Papers by Mohammad Samaei
Journal of Air Pollution and Health
Introduction: Air pollution from industrial sources is a growing problem increasing the amount of... more Introduction: Air pollution from industrial sources is a growing problem increasing the amount of air pollution by emitting various gaseous pollutants such as Nitrogen Oxides (NOx). This study analyzed Nitrogen dioxide (NO2) emissions using American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) from the stacks and flares of a gas refinery in the Middle East. Materials and methods: The NO2 emissions were measured from the stacks and flare of the refinery (231 samples). The distribution of emissions was investigated over a statistical period of 1 year for an average time of 1 h using the AERMOD dispersion model in an area of 25×25 km2. The predicted concentrations were compared with national and international standards and are plotted for the desired zones. Results: Comparison of simulation results with national and international clean air standards showed that NO2 emission modeled in all periods of 4 seasons is higher than the standard. Examination ...
Health Scope
Background: The water crisis in different parts of the world forces people to manage water resour... more Background: The water crisis in different parts of the world forces people to manage water resources. Greywater can be used to reduce water stress. The annual rainfall average in Iran is hardly one-third of the world. In this study, the treatment of synthetic greywater at low, medium, and high organic load and real greywater (RGW) by a combined process of ozonation/granular activated carbon (GAC)/ultrafiltration (UF) have been investigated. Objectives: This study aimed to find a greywater treatment method that is effective, new, environment-friendly, and cost-effective. Methods: Chemicals and commercial compounds were used to prepare synthetic greywater, and the research pilot was developed. After several preparation steps, the GAC was transferred to a GAC reactor. A continuous flow of synthetic greywater entered the treatment system with low: 6.1, medium: 12.2, and high: 18.3 gCOD/L.d organic loading rates for 6 months. Next, the RGW samples from a residential complex in Shiraz, Ir...
Journal of health sciences and surveillance system, 2016
Background: Heavy metals have destructive and irreversible effects on the human, plants and anima... more Background: Heavy metals have destructive and irreversible effects on the human, plants and animals. Some industries in Yazd enter industrial wastewater to municipal wastewater collection system. This can lead to high levels of heavy metals in wastewater and in turn in the wastewater treatment plant effluent. Methods: This study was carried out during four months from December 22, 2009 to May 20, 2010. The experiment was performed on the inflow, outlet of anaerobic pond and first and second facultative ponds of wastewater treatment plant and then transferred to the laboratory and measured by atomic absorption spectroscopy. Results: The results of the experiments showed that the average cadmium concentrations in the inflow, anaerobic pond outlet, and first and second facultative pond outlet were 0.0066, 0.0087, 0.0076, and 0.0083µg/l, respectively. The average amounts of chromium in the inflow, anaerobic pond outlet, and first and second facultative pond outlet were 0.0076, 0.0065, 0...
