Characterization of beta-lactamase producing Enterobacterales isolated from an urban community wastewater treatment plant in Iran.

Background and Objectives: he occurrence and characteristics of Extended Spectrum- and AmpC-ß-lactamase producing Enterobacterales (ESBL-PE and AmpC-PE) in an urban wastewater treatment plant (WWTP) were investigated. Materials and Methods: A total of 30 wastewater samples were collected from all sections of WWTP. Enterobacterales were isolated and identified using standard microbiological tests. The antibiotic resistance profile was determined by the Kirby-Bauer disk diffusion method. Phenotypic screening for ESBL-PE and AmpC-PE isolates was performed by double-disk synergy and boronic acid disk potentiation tests, respectively. The isolates were examined for AmpC- and ESBL-encoding genes by PCR and sequencing methods. Results: Among 146 Enterobacterales isolates, 8.9% (n=13) [ESBL-only; 5.48% (n=8) and ESBL + AmpC; 3.42% (n=5)] were ESBL-producers and 15.75% (n=23) [AmpC-only; 12.33% (n=18) and ESBL + AmpC; 3.42% (n=5)] AmpC-producers. Hafnia spp. with 33.33% (n=1/3) and E. coli with 20.58% (n=7/34) [ESBL-only; 17.64% (n=6/34) and ESBL + AmpC; 2.94% (n=1/34)] were the most common ESBL-producing bacteria. Enterobacter spp. with 37.50% (n=6/16) of isolates were the most common AmpC-producing organisms. ESBL- and/or AmpC-producing isolates were identified in all parts of the WWTP including 80% (n=8/10) of samples taken from effluent. Among ESBL-producing isolates, bla CTX-M , bla TEM, and bla SHV ESBL-encoding genes were found in 61.5% (n=8), 15.3% (n=2), and 7.7% (n=1) of isolates, respectively. All CTX-M-type enzymes belonged to the CTX-M-1 group and CTX-M-15 subgroup. bla TEM and bla SHV type genes belonged to bla TEM-20 and bla HSV-12 subtypes, respectively. bla DHA with 73.9% (n=17/23), and bla CIT and bla FOX with 30.4% (n=7/23) each, were the most common AmpC-encoding genes among AmpC-producing isolates. Overall, 75% of ESBL-producing and 55.5% of AmpC-producing isolates exhibited multi-drug resistance phenotypes. The organisms were most resistant against ampicillin (82.2%) nalidixic acid (43.8%) and cephalexin (41.1%). Conclusion: ESBL- and AmpC-producing Enterobacterales spp. with diverse genetic resistance backgrounds in WWTP effluent poses a significant risk to public health.

Investigation of the link between the type and concentrations of heavy metals and other elements in blood and urinary stones and their association to the environmental factors and dietary pattern.

BACKGROUND: Kidney and urinary tract stones are among the most common and important health problems, the prevalence of which is increasing nowadays due to a sedentary lifestyle, improper nutrition, destructive habits in fluid consumption, and improper use of medications. One of the causing factors in the formation of urinary stones is heavy metals. These metals present in tiny amounts in the environment and enter the nature and food cycle due to industrial activities and practices that are not compliant with environmental laws. METHODS: In this context, the present case-control study was conducted to determine the concentrations of heavy metals and other urinary stone-forming elements in both blood and urinary stones and investigate their relationship with environmental factors and dietary patterns in people with urinary stones in Ardabil city in 2022. The sampling of blood and urinary stones was done randomly from patients with urinary stones who were admitted to the Urology Clinic of Imam Reza Hospital, Ardabil. ICP-MS was used to measure the concentrations of heavy metals in the samples. The obtained data were analysed by chi-square test, ANOVA test, t-test, and Tukey test. RESULTS: The body mass index (BMI) was 27.39 ± 3.72 in the case group and 26.37 ± 2.95 in the control group. The copper and selenium concentrations in blood and urinary stones were higher than in other metals. There was a significant relationship between the history of kidney stones and the probability of developing kidney stones. Moreover, a meaningful relationship was found between the concentration of lead element and the formation of kidney stones. The results showed a significant difference in the concentration of nickel and copper in people who consumed vegetables on a daily basis with those with different types of kidney stones. CONCLUSION: The comparison amongst the concentration of heavy metals in various kinds of urinary stones showed that the amount of lead metal was higher in calcium phosphate stones than in calcium oxalate stones.

