Petroleum Refinery Wastewater Research Articles

Combined natural flotation and chemical precipitation for the treatment of vegetable oil refinery wastewater

Combined natural flotation and chemical precipitation for the treatment of vegetable oil refinery wastewater

Mn (Cex)/γ-Al2O3 Catalysts with Notably Improved Performances for Catalytic Ozonation of Pollutants in Petroleum Refinery Wastewater

Mn (Cex)/γ-Al2O3 Catalysts with Notably Improved Performances for Catalytic Ozonation of Pollutants in Petroleum Refinery Wastewater

Green nanocatalyst for the photocatalytic degradation of organic pollutants in petroleum refinery wastewater: Synthesis, characterization, and optimization

The synthesis of green nanocatalysts is an emerging branch of current nanotechnology due to its numerous advantages, including high efficiency, sustainability, cost-effectiveness, biocompatibility, and eco-friendliness. In this study, a thermal technique was employed to prepare a novel green nanocatalyst (GNC) from the sepals of waste tomato (WT) plants, and this GNC was investigated to determine its efficiency in degrading the chemical oxygen demand (COD) during a photocatalytic process of simulated petroleum refinery wastewater (PRW). The characterization of the waste tomato-green nanocatalyst (WT-GNC) was performed using various techniques, including X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), Brunauer–Emmett–Teller (BET) analysis, and Fourier-transform infrared (FTIR) spectroscopy, which revealed that the synthesized WT-GNC possessed an excellent catalytic quality. This work examined the key factors affecting the degradation rates, such as the type of light source (UV or LED) and its arrangement (outside or inside the reactor), aeration rate, pH, catalyst dose, irradiation time, temperature, and initial COD concentration. The WT-GNC degraded 99.9 % of the COD (residual = 1 ppm) under the optimal operating conditions (pH = 7, WT-GNC dose = 0.25 g/L, irradiation time = 90 min, temperature = 25 °C, and initial COD = 1326 ppm) under UV lamps located around the inside of the reactor wall. Ultraviolet (UV) light is highly effective in degrading the COD compared to visible LED lights. The reaction followed the pseudo-first-order kinetic model (R2= 0.998) with k = 0.0367 min−1. The WT-GNC exhibited good reusability and stability and could reduce 76.3 % of the COD after the fifth consecutive cycle. Therefore, this novel GNC can serve as a cost-effective, efficient, stable, and eco-friendly photocatalyst to lower the COD of PRW to meet the World Health Organization (WHO) standards. In addition, it can be recovered and reused several times.

Treatment of Oil Refinery Wastewater Polluted by Heavy Metal Ions via Adsorption Technique using Non-Valuable Media: Cadmium Ions and Buckthorn Leaves as a Study Case

Treatment of Oil Refinery Wastewater Polluted by Heavy Metal Ions via Adsorption Technique using Non-Valuable Media: Cadmium Ions and Buckthorn Leaves as a Study Case

Removal of chemical oxygen demand from real petroleum refinery wastewater through a hybrid approach: Electrocoagulation and adsorption

In the Algiers refinery's effluent treatment plant (ETP), conventional methods fall short in handling highly concentrated liquid effluents, especially in biological treatment. Consequently, there's an urgent need for advanced pre-treatment. This study investigated the efficacy of a hybrid adsorption electrocoagulation (AD-EC) process for treating Algiers refinery effluent. The study focused on assessing the AD-EC method's capacity to remove crucial contaminants: COD, turbidity, and TSS. In the EC process, aluminum electrodes were used, and activated carbon was the adsorbent. Unfavorable operational conditions were applied for hybrid AD-EC processes including the adsorbent dosage, current density, and electrolysis duration. The SEM/EDS and BET were employed to analyze the solid generated. The result indicated that the hybrid process presented an economy of the treatment time, and was well efficient in removing COD, TSS, and turbidity. The treatment resulted in removing 82 % of COD, 96.5 % of turbidity, and 98.64 % of TSS, all well within the specified range of discharge limits set by Algeria. Likewise, these results confirm a synergistic effect between AD and EC. Moreover, this hybrid approach offers potential as a practical tertiary treatment step, enhancing the effluent quality and overall biological treatment efficiency, and providing a promising solution to the ETP.

