Grease Removal Research Articles

TREATMENT OF WASTEWATER GENERATED FROM AUTOMOBILE SERVICE STATIONS USING CORN COB AS ADSORBENT

Automobile wastewater is one among the heavily contaminated wastewater consisting of harmful elements such as surfactants, oil and grease, dust particles, and various dissolved and suspended solids. In this study, car wash water from an automobile wash center in Chennai, Tamil Nadu was collected and treated with waste from corn crops that is inedible. The increase in automobile industries and similar wash centers is contributing to environmental contamination. Due to the low cost and availability, the efficiency of removal of pollutants, and since it promotes environmental sustainability, natural materials are adopted more than chemicals. The study adopted using a column adsorption process and it showed good results in the physiochemical characteristics where it has adsorbed oil and grease, TDS, and TSS. Oil and grease removal by 71.4% was observed whereas the biochar was found to be effective with an 89% reduction in total dissolved solids and more than 50% decrease in parameters such as TSS, COD, conductivity, oil and grease, and total alkalinity. The adsorption isotherm was studied with varying particle size and bed height along with the comparison of removal efficiency of various parameters in this experimental investigation.

Treatment of Dairy Wastewater with Pretreatment Techniques and Sequencing Batch Reactor for the Removal of Pollutants: Kinetics and Optimization

In order to remove pollutants like BOD, COD, TKN, TP, TSS, sulphates, chlorides, oil and grease effectively, this study outlines the treatment of dairy effluent by employing the advanced oxidation process (AOP) as pretreatment method with a sequencing batch reactor. It also describes the impact of aeration time and bacterial mass concentration (MLSS) in the sequencing batch reactor for pollutant removal. The high percentage of nutrient contents can be removed by the sequencing batch reactor (SBR), which only needs a single tank for the entire treatment procedure. The pretreatment technique of a combination of ozone and AOP was introduced into the dairy effluent to increase the removal efficiency of pollutants. In this research, the optimal conditions for ozone were a pH of 10, a reaction time of 5 minutes, and an amount of H2O2 of 10 mL/L. The experiments were conducted in the 4 L Plexiglas reactor and the analysis was carried out for different aeration times of 4, 6, 8, 12, 16 and 24 h at the different MLSS concentrations of 2100, 2400, 2900, 3200, 3700 and 4200 mg/L after the addition of ozone and hydrogen peroxide. In this analysis, the higher percent removal of BOD, COD, TKN, TP, TSS, sulphates, chlorides, oil and grease was obtained for the MLSS of 2100 mg/L at the aeration time of 16 h. The percent removal of above pollutants for the above MLSS concentration was in the order of 99.8%, 99.6%, 76.7%, 99%, 99.3%, 34%, 46% and BDL, respectively. The GC-MS analysis was carried out to find the level of contaminants present in the raw and treated water. Further, the sludge analysis was done for the wasted sludge to find its characteristics and its uses. This study suggests that at low MLSS concentrations, a large percentage of pollutants can be removed.

EFFECT OF PALM OIL BUDLE ASH ON REDUCTION OF OIL/FAT HOSPITAL WASTEWATER

Activities in healthcare facilities have a negative impact in the form of pollution due to waste disposal without proper processing. One of the most dangerous is lipid or fat waste in wastewater. Lipids are also a threat to the aquatic environment, such as those found in ditches and rivers. Oil/fat will cause pollution in the river and in the processing plant itself thereby reducing the efficiency of wastewater treatment. Oil and grease removal usually uses physical methods, namely by trapping oil/fat with a grease trap. The second uses a flotation process utilizing the force of gravity. It is hoped that the ash of empty palm fruit bunches can be used to reduce the oil/fat content in hospital wastewater as another alternative to set aside oil and grease. This research was conducted to determine the relationship between quantitative variables to determine the model to be used. The distribution of the dots on a scatter plot chart can show the relationship between variables. The relationship studied is in the form of patterns that are observed visually and to obtain correlation determinants and equations (models) of the relationship between variables through scatter plot graphics. The results of this study indicate that there is a relationship between the addition of empty palm fruit bunch ash to the reduction of oil and fat. Adding 0.1 mg.l-1 of empty palm fruit bunch ash resulted in an average decrease in oil and fat content of 60.34%; The addition of 0.2 mg.l-1 resulted in a decrease of 75.38% and the addition of 0.5 mg.l-1 after a decrease of 90.42%. To reduce the oil and fat content to 0 (zero) (perfect emulsion) to 3.25 mg.l-1 sample from the simple regression equation (y = -4.8969x + 2.3919) is 0.47 g/liter of waste water or 0 .47 kg/m3 of wastewater.
 

