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In this research, nanoparticles of NiFe2O4, Zn0.5Ni0.5Fe2O4, TiO2-Zn0.5Ni0.5Fe2O4 and TiO2-Zn0.5Ni0.5Fe2O4-rGO were synthesized respectively by combustion sol-gel method, co-precipitation and two nanocomposite samples by physical mixing method. For the characterization of nanoparticles from Fourier transform infrared (FT-IR) analysis, X-ray diffraction pattern (XRD), Scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), Diffuse Reflectance Spectroscopy (DRS) and porosimetry measurements. Adsorption and desorption have been used with BET. The results show that the synthesized particles are nanoscale ,and the absorption process takes place inside the holes. Also, the advanced oxidation process (AOP) was evaluated using photocatalyst for nanoparticles and the best performance was TiO2-Zn0.5Ni0.5Fe2O4-rGO nanocomposite with saturation magnetism (emu/g) of 65.88 with It showed a destruction of 95%.

AbstractDue to the increase in population and industrial activities, the demand for clean water has increased. On the other hand, the amount of fresh water has decreased; As a result, wastewater treatment, including municipal and industrial wastewater, has become very necessary. One of the wastewater treatment methods is the Advanced Oxidation Process (AOP). This research used the advanced oxidation process using the photo-catalyst based on modified activated carbon to treat municipal wastewater in Yasouj City. Activated carbon was prepared from the walnut shell using the chemical activation method and then modified by a composite of ZnO and SnO2 nanoparticles and used as a photo-catalyst in the designed reactor for wastewater treatment. The results of FTIR, XRD, and EDX analyses confirmed the presence of ZnO/SnO2 nanoparticles on the modified activated carbon surface. Due to the coating of these nanoparticles on the surface of the activated carbon and inside its pores, the specific surface area of the modified activated carbon is greatly reduced compared to the activated carbon. The results of the DRS analysis show the low band gap of the synthesized photocatalyst and its applicability in the presence of visible light. To optimize the effect of the parameters, the central composite design method was used to design the experiment. The results showed that the maximum amount of COD reduction of 97.41% has been achieved at a pH of 3, the amount of photocatalyst of 1.25 g/L, and the duration of light irradiation of 45 minutes.

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: 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.

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 H2 O2 and PMS in degrading Remdesivir. Materials and Methods: The photoreactor was investigated with VUV and UVC lamps in combination with H2 O2 and PMS for Remdesivir degradation. Also, the effect of variables such as solution pH, H2 O2 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 H2 O2 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 H2 O2 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/H2 O2 > VUV/PMS > VUV > UVC/H2 O2 > UVC/PMS > UVC. The hydroxyl radical was the main reactive oxygen species that led to the decomposition of Remdesivir. The continuous operation of VUV/H2 O2 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 H2 O2, the VUV/H2 O2 process can be introduced as an efficient technology for the removal of antiviral drugs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Photocatalytic removal of bisphenol A, one of the most widely and emerging pollutants in the aquatic environment, was investigated by advanced oxidation process under natural sunlight. The removal process by a metal-organic framework, synthesized with phosphonic acid ligand, namely STA-12 (Fe) and hydrogen peroxide revealed excellent results. Therefore, the optimal conditions for the degradation of bisphenol A by the photo-Fenton mechanism were studied. The removal process follows the first-order kinetics with respect to the contaminant and a significant synergy was observed in the catalytic system of hydrogen peroxide/sunlight/STA-12 (Fe). The Optimal values for pH, irradiation time, catalyst amount and H2O2 dosage for oxidation of bisphenol A in 30 mg / l aqueous solution were determined to be 5, 90 minutes, 10 mg and 12 μl, respectively. Under these conditions, the best removal efficiency was 79.8%. Also, the mineralization value of organic pollutant was determined to equal 51% by measuring TOC. To determine the most important species that affected the photocatalytic reduction, trapping experiments were carried out, using various kinds of scavengers and the results showed that the hydroxyl radicals (•OH) are the main oxidizing agent in the photocatalytic system and superoxide radical and the holes in the photocatalyst surface are less involved in the process of contaminant degradation. Finally, a probable reaction mechanism has been investigated in detail. In addition, the catalyst has recyclability and stability in the photocatalytic reaction. This study is the first report for application of a phosphonate-based MOF for the removal of an emerging pollutant with a photo-Fenton mechanism and presents a new example of solar-driven advanced oxidation process for the treatment of aquatic sources and environmental protection.

