Publications by authors named "Mehdi Farzadkia"

7 Publications

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Degradation of furfural in aqueous solution using activated persulfate and peroxymonosulfate by ultrasound irradiation.

J Environ Manage 2020 Jul 22;266:110616. Epub 2020 Apr 22.

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

Furfural is a toxic compound that can cause many problems for human health and the environment. In this study, we addressed the degradation of furfural in aqueous solution using the activated persulfate (SPS) and peroxymonosulfate (PMS) through the ultrasonic (US) wave. Besides, the effect of various parameters (pH, oxidizing dose, initial furfural concentration, US frequency, Inorganic anions concentration, and scavenger) on SPS + US (SPS/US) and PMS + US (PMS/US) processes were examined. The results showed, in order to furfural removal, the US had excellent efficiency in activating SPS and PMS, as in SPS/US and PMS/US processes, 95.3% and 58.4% of furfural (at 25 mg/L concentration) was decomposed in 90 min, respectively. The furfural degradation rate increased with increasing oxidizing dose and US frequency in both SPS/US and PMS/US processes. Considering the synergistic effect, the best removal rate has occurred in the SPS/US process. In the SPS/US and PMS/US processes, furfural removal increased at natural pH (pH 7), and the presence of inorganic anions such as NO and Cl had negative effects on furfural removal efficiency. Also CO and HCO acted as a radical scavenger in the SPS/US process but these anions in the PMS/US process produced more SO radicals, and subsequently, they increased the furfural degradation rate. The results also showed that the predominant radical in the oxidation reactions is the sulfate radical. This study showed that the SPS/US and PMS/US processes are promising methods for degrading organic pollutants in the environment.
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http://dx.doi.org/10.1016/j.jenvman.2020.110616DOI Listing
July 2020

Stochastic exposure and health risk assessment of rice contamination to the heavy metals in the market of Iranshahr, Iran.

Food Chem Toxicol 2018 May 30;115:405-412. Epub 2018 Mar 30.

Department of Environmental Health Engineering, School of Public Health, Sabzevar University of Medical Sciences, Sabzevar, Iran. Electronic address:

An investigation of some heavy metals content in rice (Oryza sativa) and associated health risks was carried out for residents of Iranshahr city, Iran. Average daily rice consumption of the citizens and most widely used rice brands in the market of Iranshahr were determined using a questionnaire. Besides, the concentration of heavy metals in the gathered rice samples was measured by inductively coupled plasma mass spectrometry (ICP-MS). Monte Carlo uncertainty simulation was utilized in conducting exposure assessment and investigating the non-carcinogenic effects of the studied elements as well as the carcinogenic effect of As. Concentrations of As, Cd, Pb, Cu, Al, and Mo were 0.369 ± 0.094, 0.0337 ± 0.039, 0.123 ± 0.14, 3.095 ± 439.42, 39.6 ± 14.73, and 1.106 ± 0.133 mg kg, respectively. Al (0.18 ± 0.15 mg kg d) and Cd (0.00015 ± 0.00034 mg kg d) were the highest and lowest estimated daily intake, respectively. Except As (5.23 ± 4.01), the calculated hazard quotient for investigated elements showed no non-carcinogenic health risk. Besides, the simulation of the carcinogenic risk effect for As (2.37E-3) revealed that the ingestion of the studied rice brands would cause cancer risk due to lifetime consumption. Results show that consumption of rice in the Iranshahr city is a potential source of exposure to the studied elements.
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http://dx.doi.org/10.1016/j.fct.2018.03.040DOI Listing
May 2018

Bisphenol A removal from aqueous solutions using novel UV/persulfate/HO/Cu system: optimization and modelling with central composite design and response surface methodology.

J Environ Health Sci Eng 2016 1;14:19. Epub 2016 Dec 1.

Research Center for Environmental Health Technology, School of Public Health, Iran University of Medical Sciences, Tehran, Iran ; Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.

Background: Bisphenol A is a high production volume chemical widely used in manufacturing polycarbonate plastics and epoxy resins used in many industries. Due to its adverse effects on human health as an endocrine disruptor and many other effects on the various organs of the human body as well as aquatic organisms, it should be removed from the aquatic environments. This study aimed to mineralisation of BPA from aquatic environments by application of novel UV/SPS/HO/Cu system and optimization and modelling of its removal using central composite design (CCD) from response surface methodology (RSM).

Methods: CCD from RSM was used for modeling and optimization of operation parameters on the BPA degradation using UV/SPS/HP/Cu system. Effective operation parameters were initial persulfate, HO, Cu and BPA concentration along with pH and reaction time, all in three levels were investigated. For analysis of obtained data ANOVA test was used.

Results: The results showed that a quadratic model is suitable to fit the experimental data ( < 0.0001). Analysis of response surface plots showed a considerable impact of all six selected variables which BPA and Cu initial concentrations have been the highest and the least impact on the process, respectively. -value of model was 54.74 that indicate significance of the model. The optimum values of the operation parameters were determined. The maximum removal of BPA was achieved 99.99 % in optimal conditions and in that condition TOC removal was about 70 %. Finally, validation and accuracy of the model were also evaluated by graphical residual analysis and the influential diagnostics plots. The higher relevance between actual and predicted values demonstrated the validation and applicability of the obtained equation as the model.

