Showing 29 results for Toc
Somaye Akbari, Gholamreza Moussavi, Stefanos Giannakis,
Volume 14, Issue 4 (3-2022)
Abstract
Background and Objective: Imidacloprid, a neonicotinide plant toxin, is used as an insecticide in agriculture. Due to its high degradation resistance and water solubility it is of highly concerns. Therefore, the aim of this study was to investigate the degradation of imidacloprid by modified magnesium oxide catalyst under irradiation of light and peroxymonosulfate.
Materials and Methods: In this study, modification of magnesium oxide with nitrogen was made by sol-gel method and then iron oxide nanoparticles was used as a magnetic source. Operational parameters were catalyst loading, peroxymonosulfate concentration, reaction time and common anions (nitrate, bicarbonate and chloride). Residual concentration of contaminant was measured by high performance liquid chromatography (HPLC) and mineralization rate was evaluated by measuring TOC.
Results: The results of the study showed that the photocatalytic degradation of the pollutant in the optimal condition was as following: catalyst concentration= 150 mg/L, peroxymonosulfate = 75 mg/L and reaction time= 60 min was 88%. Moreover, at optimum condition, the rate of mineralization was obtained 52%. Results comparison for prepared catalyst under light and dark condition indicated that the as-made catalyst is photocatalytic.
Conclusion: The as-prepared catalyst can be activated as a photocatalyst under LED light and proxymonosulfate for removal of organic pollutants.
Narjes Khodaygani, Roya Mafigholami,
Volume 14, Issue 4 (3-2022)
Abstract
Background and Objective: Pharmaceutical wastewater has a high level of pollution load that should be treated before discharging to the environment. Integrated processes using different mechanisms are one of the most fruitful methods in wastewater treatment. In this study, combined Integrated Fixed Film Activated Sludge (IFAS) and photocatalytic processes are utilized using of Fe3O4/TiO2 nanocatalysts to decrease the COD value of pharmaceutical wastewater.
Materials and Methods: In this study, the variables of each process are optimized using Response Surface Methodology (RSM). In the IFAS process, the variables were dissolved oxygen (DO), media filling percentage and hydraulic retention time (HRT); while in the photocatalytic process, the effects of pH of wastewater, catalyst dose and reaction time were investigated.
Results: In optimal conditions (DO 3 mg/L, HRT 24 h and media filling percentage 65%), COD removal rate was obtained 59.15%. With the initial concentration of 1725 mg/L COD and the mentioned efficiency, the concentration of COD in the effluent diminished to 704 mg/L. However, in the photocatalytic process, during optimal conditions (pH 6.8, reaction time 105 min and catalyst dose 60 mg/L), The efficiency of the process was determined 81%, which by considering the input COD (704 mg/L), the output concentration was reduced to 134 mg/L.
Conclusion: According to the standards provided by the Environmental Protection Agency (EPA), the effluent from the combined process can be discharged into the environment.
Nahid Rashtchi, Soheil Sobhanardakani, Mehrdad Cheraghi, Amirreza Goodarzi, Bahareh Lorestani,
Volume 15, Issue 2 (8-2022)
Abstract
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.
Anasheh Mardiroosi, Hanieh Fakhri, Ali Esrafili, Masoumeh Hasham Firooz, Mahdi Farzadkia,
Volume 15, Issue 4 (3-2023)
Abstract
Background and Objective: Pharmaceutical compounds can cause potential risks to aquatic and terrestrial organisms. So far, different methods have been used to eliminate these pollutants, photocatalytic processes are one of the most efficient processes to eliminate pharmaceutical compounds. In this study, the efficiency of a novel MOF-based nanocomposite, PMo/UiO-66 as a photocatalyst for amoxicillin degradation under visible light irradiation was evaluated.
Materials and Methods: The study of the chemical decomposition of amoxicillin using the PMo/UiO-66 system was conducted at different stages. First, the PMo/UiO-66 MOF nanocomposite was synthesized using the solvothermal method, then the properties of the synthesized nanocomposite were investigated using XRD, FTIR, and SEM techniques. The effect of different operational parameters such as pH (3, 6, and 9), catalyst concentration (15, 20, 25, and 30 %w/w), initial concentrations of amoxicillin (20, 30, 40, and 50 mg/L) at different times on the removal efficiency was investigated. The reusability of the catalyst for four cycles was assessed.
Results: The results showed that PMo/UiO-66 nanocomposite at pH 6, 25 %w/w nanocomposite concentration, and the amoxicillin concentration of 20 mg/L led to complete decomposition of amoxicillin after 120 min. The kinetic of amoxicillin removal followed the first-order model. Reusability tests showed that the photocatalytic efficiency of the synthesized catalyst was not substantially reduced after four cycles.
Conclusion: The current study confirmed that the PMo/UiO-66 system has an appropriate efficiency for photocatalytic removal of amoxicillin under optimized test conditions.
Maryam Heidari Yeganeh, Soudabeh Ghodsi, Sajad Mazloomi,
Volume 15, Issue 4 (3-2023)
Abstract
Background and Objective: One of the basic strategies to reduce the prevalence of diseases among people in society, especially children and adolescents, during the epidemic of COVID-19 disease, is to observe hygiene and personal protection behaviors. The present study was conducted to determine the level of compliance with health protocols in primary schools of Ilam city during the outbreak of the SARS-CoV-2 in 1400-1401.
Materials and Methods: This descriptive-cross-sectional study was conducted in primary schools of Ilam city with a statistical sample of 49 schools (25 girls' schools and 24 boys' schools). In this study, the 2019 new coronavirus disease care and control checklist was used in schools, which has 15 questions with a total score of 100. Data with Kolmogorov-Smirnov and T-Test statistical tests using SPSS software. V21 was analyzed.