Improvement of the Rhizoremediation efficiency of PAHs contaminated soil under cysteine treatment along with modeling
Environmental Nanotechnology, Monitoring & Management, 2021
Abstract Polycyclic Aromatic Hydrocarbons (PAHs) are a group of pollutants with mutagenic and car... more Abstract Polycyclic Aromatic Hydrocarbons (PAHs) are a group of pollutants with mutagenic and carcinogenic properties. This study aimed to assess the effects of cysteine on the growth and resistance of the Festuca plant against PAHs-induced stress. The experiment was designed in six different groups and included control, contaminated soil with pyrene (Py) and phenanthrene (Phe) (200, 300, and 400 mg kg−1), and supplementation with cysteine (100, 200 mg L-1), all with or without the cultivation of Festuca grass. During the two 45- and 90-day periods, changes in the population of bacteria, the activity of soil enzymes: dehydrogenase (DHA) and peroxidase (POD), and the level of pyrene and phenanthrene removal were investigated. Furthermore, the Response Surface Methodology (RSM) model was also applied to determine the relationships between input and response parameters. Then, using the sensitivity analysis by Monte Carlo simulation, the effect of the examined parameters on the response parameters was determined. The results demonstrated that cysteine supplementation, along with Festuca cultivation, increased the number of bacteria, improved the activity of enzymes, and elevated the elimination of PAHs (p-value
Process Safety and Environmental Protection, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Survey of knowledge and practice of yazd people regarding municipal solid waste management in 2008
Background: Waste production is an integral part of human life. This waste should be eliminated f... more Background: Waste production is an integral part of human life. This waste should be eliminated from human life and be recyeled again into material and energy. Effective steps have to be taken to improve public health. So for a good management of materials, this study aimed to clarify the knowledge and practice of Yazd people in the management of municipal solid waste in 2008. Methods: This is a descriptive, cross-sectional study which was conducted by filling up questionnaires. Validity of the data and monitoring was performed by using Cronbach alpha test. Totally 300 questionnaires were completed in different parts of the city of Yazd. The data were then entered into the software SPSS.11.5 and were analyzed by Chi-square test and frequency distribution tables and charts. Results: The results of the study showed that performance of the citizens regarding separation of waste from the beginning and transportation of waste to the collection vehicle is not in a good condition, the perf...
Prediction of the energy content of the municipal solid waste
International Journal of Environmental Health Engineering, 2012
Scientific Reports
Diesel oil is known to be one of the major petroleum products that can pollute water and soil. So... more Diesel oil is known to be one of the major petroleum products that can pollute water and soil. Soil pollution caused by petroleum hydrocarbons has substantially impacted the environment, especially in the Middle East. In this study, modeling and optimization of hexadecane removal from soil was performed using two pure cultures of Acinetobacter and Acromobacter and consortium culture of both bacterial species using artificial neural network (ANN) method. Then the best ANN structure was proposed based on mean square error (MSE) as well as correlation coefficient (R) for pure cultures of Acinetobacter and Acromobacter as well as their consortium. The results showed that the correlations between the actual data and the data predicted by ANN (R2) in Acromobacter, Acinetobacter and consortium of both cultures were 0.50, 0.47 and 0.63, respectively. Despite the low correlation between the experimental data and the data predicted by the ANN, the correlation coefficient and the precision of ...
International Journal of Health System and Disaster Management, 2015
Aims: One of the best available alternatives to face the energy and environment problem is to ten... more Aims: One of the best available alternatives to face the energy and environment problem is to tend renewable energies. The main aim of this study is producing biogas from garbage bioliquid (leachate). Materials and Methods: This study was conducted at wide range of organic loading rate (OLR = 0.93-25 g COD l-1 d-1) by varying hydraulic retention times (HRT = 23 and 12 hsr) and initial COD of 1.85-25 g l-1. pH variations, COD, SCOD, rbCOD and VFAs degradation, biogas and methane production were considered in this study. Results: The COD removal efficiencies were in the range of 76-81% depending on loading rates applied. The maximum volumetric methane production rate (VMPR) of 5.7 l CH4 l-1 d-1 was achieved at the OLR of 19.65 g COD l-1 d-1. About 85% of removed COD during the biodegradation was converted to methane. Conclusion: The results have shown that the anaerobic sequencing batch reactor (ASBR) reactor could be an appealing option for changing composting leachate into useable products such as biogas and other energy-rich compounds, which may play a serious role in meeting the world's ever-increasing energy requirements in the future.
