Refinery Wastewater Treatment Research Articles

Electrochemical process for petroleum refinery wastewater treatment to produce power and hydrogen using microbial electrolysis cell.

This research aims to assess the microbial electrolysis cell (MEC) fed with petroleum refinery wastewater (PRW) to produce power density and bio-electrochemical hydrogen. The MEC produces a maximum bio-electricity of 21.4mA and a power density of 1200123.90 W/m2 with a loading of chemical oxygen demand (COD) of 17000mg/L. Due to catalyzed oxidation of complex compounds in PRW with a maintained microbial biofilm growth was observed after 90 d of operation of MEC. Results showed that the oxidation of organic substances in PRW enhanced the size in the growth of microbial film which further increased the generation of electrons leading to current density of 5890mA/m2. The COD removal efficiency of MEC was found to be 89.9%. The bio-electricity and hydrogen production of the MEC was estimated to be 24.5mA and 19.2 L respectively when loaded with PRW having a COD of 17500mg/L after 130 d. Present experiments demonstrate the efficiency of MEC technology efficiency in treating petroleum wastewater with the help of microbial biofilm.

Treatment of vegetable oil refinery wastewater by sequential electrocoagulation-electrooxidation process

In the present study a sequential process composed of electrocoagulation (EC) followed by electrooxidation (EO) was utilized at the laboratory scale to remove the chemical oxygen demand (COD) from wastewater generated in Iraqi vegetable oil refinery plant.in the EC, impacts of operating variables such as current density (10–30 mA cm-2) and pH (4–10),and EC time (30–90 min) on the COD removal (RE%) were investigated using response surface methodology (RSM) based on Box- Behnken design(BBD). a mathematical correlation that relates the operating factors with RE% was developed and its regression coefficient was 99.02% confirming the significant of the model. Response surface plots showed that RE% increased with increasing current density and time while it decreased with increasing pH. The optimum removal with a lower cost for EC process were achieved at current density of 30mA/cm2, pH of 4, and electrolysis time of 90 min in which RE% of 69.19% was obtained with requirement of 0.513kWh/kg COD as specific energy consumption (SEC). The effluent exit from EC was treated by EO for a period of 240min at a current density of 30mA/cm2 and an initial pH value of 4 to obtain RE% of 96% at SEC of 1.554 kWh/kg COD. Combining EC with EO resulted in a total RE% of 98.72% and a total SEC of 2.067 kWh/kg COD. Based on the results of present study, the applicability of a sequential electrocoagulation-electrooxidation process for treatment vegetable oil wastewaters is feasible.

Treatment of petroleum refinery wastewater by chemical coagulation method: determination of optimum removal conditions using experimental design

Treatment of petroleum refinery wastewater by chemical coagulation method: determination of optimum removal conditions using experimental design

Structure design and industrial experiment of compact flotation unit for refinery wastewater treatment

The compact flotation unit (CFU) has been widely used in offshore oilfield-produced water treatment with the characteristics of compact structure and high oil removal efficiency. However, there is no published literature talking about CFU’s application in refinery wastewater treatment. In this paper, an innovative designed two-stage series BIPTCFU process diagram for refinery wastewater treatment was proposed. The structural design of the core BIPTCFU with a capacity of 20 m3/h was also carried out. After that, the manufactured industrial prototype of BIPTCFU-III-20 was tested in a SINOPEC petrochemical wastewater treatment plant. The single-factor operation test results show that with the increase of gas-liquid volume ratio, the oil removal efficiency of the BIPTCFU-III-20 increases first and then stabilizes. The reason can be ascribed to the microbubble number density which contributes to the oil removal efficiency. With the increase of inlet water flow rate, the oil removal efficiency first increases and then decreases. The reason is that as the inlet flow rate increases and approaches the rated treatment capacity, a stable swirling flow field is gradually formed in the vessel which benefits to the oil removal performance. While when the inlet water flow rate exceeds the rated capacity, the calculated hydraulic retention time was too short to complete the air flotation process. Under the optimal operation parameters, the oil removal performance of the BIPTCFU-III-20 on refinery wastewater was remarkable, and the average oil removal efficiency was 81.65 % when the inlet oil content was higher (1307 mg/L ∼ 4486 mg/L). While, when the inlet oil content is lower (150 mg/L ∼ 393 mg/L), the average oil removal efficiency was 77.75 %. The effect of low inlet oil content on the oil removal rate is more significant than that of high oil content. Based on the above basic research results, an industrial BIPTCFU with a rated capacity of 100 m3/h was constructed. The remarkable oil removal performance of the refinery wastewater was further verified.