Background and purpose: Wastewater olive processing industries have significant amounts of organic compounds resistant to biodegradation which are hazardous if not treated and discharged to the environment. Advanced oxidation processes such as Fenton process have been considered to increase and improve the biological degradability of this type of wastewater. Current study aimed at investigating the efficiency of Fenton process in olive oil mill wastewater treatment. Materials and methods: A laboratory-scale experimental study was carried out. Wastewater properties of olive oil such as COD, BOD5, TOC, color, and turbidity were determined, then the efficiency of Fenton process in wastewater treatment was evaluated. The effects of parameters such as ferrous ion, hydrogen peroxide concentration, pH, time, etc. on the performance of the process were determined. Then, the optimal conditions were found for the Fenton process. All examinations were done according to Standard Methods for the examination of Water and Wastewater. Results: Concentrations of COD and BOD were 67427 and 22400 mg/L, respectively. The highest removal rates in optimum conditions for major pollutants such as COD, BOD, TOC, and color were 81.9%, 60.13%, 57.43%, 44.2%, and 91.7%, respectively obtained at 150 minutes. Conclusion: Fenton process by producing hydroxyl radicals can highly remove pollutants resulting from olive oil waste and can be applied before biological processes.

Background and Aim: Among the industries the dairy of the industry to recognize one of the most polluting Sources due to the presence of a high percentage of organic matter in the effluent. Recently, advanced oxidation processes, including Ultrasonic-persulfate with production of free radical such as sulfate and hydroxyl radicals is the efficient processes in wastewater treatment. Therefore, the aim of this study was evaluation efficiency of US-persulfate processes in treatment synthetic dairy wastewater. Materials and Methods: This research was an experimental-laboratory study. In this study, dry milk was used to make synthetic dairy wastewater and effect of pH (3, 5, 7, 9, 11), persulfate concentrations (50, 100, 250, 500, 750 mg/L), contact time (10, 30, 45, 60, 90 min) and intensity of waves US (35, 37, 130 kHz) was investigated on efficiency and the process efficiency was measured by calculating the residual chemical oxygen demand using spectrophotometrically at a wavelength of 600 nm. Results: According to the results, the efficiency increased by decreasing the pH value, increasing the concentration of hydrogen peroxide to an optimal level and increasing the contact time and ultrasound intensity and also was found that the efficiency of US-persulfate process at pH 3, concentration of persulfate500 mg/L, intensity of US 130 kHz and contact time 60 min had the highest efficiency that the amount of this efficiency was 74/53% and 61/1% for synthetic dairy wastewater and actual dairy sewerage respectively. Conclusion: According to the results, the acoustic-activated peroxylate process can be a good and high-performance method for removing organic matter from dairy wastewater.

Organic contaminants in industrial wastewater are mostly non-biodegradable, so advanced oxidation processes (AOPs) should be used as a promising alternative for conventional treatment processes. In this investigation, degradation of an organic dye was studied in a fluidized bed reactor, using Fenton heterogeneous process. Application of fluidized bed reactor in this process makes it more effective because of high mass transfer and turbulence rate. Pyrite is a natural mineral ironstone which is abundant on earth and is known as a sustainable catalyst for AOPs. In the first part of this study, computational fluid dynamics (CFD) simulation was prepared, which showed a good agreement with the experimental results in dye removal efficiency and hydrodynamics of the reactor. In the second part of the study, a kinetic model was developed for evaluating the hydrodynamic effects on the heterogeneous Fenton reaction in a fluidized bed reactor. Unlike the CFD model, the provided kinetic model does not contain the momentum and mass transfer balances. The CFD results were more similar to the experiment results than the kinetic model. It showed that some of the components that were involved in this process had smaller eddy dissipation rate compared to the kinetic rate.

