Publications by authors named "Davoud Balarak"

10 Publications

  • Page 1 of 1

Utilization of MWCNTs/AlO as adsorbent for ciprofloxacin removal: equilibrium, kinetics and thermodynamic studies.

J Environ Sci Health A Tox Hazard Subst Environ Eng 2021 Jan 27:1-17. Epub 2021 Jan 27.

Division of Sustainable Development, College of Science and Engineering, Hamad Bin Khalifa University, Education City, Doha, Qatar.

In the present study, the adsorption behavior of ciprofloxacin (CIP) from aqueous solution onto MWCNTs/AlO was studied using batch experiments. Physical characterization of MWCNTs/AlO was determined by SEM, XRD, and BET. The effective parameters investigated included: initial CIP concentration, contact time, MWCNTs/AlO mass, and temperature. Based on experimental results and correlation coefficients, the rate of CIP adsorption followed the pseudo-second-model kinetics. Complete compatibility of the adsorption isotherm process was achieved with the Langmuir model, and the maximum adsorption capacity reached 41.73 mg/g under the optimized conditions (pH = 7, MWCNTs/AlO dose = 1.2 g/L, contact time = 60 min, initial concentration = 10 mg/L, and temperature= 45 °C). The adsorption capacities based on the Langmuir model at different temperatures, 273, 288, 303, and 318 K, were equal to 72.18, 75.92, 79.65, and 83.47 mg/g, respectively. The determined parameters of the thermodynamic studies demonstrated the endothermic and spontaneous nature of the biosorption. The mean free energy was estimated from D-R isotherm model to be 0.316-0.707 KJ/mol, which clearly proved that the adsorption experiment followed a physical process. The data suggest that MWCNTs/AlO could be used as a highly effective adsorbent material with a high capacity for the removal of antibiotics from water and wastewater.
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http://dx.doi.org/10.1080/10934529.2021.1873674DOI Listing
January 2021

Human health risk assessment of trace elements in drinking tap water in Zahedan city, Iran.

J Environ Health Sci Eng 2019 Dec 20;17(2):1163-1169. Epub 2019 Dec 20.

1Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.

Daily intake of elements through the consumption of drinking water, due to its detrimental effects, is accounted for an important concern. Although the health risk assessment of heavy metals in different water sources has extensively carried out in various studies, the effect of age and the concentration of all trace elements in drinking tap water have neglected. Therefore, this study was conducted to evaluate the concentrations of heavy metals, e.g., As, Cd, Cr, Ni, Pb, B, Al, Hg, Mn, Zn, Cu, Fe, Se and Ba in the drinking tap water of Zahedan city and to estimate their non-carcinogenic and carcinogenic effects. Moreover, this is the first research in Iran that has also been dedicated to complete investigation on daily intakes of trace elements in tap water. A total of 155 samples of drinking water were randomly taken from the tap water and were analyzed using ICP-OES device. The estimation of the carcinogenic and non-carcinogenic risks of analyzed elements was carried out based on the guidelines of the U.S EPA. The hazard index (HI) values for children and adult age groups were 9.84E-01 and 4.22E-01, respectively. The cumulative Excess Lifetime Cancer Risk (ELCR) for carcinogenic trace elements was in range of tolerable carcinogenic risk 10 to10 and for all carcinogenic elements were in the order of Pb > Cd > Cr. It also detected that the total carcinogenic risks of the Cd, As and Cr in water samples through the ingestion route are at the levels of "low risk" and "low-medium risk".
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http://dx.doi.org/10.1007/s40201-019-00430-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985301PMC
December 2019

An overview report on the application of heteropoly acids on supporting materials in the photocatalytic degradation of organic pollutants from aqueous solutions.

PeerJ 2018 12;6:e5501. Epub 2018 Sep 12.

Department of Environmental Health Engineering, School of Public Health, Social Development & Health Promotion Research Center, Gonabad University of Medical Sciences, Gonabad, Iran.

Organic pollutants contaminate water resources and the environment when discharged into water streams. Also, the presence of these materials in incompletely treated or untreated wastewater leads to serious environmental hazards. The hydroxyl radicals and holes are regarded as the most oxidant species in the degradation of organic pollutants using the studied composites. The results of this review show that heteropoly acids on supporting materials could be considered as appropriate photocatalysts in the removal of organic pollutant from aqueous solutions.
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http://dx.doi.org/10.7717/peerj.5501DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139020PMC
September 2018

Probabilistic risk assessment of exposure to fluoride in most consumed brands of tea in the Middle East.

Food Chem Toxicol 2018 May 19;115:267-272. Epub 2018 Mar 19.