New kinetic models for predicting the removal of oil and grease from food-processing industry wastewater

Biochemical accumulation rate of Serratia marcescens SA30 to remove the oil and grease (O&G) contaminant from a wastewater can be described using the kinetic models of packed-bed column reactor (PBCR) treatment system. The aim of this study was to develop the linear and logarithmic equations for predicting the efficiency of O&G removal from food-processing industry wastewater. The results showed that the performance of PBCR treatment process can achieve nearly 100% efficiency when the PBCR experiments were run using the initial O&G concentrations of 26.9 and 33.5 g L−1 with a volumetric flow rate of 0.18 L h−1. The applicability of the linear and logarithmic equations represented a quick and reliable method to monitor the trend of O&G removal by the PBCR treatment process contributes to strengthening the future biotechnological methods of treating oil-contaminated wastewater in the tropical environment.

Application of isotherm models to combined filter systems for the prediction of iron and lead removal from automobile workshop stormwater runoff

Langmuir and Freundlich isotherm adsorption models were used to predict iron and lead removal from automobile workshop stormwater runoff. Combined low-cost filter systems consisting of granular activated carbon–rice husk (GAC–RH) and river gravel–granular activated carbon (GR–GAC) were used in this study. The effects of adsorbent dosage and contact time on the adsorption capacity of the adsorbents, as well as the removal efficiencies of the adsorbent systems, were also investigated. The results for the Langmuir model generally showed favourable adsorption processes., with all RL values < 1 (in the range 0.358–0.518). The Langmuir model gave better predictions for iron and lead removal, with high R2 values (in the range 0.842–0.969), while the root mean square error (RMSE) values ranged from 0.002 to 2.366. The Freundlich model parameters indicated chemisorption processes with all n values < 1 (in the range 0.1296–0.4675). R2 values were in the range of 0.634–0.916 while RMSE values ranged from 0.002 to 0.1765. Additionally, the removal efficiencies for iron and lead using GAC–RH filter system (54% and 48%, respectively) were found to be higher than those obtained using GR–GAC filter system (35% and 25%, respectively). The adsorption capacities of the adsorbents decreased with increased dosages of the adsorbent, with optimum adsorbent dosage of 0.5 g and equilibrium contact time of 80 min for the combined filter adsorbents. Further research towards modifying adsorbents for removal of oil and grease from polluted automobile workshop stormwater runoff are warranted.

Induced air flotation for fat, oil, and grease recovery in urban wastewater: A proposed methodology for system optimization and case study

Induced air flotation (IAF) is a well-known technology that is widely applied in urban wastewater treatment plants (WWTP) for fat, oil, and grease (FOG) removal. However, most IAF systems are not optimized and typically operate with fixed parameters, regardless of inflow variations. Furthermore, the optimization of IAF systems is limited by the lack of equipment in WWTP laboratories to determine FOG concentrations in wastewater. In this study, an adapted sulfo-phospho-vanillin method for FOG quantification in wastewater is proposed for optimization and automation of the IAF system. The proposed methodology requires simple equipment that is widely available in WWTP laboratories, paving the way for in situ FOG determination. The method was successfully employed to determine the optimal operating conditions of the IAF system in terms of hydraulic retention time and organic loading rate. Furthermore, a full-scale IAF system was optimized using this methodology and its energy demand was reduced by 40 %.

Investigating the correlation of nitrates and phosphates to the effective removal of Fats, Oils, and Grease in Two Mangaung Municipal Wastewater Treatment Plants

This study is about the effectiveness of wastewater treatment technologies in two treatment plants at Mangaung Municipality in South Africa. The removal of FOG, nitrogen and phosphorus is an important component of wastewater treatment. Therefore, the study aims at investigating the effectiveness of the two treatment technologies (biological trickling filter and activated sludge) in the wastewater treatment plants studied. Grab samples of the influent and effluent of the North East Wastewater Treatment Plant (NEWTP) and the Bloemspruit Wastewater Treatment Plant (BWTP) were collected per week over a period of five months. The laboratory analysis of FOG followed the description of the Environmental Protection Agency (EPA) 1664B. Hexane extraction and gravimetry-PBM method was used in the analysis. Nitrates were analysed using a SOP Chem 005 Spectroquant Nitrate test while phosphates were analysed using a Spectroquant Prove spectrophotometer in the laboratory. The results showed that the trickling filter from BWTP removed FOG by 61.36% while the activated sludge from NEWTP removed FOG by 52.81% which showed that the both of the two treatment technologies work the same and are ineffective in the removal of FOG. However, the nitrates and phosphates present in the effluent were found to be within the effluent discharge standards.