Vegetable Oil Refinery Wastewater Treatment by Using the Cactus as a Bio-flocculant in the Coagulation-Flocculation Process

Vegetable Oil Refinery Wastewater Treatment by Using the Cactus as a Bio-flocculant in the Coagulation-Flocculation Process

Development of microalgae and agrobost mutualism symbiotic technology in the aerobic treatment of sago refinery wastewater

Sago wastewater is 94% of the water produced from the sago processing that could pollute the environment. One of the biological treatments to solve this problem is the use of mutualism symbiotic between the microalgae Chlorella sp. and agrobost with the addition of 5.000 lux constant light. The purpose of this research was to develop symbiotic technology for microalgae and aerobic bacteria in the decomposition of liquid sago waste, in particular for optimizing the photosynthesis process. Furthermore, the reduction of BOD, COD, and organic content could be fast and effective. The research applied a Completely Randomized Design (CRD) with five treatments and three replications. The treatments were addition of 800 ml/l (7.595 log cell/ml) as much to sago waste at variation of concentrations (0% v/v,1% v/v, 2%v/v, 3% v/v, 4%v/v). Data were statistically analyzed using the Analysis of Variance, followed by Duncan’s New Multiple Range Test (DNMRT) at the level of 5%. The result showed that the addition of agrobost microorganisms significantly affected BOD, COD, DO, and pH of sago wastewater. The treatment selected from the results of this study was the P4 treatment with the highest reduction on day 7 with a BOD value of 116.06 mg/l, COD 200.90 mg/l, DO 6.62 mg/l, and pH 8.90.

Treatment of petroleum refinery wastewater by electrofenton process using a low cost porous graphite air-diffusion cathode with a novel design

A low-cost micro porous graphite air diffusion cathode (MPGADC) has been utilized successfully for the in-situ hydrogen peroxide generation via O2 reduction in 0.05 M Na2SO4. Using a tubular electrochemical reactor with a novel design composed of MPGADC as a cathode and a hollow cylinder porous graphite as an anode, a maximum of 68 mg/ L of H2O2 was produced at a current density of 25 mA/cm2, an air flow rate of 3 L/min, and a pH value of 3. Electro-Fenton (EF) process was adopted to remove the chemical oxygen demand (COD) from the wastewater of Al-Dora petroleum refinery in Iraq using this new style of tubular electrochemical reactor. Based on the response surface methodology (RSM) with Box-Behnken design (BBD), the effect of EF operating parameters on the COD removal was investigated.The optimal conditions for maximizing COD removal efficiency (RE%) with lowering specific energy consumption (SEC) using EF process were determined to be a current density of 6.66 mA/cm2, Fe2+ concentration of 0.80 mM, and an electrolysis duration of 60 min, in which RE% of 94% with SEC of 3.75 kWh/kg COD were achieved. In addition, the results demonstrated that the current density has the greatest influence on the COD removal, followed by electrolysis duration and then Fe2+ concentration. Furthermore, current density has the greatest impact on the specific energy consumption, followed by time, while Fe2+ concentration has a negligible effect. The high R2 value (98.33%) confirmed the goodness of fitting the model equation. These results established the viability of employing the new cathode design for the EF process in treatment of petroleum refinery wastewaters.

