Iranian Journal of

Background and Objective: Increased use of pesticides and chemical fertilizers in agriculture in order to increase the productivity of fertile lands has led to pollution of water resources with a variety of pollutants, including herbicides. In this study, a new polymer magnetic nanoadsorbent named PV/S-g-3D-GO/N was synthesized and used to remove 2,4-D and MCPA herbicides from aquatic environment.
Materials and Methods: To investigate the synthesized nanoadsorbent structure FTIR, FESEM, TEM, XRD, VSM and TGA techniques were used and the effect of parameters affecting the optimal removal of herbicides by the adsorbent, including pH, temperature, contact time, adsorption dose and initial herbicide concentration was investigated. The kinetic, isotherm and thermodynamic studies of adsorption were also investigated.
Results: The results showed that in the optimal adsorption conditions including pH 3 for both herbicides, contact time of 180 min for 2.4-D herbicide and 300 min for MCPA herbicide, absorption dose 5 g/L and temperature 50°C for both herbicides, the maximum absorption capacity (q_max) was 5.62 mg/g for 2.4-D and 4.94 mg/g for MCPA. The synthesized nanoparticles that were used to remove 2,4-D and MCPA herbicides from real samples were totally successful (100% removal efficiency). For both herbicides studied, the isothermal data followed the Longmuir model (2,4-D: R² = 0.995; MCPA: R² = 0.998), and the kinetics of the adsorption process was a pseudo-second-order model (2,4-D: R² = 0.991; MCPA: R² = 0.999).
Conclusion: The results of the present study indicate that the synthesized nano-adsorbent can be used to remove phenoxic herbicides from agricultural runoff as well as water sources contaminated with the studied herbicides.

Background and Objective:  Arsenic has long been considered as a heavy metal and toxic pollutant due to its potential to harm the human health and the environment. Adsorption is one of the mechanisms for arsenic removal from wastewater. Therefore, the purpose of this research was to investigate the feasibility of synthesized chitosan-zirconium magnetic nano fiber on arsenic adsorption from wastewater and to evaluate its kinetic and isotherm models.
Materials and Methods: Synthesis of nanofibers was performed by electrospinning method and the optimal formulation was determined following the experimental design. Then, kinetics and isotherms of arsenic adsorption on the as synthesized nanofibers were investigated. The prepared nanofiber was characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopes (FESEM), Infrared Fourier Transform (FT-IR) and Vibrational Sampler Magnetic Meter (VSM).
Results: The optimal formulation was obtained: 2.84% chitosan, 0.97% nano-zirconium and 0.94% nano-iron. The adsorption of arsenic on synthetic fibers was found to follow quasi-first-order kinetics and the Freundlich isotherm. Furthermore, the effect of initial concentrations of arsenic, contact time, temperature and pH on arsenic adsorption were surveyed. The optimal condition for nitrate arsenic adsorption was obtained at initial concentration of 70 mg/L, 45 min contact time and at pH 3.
Conclusion: According to the results, the synthesized nanofiber displayed a regular network structure with the distribution of the Zr-nanoparticles in its shape. Also, according to the form of magnetometric analysis, it was found that chitosan-nanosirconium magnetic nanofibers are well magnetized and are free magnetic.  Finally, it can be concluded that the synthesized nanosorbent has a high potential for arsenic removal from industrial effluents.

Background and Objective: Synthetic wetlands are engineering systems that use natural plants, soils and organisms to purify municipal polluted water and remove nitrate.
Materials and Methods: In this study, three systems were considerd as soil culture, three systems as plant cultivation on floating plates and three other systems without plant and porous bed as. The experiments were done three times within six months. The hydraulic retention times were 1, 3 and 5 days. The experimental design consisted of a factorial split-plot design. The analysis of variance showed that the efficiency of nitrate removal was affected by the type of constructed wetland, HRT, and temperature changes (p≤0.01).
Results: At the HRT of 1 day, the average efficiency of nitrate removal by the soil culture, plant cultivation on floating plates and control  were 14.34%, 12.09% and 10.51%, respectively. At the HRT of 3 days, the average efficiencies were 17.62%, 15.76% and 13.54%, respectively. At the HRT of 5 days, the efficiencies were increased and they were 17.75%, 17.66% and 16.08%, respectively.
Conclusion: The results showed that the soil culture were more efficinet in removing nitrate .Also, the Cyperus alternifolius plant has the potential of nitrate phytoremediation.

