treatment of UOG wastewater with high wetting potential. Comparative investigations on these two wetting mitigation strategies are valuable for rational selection of appropriate strategies to promote practical applications of MD to industrial wastewater treatment. • Membrane wetting occurs in MD treatment of UOG wastewater. • Pretreatment and omniphobic membranes as wetting mitigation strategies. • Pretreatment outperforms omniphobic membranes. • Key surfactant classes removed by pretreatment are identified.

Slippery, Water-Infused Membrane with Grooved Nanotrichomes for Lubricating-Induced Oil Repellency.

Water, abundant and ubiquitous in nature, is an easy yet powerful resource for the creatures to survive by putting together with their topologies interfacing their living environment. Here, a slippery, water‐infusing surface (SWIS) that retains a thick and stable water layer on the membrane is presented, robustly maintaining the oil repellency against the pressure and friction of immiscible liquids. Inspired by the plant trichome structures and their function, grooved nanotrichome, formed on the fibrous membrane by the oxygen plasma etching, induces robust water lubrication on the SWIS. SWIS membrane repels and separates highly viscous and adhesive oils in air and underwater by preventing oils from adhering to the lubricating surface. Repeated tests both in air and underwater confirm the antiadhesion and self‐cleaning properties of the SWIS. The SWIS oil scooper, fixed on a frame with a handle, successfully collects spilled oil on a pilot‐scale oil spill site and a real ocean oil spill site by simply scooping and recovering the oil. In addition, SWIS membrane is expected to help protect environments with further applications such as oil‐wastewater treatment and oil separation in food.

Treatment of vegetable oil wastewater by a conventional activated sludge process coupled with electrocoagulation process.

The present work aims to study chemical oxygen demand (COD), oil-grease, and color removal from vegetable oil wastewater by combined electrocoagulation and activated sludge processes. For this purpose, the sample was pretreated using electrocoagulation by various optimization parameters such as electrode type (Al-Al and Fe-Fe), current density (100-400 A/m2 ), pH (2-8), and electrolysis time (15-180 min). The results showed that 89.3% of COD, 100% of oil-grease, and 66.2% of color were removed by electrocoagulation under the conditions of 300-A/m2 current density, pH 2, and 180-min reaction time with Al-Al electrode pairs. Then, the effluent of electrocoagulation was treated by an activated sludge process. The results depicted that the activated sludge process was also effective for vegetable oil wastewater treatment and it enhanced 98.9% COD and 79.2% color removal efficiency. The effluent of the combined process was very clear, and its quality exceeded the direct discharge standard of the water pollution control regulation. The laboratory-scale test results indicate that the combined electrocoagulation and activated sludge process is feasible for the treatment of vegetable oil wastewater. PRACTITIONER POINTS: Vegetable oil wastewater was treated by combination of electrocoagulation and activated sludge processes. The combined electrocoagulation and activated sludge processes supplied 99.9% COD, 100% oil-grease, and 93.0% color removal efficiency. The laboratory-scale test results indicate that the combined EC-SBR processes were feasible for the treatment of vegetable oil wastewater.

Optimization of sonication-assisted synthesis of magnetic Moringa oleifera as an efficient coagulant for palm oil wastewater treatment

Optimization of the sonication-assisted synthesis of magnetic Moringa oleifera (MMO) was carried out, to produce an efficient coagulant for palm oil mill effluent treatment. Response surface methodology (RSM) was used to analyse the effect of magnetic nanoparticles (MNPs) composition, sonication time and sonication temperature on coagulation performances to remove total suspended solid (TSS), colour, chemical oxygen demand (COD) and sludge volume index (SVI)). The RSM analyses indicate 1.0 wt% of MNPs, 2.35 min and 50 °C as the optimal MNPs mass fraction, sonication time and sonication temperature, respectively in order to fabricate an efficient MMO coagulant. The analysis of variance (ANOVA), indicate that mass fraction of MNPs and sonication temperature are the most significant parameters. From the statistical analysis, the sonication time did not exert any influence on the fabrication of MMO as well as its coagulation performance. At the optimum conditions, 83.3%, 28.1%, 85.2% removal of TSS, colour, COD as well as 485 mL/g of SVI were respectively achieved. This paper also present the characterization studies on the synthesized MMO using Fourier transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy and vibrating sample magnetometer analysis. • Magnetic Moringa Oleifera (MMO) coagulant was synthesized via ultrasonic-assisted technique. • Optimization study on synthesis conditions was carried out by response surface methodology. • Magnetic composition and sonication temperature were the significant synthesis factors. • The developed MMO coagulant exhibited ferromagnetic properties.

