Iranian Journal of

Background and Objective: In countries such as Iran that are facing with water scarcity and water crisis, paying attention to the quantity, quality and sustainable use of water resources is very significant. Petrochemical processes discharge pollutants into the environment, contaminating surface water resources. Therefore, treatment of the wastewater of these industries is necessary. Due to the capabilities of AHP process such as generalization, consideration of various parameters, multi-dimensional selection and quantifying the qualitative parameters by experts, the current study was carried out to select the best wastewater treatment alternative for HDPE plant of petrochemical research and technology company-Arak center based on AHP in 2016.
Materials and Methods: In this study, both sequencing batch reactors (SBR) and extended aeration activated sludge (EAAS) systems based on environmental, technical-functional, economic and management criteria's according to the expert's opinion were weighted. Then, the paired comparisons of the selected wastewater treatment systems for each criterion were developed. Finally, the results were analyzed to select the best wastewater treatment systems for HDPE unit of petrochemical industries using Expert Choice 11 Software.
Results: The results showed that the SBR wastewater treatment system was the best method for the wastewater treatment of HDPE plant of petrochemical research and technology company-Arak center as compared with the ESSA system. Also, consistency ratio was ranged from 0 to 0.10 in all emphases. Based on the results of the sensitivity analysis, the SBR system had the highest priority of economic and environmental criteria. The ESSA system had the highest priority of technical-functional and management criteria.
Conclusion: Based on the results, although ESSA method requires more maintainance and management than the SBR method, due to increasing requirement for the compliance of the output effluent quality with permissible limits and the need for less land for the establishment of the treatment plant, the SBR method was selected to be the most suitable process for HDPE plant wastewater treatment.
 
 

Background and Objective: Heavy metals are the most frequent pollutants of urban soils. In general, human health and especially children are directly at risk if the soil is being accidentally ingested orally or nasally. Therefore, this study was conducted to assess potential ecological risk index (RI) of Pb, Cd, Cr and Cu in surface soils of urban parks in Tehran City in 2016.
Materials and Methods: A total of 60 surface soil samples were collected from Mellat, Laleh, Velayat, Ekbatan and Pirouzi parks. The heavy metals contents in samples were determined using ICP-OES after acid digestion of soil samples. Also, RI of heavy metals was determined. All statistical analyses were performed according to the Shapiro-Wilk test, One-Way ANOVA, One Sample T-Test and Pearson Correlation Coefficient.
Results: The lowest and highest contents of the metals (mg/kg) with an average of 0.52 ± 0.25 and 153.81 ± 31.83 were related to Cd and Pb, respectively. Pb and Cu were higher than MPL. Also, the highest surface soil contamination was related to Velayat Park located at the south of Tehran. The value of RI was 99.16 and therefore the soil contamination was categorized in low ecological risk.
Conclusion: Although the value of RI categorized as low ecological risk, due to mean concentrations of Pb and Cu were higher than MPL, control of soil-contamination sources, periodic monitoring of surface soil in the urban parks where citizens spend most of their free time. Additionally, it should be avoided to construct urban parks close to the regions with high traffic intensity.
 

Background and Objective: Environmental pollution emitted from industrial areas while enter the food chain can cause serious adverse health effects. Therefore, this study was conducted to use Ziziphus spina-christi and Prosopis cineraria leaves as bio-indicators of environmental pollution emitted from the complex of Steel Company.
Materials and Methods: In this descriptive study, a total of 90 surface soil samples and also 90 leave samples were collected. After acid digestion of samples, the heavy metal contents were measured using atomic absorption spectrophotometer. Also, the Bioconcentration Factor (BCF) of metals were computed. All statistical analyses were performed using SPSS statistical package.
Results: The highest content of the metals (mg/kg) with an average of 2180.3 ± 202.3 and 2237.9 ± 315.1 for Fe, 76.6 ± 9.6 and 114.3 ± 4.5 for Pb and 69.2 ± 16.8 and 107.2 ± 6.8 for Cd were found to be in Z. spina-christi and P. cineraria unwashed leaves respectively. Also, the BCF of all studied metals were higher than 1.
Conclusion: Based on the values of BCF, it can be concluded that Z. spina-christi and P. cineraria can be considered as a suitable species for phytoextraction of heavy metals in the most polluted regions including industrial and urban areas.
 