Background and Objective: Global market growth of reverse osmosis (RO) has led to an increase in annual disposal of membrane wastes. Therefore, evaluation of membrane waste management strategies is important to reduce their adverse environmental impacts. Due to the widespread domestic RO membrane market and their economic considerations, this study aims at investigation the direct recycling methods of RO membranes to extend their life cycles.
Materials and Methods: Academic search engines and citation databases such Scopus and PubMed was used to retrieve relevant papers. Selected documents were analyzed and compared in three aspects of technical, economic and environmental issues. 
Results: Direct recycling of RO is performed with fouling removal and degradation of polyamide layer (PA) using oxidizing agents like KMnO₄ and NaOCl. The degradation rate of the PA layer is controlled by optimizing the oxidant concentration during the oxidation process. Factors such as the type of membrane used, its storage conditions, the operating units’ conditions and the final expected product will determine the required concentration-time values. Strategies to reduce these values are very important from an economic and environmental point of view. Decreasing the concentration of oxidizing agent reduces the chlorinated and halogenated compounds emitted from the oxidizing unit which subsequently lessen their harmful environmental impacts and reduces the energy consumption required for treatment.
Conclusion:  The conversion of RO membranes to porous filters is technically possible by optimizing the conditions. In addition, the proper choice of RO membrane and final product type lead to economic and environmental productivity.

Background and Objective: In the present research, the synthesis and characterization of ZnS nanoparticles in zinc blend crystallite phase via hydrothermal method were reported. Advanced oxidation processes using nanophotocatalysts are one of the most efficient methods for removing the dyes with complex organic compounds from textile and industrial wastewaters. The photocatalytic performance of nanoparticles is drastically affected by their structural and optical properties. One of the most important features affecting the photocatalytic degradation of nanoparticles is their optical bandgap width, which is an important factor in the radiant photons in the visible and UV region and the production of active radicals to destroy the complex carbon pollutants. The optical bandgap width, like other properties of nanoparticles is affected by three important geometric parameters, including particle size, dimension and shape. It is also a function of synthetic chemistry, i.e. the precursors and the fabrication methods. The aim of the present study was to investigate the nanostructure of zinc-sulfide synthesized nanoparticles, optical properties and photocatalytic effect on the degradation of Methylene Orange dye.
Materials and Methods: The experiment of degradation of dye consisted of 70 mg of synthesized nanoparticles in 100 mL of dye solution containing 3.75 ppm of Methylene Orange dye at pH = 5.5. The experimental steps were repeated three times. Nanostructure characterization of three-dimension ZnS nanoparticles was specified by X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, transmission electron microscopy, Furrier transform infrared, ultraviolet-visible spectroscopy and N₂ adsorption-desorption.
Results: The lattice characteristics such as density, specific surface area, size, strain, stress and deformation energy density are specified using Williamson-Hall (W-H) and Halder-Wagner (H-W) analysis. The photocatalytic degradation rate (k) of Methylene Orange was calculated to be 0.052 1/min, whilst after 60 minutes about 95% of the dye was photodegraded. The N₂ adsorption-desorption calculations determined the mean pore diameter, specific surface area (S_BET) and total porosity volume as 20.69 nm, 19.12 m²/g and 0.065 m³/g, respectively. The bandgap of fabrication ZnS has been evaluated from the Tauc's equation to be 3.47 eV. Compared with ZnS nanoparticles made by the hydrothermal method in the wurtzite crystallite phase (sample 2), the synthesized sample (sample 1) shows less lattice strain and stress, less crystallite size and also revealed the higher photocatalytic activity.
Conclusion: The pure zinc-sulfide nanoparticles without metal or ceramic dopants in the cubic zinc-blend crystallite phase are synthesized using the hydrothermal method. The precursors used in the synthesis of zinc-sulfide nanoparticles include zinc chloride and thioacetamide in the presence of oleic acid as a collecting agent. High photocatalytic activity of ZnS nanoparticles was confirmed by the degradation or dechlorination of Methylene Orange solution under UV light irradiation. Compared to similar studies, the results show that reducing the optical bandgap from 3.84 eV to 3.47 eV increases the degradation rate from 0.031 to 0.052. In this study, it was shown that synthesized zinc-sulfide nanoparticles by hydrothermal method, was able to decrease optical gap bandwidth and subsequently increased photocatalytic activity.