Fenton process for the treatment of wastewater effluent from the edible oil industry.

The present study intends to investigate the performance of the Fenton reaction as one of the most efficient (AOPs) in a batch mode for treating wastewater effluent from the edible oil industry, as well as the parameters that influence the reaction, such as pH, hydrogen peroxide (H2O2), and ferrous sulfate heptahydrate (FeSO4.7H2O) doses at various reaction times. The response surface methodology (RSM) was applied with a central composite design (CCD) for optimizing the responses of pollutant removals. The obtained results indicated that the authenticated response to the chemical oxygen demand (COD) removal was 93.52%, at optimum values of pH, FeSO4.7H2O dose, H2O2 dose, and reaction time of 3, 1 g/L, 8.38 g/L, and 50 min, respectively. Furthermore, the authenticated response to oil and grease (O&G) removal was 99.8%, at optimum values of pH, FeSO4.7H2O dose, H2O2 dose, and reaction time of 3, 0.71 g/L, 8.7 g/L, and 37.4 min, respectively. Under these conditions, the residual COD and O&G after Fenton oxidation become 155.4 mg/L and 10 mg/L, respectively.

A Low Cost Material for Treatment Wastewater Contained Petroleum Pollution

One of the major problems facing the water environment is the pollution resulting from petroleum, refineries and oil industries which resulting a great danger to humans, aquatic organisms and water resources in the world. In this study, Conocarpus plant was employed as natural adsorbent substance which performed to reduce the concentration of contaminates exiting in the petroleum wastewater. The pollutants that have been removed are phenol, grease and oil. The laboratory experiments using Bach technique. Maximum efficacy of phenols removal was (83.694 %) at pH of (3.7). The highest efficacy of oil and grease removal (99.861 %) achieved at adsorbent mass of (15g), pH (9.77) and time of (120 min.). The Conocarpus plant has been shown to be effective in removing of pollutants (phenols, oil and grease) from wastewater. Efficacy of phenol removing progressed in increasing with adsorbent mass. The acidic pH value contributes greatly to increasing the efficiency of removal for both phenols, oils and grease. Maximum. amount of oil and grease adsorbed in solid phase was (17.369 mg/g). The results demonstrated that Conocarpus plant as natural adsorbent can be efficiently applied in refiners, grease and petroleum industry for eliminating pollution.

바이오가스화를 위한 음폐수 내 유분의 영향

The grease contained in the food wastewater is not easily decomposed at a short residence time and may cause scum by combining with the solids in the food wastewater. Therefore, it is necessary to effectively remove the grease in order to efficiently treat the food wastewater and solve the operational problems in the anaerobic digester. The purpose of this research was to compare the grease effects for biogas production before and after grease removals in food wastewater using by two-phase anaerobic digestion process. After removing the grease in the food wastewater, the anaerobic digester could be operated stably, and the biogas production was also high. Biosorp and ferric chloride had an excellent effect on removing hydrogen sulfide (H₂S) in the digester. Considering economic feasibility and convenience, ferric chloride is judged to be more suitable for hydrogen sulfide removal than Biosorp.

AN INNOVATIVE SOLUTION FOR THE TREATMENT OF POULTRY INDUSTRY WASTEWATER WITH ADVANCED HYBRID TECHNOLOGY SONO-PHOTOCATALYSIS