A chalcone organic gel for oil spill recovery and wastewater treatment

Oil spillage and water pollution are serious environmental disasters, which have a serious impact on the economy and ecosystem. To protect the environment，we have synthesized a new type of chalcone derivative (G1) gel. G1 can form gels in many organic solvents, fuels and edible oils. The FT-IR, SEM and XRD studies show that there are π-π stacking, Van der Waals and intermolecular Hbonding force in the G1 gel self-assembly process. 3D networks structure provides a strong basis for the adsorption of dyes and the adsorption efficiency could be as high as 97.2%. The G1 can selectively gel in organic water pollutants, with recyclability. Even in the presence of salt, acid and alkali, it can be successfully used to recover spilled oil from oil-water mixture.

A review on recent advances in the application of biosurfactants in wastewater treatment

Microorganisms produce a variety of non-conventional surface-active molecules, known as biosurfactants. The biosurfactants find diverse applications in the oil industry, agriculture, emulsifiers, and wastewater treatment, to name a few. Since they are produced from microbes, advantages such as biodegradability, lower toxicity, and environmental compatibility can be leveraged compared to the chemical surfactants. Recently, biosurfactants found potential usability in treating wastewater generated from various domestic, industrial, and agricultural sources. The application of biosurfactants in wastewater treatment is mainly due to their excellent foaming ability, specific activity, and high selectivity under wide operation window of temperature, pH, and salinity. Wastewater treatment with use of low cost biosurfactant is one of the important suitable goal in treating the wastewater since biosurfactants can be produced from cheap material and cause less damage to the environment by replacing surfactants produced from petroleum crude. This review focuses on the recent developments in biosurfactant production using waste materials such as food and agricultural residues, industrial waste, and animal waste and their application in wastewater treatment processes such as contaminant degradation, oil–water separation, heavy metal removal, and effluent flotation. The characteristics of the biosurfactants produced from cheap materials are compared with that of synthetic surfactants. In fact, the characteristics of both types of surfactants are found to be similar. The ability of biosurfactants for pollution removal from wastewater is extensively reviewed and presented. Finally, the review also evaluates the economic feasibility of biosurfactant production on commercial scale and their industrial scale wastewater treatment application.

Use of artificial neural network and adaptive neuro-fuzzy inference system for prediction of biogas production from spearmint essential oil wastewater treatment in up-flow anaerobic sludge blanket reactor

Two artificial intelligence (AI)-based models, namely feed-forward backpropagation artificial neural network (ANN) and multi-layer adaptive neuro-fuzzy inference system (ANFIS), were developed to estimate the biogas production in an up-flow anaerobic sludge blanket (UASB) reactor. The models' input variables including influent chemical oxygen demand (COD), pH, effluent mixed liquor suspended solids, effluent mixed liquor volatile suspended solids, turbidity removal, oil and grease removal, COD removal, phenol removal, and effluent volatile fatty acids and alkalinity were collected from an UASB reactor fed with spearmint essential oil wastewater (SEOW) during 141 consecutive operating days. The determination coefficient, root mean square error, and relative root mean the ANN model's square error reached 0.975, 2650 mL/d, and 0.234%, respectively, while those of ANFIS model reached 0.956, 3517 mL/d, and 0.315%, respectively. The results achieved herein demonstrated that two AI-based models were successful to estimate the biogas production in a lab-scale UASB reactor treating SEOW with high accuracy and low error.

Silver doped titania nanotubes incorporated photocatalytic dual layer antibiofouling hollow fiber membrane for palm oil wastewater treatment

Photocatalytic dual layer hollow fiber membrane (DLHFM) is advantageous over its single layer counterpart due to a better photocatalyst dispersion on the outer layer to maximize the potential of the photocatalyst in improving the overall membrane performance. In this study, a polyvinylidene fluoride (PVDF) dual-layer hollow fiber membrane with antibiofouling properties was successfully synthesized via dry-wet spinning phase inversion method, where the Ag-TNT was incorporated onto the outer layer membrane for photocatalytic degradation of AT-POME pigments in a submerged membrane photoreactor (SMPR). The results revealed that the incorporation of Ag-TNT into the PVDF matrix increased pure water flux from 16.20 L/m2 h for pristine PVDF membrane to 37.12 L/m2 h. The synergistic advantages of photocatalysis and membrane filtration was exhibited by the photocatalytic Ag-TNT membrane which showed the highest AT-POME color removal efficiency of 84.0% compared to the other membranes prepared in this work. With the presence of silver nanoparticles, the modified membrane exhibited antibacterial efficiency of 95.8% with a 1.73 mm inhibition zone around the membrane against P. aeruginosa. Based on the results obtained, the photocatalytic PVDF Ag-TNT membrane showed immense potential as an innovative technology for water reclamation in the palm oil industry.