Investigating SARS-CoV-2 RNA in five municipal wastewater treatment plants, hospital wastewater and wastewater collection networks during the COVID-19 pandemic in Ardabil Province, Iran.

Since 2019, the outbreak of coronavirus with acute respiratory symptoms has caused an epidemic worldwide. Transmission of the disease through respiratory droplets was announced as the main mode of transmission in 2020. But in this study, we discussed the method of indirect transmission of the virus through sewage. In this study, effluents related to urban and hospital wastewater treatment plants in 5 regions of Ardabil Province (northwest of Iran) were investigated. In this research, 120 samples were kept in pre-test conditions (temperature -20 degrees Celsius). To identify the viral genome, special primer and chain reaction probe targeting ORF1ab and N (nucleoprotein gene) genes were used. Out of a total of 120 samples, a total of 3 samples were positive. Wastewater epidemiology (WBE) can be considered as a cost-effective method in the diagnosis and prediction of pathogenic agents. And be considered an effective method for decision-making in order to protect the health of citizens.

Identification coronavirus (SARS-CoV-2) and physicochemical qualities in various water sources and the efficiency of water treatment plants in their removal- case study: Northwest region of Iran.

The presence of SARS-CoV-2 virus in water resources and the transmission of diseases caused by it is one of the factors threatening the quality of water resources. This study for the first time concentrates on the presence of SARS-CoV-2 in water resources an urban location. In the present study, the samples were collected from known depth (30-50 cm) of rivers, dams and lakes. In each sample of water collected, different parameters such as residual chlorine, pH (phenol red), turbidity, total dissolved solids and temperature were also measured. Out of 267 samples, two samples were detected to be positive which their Ct values were 34.2 and 35.67. The existence of viable form of this virus in water and wastewater may be associated with issues for providing public health and difficulties in implementation of pandemic control strategies, and this situation can be exacerbated in developing countries that do not have adequate access to sanitation and safe water.

SARS-CoV-2 in municipal wastewater treatment plant, collection network, and hospital wastewater.

The current outbreak of coronavirus disease (COVID-19) has led to creating a public health emergency conditions since 2019. COVID-19, which is caused by SARS-CoV-2, is spread via human-to-human transmission by direct contact or droplets. Through conducting this study, we were looking for detecting SARS-CoV-2 in wastewater produced in Iran country (Ardabil, Nir, Khalkhal, and Kowsar) (wastewater collection network, wastewater treatment plant, and hospital wastewater). In this research, samples (n=76) were collected from influent and effluent of municipal and hospital wastewater treatment plants, and some samples were also collected from Ardabil municipal wastewater manholes. The sampling duration included the white (lower risk of COVID-19) and red (high risk of COVID-19) conditions. Samples were stored at -20 °C for further diagnostic tests. The specific primer and probe real-time reverse transcriptase-polymerase chain reaction (real-time PCR) targeting ORF1ab and N genes (nucleoprotein gene) were applied to detect viral genomes of the SARS-CoV-2 virus in the wastewater samples. Out of 76 samples, a total of 15 samples (19.73%) collected from wastewater in Ardabil province (Ardabil, Nir, Khalkhal, and Kowsar), were positive in terms of SARS-CoV-2. Wastewater epidemiology can facilitate detection of the incidence of pathogens through metropolises, measurement of population prevalence without direct testing, and provision of information to the public health system about the efficiency of intervening efforts. Graphical abstract.

Estimation of long-term and short-term health effects attributed to PM2.5 standard pollutants in the air of Ardabil (using Air Q + model).

Clean air is considered as a basic need for human health. However, air pollution is a significant threat to health in developed and developing countries. The aim of this study was to estimate the health effects attributed to PM2.5 pollutants in the air of Ardabil in 2018 (using Air Q + model). Raw data related to particles were collected from the Department of Environment and processed in Excel software and converted into an input file of the Air Q + model, and in the final stage, by considering appropriate epidemiological parameters and combining these data with air quality data, it was possible to estimate the health effects of air pollution. The results showed that the average annual concentrations of PM2.5 and PM10 were 15.47 and 30.94 in the study year, respectively. The total number of deaths due to ALRI, COPD, lung cancer, IHD, and stroke deaths on average during the study period were estimated to be 73, 11, 7, 15, and 14 deaths, respectively, which include 14.62, 15.78, 4.9, 12.43, and 11.6% of deaths due to ALRI, COPD, lung cancer, IHD, and stroke deaths, respectively. In conditions of concentration above 5 µg/m3, attributed proportion, total number of attributed cases and number of attributed cases per 100,000 population (with moderate relative risk and confidence interval of 95%) for cardiovascular diseases have been estimated to be 0.95% 103 people and 42.19 people. Also, the attributed proportion, the total number of attributable cases, and the number of attributable cases per 100,000 population (with moderate relative risk and confidence of 95%) for the admission of respiratory diseases have been estimated at 97.1%, 68 persons and 3 persons, respectively. Our results suggest that particle exposure even at low concentrations is associated with an increased risk of overall mortality and specific cause mortality and hospital admissions for respiratory and cardiovascular diseases.