<p>Poultry slaughterhouse wastewater (PSWW) is a crucial concern fundamentally due to extensive generation and related substantial amounts of recalcitrant organic content due to high COD and oil and grease (O&G) levels. Hybrid advanced oxidation processes are promising, green, and innovative options to treat various industrial wastewater; to date, this potential has not been implemented to high-strength wastewater from the poultry industry. This work aims to investigate the combination of ultrasound and photocatalysis processes in the treatment of poultry slaughterhouse wastewater for the removal of COD and O&G under different operating conditions such as catalyst type (TiO2 and ZnO), irradiation type (UVA365 and UVC254), catalyst dosage (0.5-2.5 g/L), pH (2–10), hydrogen peroxide concentration (0-10 mM) and operation time (30-180 min). Taguchi’s experimental design based on the L36 orthogonal array was adequately applied to optimize the process. The finding results presented that ZnO concentration of 2.5 g/L, pH 2, and operation time of 180 min under UVC254 were optimum parameters to achieve maximum COD removal while, ZnO concentration of 1.5 g/L, pH 6, H2O2 concentration of 5 mmol/L and operation time of 30 min under UVC254 were optimum parameters to achieve maximum oil and grease removal. With these optimum conditions, the best attained COD and O&G removal yields were 54% and 99%, respectively.</p>

Statistical Optimization for Cost-Effective Production of Yeast-Bacterium Cell-Bound Lipases Using Blended Oily Wastes and Their Potential Applications in Biodiesel Synthesis and Wastewater Bioremediation

Oily wastes have been widely used to produce lipases, but there is insufficient knowledge on their use to efficiently produce cell-bound lipases (CBLs). This research aimed to optimize yeast–bacterium CBLs production using blended oily wastes by statistical optimization and their potential applications in biodiesel production and wastewater bioremediation. The co-culture of Magnusiomyces spicifer AW2 and Staphylococcus hominis AUP19 produced CBLs as high as 4709 U/L with cell biomass of 23.4 g/L in a two-fold diluted palm oil mill effluent (POME) added by 2.08% (v/v) waste frying oil, 1.72.0% (w/v) ammonium sulfate, 0.1% (w/v) Gum Arabic as an emulsifier (initial pH at 7.0) within 24 h. The CBLs were successfully applied as whole-cell biocatalysts to produce biodiesel through esterification and transesterification with 76% and 87% yields, respectively. Direct application of CBLs for bioremediation of heat-treated various POME concentrations achieved 73.3% oil and grease removal and 73.6% COD removal within 3 days. This study has shown that the blended oily wastes medium was suitable for low-cost production of yeast–bacterium CBLs and their potential applications in solvent-free biodiesel production and wastewater bioremediation. These strategies may greatly contribute to economical green biofuel production and waste biotreatment.

Enhanced sewage sludge treatment via parallel anaerobic digestion at the upper mesophilic level

Sewage mixed sludge (MS) digestion performance was ameliorated implementing the parallel digestion model for primary sludge (PS) and secondary sludge (SS) (waste activated sludge) as domestic sewage sludge fractions rich in oil and grease content at the upper mesophilic level (40 °C). Optimization of the organic loading rate (OLR) was conducted in parallel semi-continuous bench-scale digesters for PS, SS and MS. Comparatively evaluated performance and biosolid quality parameters were methane production rates, volatile solid (VS) reduction, oil and grease and nutrient content, dewaterability and electrical conductivity (EC). OLR optimization indicated different retention time needs for PS and SS stabilization and enabled 18% and 93% higher VS loading and reduction, respectively, compared to MS digestion. Inhibitory effect followed an ascending pattern as a result of OLR increase in each digestion line acting on the hydrolysis of proteinaceous matter and acetogenesis rather than methanogenesis. A high number of long chain fatty acids was detected in the raw sludges. The enhancing effect of the upper mesophilic temperature was significant in SS digestion with increased biodegradability, oil and grease removal and microbial growth compared to digestion at 35 °C. The parallel digestion system and upper mesophilic temperature proved a useful tool to enhance VS loading and reduction without worsening the stabilized biosolids’ dewaterability as a feasible model in the existing and prospective municipal wastewater treatment plants (WWTPs). The weakness of the MS digestion was diagnosed as the lower synthesis degree of biomass induced by the dilution of the substrate in PS by SS mixing which weakened the microbial tolerance to high OLR and inhibition. The output indicated the potential of parallel AD, importance of the optimization for OLR and temperature to advance the performance and flexibility of the sludge line practice in municipal WWTPs.