Background and purpose: In recent years, the presence of antibiotics in aquatic environment has received increasing attention. These compounds remain in the environment, because of incomplete elimination in conventional wastewater treatment processes. Advanced oxidation processes are used to remove many pollutants. The aim of this study was to evaluate the efficiency of sono-fenton degradation in removal of sulfacetamide in presence of zerovalent iron nanoparticles. Materials and methods: An experimental-laboratory scale study was carried out in which NZVI was synthesized through reducing iron sulfate by sodium borohydride. The effects of some variables such as pH (3-9), NZVI concentration (1-8g/L), H2O2 concentration (0.05-2 M) and contact time (5-90 min) were investigated on the process efficiency. Concentration of residual antibiotic was analyzed by HPLC-UV equipped with a C18 column. Results: The maximum removal efficiency was observed at pH=3, 60 min contact time, 5 g/L NZVI concentration and H2O2 concentration of 1 M. In these optimal conditions, the removal efficiency was 91% and COD removal degree was 27%. Conclusion: The experiments showed that the sonocatalytic process using NZVI nanoparticles along with adding H2O2 as an oxidant is an efficient method to remove sulfacetamide and other biological resistant compounds.

Background and purpose: Industries are one of the main sources of producing wastewater accounting for 20% of water pollution. Treatment of dye wastewaters is one of the major challenges in textile industry. The aim of this study was to investigate the performance of advanced oxidation processes, Fenton-Peracetic acid and Photo-Fenton-Peracetic acid for removal of methylene blue (MB) dye from aqueous solutions. Materials and methods: We conducted an experimental study in which the effects of operating parameters such as pH (3-9), contact time (2-30 min), Peracetic acid concentration (5-50 mg/L), ferric chloride concentration (5-200 mg/L), and methylene blue concentration (5-100 mg/L) were investigated on the removal efficiency of MB dye in the presence and absence of ultraviolet radiation. The experiment was conducted in a batch reactor and the efficiency of method to remove color was measured using a spectrophotometer. Results: In current study the highest removal efficiency (99%) was attained by Fenton-Peracetic acid process under the optimized conditions as follows: pH 3, Peracetic acid concentration 30 mg/L, ferric chloride concentration 60 mg/L, methylene blue concentration 10 mg/L, and contact time of 30 min, but, the same amount of color was removed in shorter time (20 min) by Photo-Fenton-Peracetic acid process. Conclusion: High removal efficiency of the Photo-Fenton-Peracetic acid process in a relatively short time, which is because of hydroxyl radical production, show that this process can effectively be applied to remove MB dye and can be considered as a suitable alternative to conventional systems for treatment of wastewaters containing similar organic matters.

Background and purpose: Due to the poor performance of industrial dye settings about 50% of the washing dye liquor is discharged into the environment. Inappropriate discharge of dye-containing effluents is undesirable because of their color, resistance to biological treatment systems, toxic, and their carcinogenic or mutagenic nature to life forms. In the present study we investigated the photocatalytic degradation of reactive yellow 147 using magnetic Fe3O4@SiO2@TiO2. Materials and methods: A central composite design (CCD) under response surface methodology (RSM) was employed to study the interaction between some parameters, including photocatalyst dose, solution pH, and temperature in order to optimize the removal condition of Reactive Yellow 147 via photocatalytic process. Therefore, 20 tests were designed in Design Expert Software (version 7.0.0). All of these Factors were classified in 5 levels +α, +1, 0, -1, -α. Results: There was an increase in removal efficiency with increase in the photocatalyst dosage of Fe3O4@SiO2@TiO2 and with decrease in the temperature. Under acidic conditions, the photocatalytic process was more efficient than that under alkaline conditions. The results also indicated that the application of RSM method not only helped to find the optimum levels of experimental parameters, but also proved that the role of initial pH of the solution and temperature were much more dominant than that of photocatalyst dosage in the photodegradation Reactive Yellow 147 under UV light exposure. Conclusion: Current study showed that photocatalytic process with optimization of effective operational factors, is highly efficient in removal of Reactive Yellow 147. The regenerated as-synthesized photocatalyst shows high stability and high efficiency in the degradation of Reactive Yellow 147 even after ten times of successive reuse without a significant drop in removal efficiency which makes this process economical.