An Electrocoagulation Process Operated at Batch Recirculation Mode for Treatment of Refinery Wastewaters: Optimization via Response Surface Methodology

An Electrocoagulation Process Operated at Batch Recirculation Mode for Treatment of Refinery Wastewaters: Optimization via Response Surface Methodology

Interactive effects of dual short-chain n-alkanes on removal performances and microbial responses of biotrickling filters

Enhanced biotrickling filtration at the presence of surfactants could be competitive in treatment of waste gas streams polluted by hydrophobic volatile organic compounds (VOCs) such as light hydrocarbons, while few such reports are available. Herein, biotrickling filters (BTFs) were applied to investigate the removal performances for binary-component n-alkanes (n ≤ 6) at the presence of sodium dodecyl benzene sulfonate (SDBS), and the microbial responses were also examined. Interestingly, results showed that the existence of shorter chain n-alkanes promoted the removal of longer chain n-alkanes, as the elimination capacities (EC) of BTF for n-hexane increased by 44 ± 1.2 % when there was methane in incoming gas stream. While the presence of longer chain n-alkanes antagonistically affected shorter chain n-alkane removal, as EC for methane decreased by 65 ± 8.1 % at the presence of n-hexane. Additionally, the presence of SDBS improved the mixed n-alkane removal. EC of the BTF with 15 mg/L SDBS for mixed propane and n-hexane reached 55 ± 1.4 and 31 ± 0.5 g/m3·h respectively, which increased by 90 ± 4.6 % and 47 ± 0.9 % compared with those without SDBS. The richness of Bacillus and Sporosarcina was improved in the BTF fed with SDBS. Moreover, the presence of SDBS improved the content of hydrophobic proteins and the activity of fluorescent substances inextracellular polymeric substances. Also, both the activities of ATPase and the antioxidant capacity of microbial cells exhibited higher than that when SDBS was not added. These data could lead to a better understanding and more reasonable design of biotrickling filtration to remove n-alkanes from waste gas streams of refinery wastewater treatment plants.

Molecular transformation of dissolved organic matter in refinery wastewaters: Characterized by FT-ICR MS coupled with electrospray ionization and atmospheric pressure photoionization

Dissolved organic matter (DOM) in refinery wastewater is an extremely complex mixture of various organic compounds. Using mass spectrometry, it is impossible to characterize all of the DOM molecules with only one ionization source. In this study, negative-ion, electrospray ionization (ESI), positive-ion ESI, and positive-ion atmospheric pressure photoionization (APPI) were coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to analyze the molecular composition of DOM in a refinery wastewater stream during the treatment process. There were obvious differences in the heteroatom composition, number of DOM constituents, and chemical properties in refinery wastewater under the three ionization modes. Acidic CHO and CHOS compounds detected by (−)ESI, basic CHN and CHON compounds detected by (+)ESI, and hydrocarbons detected by (+)APPI were analyzed to determine the molecular transformations that occurred during treatment. In an anaerobic biological treatment process, acidic CHO and CHOS compounds with a high oxygen content were preferentially removed, and acidic CHO and CHOS compounds with a low oxygen content were produced. In an aerobic biological process, acidic CHO and CHOS compounds with a low oxygen content were preferentially removed, and acidic CHO and CHOS compounds with a high oxygen content were produced. The whole biological treatment process has a poor removal efficiency for CHN and CHON compounds, and hydrocarbons. An activated carbon (AC) adsorption process removed different heteroatom compounds mainly with a low oxygen content for acidic and basic compounds. The transformation mechanism of CHO and CHOS compounds in the biological treatment process was analyzed by the Kendrick mass defect (KMD) theory and a mass difference network analysis. In the anaerobic process, large amounts of oxygenated CHO and CHOS compounds were degraded by decarboxylation, deoxydation, demethoxylation, and dehydration reactions, and converted to lower oxygen content compounds. In the aerobic processes, these low oxygen CHO and CHOS compounds mainly underwent carboxylation and oxidation reactions. This study determined the transformation characteristics and mechanisms of different types of organic compounds in refinery wastewater during the treatment process. The results provide guidance for the design and optimization of technologies for refinery wastewater treatment. • Molecular composition of DOM in refinery wastewater was characterized by ESI and APPI FT-ICR MS. • Transformation characteristics and mechanism of different types of compound were investigated. • Biological process could remove acidic CHO and CHOS compounds. • AC adsorption process removed various different heteroatom compounds.