The Perspective and Challenge of Nanomaterials in Oil and Gas Wastewater Treatment

Oil and gas wastewater refers to the waste stream produced in special production activities such as drilling and fracturing. This kind of wastewater has the following characteristics: high salinity, high chromaticity, toxic and harmful substances, poor biodegradability, and a difficulty to treat. Interestingly, nanomaterials show great potential in water treatment technology because of their small size, large surface area, and high surface energy. When nanotechnology is combined with membrane treatment materials, nanofiber membranes with a controllable pore size and high porosity can be prepared, which provides more possibilities for oil–water separation. In this review, the important applications of nanomaterials in wastewater treatment, including membrane separation technology and photocatalysis technology, are summarized. Membrane separation technology is mainly manifested in ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO). It also focuses on the application of semiconductor photocatalysis technology induced by TiO2 in the degradation of oil and gas wastewater. Finally, the development trends of nanomaterials in oil and gas wastewater treatment are prospected.

Performance of Horizontal Roughing Filter for Colour Removal of Palm Oil Mill Effluent Using Natural Adsorbent

Palm oil wastewater treatment was investigated via a filtration process using raw and calcinated limestone. Column studies were conducted using different limestone sizes (4, 12, and 20 mm), calcination temperature (800 °C and 600 °C) and various filtration rates (20, 60, and 100 mL/min), and a comparison was made with raw limestone under similar conditions. The response surface methodology using central composite design was employed to optimize the process parameter. The experimental data was analyzed via the analysis of variance to identify the interaction between the parameters and the dependent parameter. The results showed that the colour removal increased with an increase in temperature (800 °C) for filtration rate of 20 mL/min, the retention time of 317 min and the smaller size (4 mm) of limestone, and decreased with an increase in the filtration rate and size of raw limestone. Based on the achieved results, the optimum condition for colour removal was at temperature 800 °C (61%), 600 °C (56%) and raw limestone (49%), respectively, with the same experimental setup (flow rate of 20 mL/min and limestone size of 4 mm). According to the statistical analysis, quadratic models demonstrated significant values (0.000) for the response (colour). Freundlich and Langmuir isotherms also provided good correlation coefficient for colour removal. The data conforms to the Langmuir isotherm with the best fit model (R2 = 0.7).

Adsorption of diesel oil onto natural mud shale: from experimental investigation to thermodynamic and kinetic modelling

ABSTRACT A natural mud shale (MS) from Yichang Area, China was for the first time experimentally examined for its potential application to oily effluents treatment. The mineralogical compositions, surface structures and pore size distribution of the prepared MS particles were characterised using various advanced analytical technologies, respectively. The performance of the MS particles during the model diesel oil wastewater treatment was examined based on the designed adsorption experiments. Isothermal and kinetic features were investigated according to a variety of adsorption models. The results showed that some pores, cavities and fractures were distributed on the surface of MS particles. The efficiency of MS particles for removing diesel oil from the model oily effluent was associated closely with experimental conditions including the mass of MS particles, initial diesel levels, residence time and pH values. Equilibrium adsorption isotherms conformed to Langmuir model, indicating that the adsorption of diesel oil onto MS particles tended to monolayer adsorption. Kinetics of adsorption of diesel oil on MS complied with the pseudo-second-order model. This suggested that the whole oil removal rate was mainly controlled by chemisorption. Results of our study indicates potential utilisation of unmodified MS particles as an abundant and inexpensive adsorbent for low-concentration diesel oil wastewater.

Effect of Electrode Material on the Removal of Industrial Oil and Soap Wastewater Using Electrocoagulation Process

Treatment of oil and soap industrial wastewater using aluminum and iron electrode material has been investigated in this study to compare for each electrode, the performance of the electrocoagulation process. The effectiveness of relevant industrial wastewater characteristics such as the chemical oxygen demand (COD) and oil-grease removal effects of major operating parameters such as medium pH value, electrode material, and current density, and running time and energy consumption were studied. All experiments were done in an electrocoagulation cell with an effective volume of 500 mg/ liters. Under the same operating conditions, it was observed that aluminum electrodes have higher efficiency of removal than iron electrodes. COD and O&G removal efficiencies of 94.93%, 90.20% and 27.49%, 13.27% were observed for aluminum and iron electrode in a special case with optimum initial pH value, maximum current density, time, and initial COD concentration equal to 3, 73.33 A/m2, 30 min, 19750 mg/l, respectively. The electrode energy consumptions for each electrode material have been calculated to be 1.68, 3.04 KWh/kg COD for Aluminum and iron respectively at 15 volts. It can be concluded that the electrocoagulation process using aluminum electrodes is efficient for COD and O&G removal from industrial wastewater