In this work, discoloration of basic yellow 28 using sonoelectrochemical method in presence of titanium dioxide nanoparticles was investigated. The respond surface methodology (RSM) was applied for optimization of discoloration. The influence of different factors such as applied potential, amount of titanium dioxide nanoparticles, time and solution pH was evaluated on discoloration. A mathematical model was presented to prediction of discoloration with RSM. The results shown that time has highest effect on discoloration efficiency, pH, applied potential and amount of titanium dioxide nanoparticles has also effective factors. The sonoelectrochemical route in presence of TiO2 nanoparticles has better performance on discoloration comparing with other methods including sonoelectrochemistry, sonochemistry in presence of hydrogen peroxide, sonochemistry in presence of hydrogen peroxide/TiO2 nanoparticles and electrochemistry in presence of TiO2 nanoparticles at optimum condition, i.e. pH= 8.0, 1.1 V applied potential, 0.96 g/L TiO2 nanoparticles and 119 min.

Introduction and purpose: The release of chlorinated organic compounds (COCs) is accounted as a danger for public health and environment due to their harmful effects such as carcinogenicity, toxicity, and flammability. Trichlorethylene (TCE) is one of the most famous COCs, which is commonly used as a solvent for dry-cleaning and industrial degreasing and contaminates soil and groundwater. Thus, it is considered as a possible carcinogenic compound (class B2) for humans. Therefore, this study was to evaluate the effect of zerovalent iron nanoparticles (nZVI) in degradation of TCE. Methods: Iron nanoparticles were prepared through the Ferric Chloride revival method by sodium borohydride. The properties of nanoparticles were determined using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. In addition, the effect of pH, concentration of trichloroethylene, iron nano-particle dosage, and contact time were studied on TCE removal efficiency. Box Behnken model was used to investigate the interaction of these variables. Analysis of variance was considered as the statistical method for analysis of responses. Results: Results showed that the degradation efficiency was equal to 91.23% in optimal conditions (pH=3, nanoparticles dose= 0.63 g/l, TCE concentration= 11 mg/l, and contact time= 86 min). The results of kinetic studies revealed that TCE degradation by nZVI follows first-order kinetic model. Conclusion: It is conclude that zero-valent iron nanoparticles have a good efficiency in the degradation of TCE. On the other hand, separation of these nanoparticles is simple due to its magnetism properties, which can improve the use of these nanoparticles.

Background and purpose: Wastewater olive processing industries have significant amounts of organic compounds resistant to biodegradation which are hazardous if not treated and discharged to the environment. Advanced oxidation processes such as Fenton process have been considered to increase and improve the biological degradability of this type of wastewater. Current study aimed at investigating the efficiency of Fenton process in olive oil mill wastewater treatment. Materials and methods: A laboratory-scale experimental study was carried out. Wastewater properties of olive oil such as COD, BOD5, TOC, color, and turbidity were determined, then the efficiency of Fenton process in wastewater treatment was evaluated. The effects of parameters such as ferrous ion, hydrogen peroxide concentration, pH, time, etc. on the performance of the process were determined. Then, the optimal conditionswere found for the Fenton process. All examinations were done according to Standard Methods for the examination of Water and Wastewater. Results: Concentrations of COD and BOD were 67427 and 22400 mg/L, respectively. The highest removal rates in optimum conditions for major pollutants such as COD, BOD, TOC, and color were 81.9%, 60.13%, 57.43%, 44.2%, and 91.7%, respectively obtained at 150 minutes. Conclusion: Fenton process by producing hydroxyl radicals can highly remove pollutants resulting from olive oil waste and can be applied before biological processes. [ABSTRACT FROM AUTHOR]

Background and Aim: Among the industries the dairy of the industry to recognize one of the most polluting Sources due to the presence of a high percentage of organic matter in the effluent. Recently, advanced oxidation processes, including Ultrasonic-persulfate with production of free radical such as sulfate and hydroxyl radicals is the efficient processes in wastewater treatment. Therefore, the aim of this study was evaluation efficiency of US-persulfate processes in treatment synthetic dairy wastewater. Materials and Methods: This research was an experimental-laboratory study. In this study, dry milk was used to make synthetic dairy wastewater and effect of pH (3, 5, 7, 9, 11), persulfate concentrations (50, 100, 250, 500, 750 mg/L), contact time (10, 30, 45, 60, 90 min) and intensity of waves US (35, 37, 130 kHz) was investigated on efficiency and the process efficiency was measured by calculating the residual chemical oxygen demand using spectrophotometrically at a wavelength of 600 nm. Results: According to the results, the efficiency increased by decreasing the pH value, increasing the concentration of hydrogen peroxide to an optimal level and increasing the contact time and ultrasound intensity and also was found that the efficiency of US-persulfate process at pH 3, concentration of persulfate500 mg/L, intensity of US 130 kHz and contact time 60 min had the highest efficiency that the amount of this efficiency was 74/53% and 61/1% for synthetic dairy wastewater and actual dairy sewerage respectively. Conclusion: According to the results, the acoustic-activated peroxylate process can be a good and highperformance method for removing organic matter from dairy wastewater. [ABSTRACT FROM AUTHOR]