Phytotoxicity assessment of treated vegetable oily wastewater via environmentally coagulation/flocculation and membrane filtration technologies using lettuce (Lactuca sativa) seeds.

The present investigation highlights the necessity of monitoring some basic physico-chemical water quality indicators and their phytotoxic effect using ecotoxicological bioassays such as "seed germination tests." The phytotoxicity of raw and treated vegetable oil refinery wastewater (VORW) using different treatment processes was assessed through some physiological responses (relative seed germination (RSG), seedling elongation, and germination index (GI)) using Lactuca sativa cultivar. Biotest results of different raw water samples revealed a noticeable correlation between the organic matter content and water phytotoxicity. In fact, VORW showed a very low RSG (17 ± 0.7 to -47 ± 0.58%) and high phytotoxic effects (GI < 50%). The use of coagulation/flocculation (CF) allowed a satisfactory phytotoxicity removal where RSG obtained ranged from 83 ± 1.58 to 90 ± 1.2%. However, the effluent still presents high to moderate phytotoxicity since GI remained below 80% which indicates the presence of toxic elements remaining after CF treatment. When VORW were treated using membrane processes, their phytotoxicity was gradually decreased with the decrease in the membrane pore size. The use of microfiltration membranes (MF), with pore size of 5 µm, 1.2 µm, 0.45 µm, and 0.22 µm, showed RSG values ranged from 37 ± 1.15 to 77 ± 1.68% and GI of less than 80% indicating a moderate to high phytotoxicity. However, the use of ultrafiltration (UF) membranes with molecular weight cut-off (MWCO) of 100 kDa, 30 kDa, and 10 kDa made it possible to achieve an RSG of 100% and an IG exceeding 80% showing that the VORW-treated using UF does not exhibit any phytotoxicity effect. Hence, UF appears to be the most efficient and environmentally friendly technology that could be used for safely treated VORW irrigation purposes compared to CF and MF processes.

Isolation and study of cyanobacterial cultures from oil refinery wastewaters

Wastewater from oil refineries, as well as other chemical industries, has specific features. Phototrophic microorganisms are commonly used to treat wastewater containing toxic components, such as oil and petroleum products. Cultivating microalgae and cyanobacteria in nutrient-rich wastewater can yield high biomass for simultaneous biotreatment, making it a more cost-effective and environmentally friendly approach. This study investigated the species composition of microalgae in wastewater from oil refineries in the Atyrau region. The results showed that Cyanophyta representatives dominated the microalgae composition in the enrichment culture. The presence of cyanobacteria in the wastewater was attributed to the high nutrient and calcium content of the organic matter. An axenic culture of the cyanobacterium Anabaena sp. was isolated to study its ability to grow and degrade different concentrations of motor oil. The results indicate the potential of Anabaena sp. strain in remediating aquatic environments contaminated with petroleum products.

Electrochemical Treatment of Petroleum Refinery Wastewater Using SnO2 and Graphite Anodes

Electrochemical Treatment of Petroleum Refinery Wastewater Using SnO2 and Graphite Anodes

Correlations between microbial taxonomies and wastewater quality parameters in a full-scale petroleum refinery wastewater treatment plant