Results: The results of this study showed that the highest and lowest scores are respectively related to the parameters of school health assessment before reopening (100 percent) and screening of people in terms of vaccination by PCR test (zero percent). The average score of compliance with the checklist was 74.3 in girls' schools and 74.38 in boys' schools. Also, the results of the T-Test showed that there is no significant relationship between the mean scores of girls' and boys' schools (p<0.05).
Conclusion: The results of the present study showed that the score obtained for compliance with the checklist parameters of all schools in Ilam city is less than 85 points, and the main reason for this is the non-compliance of the screening parameter of people in terms of vaccination/PCR test in schools.
Mojtaba Yeganeh, Sevda Fallah, Hanieh Fakhri, Mahdi Farzadkia,
Volume 17, Issue 1 (6-2024)
Abstract
Background and Objective: Phenol compounds are commonly applied as raw materials in the production of pesticides, herbicides, and dyes. These compounds are toxic to animals, plants, and microorganisms. In this study, the sonophotocatalytic degradation of 2,4-dinitrophenol in aqueous solutions was investigated using organic-mineral polymer catalysts containing Zink and Cobalt oxides under visible light and ultrasonic (US) irradiation.
Materials and Methods: The characteristics of the synthesized catalyst were determined using XRD, FTIR, and SEM techniques. The effect of several key parameters, including pH (3-9), catalyst dosage (0.3-1 g/L), time (0-90 min), US power (100-200 W/m2), and initial concentration of 2,4-dinitrophenol (20-100 mg/L), on the degradation efficiency was also investigated.
Results: After 75 minutes of sonophotocatalytic processing, complete degradation of 2,4-dinitrophenol (20mg/L) was achieved with catalyst dosage of 0.5 g/L, pH of 9.0, and US intensity of 200 W/m2. Kinetic studies indicated that the sonophotocatalytic degradation process followed a first-order kinetic model. The results of radical scavenging experiments confirmed that HO° and O2˚- radicals are the main oxidative species involved in the degradation of 2,4-dinitrophenol. Furthermore, the reuse of the catalyst for five consecutive tests showed a slight decrease in removal efficiency.
Conclusion: The results demonstrate that the sonophotocatalytic process, using the modified organic-mineral polymers with mixed Zink and Cobalt oxides catalyst, can be an effective method for removing 2,4-dinitrophenol from aqueous media.
Seyed Khabat Naynava, Bahareh Lorestani, Mehrdad Cheraghi, Soheil Sobhanardakani, Behzad Shahmoradi,
Volume 17, Issue 3 (12-2024)
Abstract
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.
Raziyeh Zandipak, Nader Bahramifar, Habibollah Younesi, Mohammad Ali Zolfigol,
Volume 17, Issue 4 (3-2025)
Abstract
Background and Objective: Dyes are significant pollutants that pose serious hazards to humans, animals and other organisms. They are not biodegradable through aerobic treatment processes, making their removal from industrial wastewater through photocatalytic processes essential. This research aimed to synthesize an imide-conjugated polymer photocatalyst for the first time and evaluate its effectiveness in removing Rhodamine B dye from aqueous solutions.
Materials and Methods: In this applied research, an imide conjugated polymer was synthesized and employed as a photocatalyst for the removal of Rhodamine B from aqueous solutions. The polymer was characterized using Scanning Electronic Microscopy (SEM), Transmission electron microscopy (TEM), Atomic force microscopy (AFM), X-Ray Diffraction (XRD), Thermogravimetric Analysis, Fourier transform infrared spectroscopy (FTIR), and Diffuse reflectance spectroscopy (DRS) methods. The study also assessed the influence of variables, including pH (4-9), photocatalyst concentration (0.01-0.04 g/L), and contact time (0-120 min), on the removal efficacy of Rhodamine B.
Results: The findings indicated that removal efficiency increased to 99% at a contact time of 45 minutes and a photocatalyst concentration of 0.02 g/L. The optimal pH for Rhodamine B removal was found to be 7.
Conclusion: The imide conjugated polymer proved to be an effective and accessible photocatalyst for the removal of rhodamine B from industrial wastewater under visible light.
Ramazanali Dianati Tilaki, Roghayeh Kaseb, Esmaeil Babanejad Arimi, Mohammad Dianati,
Volume 18, Issue 3 (12-2025)
Abstract
Background and Objective: Benzene is a carcinogenic volatile organic compound commonly found in polluted air. This study aimed to remove benzene from air using a TiO₂–Bi2O₃ composite photocatalyst immobilized on glass foam under ultraviolet (UV) light irradiation.
Materials and Methods: Glass foam coated with the TiO₂– Bi2O₃composite was placed in a quartz reactor, which was connected to an air pump inside a sealed glass chamber. A UV lamp (254 nm) was installed next to the reactor. Known volumes (µL) of benzene were injected into the chamber through a septum. When the pump was activated, benzene-contaminated air passed through the photoreactor. Benzene concentration was measured by collecting air samples from the chamber and analyzing them using a GC-FID device.
Results: XRD spectra and SEM images confirmed the presence of TiO₂ and Bi2O₃, while BET analysis verified the mesoporous structure of the composite photocatalyst. The surface adsorption of benzene by the composite was 15% and followed the Langmuir model. The process kinetics were first-order, and the removal efficiency decreased with increasing benzene concentration. At a benzene concentration of 39 ppm, the removal efficiency after 75 minutes of TiO₂ and UV irradiation was 75%, whereas for TiO₂– Bi2O₃ under similar conditions, the efficiency increased to approximately 90%.
Conclusion: Using a TiO₂– Bi2O₃ composite photocatalyst under UV-A irradiation improved benzene removal efficiency by about 15% compared with TiO₂alone.