Background and purpose: In recent years, the presence of antibiotics in aquatic environment has received increasing attention. These compounds remain in the environment, because of incomplete elimination in conventional wastewater treatment processes. Advanced oxidation processes are used to remove many pollutants. The aim of this study was to evaluate the efficiency of sono-fenton degradation in removal of sulfacetamide in presence of zerovalent iron nanoparticles. Materials and methods: An experimental-laboratory scale study was carried out in which NZVI was synthesized through reducing iron sulfate by sodium borohydride. The effects of some variables such as pH (3-9), NZVI concentration (1-8g/L), H2O2 concentration (0.05-2 M) and contact time (5-90 min) were investigated on the process efficiency. Concentration of residual antibiotic was analyzed by HPLC-UV equipped with a C18 column. Results: The maximum removal efficiency was observed at pH=3, 60 min contact time, 5 g/L NZVI concentration and H2O2 concentration of 1 M. In these optimal conditions, the removal efficiency was 91% and COD removal degree was 27%. Conclusion: The experiments showed that the sonocatalytic process using NZVI nanoparticles along with adding H2O2 as an oxidant is an efficient method to remove sulfacetamide and other biological resistant compounds. [ABSTRACT FROM AUTHOR]

Background and purpose: Industries are one of the main sources of producing wastewater accounting for 20% of water pollution. Treatment of dye wastewaters is one of the major challenges in textile industry. The aim of this study was to investigate the performance of advanced oxidation processes, FentonPeracetic acid and Photo-Fenton-Peracetic acid for removal of methylene blue (MB) dye from aqueous solutions. Materials and methods: We conducted an experimental study in which the effects of operating parameters such as pH (3-9), contact time (2-30 min), Peracetic acid concentration (5-50 mg/L), ferric chloride concentration (5-200 mg/L), and methylene blue concentration (5-100 mg/L) were investigated on the removal efficiency of MB dye in the presence and absence of ultraviolet radiation. The experiment was conducted in a batch reactor and the efficiency of method to remove color was measured using a spectrophotometer. Results: In current study the highest removal efficiency (99%) was attained by Fenton-Peracetic acid process under the optimized conditions as follows: pH 3, Peracetic acid concentration 30 mg/L, ferric chloride concentration 60 mg/L, methylene blue concentration 10 mg/L, and contact time of 30 min, but, the same amount of color was removed in shorter time (20 min) by Photo-Fenton-Peracetic acid process. Conclusion: High removal efficiency of the Photo-Fenton-Peracetic acid process in a relatively short time, which is because of hydroxyl radical production, show that this process can effectively be applied to remove MB dye and can be considered as a suitable alternative to conventional systems for treatment of wastewaters containing similar organic matters. [ABSTRACT FROM AUTHOR]

Background and purpose: Due to the poor performance of industrial dye settings about 50% of the washing dye liquor is discharged into the environment. Inappropriate discharge of dye-containing effluents is undesirable because of their color, resistance to biological treatment systems, toxic, and their carcinogenic or mutagenic nature to life forms. In the present study we investigated the photocatalytic degradation of reactive yellow 147 using magnetic Fe3O4@SiO2@TiO2. Materials and methods: A central composite design (CCD) under response surface methodology (RSM) was employed to study the interaction between some parameters, including photocatalyst dose, solution pH, and temperature in order to optimize the removal condition of Reactive Yellow 147 via photocatalytic process. Therefore, 20 tests were designed in Design Expert Software (version 7.0.0). All of these Factors were classified in 5 levels +α, +1, 0, -1, -α. Results: There was an increase in removal efficiency with increase in the photocatalyst dosage of Fe3O4@SiO2@TiO2 and with decrease in the temperature. Under acidic conditions, the photocatalytic process was more efficient than that under alkaline conditions. The results also indicated that the application of RSM method not only helped to find the optimum levels of experimental parameters, but also proved that the role of initial pH of the solution and temperature were much more dominant than that of photocatalyst dosage in the photodegradation Reactive Yellow 147 under UV light exposure. Conclusion: Current study showed that photocatalytic process with optimization of effective operational factors, is highly efficient in removal of Reactive Yellow 147. The regenerated as-synthesized photocatalyst shows high stability and high efficiency in the degradation of Reactive Yellow 147 even after ten times of successive reuse without a significant drop in removal efficiency which makes this process economical. [ABSTRACT FROM AUTHOR]