Integrated Photocatalytic Oxidation and Adsorption Approach for the Robust Treatment of Refinery Wastewater Using Hybrid TiO2/AC

This study reports the removal of hydrocarbon (HC) pollutants from petroleum refinery wastewater by integrated photocatalytic oxidation and adsorption using a TiO2/AC hybrid material. The hybrid adsorbent/catalyst was prepared by the impregnation of TiO2 over AC and characterized by FTIR, SEM, EDX, and XRD analyses. Under the optimized reaction conditions of pH 3, 30 °C, and 1000 mg TiO2/AC per 500 mL of sample in 50 min, the integrated photocatalytic oxidation-adsorption achieved a net percentage removal of benzene, toluene, aniline, and naphthalene of 91% from model HC solutions. Under these conditions, for the treatment of real refinery wastewater, TiO2/AC caused a 95% decrease in chemical oxygen demand (COD). The integrated photocatalytic oxidation and adsorption using TiO2/AC showed a clear advantage over the individual adsorption and photocatalytic oxidation using AC and TiO2, whereby about the same level of removal of model HCs and a decrease in the COD of refinery wastewater was attained in 105 min and 90 min, respectively, utilizing larger adsorbent/catalyst dosages. GC-MS analysis revealed that during the integrated process of adsorption-photocatalytic oxidation, all the parent HCs and oxidation byproducts were completely removed from the refinery wastewater. Based on the outstanding performance, cost-effectiveness, and environmental greenness, the newly designed TiO2/AC via the integrated adsorption-photocatalytic oxidation can be counted as an effective alternative route for the large-scale processing of refinery wastewater.

Thermal hydrolysis of solid fraction reduces waste disposal and provides a substrate for anaerobic photobiological treatment of refinery wastewater

In this study, a photoanaerobic PPB-based biological system for the treatment of refinery wastewater and oily sludge pretreated by thermal hydrolysis has been studied within the framework of sustainability.

Experimental study of chemical oxygen demand removal by electrochemical oxidation treatment of petroleum refinery wastewater by using response surface methodology

Experimental study of chemical oxygen demand removal by electrochemical oxidation treatment of petroleum refinery wastewater by using response surface methodology

Facile Synthesis of Silver Nanoparticles from Mesquite Tree Leaves for Refinery Wastewater Treatment

Green synthesis of nanoparticles has gained significant importance, and it has become the one of the most preferred synthesis methods. Mesquite or Prosopis juliflora is an aggressive, thorny tree is threatening the ecology and has a negative impact on the environment, and animal health as it absorbs nutrients from soil, prevents the water flow in aflaj. Therefore, the purpose of this research is to synthesize silver nanoparticles (AgNPs) from mesquite leaf extract by green extraction technique for the refinery wastewater treatment applications. The AgNP’s are characterized by Fourier Transform Infrared spectroscopy (FTIR), Energy Dispersive X - Ray Analysis (EDX), UV-visible spectroscopy, and Scanning Electron Microscopy (SEM) analyses to determine the functional groups, morphology, and elemental composition. The synthesized AgNP’s are utilized for the treatment of refinery wastewater by performing a series of experiments by varying the processing parameters (pH, mixing duration, agitation speed, and dosage of nanoparticles) and the optimum treatment conditions were established. This research aims to convert the mesquite tree leaves into a value added product, AgNP’s for the refinery wastewater treatment, thereby reduce its impact on the environment. Additionally, this research is in line with the United Nations Sustainable Development Goals (UNSD-6, clean water and sanitation) and also supports the Oman Vision 2040.