Background and Objective: Access to safe water is critical for protecting human health. Turbidity is one of the main physical parameters that affect the quality of water from both health and aesthetical points of view. Therefore, waters should be treated based on the standards set for turbidity before consumption. This study was performed to determine the performance of a bench-scale baffled filter system for removing the turbidity, microbial population, and total organic carbon (TOC) from the contaminated water.
Materials and Methods:  A lab-scale Plexiglas baffled filter consisting of five compartments with a total working volume of 2 L was designed and constructed. The polyurethane foam cubes were used as filter media. The effect of turbidity (10, 50, and 100 NTU) and surface overflow rate (SOR: 7.5, 10 and 15 m/h) was investigated on the performance of the developed system.
Results: A direct relationship between turbidity, TOC, and microbial density was observed in the inlet water. The efficiency of the baffled filter in the removal of turbidity and the period of the filter operation run both enhanced as the SOR was either decreased or the inlet turbidity was increased. In addition, almost complete removal of TOC from the inlet water was noticed.
Conclusion: The results of the present study indicated that the baffled filter system with sponge media can be a novel and effective method for the removal of turbidity, microbial contaminants and TOC from the natural surface water.

Background and Objective: Chlorpyrifos (CPF), an organophosphate pesticide, has been widely used in the agricultural industry and may cause environmental damage. The present study aimed to evaluate the potential application of Fe(VI) and Fe(VI)/PMS processes for oxidation of CPF in water after pretreatment with ferric chloride coagulant.
Materials and Methods: This study was performed in two phases including coagulation and flocculation process and advanced oxidation process (AOP). In the first phase, the coagulation process was performed for turbidity removal by ferric chloride (FeCl₃). In this phase, using a central composite design (CCD) with R software, the combined effect of four variables including initial turbidity, initial pH, coagulant dose and contact time was investigated. The supernatant from this process was transferred to the next phase for further analysis. In the AOP phase, the effect of Fe(VI) and Fe(VI)/PMS oxidants were investigated separately.
Results: In the first phase (coagulation and flocculation), FeCl₃ showed the highest efficiency (95.79%) at alkaline pH (pH=8). In the next phase (AOP), the results showed that the degradation efficiency of Fe(VI)/PMS process was higher compared to sole Fe(VI) process at all pHs. Also, by examining the reaction kinetics, it was found that after the coagulation process by FeCl₃, the removal rate in the Fe(VI)/PMS process is 1.5 times higher than the Fe(VI) process.
Conclusion: Due to the high removal efficiency and higher degradation rate of Fe(VI)/PMS process, this technique can be used as a relatively effective method in removing chlorpyrifos from aqueous solution.
 

Background and Objective: With increasing water pollution, serious water shortages and increased pressure to save water, recycling and reuse of water has attracted more attention in various industries. Removal of silica from cooling water is essential for recycling and reuse of water. The aim of this study was to remove silica from water using magnesium oxide nanoparticles (MgO) synthesized by chemical deposition method.
Materials and Methods: Synthetic nanoparticles were successfully determined using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). To determine the optimal adsorption conditions the batch system, the effect of important parameters such as pH (2-8), contact time (0-150 min), initial concentration of silica solution (50-1000 mg/L), adsorbent amount (0.01-0.14 g) and temperature (25-60 ˚C) were studied.
Results: Under optimal conditions, an almost removal of 200 mg/L silica solution was achieved in 60 min reaction time. Equilibrium data were analyzed using the Langmuir and Freundlich isotherms. The adsorption process can be well described by the Langmuir model, and the maximum adsorption capacity was calculated as 75.76 mg/g. Synthetic data were analyzed using pseudo-first-order and pseudo-second-order equations. The pseudo-second-order model showed good agreement with the obtained data (R² = 0.9949).
Conclusion: Due to the high potential of magnesium oxide nanoparticles in silica removal, it can be a good candidate for the removal of silica and industrial wastewater treatment.
 