Investigation of SARS-CoV-2 in hospital indoor air of COVID-19 patients' ward with impinger method.

In December 2019, all nations learnt about the emergence of a pandemic of coronavirus disease (COVID-19), induced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is a member of the ß-coronavirus group. As SARS-CoV-2 has the potentiality of leading to life-threatening respiratory failure, its transmission routes need to be characterized. Yet, the possibility of airborne transmission is still debated. This study was performed to evaluate potential hospital indoor air viral quality in order to detect SARS-COV-2. For this purpose, an impinger method was used to monitor the SARS-COV-2 virus in the air. Thus, 33 samples were collected from 8 different hospital locations. The sampling time was between 50 and 60 min with a sampling flow rate of 28 L/min. Air samples were taken from 2 to 5 m away from the patients' beds. Temperature, relative humidity, and CO2 concentration were 28, 37, and 438 ppm, respectively. The results indicated that air samples which were 2 to 5 m away from the patients' beds were negative for the presence of the virus. According to the obtained results, it is suggested that airborne transmission may not have much effect on this pandemic. However, as the patients with SARS-CoV-2 were hospitalized in rooms with negative air pressure, the results might have been negatively affected. Graphical abstract.

Investigation of SARS-CoV-2 virus on nozzle surfaces of fuel supply stations in North West of Iran.

There are several ways for transmitting the SARS-CoV-2 virus to humans, and one of these ways is the contact with infected surfaces. Fuel stations have been a major concern for people and health experts due to the frequent use of common nozzles. This study was performed to identify the COVID-19 virus in the nozzles of fuel supply stations. In the current research, 25 fuel supply stations along the main street ways were investigated to recognize Coronavirus infection on the surfaces of the nozzles. For each fuel supply station, 4 nozzles were chosen (a total of 100 samples). The sampling was carried out at two periods of time, that is, before and after quarantine restrictions. Swapping was used for surface sampling, and Real-time PCR was used to determine the positive and negative results. The results showed that out of nine fuel supply stations (36 samples of nozzle surfaces), five were positive for the presence of SARS-CoV-2 on the nozzle surfaces before the corona restriction. The results showed that in the conditions after corona restriction, all samples were negative in terms of the presence of SARS-CoV-2 on the surfaces of the nozzles. In spite of the fact that gas stations can be one of the foremost inclined places for the transmission and spread of coronavirus due to the nearness and visit of individuals, but through the observance of health behaviors and implementing some procedures, cutting the transmission chain in gas stations can be facilitated.

Health risk assessment of heavy metals in dust particles precipitated on the screen of computer monitors.

Dust is an important factor to indoor pollution that contains suspended particles and heavy metals. Since today, use of computer has become an essential part of human life. Therefore, this study aimed to compare the amount of heavy metals deposited on CRTs and LCDs and their risk assessment. Ten dust samples for each type of monitor were collected from CRT and LCD screens in accordance with the standard OSHA ID-125 and ID-206, wet filter wipe method. Concentrations of Pb, Hg, Cd, Cr, and Cu were measured by inductively coupled plasma-optical emission spectrometer. Exposure and risk assessment of these elements were estimated using USEPA's exposure parameters. The average concentrations of heavy metals in the dust on CRTs (0.82 mg/kg) were higher than LCD screens (0.69 mg/kg). Cr with 62.824% and Hg with 0.849% had the highest and lowest average concentration in both types of monitors. The non-carcinogenic risk and carcinogenicity indexes of CRT monitors were 0.0009, and 3.94 × 10-11 and for LCD monitors were 0.0008 and 2.94 × 10-11. In both monitors, ingestion is the main route to exposure with heavy metals. The average concentration of heavy metals in CRT dust. HI values for studied metals in dust of CRTs and LCDs were less than safe limit of 1. Because RI < 10-4, cancer risk of studied elements in dust can be ignored.