In this study, we investigated the correlations between microbial taxonomies and wastewater properties in a full-scale petroleum refinery wastewater biotreatment system, comprising one anoxic tank and two aerobic tanks. Over one hundred organic compounds, mostly aromatics, were detected in the anoxic tank influent, with dominants being cresols and anilines. While the biotreatment process effectively removed most organic components, n-alkanes remained in the effluent of the second aerobic tank. Thauera and Ignavibacterium were the dominant genera across all tanks. Betaproteobacteria substantially decreased in the second aerobic tank where the aromatic compounds were depleted. The correlation network displayed two distinct microbial clusters. Genera in cluster I were generally positively correlated with each other and tended to co-occur, while genera in cluster II were subdivided into two small groups that were negatively correlated with the other group members. Mantel test showed that pH, nitrite and n-alkanes were potential determining factors influencing the overall community assembly. This study provides valuable insights into the chemical changes and microbial taxonomy in a complex petroleum refinery wastewater treatment system, establishing a foundation for further studies on the community regulation strategies within similar biotreatment systems.

Effect of temperature and total dissolved solids on the performance of activated sludge process for oil refinery wastewater: Case Study

Effect of temperature and total dissolved solids on the performance of activated sludge process for oil refinery wastewater: Case Study

Neuro-fuzzy modelling of a continuous stirred tank bioreactor with ceramic membrane technology for treating petroleum refinery effluent: a case study from Assam, India.

A continuous stirred tank bioreactor (CSTB) with cell recycling combined with ceramic membrane technology and inoculated with Rhodococcus opacus PD630 was employed to treat petroleum refinery wastewater for simultaneous chemical oxygen demand (COD) removal and lipid production from the retentate obtained during wastewater treatment. In the present study, the COD removal efficiency (CODRE) (%) and lipid concentration (g/L) were predicted using two artificial intelligence models, i.e., an artificial neural network (ANN) and a neuro-fuzzy neural network (NF-NN) with a network topology of 6-25-2 being the best for NF-NN. The results revealed the superiority of NF-NN over ANN in terms of determination coefficient (R2), root mean square error (RMSE), and mean absolute percentage error (MAPE). Three learning algorithms were tested with NF-NN; among them, the Bayesian regularization backpropagation (BR-BP) outperformed others. The sensitivity analysis revealed that, if solid retention time and biomass concentrations were maintained between 35 and 75h and 3.0g/L and 3.5g/L, respectively, high CODRE (93%) and lipid concentration (2.8g/L) could be obtained consistently.

Bio-synthesized ZnO nanoparticles and sunlight-driven photocatalysis for environmentally-friendly and sustainable route of synthetic petroleum refinery wastewater treatment

The design of a green photocatalytic system that harnesses renewable and eco-friendly constituents holds the potential to offer valuable insights into alternative strategies for treating toxic multi-components in refinery water effluents. A significant challenge in implementing a practical and viable approach is the utilization of solar energy—an abundant, natural, and cost-effective resource—for photochemical processes within advanced oxidation processes. In this study, we explored the use of zinc oxide nanoparticles (ZnO NPs) as photocatalyst prepared via an environmentally friendly synthesis approach, resulting in the formation of crystalline wurtzite nanoparticles, with an average size of about 14 nm relatively spherical in shape. Notably, the extract derived from Moringa oleifera was employed in this investigation. These nanoparticles were characterized and validated using various characterization techniques, including X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy. For comparison, conventionally synthesized ZnO NPs were also included in the evaluations. The findings reveal that, under illumination, biosynthesized ZnO nanoparticles (NPs) exhibit photocatalytic performance in effectively breaking down the organic compounds present in synthetic petroleum wastewater. Photochemical analysis further illustrates the degradation efficiency of Green-ZnO, which, within 180 min of irradiation resulted in 51%, 52%, 88%, and 93% of removal for Phenol, O-Cresol. Under optimal loading conditions, NPs produced via the green synthesis approach perform better when compared to chemically synthesized ZnO. This significant improvement in photocatalytic activity underscores the potential of eco-friendly synthesis methods in achieving enhanced water treatment efficiency.