Background and Objective: Monitoring of traffic emissions is a good way to build a safe ecosystem for living organisms. Therefore, the present study was conducted to assess the feasibility of using Achillea wilhelmsii and Cardaria draba located along the suburban roads of Hamadan for Zn, Pb and Ni removal by their aerial and underground organs in 2020.
Materials and Methods: In this descriptive study, after selecting 3 sampling stations, a total of 126 plant samples and 63 soil samples were collected. In the laboratory, the samples were prepared, and were then digested with acid. Subsequentely, the concentration of each heavy metal was measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Moreover, bioconcentration factor (BCF), bioaccumulation factor (BAF), transfer factor (TF) and metal accumulation index (MAI) were also calculated. Statistical analyses of the results were performed using SPSS statistical software.
Results: The mean values of BCF and BAF in both A. wilhelmsii and C. draba for all tested elements were greater than 1. On the other hand, A. wilhelmsii showed TF greater than 1 for zinc while C. draba showed TF greater than 1 for zinc and lead. The highest mean values of MAI in unwashed and washed shoots and roots of A. wilhelmsii were 98.48, 64.87 and 72.38, respectively.
Conclusion: Based on the calculated average values of BCF, BAF and TF of each elements, it can be argued that A. wilhelmsii and C. draba species have the potential of phytoextraction and Phytostabilization of the measured heavy metals and can be used for biomonitoring and bioremediation from soil and air in the heavy metals polluted areas.

Background and Objective: Soils and sediments contamination with trace and toxic elements lead to potential ecological risk and adverse effects on human health and so have been the cause of increasing concern worldwide. Therefore, this study was carried out to potential ecological risk assessment of As, Cd, Ni and V in surface sediments of Khazar Abad, southern parts of Caspian Sea in 2019.
Materials and Methods: In this descriptive cross-sectional study, a total of 36 surface sediment samples were collected from 12 sampling sites. After samples preparation, the elemental contents were determined using ICP-OES. Also, potential ecological risk factor (Eⁱ_r) and cumulative potential ecological risk index (RI) were calculated. All statistical analyses were performed by SPSS software.
Results: Based on the results obtained, the mean contents of As, Cd, Ni and V in analyzed samples were found to be 12.7, 0.191, 35.0, and 31.9 mg/kg, respectively. The computed values of Eⁱ_r  showed that factor values were decreased in the order Cd > As > Ni > V. Additionally, the mean values of RI with 53.7 indicated that all the examined elements have the "low potential ecological risk".
Conclusion: Accordingly, although the examined elements have shown a low potential ecological risk, cadmium with 46.4% and arsenic with 45.4% mean values of RI can cause for concern. Therefore, source identification and management of organic and inorganic pollutants and also periodic monitoring of water and sediments as the sink of environmental pollution are recommended.

Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants produced by anthropogenic activities that contaminate all environmental matrices, including soils, and can enter the food chains. Therefore, this study was conducted for the analysis of PAHs compounds content in agricultural soils of Hamedan city, west of Iran, in 2021.
Materials and Methods: a total of 36 surface soil specimens were collected from 12 sampling sites in agricultural soils and after extraction of analytes based on the soxhlet method, the gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, soil samples were further analuzed for the amounts of pH, electrical conductivity (EC), and total organic carbon (TOC). Statistical analysis was performed using SPSS software.
Results: Results showed that 16 PAHs (∑16PAHs) total concentrations ranged from 435 to 3292 µg/kg with an average value of 1806 µg/kg. PAHs with higher molecular weight (≥ 4 rings) were dominant in PAHs profiles accounting for 78%. Based on the results, the mean concentrations of all 16 PAHs were lower than MPC established by MHWaS. Furthermore, the mean concentrations of Pyr, B(a)A, Chy, B(b)F, B(k)F­, B(a)P, and B(ghi)P were higher than the MPC established by the Iranian Department of Environment.
Conclusion: Based on the results obtained, as the mean contents of some PAHs were higher than the MPC, therefore, periodic monitoring of soil contamination with PAHs is recommended for the environmental and human health aspects.
 