Evaluation of masks' internal and external surfaces used by health care workers and patients in coronavirus-2 (SARS-CoV-2) wards.

One of the simplest and most effective individual measures is to wear a mask to prevent the spread of respiratory droplets from carriers to healthy people and patients admitted to corona wards and their staff. This research aimed to investigate the contamination of internal and external surfaces of various masks used by patients and staff with SARS coronavirus, as well as the possibility of airborne transmission in Imam Khomeini Hospital, Ardabil. For this purpose, twenty-five staff members and ten patients participated voluntarily in this cross-sectional study. Sampling was performed using swaps on both sides (inside and outside) of various surgical masks, N-95, and filtering face piece FFP2 through standard methods in compliance with the relevant conditions and from a surface of at least 5 cm2. Next, the collected samples were immediately transferred to a laboratory and analyzed by real-time PCR method to detect the presence of SARS-CoV-2 virus after viral genome extraction. Based on the obtained results, from a total of 30 collected samples (25 of personnel masks plus 5 samples of hospitalized patients' masks). A total of 60 masks were sampled. For every collected sample, the researchers studied both inside and outside of the mask. Upon analyzing the data, it was showed that 6 mask samples were positive for the presence of coronavirus. Nonetheless, all samples taken from both inside and outside of the personnel masks (N-95 and FFP2 types of masks) were negative. Among the 6 positive samples, four cases were related to the internal part, one case to the outer part of the three-layer surgical masks, and one to the outer part of the N-95 masks in hospitalized patients. As masks reduce the concentration of virus particles, they can play an important role in creating immunity.

Evaluation of knowledge and health behavior of University of Medical Sciences students about the prevention of COVID-19.

BACKGROUND: Coronaviruses are a large family of viruses that have symptoms ranging from the common cold to severe respiratory syndromes. OBJECTIVE: The purpose of this study is to provide appropriate strategies to raise knowledge and health behavior of students of the University of Medical Sciences to prevent COVID-19. METHODS: This study was conducted as a cross-sectional and descriptive study, and the online questionnaire was used by random sampling. Our sample size was 360 subjects and the statistical population was the students of the University of Medical Sciences. We used the nonparametric test (Kruskal Wallis, Mann-Whitney U) and (Chi-Square & t-test) for statistical analysis. RESULTS: The test results were statistically significant for students' health behavior (p < 0.01, df -99). The knowledge of women was higher than men (F = 5.32, p < 0.02). CONCLUSION: The results show that the Ministry of Health has acted well in promoting students' knowledge and health-promoting behaviors. Therefore, it is recommended that such research be conducted in the public statistical population.

Investigation of SARS CoV-2 virus in environmental surface.

The prevalent respiratory viruses such as SARS-CoV-2 probably persist for a long time on fomites and environmental surfaces. Some recent studies have detected SARS-CoV-2 RNA on the surface of cell phones, door handles and other items in the inhabited sites of confirmed cases. For the aim of this study, a total of 50 environmental surface samples of SARS-CoV-2 was collected from Imam Khomeini Hospital in Ardabil. Forty-one environmental surface samples were proved negative for SARS-CoV-2 RNA while nine surface samples were positive. Our findings regarding surfaces contaminated with the virus are consistent with the results of recent similar researches as it was revealed that a number of different samples taken from hospital surfaces such as handles, cupboards, light switches, and door handles were positive for the presence of SARS-Cov-2.

Investigating the relationship between occupation and SARS-CoV2.

BACKGROUND: Coronaviruses are a large family of viruses that have symptoms ranging from simple symptoms of colds to severe respiratory syndromes. In December 2019, cases of unknown pneumonia first appeared in Wuhan, China. OBJECTIVE: The purpose of this study was to investigate the relationship between occupation and COVID-19 in the Ardabil Imam Khomeini hospital. METHODS: This research was conducted as a cross-sectional and descriptive study. The questionnaires used in this study included demographic information to obtain the required information such as age, sex, clinical symptoms, underlying disease, type of drug used, smoking, occupation, hours of work, number of daily clients, use of mask or shield, type of working hours, weight and height and body mass index, number family, place of residence, role in the family, presence of an infected person in the family, communication with the suspect, observance or non-observance of health protocols. Our sample size consisted of 774 subjects, all patients at the Ardabil Imam Khomeini Hospital. The subjects were selected randomly. RESULTS: The results of this study showed that the mean age of patients was 56.70 years, with a standard deviation of 18.20 years. Three hundred and sixty participants (46.5%) were female, and 414 (53.5%) were male. In terms of occupation distribution, 317 patients (41%) were housewives. In addition, 57 people (7.4%) were farmers or ranchers. CONCLUSION: In general, it can be concluded that due to severity of infection and threat posed by Coronavirus and the risk of infections between different occupations like the taxi driver and medical staff, it is very important to find out what jobs are in the big threat.