Department of Environmental Health Engineering, Gonabad University of Medical Sciences, Gonabad, Iran. Electronic address:

The aim of this study was to evaluate the fluoride concentration in seven most consumed brands of tea in the Middle East which was imported to Iran through Zabol County. In the present study, the health risk of exposure to fluoride was estimated using a probabilistic approach. Monte Carlo simulation and sensitivity analysis were applied to quantify uncertainties in risk estimation. The highest mean and 95th percentile of chronic daily intake (CDI) was observed for children group. Iranian tea and Kenya tea had maximum CDI and target hazard quotient (THQ) values among studied brands of tea which followed by Green tea, Taksetare tea, Ceylan tea, Red tea, and White tea. These result indicated that there were significant risks of exposure to fluoride in most of studied brands of tea for children (THQ>1). Sensitivity analysis showed that fluoride concentration and daily intake were the most influential variables in three exposed populations. In conclusion, the fluoride concentration in some studied brands of tea is high and it put children at risk risks of exposure to fluoride.
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http://dx.doi.org/10.1016/j.fct.2018.03.023DOI Listing
May 2018

Removing 2,4-dichlorophenol from aqueous environments by heterogeneous catalytic ozonation using synthesized MgO nanoparticles.

Water Sci Technol 2017 Dec;76(11-12):3054-3068

Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran E-mail:

2,4-Dichlorophenol (2,4-DCP) is one of the seriously toxic chlorophenol compounds found in agricultural environments, in water disinfected by chlorine, and in outgoing effluents from the pulp and paper industries and paper manufacturing factories. This research studied the feasibility of using MgO nanoparticles (MgO-NPs) as a catalyst in the ozonation process for removing 2,4-DCP from aqueous environments under laboratory conditions. This study was conducted using a laboratory-scale semi-continuous reactor. It studied the effects of critical variables such as solution pH, ozonation time, dose of MgO-NPs and initial 2,4-DCP concentration. A statistical model of response surface model (RSM) was designed and utilized to obtain the optimum experimental conditions. Analysis of the data showed that initial concentration of 2,4-DCP and dose of MgO-NPs had the maximum effect on the response variable (percentage degradation of 2,4-DCP). Moreover, based on analysis of variance on the model, the optimum removal conditions were reaction time of 50 min, pH > 7, initial 2,4-DCP concentration of less than 50 mg/L, and an MgO-NPs dose of 0.3 mg/L. Under these optimum conditions, a removal efficiency of 99.99% was achieved. In addition, results indicated that catalytic ozonation in the presence of MgO-NPs was very efficient at removing 2,4-DCP from aqueous environments.
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http://dx.doi.org/10.2166/wst.2017.479DOI Listing
December 2017

Relationship between musculoskeletal disorders and anthropometric indices among bus drivers in Zahedan city.

Int J Occup Saf Ergon 2018 Sep 4;24(3):431-437. Epub 2017 Aug 4.

e Department of Epidemiology and Biostatistics , Iranshahr University of Medical Sciences , IR Iran.

Introduction: Most work-related musculoskeletal disorders (MSDs) are associated with improper postures and poorly designed workstations. This study is an attempt to examine the prevalence and severity of MSDs as well as anthropometric dimensions among city bus drivers.

Methodology: This cross-sectional study was carried out on 60 male bus drivers. A body discomfort chart was used to evaluate MSDs. Spearman correlation was employed to examine the relationship between body size and the severity of discomfort.

Results: Data analysis showed that discomfort reported in the lower back (33.3%), upper back (18.3%) and knee (15%) was severe and there was a direct and significant correlation between the body mass index and the severity of discomfort in the shoulder, arm and hip (p < 0.05). However, the results showed that eye sitting height and sitting height had significant inverse relationships with discomfort in the ankle and elbow (p < 0.05).

Conclusion: The results of the study can be used to address ergonomic risk factors and reduce their associated disorders. The findings of the study can be used in training programs to educate drivers how to decrease the risk associated with work-related MSDs by adopting appropriate behavior strategies.
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http://dx.doi.org/10.1080/10803548.2017.1334335DOI Listing
September 2018

Studies on the adsorption of amoxicillin on multi-wall carbon nanotubes.