Background and purpose: Trihalomethanes and haloacetic acids are formed through chlorination of waters containing natural organic matters and pose potential health problems. So, it is necessary to remove humic acid as the most significant natural organic matter in water. The aim of this study was to evaluate the efficiency of catalytic ozonation in removal of humic acid in presence of local green and red montmorillonite. Materials and methods: Green and red soils were collected from Sarcham area in Ardabil, Iran and used as catalysts after cleaning up. The variables in this study included initial pH of the solution, catalyst dosage, reaction time, and initial concentration of the pollutant. Results: The efficiency of catalytic ozonation process increased by increase in contact time, pH, and doses of catalysts and also by decrease in initial concentration of humic acid. In COP process, 100% removal of humic acid (10mg/l) was achieved at natural pH in 15 and 20 min in presence of green and red soils, respectively. Compared with conventional ozonation, presence of radical scavengers such as nitrate, chloride, sulphate and carbonate at high concentrations were found to have minor effects on reducing the efficiency of catalytic ozonation process. Conclusion: Based on this study, green and red soils highly increase the efficiency of catalytic ozonation process. Due to the low cost and availability of these soils, they can be used as catalysts to remove humic acid in catalytic ozonation process or other similar processes. [ABSTRACT FROM AUTHOR]

Backgrounds and Objectives: Nowadays, global concerns about nitrate in groundwater and its adverse impact on health have increased. This study aims to evaluate the efficiency of nitrate reduction from aqueous solution through modified Fenton process using Nano scale zero-valent iron. Material and Methods: This research was an experimental study and performed at laboratory scale. Nitrate reduction was conducted by advanced oxidation process of Fe°/FeІІ/FeШ/H2O2 at pH 2-10, contact time 10-90 min, nitrate concentrations of 50-300 mg/L, and the molar ratio of [H2O2]/[Fe] 0.5-5. The effect of adding H2O2, molar ratio of reagents, contact time, and pH on nitrate removal was examined and optimal conditions for each of these parameters were determined. Spectrophotometer Dr/5000 was used to measure nitrate in the effluent. Results: We found that the optimal parameters in our studywere pH 3, the molar ratio [H2O2]/[Fe°] of 0.5, and the contact time 15 min. By applying these conditions, nitrate removal efficiency at the retention time 15 min, initial nitrate concentration of 100 mg/L, iron concentration of 10 mg/L, and pH 4 for FeШ، FeІІ، Fe°، FeІІ/Fe°/H2O2 and FeШ/Fe°/H2O2 was 10.5, 27.6, 36.5, 62.3, and 74% respectively. Conclusion: According to the experimental results, it was determined that modified Fenton process using zero iron nano-particles can reduce nitrate under optimal conditions and this method can be used for the removal of similar compounds.

The present study investigates the degradation of Acid Red 14 (AR14), commonly used as a textile dye in aqueous medium through the oxidation process by UV /S2O82- under a set of variables concentration of S2O82-, Ag+, AR14 and temperature. Commonly Ag+, heat and UV light can excite S2O82− to sulfate radical form (SO4−•), a stronger oxidant (E0 = 2.60 V) than S2O82−, to enhance significantly the oxidation of contaminants. Also the changes in the absorption spectra of AR14 solutions during the photoxidation process showed that decrease of absorption peak of the dye at λmax = 514 nm indicates a rapid degradation of the azo dye. The results of this study suggest that the oxidative treatment of AR14 by peroxydisulfate with UV is a viable option for removal of the textile dyes from effluents.