Assessment of types of bacterial bio-aerosols and concentrations in the indoor air of gyms.

The presence of airborne microorganisms in indoor air (home and work) is a serious public health concern. Bio-aerosols have a significant role in indoor air pollution as they can be pathogenic or cause an allergic reaction following inhalation, ingestion or skin absorption. This study aimed to assess bacterial bio-aerosols in the indoor air concentration of gyms, and its relationship with gym area per person, temperature, and relative humidity. Sampling was performed by the National Institute for Occupational Safety and Health (NIOSH) method 0800-0999 and using an Anderson single-step sampler. Fifty-five gyms were selected with simple random sampling method and 165 samples collected for evaluation of bacterial bio-aerosols. The concentrations of airborne bacteria were measured as colony-forming units per cubic meter of air (CFU/m3) collected by impaction on to tryptic soy agar plates. The maximum and minimum densities of bacteria in the air of gyms were 877 and 117 CFU/m3, respectively. Pseudomonas, Staphylococcus and Escherichia Coli had an order of the highest to lowest frequency among the microorganisms, respectively. Generally, with increasing temperature and humidity, the density of bacteria was increased. The higher amount of the microorganisms was observed in the air of gyms in the lower available area per person. Athletes are at risk of high exposure to the bacterial bio-aerosol that can affect their health.

Waste sludge from shipping docks as a catalyst to remove amoxicillin in water with hydrogen peroxide and ultrasound.

The waste sludge from shipping docks contains important elements that can be used as a catalyst after proper processing. The purpose of this study was to remove of amoxicillin (AMX) from the aquatic environment using waste sludge from shipping docks as catalyst in the presence of hydrogen peroxide/ultrasound waves. The catalyst was produced by treating waste sludge at 400 °C for 2 h. N2 adsorption, SEM, XRD, XRF, and FTIR techniques characterized the structural and physical properties of the catalyst. The BET-specific surface area of the catalyst reduced after AMX removal from 4.4 m2/g to 3.6 m2/g. To determine the optimal removal conditions, the parameters of the design of experiments were pH (5-9), contaminant concentration (5-100 mg/L), catalyst dosage (0.5-6 g/L), and concentration of hydrogen peroxide (10-100 mM). The maximum removal of AMX (98%) was obtained in the catalyst/hydrogen peroxide/ultrasound system at pH 5, catalyst dose of 4.5 g/L, H2O2 concentration of 50 mM, AMX concentration of 5 mg/L, and contact time of 60 min. The kinetics of removal of AMX from urine (k = 0.026 1/min), hospital wastewater (k = 0.021 1/min), and distilled water (k = 0.067 1/min) followed a first-order kinetic model (R2>0.91). The catalyst was reused up to 8 times and the AMX removal decreased to 45% in the last use. The byproducts and reaction pathway of AMX degradation were also investigated. The results clearly show that to achieve high pollutant removal rate the H2O2/ultrasound and catalyst/ultrasound synergy plays a key role.

Effects of PM2.5 and NO2 on the 8-isoprostane and lung function indices of FVC and FEV1 in students of Ahvaz city, Iran.