Water Sci Technol 2017 Apr;75(7-8):1599-1606

Department of Chemistry, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia E-mail:

This study examined the feasibility of removing amoxicillin (AMO) from aqueous solutions using multi-wall carbon nanotubes. The equilibrium adsorption data were analyzed using four widely applied isotherms: Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich. The results showed that the Langmuir isotherm model fits well the obtained experimental data. The adsorption process followed the pseudo-second-order model. The activation energy was found to be 19 kJ/mol. The Standard free energy changes, ΔG, values were negative; the standard enthalpy change (ΔH), and standard entropy change (ΔS) values of the process were 4 kJ/mol and 36 J/mol.K. Results suggested that the AMO adsorption on carbon nanotubes was a spontaneous process.
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http://dx.doi.org/10.2166/wst.2017.025DOI Listing
April 2017

Investigation of Parasitic Contaminations of Vegetables Sold in Markets in the City of Tabriz in 2014.

Glob J Health Sci 2016 10 1;8(10):54811. Epub 2016 Oct 1.

Department of Environmental Health, Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.

Parasitic diseases are among the most common problems in developing countries. Various parasitic forms such as cysts, larvae and eggs of the parasite are transmitted orally through the consumption of vegetables. So, the aim of this study was to evaluate parasitic contamination of fresh vegetables consumed in the city of Tabriz. This cross-sectional study was conducted for 3 months in 2014 in Tabriz. In this study, 1620 samples from 10 kinds of vegetables (leeks, basil, mint, chives, radishes, parsley, lettuce, watercress, tarragon and coriander) were collected from 54 vegetable shops. After the washing process, centrifugation, sediment preparation and staining, each sample was examined for parasitic contamination. The parasitic infection was observed in 316 (19.5%) which 141 samples (8.7%) was related to metazoan and 175 samples (10.8%) was related to protozoan. the highest contamination was observed in leeks and the lowest in radish. Most parasitic contaminations were related to Ascaris eggs and E. coli cyst and the lowest parasitic contaminations were related to Heterophyes eggs. It can be concluded that vegetables sold in Tabriz are potential sources of human contamination with parasites. It is suggested that the use of fertilizers of human source in agriculture should be avoided.
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http://dx.doi.org/10.5539/gjhs.v8n10p178DOI Listing
October 2016

Prevalence of Intestinal Parasitic Infection among Food Handlers in Northwest Iran.

J Parasitol Res 2016 3;2016:8461965. Epub 2016 Apr 3.

Department of Environmental Health, Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.

Parasitic diseases are among the most important infectious diseases and pose health problems in many countries, most especially in developing countries. Workers at food centers could transmit parasitic infections in the absence of sanitation. This is a descriptive study conducted to determine the prevalence of intestinal parasitic infections in food clerks in the city of Tabriz in 2014. Data was recorded in the offices of the health center for all food handlers who were referred to the laboratory for demographic and stool tests to receive the health card. Parasitic infection was observed in 172 cases (3.73%) of 4612 samples. A total of 156 positive samples (90.69%) were related to protozoa and 16 (9.3%) were related to helminthes. Most of the parasitic infections were related to Giardia and Entamoeba coli and the lowest infection was related to H. nana. Also, there was a significant relationship between level of education and parasitic infection rate (P = 0.0044). But there was no significant difference between the type of infection and amount of intestinal parasites. The results show that the prevalence of intestinal parasites, especially pathogenic protozoa, is common in some food handlers. Therefore, more sanitary controls are required and increasing of education will play a crucial role in improving the health of these people.
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http://dx.doi.org/10.1155/2016/8461965DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4834171PMC
April 2016

Phytodegradation potential of bisphenolA from aqueous solution by Azolla Filiculoides.

J Environ Health Sci Eng 2014 2;12:66. Epub 2014 Apr 2.

Department of Environmental Health Engineering, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran.

Many organic hazardous pollutants such as bisphenolA (BPA) which are toxic and not easily biodegradable can concerns for environmental pollution worldwide. The objective of this study was to examine whether Azolla Filiculoides is able to remove BPA from aqueous solutions. In this study, the Azolla with different biomass (0.3, 0.6, 0.9, 1.2 g) has been cultured in solution that was contained 5, 10, 25 and 50 ppm BPA. Samples were collected every 2 days from all of containers. The analytical determination of BPA was performed by using of DR4000 uv-visible at λmax = 276 nm. The results indicated that Azolla has high ability to remove BPA from aqueous solutions. The BPA removal was 60-90%. The removal efficiency is increasing with decreasing of BPA concentration and increasing of biomass amount and vice versa. The removal efficiency was more than 90% when BPA concentration was 5 ppm and amount of biomass was 0.9gr. It is concluded that Azolla able remove BPA by Phytodegradation from the aqueous solutions. Since conventional methods of BPA removal need to high cost and energy, phytoremediation by Azolla as a natural treatment system can decrease those issues and it can be a useful and beneficial method to removal of BPA.
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http://dx.doi.org/10.1186/2052-336X-12-66DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4018667PMC
August 2014