Background and Objective: Amoxicillin (AMX) is one of the commonly used commercial antibiotics due to its high resistance to bacteria and its large spectrum against a wide variety of microorganisms, which it´s existence in the wastewater from pharmaceutical industries and hospital effluents causes unpleasant odor, skin disorder, and microbial resistance among pathogen organisms, and it can lead to the death of microorganisms which are effective in wastewater treatment. Therefore, this study was conducted to investigate of removal efficacy of AMX from aqueous solutions using GO@Fe₃O₄@CeO₂.
Materials and Methods: In this descriptive study, GO@Fe₃O₄@CeO₂ was synthesized and then used as a photocatalyst for the removal of AMX from aqueous solution. GO@Fe₃O₄@CeO₂ was characterized using X-Ray Diffraction (XRD), Scanning Electronic Microscopy (SEM), SEM-EDX elemental analysis, Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometry (VSM) methods. Additionally, the influence of variables including pH (3-11), amount of photocatalyst (0.006-0.04 g), contact time (0-150 min), and temperature (25-55 °C) was assessed on the efficacy of AMX removal. 
Results: The results indicated that removal efficiency increased up to 90 min contact time, 0.02 g of photocatalyst, and at the temperature of 25 °C. The optimum pH for AMX removal was 10.
Conclusion: GO@Fe₃O₄@CeO₂ could be an effective and available photocatalyst for the removal of AMX from industrial wastewater under UV light.

Background and Objective: Soil contamination with heavy metals is the most important challenge and common environmental, economic, and public health issue in the world. Therefore, this research was conducted to evaluate the contamination and source identification of Fe, Zn, Cd, and Cr in the surface soils of Khorramabad county, west of Iran in 2020.
Materials and Methods: In this descriptive study, after dividing the study area into 11 homogeneous units, a total of 65 surface soil samples were collected. After preparing the samples, the content of the elements was determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Also, enrichment factor (EF), pollution factor (CF), and Nemrow integrated pollution index (NIPI) were calculated. Statistical analyses of the data were performed using SPSS statistical software.
Results: The results showed that the average content of Fe, Zn, Cd, and Cr (mg/kg) in soil samples were 3.14, 1.13, 0.021, and 0.529, respectively. The EF values showed that the enrichment of Zn, Cd, and Cr was "extremely severe" and the average values of EF for the elements followed the descending order of Cd > Cr > Zn. The average values of CF and NIPI varied from 3.30×10^-5 to 0.182 and 0.043-0.136, respectively, indicating the level of "low pollution" and quality conditions of "no pollution" in all the studied stations. Based on the results of multivariate statistical analysis (PCC, PCA and HCA), Fe has a geological origin; while, Zn, Cd, and Cr mainly originated from a combination of geological processes and anthropogenic activities.
Conclusion: Although the average values of CF and NIPI showed that the study area has an acceptable soil quality, the values of EF indicated the impact of anthropogenic activities on soil contamination. Therefore, regular and periodic monitoring of soil samples as well as management and control of pollutant emission sources is recommended for maintaining environmental and human health.

Background and Objective: Antibiotics are emerging pollutants that enter the human environment through pharmaceutical, hospital, and urban wastewater. Therefore, this study was conducted to investigate of removal efficacy of tetracycline (TC) from aqueous solutions using GO@Fe₃O₄@β-CD.
Materials and Methods: In this descriptive study, GO@Fe₃O₄@β-CD was synthesized and then used as an adsorbent for the removal of TC from aqueous solution. GO@Fe₃O₄@β-CD was characterized using X-ray diffraction (XRD), Scanning electronic microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometry (VSM) methods. Also, the influence of variables including pH (3-9), amount of adsorbent (0.003-0.050 g), contact time (0-100 min), and temperature (25-55 °C) so assessed on the efficacy of TC removal. 
Results: The results of TGA analysis showed that GO@Fe₃O₄@β-CD nanoparticles were resistant to temperatures up to 400 °C. Also, the results indicated that β-cyclodextrin was uniformly dispersed on the surface of GO@Fe₃O₄.
The results indicated that removal efficiency increased up to 60 min contact time, 0.01 g of adsorbent, and decrease temperature to 25 °C. The optimum pH for TC removal was 7.0. Also, under these conditions, the adsorption process followed the Langmuir adsorption isotherm with a correlation coefficient of 0.992 and the pseudo-second-order kinetic model with a correlation coefficient of 0.997, 0.999, and 0.998. The maximum adsorption capacity of the prepared adsorbent was 357 mg/g.
Conclusion: The GO@Fe₃O₄@β-CD could be an effective and efficient adsorbent for the removal of TC from industrial wastewater.
 