Assessment of organic pollutants in petroleum refinery wastewater by LC-MS analyzer

The release of toxic and hazardous effluents from petroleum refining companies seriously threatens the poisoning of water bodies. Thus, it is necessary to determine an accurate treatment process by understanding the nature of wastewater. This work uses Liquid Chromatography-Mass Spectroscopy (LCMS), including LC-Tandem MS (LCMS/MS), ion trap (IT), and quadrupole-time-of-flight (Q-TOF) to comprehend the composition of petroleum refinery effluent. Many polar metabolites available, even as a trace fraction, can be found using advanced LCMS with defined molecular structure, which may or may not be itemized in CAS. Based on the number of carbon atoms (C1-C48), chemical reactivity (saturated, unsaturated, and aromatics), and functional group (hydrocarbons containing oxygen only and other minerals along with oxygen), substances are identified. Using LCMS/MS, 170 organic components, 77.10% negative and 22.90% positive metabolites, are quantified. A range of carbon between C8 and C48 is identified as having 6.50% C8-C12, 30% C13-C17, and 63.50% C18-C48. Higher molecular mass hydrocarbons from C22-C48 are less soluble in water and are more positively polarized, while C8-C21 hydrocarbons are more soluble under negative polarity. The principal ingredient is documented as consisting primarily of aromatic chemicals (72.30%), the majority of which are found as harmful metabolites. Further, 83% of the hydrocarbons are acknowledged to contain solely oxygen compared to other minerals in petroleum effluents. Overall, it was concluded that the direct discharge of petroleum refinery effluents without treatment may cause various health and environmental issues.

Efficient wastewater treatment in petroleum refineries: Hybrid electro-fenton and photocatalysis (UV/ZnO) process

In this study, a new hybrid system composed of a photo-catalysis (UV/ZnO) process combined with an electro-Fenton (EF) process equipped with a micro porous graphite air diffusion cathode (MPGADC) was used to treat petroleum refinery wastewater (PRW). The hybrid system was operated in a batch recycle mode and its performance was investigated and optimized using a response surface methodology (RSM). Three operating parameters affecting on the removal efficiency (RE%) of chemical oxygen demand (COD) were investigated including current density (2–10 mA/cm2), ZnO dosage (0.05–0.35 g/L), and Fe2+concentration (0.05–0.15 mM). Results showed that the optimum operating conditions can be achieved using a current density of 6.44 mA/cm2, with ZnO dosage of 0.35 g/L, and concentration of Fe2+ ions at 0.05 mM in which RE% of 90.15% was obtained with requiring a total electrical energy consumption (EECT) of 19.102KWh/m3. Furthermore, analysis of variance (ANOVA) exhibited a high value of determination coefficient (R2) close to 98.24% indicating a satisfactory fit between the obtained regression model and the experimental results. Moreover, ANOVA results revealed that current density has the most significant effect on RE% with a contribution of 52.41% followed by ZnO dosage and Fe2+ concentration both of them with a contribution of 11.64%. The comparison between the individual photo-catalysis process and hybrid process showed that RE% increases from 77.83% to 90.15% making an enhancement by 15.83% in RE% while EECT decreased from 27.171to 19.102KWh/m3 making a reduction by 29.7% in EECT. Hence, combining EF with photo-catalysis process improves the efficiency and reduced the required energy in comparison with the individual photo-catalysis process. Therefore, the combined process could be considered as an alternative, sustainable, green and cost-effective method for treatment of refinery wastewaters.

Construction of PVC/PVA WO3 3D Nanostructure Thin Film Nanocomposite for Treatment of Oil Refinery Wastewater

Construction of PVC/PVA WO3 3D Nanostructure Thin Film Nanocomposite for Treatment of Oil Refinery Wastewater