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: This study aimed to provide an effective electro-catalytic system for the simultaneous reduction of nitrate and disinfection of contaminated water by the electro-catalytic performance of Ni-Fe/Fe₃O₄ cathode.
Materials and Methods: At first, the Ni-Fe electrode was synthesized by the electro-deposition process. Then its physical properties were analyzed by scanning electron microscopy (FESEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, and photoelectron X-ray spectroscopy (XPS). Simultaneous disinfection and reduction of nitrate were performed under the following conditions: 15 mg Fe₃O₄ nanoparticles, pH 6.5, NaCl 10 mM, 50 mg/L nitrate, 10⁵ CFU/mL and current density 4 mA/cm².
Results: According to the results obtained in the absence of nitrate, 100 % of Escherichia coli bacteria were disinfected after 12 minutes. In the presence of nitrate, the time of complete disinfection increased to 120 minutes. In the absence of bacteria, 83% of nitrate was removed in 240 minutes, and in the presence of bacteria, the nitrate reduction efficiency increased slightly to 88%. In the nitrate reduction process, nitrite (0.22 mg/L) and ammonium (3.6 mg/L) were produced. In the presence of bacteria, the amounts of nitrite and ammonium produced increased to 0.42 mg/L and 7.3 mg/L.
Conclusion: The results show the outstanding ability of Ni-Fe/Fe₃O₄ electrode in electro-catalytic reduction of nitrate and disinfection of contaminated water separately and simultaneously with high efficiency and high selectivity to nitrogen.

Background and Objective: The presence of toxic compounds, including phenol, due to industrial development, poses a threat to the environment. Utilizing hairy roots has emerged as a potential method to remove these toxins. This review aims to explore the efficacy of hairy roots in absorbing phenol pollutants and the influencing parameters.
Materials and Methods: This study was conducted using a descriptive-review method based on existing literature gathered from databases such as Science Direct, PubMed, and Google Scholar. The focus of the study was on the purification of phenol using hairy roots. Keywords such as Phytoremediation, Hairy root, Phenol, and Transgenic roots were used for data collection.
Results: Results show successful phenol removal by hairy roots, potentially attributed to abundant production of peroxidase enzymes. Various factors, such as hydrogen peroxide (H₂O₂), incubation time, pH, plant species, and pollutant concentration, impact phenol removal efficiency. Notably, plants like Brassica napus, rich in peroxidase enzymes, exhibit high efficiency in removing phenol pollution up to 500 mg/L, with H₂O₂ and within a pH range of 4-9.
Conclusion: In conclusion, hair roots possess significant adsorption capacity for phenol. However, phenol concentration, contact time, pH, and temperature influence their performance. Therefore, further research is required to explore optimal conditions for phenol removal.
 

Background and Objective: Vacuum Ultraviolet (VUV)-based advanced oxidation is a new category of advanced purification processes, so this study aimed to compare the efficiency of VUV and Ultraviolet-C (UVC) processes in combination with H₂O₂ and PMS in degrading Remdesivir.
Materials and Methods: The photoreactor was investigated with VUV and UVC lamps in combination with H₂O₂ and PMS for Remdesivir degradation. Also, the effect of variables such as solution pH, H₂O₂ dose, Remdesivir concentration, the presence of radical scavengers and anions, as well as hydraulic retention time was considered in the continuous process of Remdesivir removal.
Results: The findings showed that the optimal pH in the processes of VUV, UVC, and their derivatives was equal to 7. By adding 1 mM of PMS and H₂O₂ to the VUV process, the degradation efficiency of Remdesivir was increased from 92.2 ± 0.4% to 98.3 ±2.1% and 100 ± 0.3%, respectively, after 30 min. Also, in the UVC process combined with H₂O₂ and PMS, the degradation efficiency reached 77.8 ± 1.5 and 85.2 ± 1.3% after 40 min, respectively. The degradation kinetics in the examined processes were as follows: VUV/H₂O₂ > VUV/PMS > VUV > UVC/H₂O₂ > UVC/PMS > UVC. The hydroxyl radical was the main reactive oxygen species that led to the decomposition of Remdesivir. The continuous operation of VUV/H₂O₂ showed that the removal efficiency of Remdesivir reached 94.7 ±0.8% after 40 min.
Conclusion: Considering the high rate of Remdesivir degradation by adding H₂O₂, the VUV/H₂O₂ process can be introduced as an efficient technology for the removal of antiviral drugs.
 

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: Due to the presence of industrial pollutants in water sources, it is necessary to treat wastewater, especially colored wastewater. This study aims to treat wastewater containing methyl orange dye using nano mesopore SBA-16.
Materials and Methods: In this study, the effect of different parameters (pH, concentration of methyl orange, amount of adsorbent, temperature, and contact time) on the absorption of methyl orange by nanocomposite prepared with the help of Design of Experiment 7 software and Response Surface Method (RSM) was investigated.
Results: The maximum amount of pollutant removal by the adsorbent was obtained under optimal conditions of pH = 4.07, temperature 50 °C, contact time 35 minutes, initial concentration of adsorbent 10 mg/L, and amount of adsorbent 0.04 g. Also, the findings showed that the absorption behavior is most consistent with the Langmuir isotherm and the absorption process is exothermic and spontaneous at low temperatures.
Conclusion: In optimal conditions, the SBA-16 adsorbent was able to remove 98.60 % of methyl orange from the aqueous solution and the maximum adsorption capacity (qmax) for the removal of methyl orange pollutant was 37.73 mg/g. Considering the high potential of nano mesopore SBA-16 in removing methyl orange pigment, it can be considered a suitable candidate for removing colored pollutants and treating wastewater from textile factories.
 