Background and Objectives: Water pollution by pesticides has adverse effects on the environment and human health, as well .In recent years, advanced oxidation processes, have been gone through to a very high degree for pesticides removal. Poly-Aluminum chloride (PAC) used for water treatment, can be effective on pesticides removal. The aim of this research was to study the use of UV/O3 and PAC in the removal of pesticides from drinking water.Materials and Methods: In this descriptive- analytical survey, specific concentrations of pesticides (1,5,10,15,20 ppm);namely Diazinon, Chlorpyrifos, Carbaril were prepared through addition to deionized water. Dichloromethane was used for samples' extraction, samples extracted with Liquid- Liquid & Solid-phase extraction , finally entered bath reactor at pH (6,7,9) .The samples then exposed to UV/O3at contact time of (0.5,1,1.5 and 2 hours) . In the PAC pilot , the effects of various concentrations of pesticides, and PAC - ranging (12/24 and 36 ppm) were investigated for the efficacy of pesticides removal. All samples analyzed by GC/MS/MS and HPLC. Results: It was found that in UV/O3 reactor, with the rise of pH, decrease in pesticides concentration, and rise of contact time, the efficiency of removal increased too. In the PAC pilot, increase in PAC concentration and decrease in pesticides concentration , both increased the efficiency. Besides, both of the methods showed high efficiencies in the removal of both pesticides,i-e. halogenated Organophosphorus (Chlorpyrifos) , non- halogenated Organophosphorus (Diazinon) at the degree of over (%80 ); In case of carbamate pesticides (e.g. Carbaril) efficiency was over (>%90). One-Way Anova & Two -Way Anova were used to analyze the obtained data.Conclusion: According these results these two methods are suggested for the removal of pesticides from aqueous solutions.

A vast variety of pesticides are used for agricultural pests in Iran. The release of these persistent organic pollutants. into water supplies leaves adverse effects on both the environment and public health. Advanced oxidation processes have been used recently for pesticide removal. In this research, the combined UV/O3 process has been investigated for the removal of organophosphorus pesticides (Diazinon, Chlorpyrifos), Carbamate pesticides (carbaryl). In this survey, samples have been prepared by adding given concentration (1, 5, 10, 15, 20 mg/L) of the pesticides to deionized water. The samples at separation periods were exposed to the combined UV/O3 (UV=50-200 Wm-2 and O3 = 1g hr-1)in a bath reactor at different pH levels (6, 7, 9) and for different contact times (0.5,1,1.5,2 hr) and the removal efficiencies were determined. Residual concentrations were determined using GC/MS/MS and HPLC. Based on the results, increasing pH reduced pesticide concentration and increased contact time had a direct effect on enhancing removal efficiency. The combined UV/O3 process was found to have a high efficiency (>80%) in degrading both halogenated Organophosphorus(Chlorpyrifos) and non- halogenated Organophosphorus (Diazinon) pesticides. Its removal efficiency for degrading carbamate pesticide (Carbari) was found to be >90%. Based on our results, this method may be suggested for the removal of pesticides from aqueous solutions.

Phenol is one of the most common compounds found in the effluents of many industries such as petroleum refining and petrochemicals, pharmaceuticals, pesticides, paint and dye industries, organic chemicals manufacturing, etc. Due to the high toxicity of phenol, the contamination of bodies of water with this chemical is a serious problem for the environment and human health. In this study, the sonochemical, photochemical, and photosonochemical degradation of phenol in an aqueous solution were investigated. The sonochemical and photochemical experiments were carried out using a bath sonicator (500 W) working at 35 and 130 kHz frequencies and a 400W medium pressure UV lamp. Experiments were performed at initial concentrations varying from 1 to 100 mg L-1. The effects of such parameters as pH, initial phenol concentration, and oxidation period have been determined. Results showed that the effects of ultrasound wave for phenol oxidation were mainly due to hydroxyl radical production during cavitation-induced water decomposition. However, low rates of sonochemical destruction of phenol in water solution obtained. In the sonochemical process, phenol underwent degradation at a faster rate at 130 kHz than 35 kHz. Besides, it was shown that reaction rates involving hydroxyl radicals (hydrogen peroxide formation and phenol oxidation) had a maximum value at higher frequencies. The best yield was observed at 130 kHz for phenol degradation perhaps due to the greater availability of hydroxyl radical on the outer surface of cavitation bubbles. It was found that the rate of photochemical degradation of phenol was higher than sonochemical destruction. Also, the results showed that the combination of ultrasound wave and ultraviolet irradiation was considerably more effective than either ultrasound or ultraviolet light alone. Thus, based on the results of this study, the synergistic action of ultrasound and ultraviolet light is confirmed. This may be the result of three different oxidative processes: direct photochemical action, high frequency sonochemistry, and reaction with ozone (produced by UV irradiation of air). The results of the study showed that the degradation of phenol was increased by decreasing both pH value and phenol concentration in all the processes used.