Simultaneous design and integration of multiple processes for eco-industrial park development

Process integration techniques have been well established in various areas, which include energy recovery, in-plant material recovery, industrial symbiosis, energy planning, financial management, etc. Such techniques are widely applied in the research community and industrial applications. Synthesising and designing an eco-industrial park via process integration techniques is recognised as one of the most effective strategies to promote sustainable industrial systems. Feasible operating range analysis has been introduced to evaluate and determine the true operating potential of an eco-industrial park coalition without experiencing design and performance limitations. Such tool also acts as a comprehensive decision-making tool for designers to evaluate the performance of an integrated process at different operational states. In this perspective, a novel mixed-integer linear programming model is presented in this work for simultaneous design and integration of multiple processes to form an eco-industrial park. The true potential and performance of the eco-industrial park developed can be assessed at different operational states. To illustrate the proposed approach, an industrial case study on design of eco-industrial park in oil palm industry, which consists of palm oil mill, integrated biogas and wastewater treatment system, palm-based biorefinery, and combined heat and power system, is solved and presented.

Waste-to-energy: Coal-like refuse derived fuel from hazardous waste and biomass mixture

This study aimed to develop Refuse Derived Fuel (RDF) with high Calorific Value (CV) from mixed hazardous wastes and biomass. The potential utilization of newly developed RDF in cement production as a fuel substitute for coal has been investigated. In this work, five types of mixed hazardous industrial wastes (rubber waste, mixed waste, paint sludge, palm oil sludge and wastewater treatment plant sludge) and three biomass types (sawdust, paddy husk and empty fruit bunch) have been used. The newly developed RDF developed in this study has a CV of approximately 18,652 kJ/kg, and its volatile matter, fixed carbon and ash content of 32 %, 40 % and 28 %, respectively. The study is revealed that substituting 5 ton/hour of RDF in the coal only emits about 301 mg/m3 of NOx, which is within the regulatory limits in Malaysia. Besides, the emission of heavy metals, including Zinc, Arsenic, Lead, Copper, Antimony, and Chromium, was also within the regulatory limits. RDF in cement manufacturing kilns is economically and environmentally attractive, as the combustion of RDF allows for a reduction of about 2.25 kg of CO2 per kg compared to coal. In terms of the efficiency of clinker and stack gas emission values, the substitution of 15 % of RDF to the coal at a feeding rate of 5 ton per hour in cement production did not cause any processing and quality issues in the existing cement production process. The result revealed that substituting 15 % of RDF with the coal in 5000 ton/day cement plant may reduce 112.8 USD/hour in operating cost. Additionally, 140 USD/hour of net saving could be achieved by saving 2.52 ton/hour of CO2 emitted from the cement production. Overall, the results concluded that RDF is a very promising resource recovery and waste treatment option for hazardous waste management.

Development of Red Clay Ultrafiltration Membranes for Oil-Water Separation

In this study, a red clay/nano-activated carbon membrane was investigated for the removal of oil from industrial wastewater. The sintering temperature was minimized using CaF2 powder as a binder. The fabricated membrane was characterized by its mechanical properties, average pore size, and hydrophilicity. A contact angle of 67.3° and membrane spore size of 95.46 nm were obtained. The prepared membrane was tested by a cross-flow filtration process using an oil-water emulsion, and showed a promising permeate flux and oil rejection results. During the separation of oil from water, the flux increased from 191.38 to 284.99 L/m2 on increasing the applied pressure from 3 to 6 bar. In addition, high water permeability was obtained for the fabricated membrane at low operating pressure. However, the membrane flux decreased from 490.28 to 367.32 L/m2·h due to oil deposition on the membrane surface; regardless, the maximum oil rejection was 99.96% at an oil concentration of 80 NTU and a pressure of 5 bar. The fabricated membrane was negatively charged, as were the oil droplets, thereby facilitating membrane purification through backwashing. The obtained ceramic membrane functioned well as a hydrophilic membrane and showed potential for use in oil wastewater treatment.