Avaliação da eficiência de reatores anaeróbios na remoção de poluentes em efluentes do processamento de pescado

ABSTRACT The objective of the present work was to evaluate the performance of a compartmentalized anaerobic reactor (CAR) followed by anaerobic filter in real scale, effluent treatment from fish fridge processing. The work was developed in a fish fridge located in the south of the state of Minas Gerais, which has an effluent treatment plant composed of static screen, grease removal device, CAR reactor and anaerobic filter. The monitoring happened trough physical-chemical parameters of fluids and effluents from all sampling points of the plant biweekly. The parameters evaluated were temperature, pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), volatile suspended solids (VSS), volatile fatty acids (VFA) and alkalinity. Operational problems found in the primary treatment were not limiting for the system performance, which managed to meet the parameters of environmental legislation in Minas Gerais according to the efficiency of removal of COD, BOD and VSS from wastewater from fish processing.

Artificial neural network (ANN) and response surface methodology (RSM) algorithm-based improvement, kinetics and isotherm studies of electrocoagulation of oily wastewater

The work reported here focuses on the oil and grease removal from wastewater by the electrocoagulation process and using modeling and optimization for obtaining the results considering four major operating parameters, viz. current density, pH, electrode distance and reaction time. 31 experiments were designed by design of experiments (DOE) of response surface methodology (RSM) and the analysis of variance (ANOVA) studies confirmed the agreement of the experimental results. Artificial neural network (ANN) was also utilized to determine predicted response using neural networks for 4-10-1 arrangement. Both the responses predicted by RSM and ANN were in alignment with the experimental results. Maximum removal of 78% was attained under the working parameters of 80 A m– 2 , 3.6 pH, electrode distance of 0.005 m and reaction time of 20 min.

Poultry Slaughterhouse Wastewater Treatment Using Combine Anaerobic Filter with Constructed Wetland Methods

BACKGROUND: Poultry slaughterhouse wastewater has a complex composition that is very harmful to health and the environment. A two-stage system is applied to treat wastewater, consisting of an anaerobic filter (AF) combined with constructed wetland (CW). AIM: Experiments carried out under mesophilic conditions aim to evaluate the performance of a biological treatment combining AF and CW on three media filters. METHODS: Observations were made for 15 consecutive days on chemical oxygen demand (COD), BOD5, TSS, pH, and fat oils and grease FOG (35.5 mg/L). The treatment system is operated with a sewage loading of 14 m3 s-1 and an RTH of 18.2 h. RESULTS: The results showed that before processing, the average values of COD (2881.4 mg/L), BOD5 (967 mg/L), TSS (860.3 mg/L), pH (6.7), and FOG (35, 5 mg/L). The greater efficiency was obtained using gravel media, BOD5 (88.9%), COD (92.9%), TSS (93.4%), and FOG (87.3%). Optimal treatment conditions in this system were found for AF with gravel media, operating at hydraulic retention time = 4.2 h, out of a total of 18.2 h. The IB value increased from 0.3 to >0.5, indicating the combined AF and CW method is suitable for treating wastewater from poultry slaughterhouses. CONCLUSIONS: The combination of the AF method and CW is well applied to the wastewater treatment of poultry slaughterhouses, and parameters values have complied with the applicable regulations. Nevertheless, the removal of oil and grease is highly recommended in pre-treatment to inhibit the anaerobic process.

Application of Electrocoagulation in Street Food Wastewater

Street food is commonly known as ready-to-eat and go foods and beverages, which is very famous in Thailand and other Asian countries. The street food daily generates high organic content and oily wastewater from washing and rinsing plates. The discharge of street food wastewater to public drains leads to a clogged drain line and unpleasant smell. In this work, an electrocoagulation (EC) system with monopolar aluminum (Al) electrodes was developed to treat two well-known street foods; Hainanese chicken rice (HC) and noodles and dumplings (ND). The results revealed that excellent chemical oxygen demand (COD) and fat, oil, and grease (FOG) removals were achieved under a specific operating condition (i.e., an electric current of 20 mA/cm2 and electrolytic time of 10 min). The initial COD of HC wastewater decreased from 40.6 g/L to 1.9 g/L, approximately 95%, whereas the FOG decreased from 310 mg/L to 50 mg/L, approximately 84%. The lower initial COD and FOG concentrations of ND wastewater obtained approximately 98% for COD removal and 86% for FOG removal; the effluent contained 0.5 g/L of COD and 25 mg/L of FOG. In addition, a relatively low Al concentration of 0.02–0.08 mg/L was observed in the effluents. The appropriate design factors together with ease of use and fast pollutants removal were significant advantages of this study; the EC system has potential to apply to on-site street food treatment.