Journal of health sciences and surveillance system, Jan 12, 2016
Background: Biogas is obtained by anaerobic decomposition of organic wastes buried materials used... more Background: Biogas is obtained by anaerobic decomposition of organic wastes buried materials used to produce electricity, heat and biofuels. Biogas is at the second place for power generation after hydropower and in 2000 about 6% of the world power generation was allocated to biogas. Biogas is composed of 40-45 vol% CO 2 , 55-65 vol% CH 4 , and about 1% non-methaneVOCs, and non-methane volatile organic compounds. Emission rates are used to evaluate the compliance with landfill gas emission regulations by the United States Environmental Protection Agency (USEPA). BTEX comounds affect the air quality and may be harmful to human health. Benzene, toluene, ethylbenzene and xylene isomers that are generally called BTEX compounds are the most abundant VOCs in biogas. Methods: Sampling of VOCs in biogas vents was operated passively or with Tedlar bags. 20 samples were collected from 40 wells of old and new biogas sites of Shiraz' landfill. Immediately after sampling, the samples were transferred to the laboratory. Analysis of the samples was performed with GC-MS. Results: The results showed that in the collection of the old and new biogas sites, the highest concentration of VOCs was observed in toluene (0.85ppm) followed by benzene (0.81ppm), ethylbenzene (0.13ppm) and xylene (0.08ppm). Conclusion: The results of the study showed that in all samples, most available compounds in biogas vents were aromatic hydrocarbon compounds.These compounds' constituents originate from household hazardous waste materials deposited in the landfill or from biological/chemical decomposition processes within the landfill.
Journal of Water and Wastewater; Ab va Fazilab ( in persian ), 2004
Stochastic Environmental Research and Risk Assessment, Sep 15, 2021
In the present study, the health risk assessment of exposure to uoride in drinking water of south... more In the present study, the health risk assessment of exposure to uoride in drinking water of southern Iran province was performed with a de nite and probabilistic approach. Monte Carlo simulation and sensitivity analysis were used for uncertainty in risk estimation. The results showed that uoride concentration ranged between 0.1-0.9 mg/l with an average of 0.454 ± 0.205 mg/l. The distribution function followed the normal distribution. The highest uoride concentration was observed in the central and northern regions of the province. Also, the lowest concentration was obtained 0.01 mg/l. In the de nitive method, the non-carcinogenic risks associated with uoride in drinking water were in acceptable range (HQ < 1). Conducting Monte Carlo simulation indicated that the potential non-carcinogenic risk for children in the 95th percentile exceeded the safe limit of 1, which showed that there were a potential noncarcinogenic in this group. Sensitivity analysis showed that uoride concentration and water consumption had the most considerable effect in the model. Therefore, consumption of water and foods containing uoride along with excessive consumption of tea may increase human's health risks. Therefore, continuous monitoring of water sources in terms of uoride concentration along with proper diet training for residents of this province should be done.
Investigation of seasonal changes in the density and diversity pattern of fungal populations in the air around processing facilities of the composting plant
Iranian Journal of Health and Environment, Feb 10, 2021
Journal of Water and Wastewater; Ab va Fazilab ( in persian ), Dec 1, 2005
Environmental Science and Pollution Research, Oct 22, 2020
This study aimed to evaluate the effect of land use on hospital bioaerosols and determine the eff... more This study aimed to evaluate the effect of land use on hospital bioaerosols and determine the effective radius. The concentration of fungi and bacteria in indoor and outdoor air was determined by the 0800NIOSH. Then land uses were determined by Google earth within a range of 0.5-5 km around three hospitals. Data were analyzed by using Spearman correlation, and a t test was used to determine differences between groups. Data were recorded in Excel and entered into Matlab 2018 for analysis. The results of the study showed that the concentration of fungi and bacteria was higher in the indoor and outdoor hospital B (bacteria = 343-43, fungi = 106-291 CFU/m 3) (P = 0.04). Maximum land use was also found in hospitals A and B related to urban and bare, while in hospital C, they were urban and bare. Mathematical modeling has shown that the trend of land-use variation over different radii consisted of the Gaussian model (in hospital B) and Fourier series (in hospitals A and C). Besides, there was a positive correlation between the bare and fungal and bacterial concentrations. Finally, the most effective bare radius of application on the indoor and outdoor fungi was 4 and 5 km, respectively (R 2 = 0.99). The effective radius for reducing fungi and bacteria by creating green space was 0.5 and 3 km from the hospital center (R 2 fungi = − 0.99, R 2 bacteria = − 0.8). Based on these results, land use is an effective factor in airborne fungi and bacteria in hospitals. Therefore, their control and management of land use during 5 km is necessary to reduce pollution.