Recent Advancements in the Treatment of Petroleum Refinery Wastewater

The treatment of petroleum refinery wastewater (PRWW) is of great interest in industrial wastewater management. This wastewater contains a diverse concentration of contaminants such as oil and grease, petroleum hydrocarbons, phenols, ammonia, and sulfides, as well as other organic and inorganic composites. Refinery wastewater treatment has been attempted through various processes, including physical, biological, chemical, and hybrid methods, which combine two or more techniques. This review aims to summarize current research studies involved in the treatment of petroleum refinery wastewater using conventional, advanced, and integrated treatment techniques. Furthermore, it critically highlights the efficiencies and major limitations of each technique and the prospects for improvements. Several conventional treatment techniques (basically, the physicochemical and biological processes) are discussed. In this context, advanced oxidation processes (AoPs), especially electrochemical oxidation and photocatalysis, as well as integrated/hybrid processes are found to be effective in removing the recalcitrant fraction of organic pollutants through their various inherent mechanisms. These techniques could effectively remove COD and phenol concentrations with an average removal efficiency exceeding 90%. Hence, the review also presents an elaborate discussion of the photocatalytic process as one of the advanced techniques and highlights some basic concepts to optimize the degradation efficiency of photocatalysts. Finally, a brief recommendation for research prospects is also presented.

Electrooxidation using SnO2–RuO2–IrO2|Ti and IrO2–Ta2O5|Ti anodes as tertiary treatment of oil refinery effluent

AbstractIn the present work, treatability studies were carried out with oil refinery wastewater (effluent from the secondary treatment) using electrooxidation (EO) process employing two mixed oxide anodes: SnO2–RuO2–IrO2|Ti and IrO2–Ta2O5|Ti. Both electrodes' performance were compared by their capacity to generate active chlorine in a synthetic solution and organic matter mineralization of a sample with an average phenol (C6H6O) concentration of 100 mg L−1. Before degradation experiments, surface analysis, and linear sweep voltammetry tests were performed. SnO2–RuO2–IrO2|Ti anode yielded higher active chlorine, reaching an average concentration of 340 mg L−1 at 90 min of electrolysis and 25 mA cm−2. On the other hand, IrO2–Ta2O5|Ti anode only generated an average concentration of 200 mg L−1 at 90 min and 40 mA cm−2. Regarding the degradation experiments, SnO2–RuO2–IrO2|Ti anode showed the highest dissolved organic carbon removal, ranging from 26% to 40%. In addition, through a three‐dimensional excitation–emission matrix fluorescence analysis, it was possible to elucidate the degradation of C6H6O and some possible polycyclic aromatic hydrocarbons present in the effluent. The results suggested that 65%–90% of the hydrocarbons and C6H6O present in the effluent were degraded with the SnO2–RuO2–IrO2|Ti anode applying 25 mA cm−2 within the first 30 min of electrolysis, reaching almost 99% degradation at 90 min. The EO process using SnO2–RuO2–IrO2|Ti can be an alternative for tertiary treatment of oil refinery wastewater for degradation and mineralization of the remaining organic matter of secondary effluents (biological processes) via active chlorine species.

Petroleum refinery wastewater treatment using a novel combined electro-Fenton and photocatalytic process

In the current study, treatment of petroleum refinery wastewater has been successfully achieved using a novel photocatalysis-ElectroFenton system operated at a batch circulation mode and composed from a tubular electro-Fenton reactor provided with a macro-porous graphite air diffusion cathode (MPGADC) combined with a new configuration of photo reactor. The feasibility of the combined electro-Fenton with photo-catalytic process (EF + UV/ TiO2) was evaluated using response surface methodology (RSM) with Box-Behnken design (BBD). Titanium dioxide (Anatase) was used as a photo-catalyst and characterized by x-ray diffractometer (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller surface area (BET). Four main operating variables were studied: current density (5–15 mA/cm2, Fe2+concentration (0.1–0.5 mM), TiO2 dosage (0.1–0.7 g/l), and reaction time (20–60 min). Results revealed that reaction time has the most effective parameter on the EF + UV/ TiO2 process followed by TiO2 dosage, Fe2+concentration, and current density. The optimum operating conditions for maximizing COD removal (RE%) and minimizing the total electrical energy consumption (EECT)) were found to be a current density of 15 mA/cm2, Fe2+ concentration of 0.5 mM, TiO2 dosage of 0.7 g/l, and a reaction time of 54 min in which COD removal of 91.26 % was achieved with claiming EECT of 26.86 kWh/m3. Results revealed a vital improvement of using EF + UV/ TiO2 in comparison with UV/ TiO2 alone where an enhancement of 23% in RE% and a reduction by 55% of EECT were observed. Furthermore, a kinetic study was performed for EF + UV/TiO2 and UV/ TiO2 alone in which the results revealed that decay of COD obeyed a pseudo-first-order kinetic for the two processes with a high-rate constant for EF + UV/ TiO2 process.