Conclusions: According to the results, UV/SPS/HP/Cu system is an effective process in degradation and mineralisation of BPA and CCD methodology is a convenient and reliable statistical tool for optimizing BPA removal from aqueous solutions.
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http://dx.doi.org/10.1186/s40201-016-0255-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5131505PMC
December 2016

Application of solvent-assisted dispersive solid phase extraction as a new, fast, simple and reliable preconcentration and trace detection of lead and cadmium ions in fruit and water samples.

Food Chem 2015 Nov 22;187:82-8. Epub 2015 Apr 22.

Department of Chemistry, Shahid Beheshti University, Evin, Tehran, Iran.

In this research, a new sample treatment technique termed solvent-assisted dispersive solid phase extraction (SA-DSPE) was developed. The new method was based on the dispersion of the sorbent into the sample to maximize the contact surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by injecting a mixture solution of the sorbent and disperser solvent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy solution resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. After extraction, the cloudy solution was centrifuged and the enriched analytes in the sediment phase dissolved in ethanol and determined by flame atomic absorption spectrophotometer. Under the optimized conditions, the detection limit for lead and cadmium ions was 1.2 μg L(-1) and 0.2 μg L(-1), respectively. Furthermore, the preconcentration factor was 299.3 and 137.1 for cadmium and lead ions, respectively. SA-DSPE was successfully applied for trace determination of lead and cadmium in fruit (Citrus limetta, Kiwi and pomegranate) and water samples. Finally, the introduced sample preparation method can be used as a simple, rapid, reliable, selective and sensitive method for flame atomic absorption spectrophotometric determination of trace levels of lead and cadmium ions in fruit and water samples.
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http://dx.doi.org/10.1016/j.foodchem.2015.04.061DOI Listing
November 2015

The effects of Fenton process on the removal of petroleum hydrocarbons from oily sludge in Shiraz oil refinery, Iran.

J Environ Health Sci Eng 2014 Jan 14;12(1):31. Epub 2014 Jan 14.

Department of Environmental Health Engineering, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.

Background: Due to the high concentrations of total petroleum hydrocarbons (TPH) in oily sludge and their environmental hazards, the concern regarding their effects on health and the environment has increased. The main objective of this research was focused on evaluating the feasibility of using Fenton process in removing TPH in oily sludge from Shiraz oil refinery, Southern Iran.

Results: To determine optimum conditions, four different parameters were assessed at four different levels using Taguchi method. According to data, the optimum conditions were as follows: the reaction time of 1 hour, H2O2 to sample mass ratio of 15, H2O2 to Fe (II) molar ratio of 10 and pH of 5. The maximum TPH reduction rate was 36.47%. Because of the semi-solid nature of the sample and the hydroxyl radicals mainly generated in the aqueous solution, TPH reduction rate greatly improved by adding water. Ultimately, by adding 40 ml water per gram of the oily sludge under optimized conditions, the reduction rate of 73.07% was achieved.

Conclusions: The results demonstrated that this method can be used as a pre-treatment method for the oily sludge. Moreover, a complementary treatment is necessary to reach the standard limit.
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http://dx.doi.org/10.1186/2052-336X-12-31DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3896717PMC
January 2014

Kinetic and isotherm studies of adsorption and biosorption processes in the removal of phenolic compounds from aqueous solutions: comparative study.

J Environ Health Sci Eng 2013 Dec 19;11(1):29. Epub 2013 Dec 19.

Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.

The phenolic compounds are known by their carcinogenicity and high toxicity as well as creating unpleasant taste and odor in water resources. The present study develops a cost-effective technology for the treatment of water contaminated with phenolic compounds, including Phenol (Ph), 2-chlorophenol (2-CP), and 4-chlorophenol (4-CP). So, two sorbents, rice bran ash (RBA) and biomass of brown algae, Cystoseiraindica, were used and results were compared with the commercially granular activated carbon (GAC). The phenolic compounds were determined using a high performance liquid chromatography (HPLC) under batch equilibrium conditions. The effects of contact time, pH, initial adsorbate concentration, and adsorbent dosages on the removal efficiency were studied. The adsorption data were simulated by isotherm and kinetic models. Results indicated that RBA and GAC had the lowest efficiency for the removal of 2-CP, while the order of removal efficiency for C. indica biomass was as follows: 2-CP > 4-CP > phenol. The efficiency of GAC was higher than those of other adsorbents for all of the phenolic compounds. Furthermore, the adsorption capacity of RBA was found to be higher than that of C. indica biomass. The optimal initial pH for the removal of phenol, 2-CP and 4-CP was determined to be 5, 7, and 7 for RBA, GAC, and algal biomass, respectively. Kinetic studies suggested that the pseudo-second order best fitted the kinetic data.
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http://dx.doi.org/10.1186/2052-336X-11-29DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3880076PMC
December 2013

Slaughterhouse wastewater treatment by combined chemical coagulation and electrocoagulation process.

PLoS One 2012 29;7(6):e40108. Epub 2012 Jun 29.

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

Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD(5) removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0040108PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3387025PMC
November 2012