Biodegradation of n-Hexadecane in Acinetobacter Radioresistens Liquid Culture
Health Scope, Nov 10, 2013
Risk assessment and disease burden of legionella presence in cooling towers of Iran’s central hospitals
Environmental Science and Pollution Research, Jul 29, 2021
Regular monitoring and measurement of Legionella in tower water and preventive measures against c... more Regular monitoring and measurement of Legionella in tower water and preventive measures against contamination are particularly important in hospitals. This study aimed at risk assessment and disease burden because of legionella presence in cooling towers of Iran’s central hospitals. Then its correlation with temperature, pH, turbidity, residual chlorine, and EC was investigated by the Pearson test. The health risk and burden of diseases caused by Legionella exposure were determined using QMRA and DALY models. Statistical analysis and modeling were performed in MATLAB2018. Of the total samples, 30–43% was infected with Legionella. The mean concentrations in hospital A and B were 5–102.5 ± 10 and 5–89.7 ± 0.7 CFU/L, respectively. Among environmental factors, turbidity and pH were the most effective factors in increasing and decreasing Legionella concentration, respectively. According to the QMRA model, the risks of Legionella infections and annual mortality in both hospitals were 0.2–0.3, 0–0.19, 2–2.9 × 10−5, and 0–0.7 × 10−5, respectively, which was higher than the acceptable risk range for Legionella (10-4–10-7). However, the trend of its change was negatively correlated with time (RB = − 0.77). According to the results, the concentration of Legionella and the exposure risk in both hospitals were higher than the permissible range, which is necessary to decrease to 0.1 current concentrations.
مجله علوم بهداشتی جندیشاپور, Feb 7, 2018
Background and Objectives: Nitrogen is a potential pollutant of water resources. They penetrate i... more Background and Objectives: Nitrogen is a potential pollutant of water resources. They penetrate in water resources through insufficiently treated wastewater that is rich in nitrogen. The present study aimed at evaluating the efficiency of an anoxic/aerobic cycling reactor (AACR) with continuous flow in removing nitrogen and organic matter from wastewater. Methods: Experiments were performed using a reactor with continuous intermittent influent and effluent. In this reactor, 4 phases with aeration and mixing cycles were designed and efficiency of each phase in removing nitrogen compounds was evaluated at 600 mg/L chemical oxygen demand (COD) concentration, 40 mg/L ammonia concentration, and 18-to 30-hour hydraulic retention times (HRT). Results: Results demonstrated that all cycles had great performance in removal of COD. Average COD removal efficiencies in phases 1, 2, 3, and 4 were 93%, 96.3%, 96%, and 94%, respectively. In phase 2, removal efficiency of 98.7% was obtained at hydraulic retention time of 24 hours, COD concentration of 600 mg/L, and ammonia concentration of 40 mg/L. Conclusions: Phase 2 showed great efficiency in removal of nitrogen compounds. Combination of anoxic aeration stages and short cycles in anoxic/aerobic cycling reactor resulted in great performance of this reactor in removing nitrogen from wastewater. As a result, continuous influent and effluent flow, and not needing external carbon resulted in AACR good performance in removing nitrogen compounds and organic materials.
Trace elements human health risk assessment by Monte Carlo probabilistic method in drinking water of Shiraz, Iran
International Journal of Environmental Science and Technology, Feb 16, 2023
Dispersion of SO2 emissions in a gas refinery by AERMOD modeling and human health risk: a case study in the Middle East
International Journal of Environmental Health Research
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Papers by Mohammad Samaei