Cotton Spinning Waste as a Microporous Activated Carbon: Application to Remove Sulfur Compounds in a Tunisian Refinery Company

The petroleum industry plays a vital role in the economies of developing countries. Refinery wastewater pollution has increased in recent years due to the increase in the industrial and urban use of petroleum products. The present work demonstrates how textile waste can be modified into a material that can effectively remove sulfur pollutants from refinery wastewater. An economic activated carbon (AC) material was developed by using cotton spinning waste from a textile company. The chemical activation was carried out using nitric acid (HNO3), hydrogen peroxide (H2O2), and potassium hydroxide (KOH). The characterization of the obtained activated carbons was performed using the SEM, BET, and FTIR techniques. The effect of the experimental adsorption condition was investigated using both bed and batch isotherms. The results show that effluent flow has the highest effect on sulfur compound adsorption. The greatest adsorption capacity of the sulfur compounds was found to be around 168.4 mg·g−1. The equilibrium data were investigated using the Freundlich, Langmuir, Dubinin–Radushkevich, Tóth, and Sips isotherm models. The Langmuir model exhibited the best fit (R² = 0.98) for the sulfur compounds’ adsorption, which implies that their adsorption onto the synthesized AC was homogeneous. The kinetic data were tested with pseudo-first-order, pseudo-second-order, and intraparticular diffusion equations. The pseudo-second-order equation described the kinetic data well (R² = 0.99), indicating that this adsorption may be restricted by the chemisorption process. These properties under optimal conditions make the obtained ACs suitable for use in refinery wastewater treatment.

Refinery Wastewater Treatment by a Novel Three-Dimensional Electrocoagulation System Design

A novel three-dimensional electrocoagulation method was used in the current work to explore the treatment of refinery wastewater. Metal-Impregnated Granular Activated Carbon (MIGAC) was employed as a third particle electrode in the inventive design. A comprehensive investigation has been conducted to evaluate its performance. BET-specific surface area, total pore volume, X-ray Fluorescence (XRF), Energy-Dispersive X-ray spectroscopy (EDS), and Scanning Electron Microscopy (SEM) were employed for the characterization of MIGAC particle electrodes at pH=7, 30V applied voltage, 10g of particle electrodes, 175mL/min flow rate, and a supporting electrolyte (0.063M NaCl + 0.025M Na2SO4). The findings indicate that the effectiveness of Chemical Oxygen Demand (COD) elimination increased quickly after 20min to 66.93, 69.88, 77.59, 74.14, 81.26, 79.87, and 87.14% for Conventional Electrocoagulation (CEC). Three-dimensional electrocoagulation with granular activated carbon (TEC-RGAC), TEC-MIGAC (Al), TEC-MIGAC (Fe), and TEC-MIGAC (Al:Fe) with molar ratios of (1:1), (1:2), and (2:1) respectively were utilized. While turbidity removals were 99.04, 98.87, 99.23, 94.89, 92.42, 98.85, and 99.21% for CEC ,TEC-RGAC, TEC-MIGAC(Al), TEC-MIGAC(Fe), TEC-MIGAC(1:1), TEC-MIGAC(1:2), and TEC-MIGAC(2:1) respectively. The results demonstrated that the metal impregnation of GAC is an interesting method for achieving effective turbidity and COD removal from refinery wastewater. In both batch and repeat recycling tests, MIGAC with a mixture of aluminum and iron oxides removed turbidity and COD more effectively and efficiently than RGAC.

Media coalescence filtration as a novel method for pretreatment of refinery wastewater

Refinery wastewater is not only large in volume but also complex in composition. It requires multi-stage treatment to achieve discharge or reuse targets. Pretreatment plays an important role as a front-end treatment. In conventional pretreatment technologies, petroleum removal and suspension removal are carried out through inclined plate settlement combined with two-stage air flotation. This poses problems such as high energy and chemical consumption and large outputs of hazardous waste. In this study, a short-process physical pretreatment technology is designed in conjunction with combined fiber coalescer (CFC) and granular media filter (GMF). The results of the pilot test show that with no added chemicals, the treated refinery wastewater is clear and translucent, and the petroleum and suspended solids content could be reduced to less than 20 mg/L, which falls within the acceptable range of the biochemical influent index. This process could greatly reduce the generation and emission of scum and volatile organic compounds (VOCs) and provides a new technique for the low-carbon pretreatment of refinery wastewater.