Background and Objective: Zeolites are among the widely used adsorbents for the removal of arsenic-toxic pollutants. The objective of this study is to prepare granulated zeolite adsorbents using chitosan (CS/Fe-Clin) and alginate (Alg/Fe-Clin) and compare them in terms of physical appearance and arsenic adsorption efficiency.
Materials and Methods: Granular adsorbents were prepared via the ionotropic gelation method. The effects of the type and concentration of the cross-linking solution and the initial ratio of materials in granules formation, as well as the effect of initial arsenic concentration, and the amount of adsorbent used on the adsorption efficiency, were investigated. SEM, XRD, FTIR, and AAS analyses were used to confirm the results. Equilibrium data were matched with Freundlich and Langmuir isotherms.
Results: A weight percentage of 2 % iron chloride (III) and an initial ratio of 1:4 of alginate: nanocomposite for Alg/Fe-Clin and a weight percentage of 2 % (1 % sodium hydroxide + 1 % sodium tripolyphosphate) and an initial ratio of 1:3 of chitosan: nanocomposite for CS/Fe-Clin were chosen as the optimal values. Maximum adsorption efficiency of Alg/Fe-Clin and CS/Fe-Clin adsorbents was determined 88.1 and 92.9 % at dosages of 0.6 and 1 g/L and at initial concentrations of 200 and 300 µg/L, respectively. The q_max values for Alg/Fe-Clin and CS/Fe-Clin adsorbents were 11.11 and 10 mg/g, respectively. Results better fitted with Freundlich isotherm.
Conclusion: Due to the proper adsorption capacity, both synthesized adsorbents showed the ability to effectively remove arsenic; whoever, alginate binder was more efficient.
 

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.
 

Background and Objective: Humic substances are a group of high molecular weight, heterogeneous organic macromolecules formed through biological and geochemical reactions. They are recognized as one of the main precursors of by-products in water treatment processes. Humic acid compounds create various issues in water and soil treatment industries, necessitating their effective removal from water sources. Due to their small size and their ability to separate environmental pollutants, magnetic nanoparticles are used in the treatment of toxic and hazardous pollutants and in remediating contaminated environments. This study aimed to investigate the removal efficiency of humic acid using a three-dimensional magnetic nanoadsorbent and to identify the optimal conditions for removal.
Materials and Methods: First, three-dimensional magnetic graphene oxide was synthesized, and then surface modification was carried out with allyl amine/allyl glycidyl ether. The characteristics of the synthesized magnetic nanoadsorbent were determined using field emission scanning electron microscopy and the surface charge zero point. The removal of humic acid from aqueous solutions on magnetic nanoadsorbent was assessed based on pH, nanoadsorbent dosage, contact time, and temperature, with optimal conditions identified using the Taguchi method. Additionally, the adsorption isotherms, kinetics, and thermodynamics of humic acid adsorption on the magnetic nanoabsorbent were determined, with data analyzed through linear regression and determination coefficients for isotherm comparisons. The reusability of the nanoadsorbent in the humic acid adsorption mechanism was also examined. Experimental studies was conducted on well water samples from Tehran and Manjilabad (Karaj).
Results: The analyses confirmed the structural characteristics and properties of the synthesized adsorbent. Optimal removal of humic acid was achieved at pH 6, an adsorbent dosage of 0.02 g, a contact time of 120 minutes, and a temperature of 25°C, resulting in a 98% removal efficiency. Results indicated that humic acid adsorption followed the Langmuir isotherm, with kinetics corresponding to a pseudo-second-order model, yielding correlation coefficients of 0.9969 and 0.9968, respectively. Thermodynamic data showed that humic acid adsorption by the nanoadsorbent is an endothermic and favorable process.
Conclusion: The use of this nanoadsorbent in removing humic acid from aqueous solutions can be considered as an efficient method. Magnetic nanoabsorbents offer the advantages of easy separation from suspensions using a magnetic field, potential recovery through various methods, and reusability.
 

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.