A comparison of oil and grease removal from automobile workshop stormwater runoff using gravel, granular activated carbon, rice husk and conventional oil and grease (O&G) trap

Oil and grease (O&G) removal efficiencies using 4 automobile stormwater treatment systems were investigated and compared. The treatment systems used were: low-cost granular activated carbon–rice husk (GAC–RH) filter system, river gravel–granular activated carbon (GR–GAC) filter system, rice husk only (RH) filter system and the conventional PVC O&G trap (COT). Sampling of automobile stormwater from the five selected automobile workshops was carried out using the manual grab sampling methods. The treatment involved filtration using the low-cost technologies and O&G separation from stormwater. GAC–RH exhibited the highest O&G removal with an average removal efficiency of 43.2% from all the automobile workshops, followed by RH with an average removal efficiency of 31%. O&G removal using GR–GAC and COT resulted in average removal efficiencies of 28.6% and 26.8%, respectively. Further studies need to be carried out to optimize the GAC and RH low-cost filter materials for the purpose of achieving the USEPA and Nigerian effluent standards of 0.1 mg/L, since all the treatment systems produced effluents with minimum concentrations ranging between 0.8 mg/L and 3.6 mg/L.

Predesign Cost Estimation of a Potential Wastewater Treatment Plant for Jordan Petroleum Refinery-Electrocoagulation

The aim of this paper is to investigate whether simulated Jordan refinery wastewater can be treated through electrocoagulation (EC) to conform to the most stringent Jordanian norms for reusing this wastewater for irrigation of cut flowers and to perform cost analysis for a treatment plant whose core are the EC reactors. The method used for estimating the fixed (capital) costs of the treatment plant is taken from literature and is based on a study estimate (factored estimate) that depends on the knowledge of major items of equipment. Most of the operating costs are estimated based on percentages which are also taken from literature. The best percentage removal of COD, BOD, TSS, fat, oil & grease (FOG), bicarbonate (HCO3−), and phenol from simulated Jordan refinery wastewater, so that it conforms to Jordanian norms, were 84.4%, 82.1%, 27.3%, at least 98.8%, 94.9%, at least 96.7%, respectively, at a current of 10 A, treatment time of 5 min, Al/SS electrodes, and inter-electrode distance 10 mm. Overall treatment costs for the simulated wastewater was found to be 10.75 $/m3 (27 $/kg CODremoved). It is concluded that simulated Jordan refinery wastewater cannot be treated so that it conforms to the most stringent norms for using it for cut flower irrigation but could be treated to conform to the norms for using it for irrigation of cooked vegetables, parks, and playgrounds. Moreover, EC is a suitable technology for the treatment of Jordanian recalcitrant refinery wastewater and the cost for its treatment is affordable. • An affordable overall treatment cost for Jordan refinery wastewater was found. • Optimal pollutant removal efficiencies were achieved in electrocoagulation tests. • During wastewater treatment the most stringent Jordanian norms were not reached.

Investigation of the effect of current density and PH on oil and grease removal from leather industry wastewaters by electrocoagulation method

In this study, the effects of pH and current density on the removal of high concentrations of oil and grease in leather industry wastewater by the electrocoagulation method were investigated. Two different types of electrodes were used in the study. Studies with aluminum electrodes have shown that these electrodes are more effective than iron electrodes in removing oil and grease. In addition, aluminum electrodes are affected more by the system pH than iron electrodes. Studies have shown that higher oil and grease removal efficiencies are obtained below pH 4 for both electrodes. While the oil and grease removal efficiency with Al electrodes is 95% at pH 2, this value decreases to 83% at pH 6. In Fe electrodes, while the removal efficiency is 87.83% at pH 2, it decreases to 83% at pH 6. The effect of current density on oil and grease removal was examined and it was observed that the removal efficiency remained constant above a certain current density in aluminum electrodes. While the efficiency of Al electrodes is 83.31% at 0.6 mA cm-2 current density, this value has increased to about 98% at 1.2, 1.8, and 2.4 mA cm-2 current densities. In Fe electrodes, the oil and grease removal efficiency is 82.66% at 0.6 mA cm-2 current density, while it is 90% at 1.2 and 1.8 mA cm-2 current densities and 98% at 2.4 mA cm-2. These results show that the electrocoagulation process removes the oil and grease in wastewater at a high rate. This shows that this process can also be used as pre-treatment before the biological treatment of industrial wastewater with high oil and grease content.