The aim of this study was to determine the correlation between PM2.5 and NO2 pollutants and oxidative stress marker (8-isoprostane) and lung function tests (FVC and FEV1) in healthy children who were living and studying in three different areas of Ahvaz city including A1: Naderi site with high traffic, A2: Alavi Alley site with average traffic, and A3: Ein 2 site with low traffic (a rural area on the suburb of Ahvaz). 30 students in the 12-13 year-old range were selected from each studied zone (1, 2 and 3 sites) during three months of year. Of each student, one sample was taken every two weeks to measure 8-isoprostane of exhaled breath condensate (EBC). Air pollution data were collected from three air quality monitoring stations. Also, the relationship between air pollution and 8-isoprostane as well as lung function tests were determined using generalized estimating equations (GEE). The mean concentration of PM2.5 and NO2 in A1, A2 and A3 areas were 116, 92 and 45 (µg/m3) also 77, 53 and 14 (ppb) respectively. Among all studied students, there was a significant correlation between the increase of mean concentration of PM2.5 and NO2 in 1-4 before sampling day, increased 8-isoprostane concentration and decreased FEV1, while there was no significant correlation between them and decreased FVC. In A1 site, an increase in IQR (13 µg/m3) PM2.5 and IQR (6.5 ppb) NO2 on 1-4 days before sampling was associated with 0.38 unit (95% CI: 0.11, 0.65) and 1.1 unit (95% CI: 0.85, 1.35) increase in 8-isoprostane concentration, also decreased 121 ml and 190 ml FEV1, respectively. Results showed that the short-term exposure to traffic-related air pollution can decrease the values of lung function indices and increase the oxidative stress. It may adversely affect children's lungs.

Prediction of O3 in the respiratory system of children using the artificial neural network model and with selection of input based on gamma test, Ahvaz, Iran.

In recent years, concerns over the issue of air pollution have increased as one of the significant environmental and health problems. Air pollutants can be toxic or harmful to the life of plants, animals, and humans. Contrast to primary pollutants, ozone is a secondary pollutant that is produced by the reaction between primary precursors in the atmosphere. The average of air pollutant data was compiled for the purpose of analyzing their correlation with the pulmonary function of students and the FENO biomarker from the air pollutants of the Environmental Protection Agency. According to the average of 3 days, the concentration of ozone in the (S3) region was higher than the other regions, and this level was significantly different from the ANOVA test (p < 0.05). The results of artificial neural network modeling for three particular combinations in the cold season, two hidden layers with 9 and 12 neurons, with R2 = 0.859 and in the warm season, layer with 13 neurons, with R2 = 0.74, showed the best performance.

Data of adsorption of Basic Blue 41 dye from aqueous solutions by activated carbon prepared from filamentous algae.

For this data article the adsorption of Basic Blue 41 (BB 41) dye by activated carbon derived from filamentous algae (AAC) of available in agriculture waste as cheap adsorbents were examined. Activated carbon has been widely used as an adsorbent regard to its massive specific surface area, high porosity, reusability and thermal stability for the removal of pollutants from effluent. These filamentous algae grow widely in irrigation streams, causing decreasing speed of water flow and are not even eaten by livestock so are considered agricultural wastes. They can be used as precursors for activated carbon preparation and as adsorbent for the dye removal. The data of initial dye concentration (50-200 mg//L), pH of dye solution (3-9), adsorbent dosage (0.25-2 g/L), and contact time (5-200 min), were assessed. The structure of AAC was characterized by X-ray diffraction and Fourier transforms infrared spectroscopy. Activated carbon with a 94% removal of dye at concentration of 100 mg/L, pH 9, and adsorbent dose 1 g/L after 90 min. The data of isotherms and Kinetics indicated that the experimental data are fitted to Langmuir and second-pseudo-order models. Under the optimum conditions, maximum adsorption capacity of the AAC in Langmuir model enhanced to amount of 125 mg/g. According to the experimental data, filamentous algae are a suitable raw material for activated carbon production.

Efficiency of sequencing batch reactor for removal of organic matter in the effluent of petroleum wastewater.

The main aim of this research was to study the biodegradation of Methyl Tertiary Butyl Ether (MTBE) using aerobic sequencing batch reactor (SBR) at a pilot-Scale. The reactor was made of a 3 mm-thick glass cylinder with an internal diameter of 12 cm and height of 60 cm. SBR operated in five phases. The first phase was filling the reactor for about 10 min. the second phase was the main reactor for biological treatment of petroleum wastewater about 21.55 h. The third phase was the sedimentation (1 h). The fourth phase was decanting from the reactor for about 10 min. The last phase consisted of idle for about 45 min. The experiments showed that the mixed microbial mass is able to degrade high concentration of methanol up to 250 mg/l, and concentration of MTBE up to 70 mg/l for a 24 h cycle. However, the mixed microbial mass is not able to degrade MTBE with concentration more than 70 mg/l. Microorganisms were generally isolated from Fajr petrochemical wastewater treatment plant. Analysis showed that the mixed microbial mass able to biodegradation of COD up to 1350 mg/l in effluent. Aerobic SBR can be used for biological treatment of the petroleum wastewater containing pollutants such as methanol, MTBE with a promising efficiency.