Background and Objective: Nowadays, individuals spend a lot of time indoors; thus they are exposed to hazardous compounds including polycyclic aromatic hydrocarbons (PAHs) with teratogen, mutagen, and carcinogen potential. Therefore, this study was conducted to detect, and determine the content and source apportionment of PAHs in office building dust samples of Isfahan metropolis in 2023.
Materials and Methods: In this descriptive cross-sectional study, 84 indoor dust samples were collected from 28 sampling sites. After extraction of analytes, the gas chromatography/mass spectrometry (GC–MS) method was used to determine PAHs content in the samples. Molecular diagnostic ratios (MDRs) were used to determine the origin of PAH compounds. Furthermore, all statistical analyses were performed by SPSS software.
Results: The results showed that 16 priority PAHs were detected in the office building dust samples with the minimum, maximum, and mean values (µg/kg) of 4575, 16589, and 9838. Moreover, based on the results obtained, the mean contents of NAPH, FLU, PHE, FULA, PYR, BaA, CHR, BbF, BkF, BaP, DahA, BghiP, and IcdP species were higher than the maximum permissible concentration (MPC) established by Iran DOE. The results of the MDRs method indicated that although PAHs originated from both pyrogenic and petrogenic sources, the pyrogenic sources had the main role in the pollution of office building dusts with PAHs.
Conclusion: Due to risks arising from exposure to PAHs, detection, determination of contents, source identification, and especially health risk assessment of PAHs in indoor dust of other closed places such as commercial, educational, and recreational buildings as well as households is recommended.
 

Background and Objective: Monitoring and remediation of metal contaminants in aquatic ecosystems is of particular importance to estimate, control, and reduce the level of threats to alive creatures and humans. Therefore, this study was conducted to evaluate metal contamination of surface sediments and the ability to monitor and bioremediation of iron, lead, and copper by aerial and underground tissues of Typha Latifolia and Nasturtium microphyllum located along the aquatic ecosystem of the Lar River, Tehran, Iran in 2021.
Materials and Methods: In this descriptive study, after selecting four sampling sites, 48 plant samples and 12 sediment samples were collected. After preparation and acid digestion of the samples in the laboratory, the contents of the elements were determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Also, pollution index (PI), pollution load index (PLI), bioconcentration coefficient (BCF), bioaccumulation (BAF), and translocation factor (TF) were calculated. Statistical analyses of the results were performed using SPSS statistical software.
Results: The highest values of Fe, Pb, and Cu (mg/kg) in sediment samples were 11.8 ± 0.665, 0.915 ± 0.030, and 0.710 ± 0.026, respectively, and belonged to station 4; and in plant tissues 11.4 ± 1.25, 0.578 ± 0.180, and 0.298 ± 0.095, respectively, and were belonged to the roots of T. Latifolia. The PI values showed that the pollution of Fe, Pb, and Cu was "low" and the average PI values for the elements followed the descending order of Pb > Cu > Fe. The average values of PLI also vary from 0.003 to 0.006, indicating the quality conditions of "no pollution" in all the studied stations. On the other hand, T. Latifolia had a BCF > 1 and TF < 1 for Fe.
Conclusion: Based on the results obtained, it can be concluded that T. Latifolia is a suitable species for stabilizing Fe in sediments and could be used to monitor and remediate potentially toxic elements from polluted aquatic ecosystems.
 