A novel photoanaerobic process as a feasible alternative to the traditional aerobic treatment of refinery wastewater

Refinery wastewater (RWW) treatment is outdated since new wastewater management and reuse challenges require more environmental-friendly and cheap alternatives. Conventional biological treatments focused on activated sludge are highly energy-intensive and resource-dissipating processes. However, anaerobic treatments are an excellent alternative to reduce costs derived from aeration and carbon footprint. This work proposes a novel strategy for the treatment of RWW involving a photoanaerobic membrane bioreactor (PAnMBR) with a mixed culture of purple phototrophic bacteria (PPB). PPB upcycles the organic matter, nitrogen, and phosphorus in an assimilative way, leading to a much higher biomass yield and nutrient removal than aerobic cultures. The enriched PPB culture was generated from the RWW as the sole substrate without specific PPB inoculation. The RWW (exempted from sufficient nutrients) was successfully treated with additional ammonium and phosphates provided by domestic wastewater (DWW). Preliminary batch tests determined the best DWW/RWW volumetric mixing ratio at 25:75. The PAnMBR was operated for 144 days under different specific loading rates (SLR) by modifying hydraulic and solid retention times. The maximum specific loading rate (SLR) for the efficient RWW/DWW mix treatment was 0.3 mgCODinlet/mgCODbiomass·d. The COD consumption was mainly mediated by Rhodopseudomonas sp. and Rhodobacter sp. PPB genera. The PPB-based photo-anaerobic membrane reactor was able to comply with regulated parameters for wastewater discharge for the more restrictive use of reclaimed water according to the European legislation in force.

The Development of Polymeric Composite Membrane Containing Plant Waste Derived Activated Carbon and TiO2 for Raw Petroleum Refinery Wastewater Treatment

Petroleum industry results in a huge amount of harmful oily wastewater that must be properly treated. The fabricated composite membrane comprising polyvinylidene fluoride (PVDF), cassava peel-derived activated carbon (AC), and TiO2 was then developed for treating raw petroleum refinery wastewater containing high loading of organic and inorganic pollutants. This study applied different ratios of AC/TiO2 by 0, 1, 2, and 3% in the membrane fabrication solution to study the effect of composite ratio on the quality of permeate, fouling rate, and membrane tensile strength. The experimental work found that the ratio of AC/TiO2 by 3% in the composite membrane outperformed the other ratios. The additives addition by 3% could achieve more than 40, 71, 40, and 67.5% of COD, oil, BOD5, and phenol removal efficiency, respectively. It also reached a lower flux decline by 25% within 250 min of filtration time. Hermia’s model was then applied to study the fouling mechanism occurring during membrane operation. Additionally, it was indicated that membrane tensile strength was also influenced by composite ratio, where higher PVDF amount resulted in higher membrane tensile strength. Overall, this study concluded that composite membrane could be a reliable alternative for treating raw industrial wastewater to existing wastewater treatment technologies. Further research related to the composite membrane integration system with other treatment techniques can then be conducted to lengthen membrane lifespan and improve the permeate quality.

Treatment of petroleum refinery wastewater by adsorption using activated carbon fixed bed column with batch recirculation mode

Water pollution and the lack of access to clean water are general global problems that result from the expansion of industrial and agricultural activities. Petroleum refinery wastewaters consider as a major challenge to the environment and their treatment is mandatory. The present work concerns with the removal of chemical oxygen demand (COD) from petroleum refinery wastewater taken from Iraq's Al-Diwaniyah petroleum refinery plant by using an activated carb fixed-bed column operated at a batch recirculation mode. The fixed bed column used in this work was composed of three sections: upper, central, and bottom compartments. The bottom compartment serves as a feeding chamber to the central adsorption chamber while the upper compartment serves as a collecting effluent chamber. By adopting response surface methodology (RSM), in the pacts of various operational parameters such as packing level, pH, and time on the COD removal efficiency were investigated. The optimal conditions were an activated carbon packing level of 80%, pH of 5.7, and adsorption time of 73 min approximately, which resulted in a COD removal efficiency of 96.70%. The results indicated that the packing level of activated carbon had a major effect on COD elimination followed by pH, while time had a minor effect. The model equation's adequacy was demonstrated by its strong R2 value (0.975). The present study demonstrates that the adsorption system by activated carbon is an effective method for removingcondomODom Al-Diwaniyah petroleum refinery wastewaters.