Investigation of a membrane bioreactor's performances in treating sunflower oil refinery wastewater containing high oleic acid at different SRTs.

This study investigated the MBR performance, sludge morphology, and membrane fouling potential in treating sunflower oil refinery wastewater containing high oleic acid at three different SRTs of 10days, 40days, and infinite. The analysis of mixed liquor morphology including sludge volume index, PSD, EPS, and SMP showed that the sludge flocs compressibility and bioflocculation considerably improved at 40-days SRT. Additionally, at this SRT, the mixed liquor O&G, COD, and SMP accumulation were low, and the microbial activity and COD removal were enhanced. The gas chromatography/mass spectrometry analysis results confirmed the formation of three different new compounds related to non-readily biodegradable recalcitrant oily compounds and SMP at all SRTs. The analysis of mixed liquor EPS, PSD, SMP, and effluent COD at three different SRTs suggests that under the industrial conditions of MBR operation treating SORW with high oleic acid, the optimal operating conditions are predicted to be at 40-days SRT.

Removal of pollutants and accumulation of high-value cell inclusions in a batch reactor containing Rhodopseudomonas for treating real heavy oil refinery wastewater

Treating wastewater using purple non-sulfur bacteria (PNSB) is an environmentally friendly technique that can simultaneously remove pollutants and lead to the accumulation of high-value cell inclusions. However, no PNSB system for treating heavy oil refinery wastewater (HORW) and recovering high-value cell inclusions has yet been developed. In this study, five batch PNSB systems dominated by Rhodopseudomonas were used to treat real HORW for 186 d. The effects of using different hydraulic retention times (HRT), sludge retention times (SRT), trace element solutions, phosphate loads, and influent loads were investigated, and the bacteriochlorophyll, carotenoid, and coenzyme Q10 concentrations were determined. The community structure and quantity of Rhodopseudomonas in the systems were determined using a high-sequencing technique and quantitative polymerase chain reaction technique. The long-term results indicated that phosphate was the limiting factor for treating HORW in the PNSB reactor. The soluble chemical oxygen demand (SCOD) removal rates were 67.03% and 85.26% without and with phosphate added, respectively, and the NH4+-N removal rates were 32.18% and 89.22%, respectively. The NO3−-N concentration in the effluent was stable at 0–3 mg/L with or without phosphate added. Adding phosphate increased the Rhodopseudomonas relative abundance and number by 13.21% and 41.61%, respectively, to 57.35% and 8.52 × 106 gene copies/μL, respectively. The SRT was the limiting factor for SCOD removal, and the bacteria concentration was the limiting factor for nitrogen removal. Once the inflow load had been increased, the total nitrogen (TN) removal rate increased as the HRT increased. Maximum TN removal rates of 64.46%, 68.06%, 73.89%, 82.15%, and 89.73% were found at HRT of 7, 10, 13, 16, and 19 d, respectively. The highest bacteriochlorophyll, carotenoid, and coenzyme Q10 concentrations were 2.92, 4.99, and 4.53 mg/L, respectively. This study provided a simple and efficient method for treating HORW and reutilizing resources, providing theoretical support and parameter guidance for the application of Rhodopseudomonas in treating HORW.