Background and Objective: Monitoring of pollutants in urban ecosystems is of particular importance. Therefore, this study was conducted to evaluate the capability of Robinia pseudoacacia and Pinus elderica for biomonitoring of Pb, Cr and Ni in urban areas of Hamedan in 2023.
Materials and Methods: A total of 36 soils and 72 plant samples were collected from 12 sites. The contents of elements were determined using ICP-OES. Also, the values of PI, PLI, BAF, and CR indices were computed. 
Results: The highest values of Pb, Cr, and Ni (mg/kg) in soil samples with 72.2, 67.5 and 101 values belonged to the commercial, industrial, and commercial sites, respectively. The highest average content of analyzed elements in unwashed and washed leaves/needles for Pb both belonged to the commercial areas; for Cr and Ni, all belonged to the industrial areas. The average values of PI followed the descending order of Cr > Ni > Pb. The average values of PLI varied from 1.22 to 1.34. Moreover, BAF values of Pb, Cr, and Ni of R. pseudoacacia leaves and P. elderica needles were found to be in the range of 0.100-1.00. Also, the highest mean values of CR of Pb and Cr were both found in P. elderica; and the highest mean value of CR of Ni was found in R. pseudoacacia.
Conclusion: R. pseudoacacia and P. elderica could be used as suitable and efficient species for monitoring and remediation of toxic elements from soil and air in polluted ecosystems.
 

Background and Objective: Antibiotics as emerging pollutants are harmful to environmental health. Therefore, this study was conducted to investigate the efficiency of Uio-66-NH₂@CS-Iso-Gu nanohybrid for the removal of amoxicillin (AMX) from aqueous solutions.
Materials and Methods: In this study, for the first time, guanidine and isocyanate monomers are cross-linked with chitosan. The combination of this polymer with organometallic compounds contributes to its chemical/thermal stability and reusability. Uio-66-NH₂@CS-Iso-Gu nanohybrid was characterized using X-ray diffraction (XRD), Scanning electronic microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), and BET methods. Also, the effects of pH, initial concentration of AMX, contact time, and temperature were evaluated. Moreover, isotherm, kinetic and thermodynamics studies were performed.
Results: The results of TGA analysis showed that Uio-66-NH₂@CS-Iso-Gu nanohybrid was resistant to temperatures up to 400 °C. Also, optimal adsorption of AMX occurred in the first 25 min. The synthesized nanohybrid has a surface area of 101.2 m²/g and a type IV isotherm. Acidic groups were present on the synthesized nanohybrid surface based on the pHpzc = 4.7. Langmuir (for 25 °C and 45 °C) and Freundlich (for 65 °C) isotherm models and pseudo-second-order kinetic models are more appropriate to fit the adsorption data with the experimental data. The maximum adsorption capacity of the synthesized nanohybrid was equal to 56.49, 40.65, and 0.382 mg/g at temperatures of 25°C, 45°C, and 65°C, respectively. Based on the findings, Uio-66-NH₂@CS-Iso-Gu nanohybrid could be used for up to five cycles without significantly reducing their performance.
Conclusion: The results showed that Uio-66-NH₂@CS-Iso-Gu nanohybrid has a significant efficiency for removing AMX and could be used as an effective adsorbent for the treatment of wastewater containing pharmaceutical residues.
 

Background and Objective: Fenitrothion is a phosphorus-based pesticide that enters water resources through various sources,including industrial wastewater and agricultural effluent. its non-biodegradability, which results from the formation of strong chemical complexes, advanced oxidation methods are required to remove it from environmental matrices.  This study aimed to evaluate the performance of a magnetic graphene oxide nanocomposite functionalized with cerium dioxide in the removal fenitrothion from aqueous solution.
Materials and Methods: In this applied research, GO@Fe₃O₄@CeO₂ was synthesized and subsequently used as a photocatalyst for the removal of Fenitrothion from aqueous solutions. Characterization of GO@Fe₃O₄@CeO₂ was conducted using X-Ray Diffraction (XRD), Scanning Electronic Microscopy (SEM), SEM-EDX elemental analysis, Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometry (VSM) methods. The effects of various parameters, including pH (2-9), photocatalyst dosage (10-40 mg), and contact time (0-90 min), were assessed to determine their influence on fenitrothion removal efficiency. 
Results: The results demonstrated that the removal efficiency increased up to 60 min contact time, 20 mg of photocatalyst. The optimal pH for fenitrothion removal was found to be 4. Additionally, kinetic analysis of the photocatalytic removal process indicated that it followed a pseudo first-order (PFO) model.
Conclusion: The GO@Fe₃O₄@CeO₂ nanocomposite proved to be an effective and accessible photocatalyst for the removal of fenitrothion from industrial wastewater under UV light.