Background and purpose: Phthalate esters (PEs) are a large family of industrial chemicals widely used as plasticizers. Phthalates can cause endocrine disruption and cancers. Nowadays, phthalate esters are commonly used in cosmetics, adhesives and toy industries and simply get into the surface water and groundwater. The aim of this study was to evaluate the performance of UV / Na2S2O8 / Fe2+ in DEP removal from aqueous solution. Materials and methods: In this study the effect of pH, concentration of persulfate, Fe2+ concentration and contact time on removal of diethyl phthalate were studied in laboratory scale using a cylindrical-shaped reactor containing a UV-C lamp (16 watts) by batch method. The residual concentrations of Diethyl phthalate )DEP( were determined by HPL. The effects of independent parameters on DEP removal were evaluated by Multi simplex and the response surface method (box Behnken method). Results: In this study the optimum condition was obtained at pH = 11, persulfate concentration of 0.4 Mmol/L, 0.07 Mmol/L Fe2+ and 90 minutes contact time. The results showed that the DEP removal by UV / Na2S2O8 / Fe2+ process followed a first-order reaction kinetic. Conclusion: The results indicated high efficiency of UV / Na2S2O8 / Fe2+ process (95% removal under optimal condition) in removal of DEP from aqueous solutions. This efficiency demonstrates that this method is acceptable in DEP removal on industrial scale. [ABSTRACT FROM AUTHOR]

In recent years, the growth in the industries of olive oil extraction has brought about a number of environmental problems. The waste water resulting from olive oil extraction can not be naturally degraded due to the presence of phenol, volatile fatty acids, catchin, and other recalcitrants.In recent years advanced oxidation processes based on hydroxyl radical are paid special attention by scientific, research and industrial centers to degrade the pollutants. In this study, a combination of acid cracking and advanced oxidation process in terms of Fenton process have been studied. Results showed that acid cracking can remove 97, 47, 30, 63 and 57 percent of Turbidity, COD, Total Phenols, Color and Aromaticity, respectively. Fenton process in pH=3 at optimal conditions can remove 57, 97, 18 and 32 percent of COD, Total Phenols, Color and Aromaticity, respectively. Necessary time of reaction was 4 hrs and optimum concentration of H2O2 and Fe2+ ions was determined 0. 5 M and 0.02 M, respectively. Increasing temperature in the range of 25-35°C and type of iron used(ferric or ferrous) has no considerable effect in the efficiency of the process.

Background & Objectives: Disposal of pharmaceutical compounds to environment as an emerging pollutants cause concerns significantly and it is necessary to use new methods of sewage treatment for removal of these compounds. The aim of this study was to investigate the inhibition effects of metronidazole before and after using UV254/H2O2 process on specific methanogenic activity of.anaerobic biomass Materials & Methods: Fourteen anaerobic digestion tests were carried out at batch scale before and after using UV254/H2O2 process in 500 ml reactors with 30% anaerobic biomass and 70% substrate. The liquid displacement method was used. Duration of each test was in the range of 10-17 days. Results: Cumulative Biomethane production in concentrations of 1, 5, 10, 25, 50, and 100 mg/l metronidazole was 34.04, 95.12, 100.86, 3.28, 27.88, and 6.97 ml respectively. This production was 800.73, 243.54, and 10.66 ml in concentrations of 25, 50, and 80 mg/l respectively using UV254/H2O2 process as pretreatment at 60 min retention time. Biomethane production in concentrations of 80,120, and 150 mg/l was 377.2, 380.48, and 63.14 ml respectively at 90 min retention time. Conclusion: Different concentrations of metronidazole had an inhibition effect on anaerobic digestions and therefore the efficient pretreatment method is needed to reduce this inhibition effect. The UV254/H2O2 process is an effective method for degradation and conversion of metronidazole to more biodegradable compounds for anaerobic bacteria consumption and, in turn, to increase biogasproduction in anaerobic digestions. [ABSTRACT FROM AUTHOR]

Backgrounds and Objectives: Nowadays, global concerns about nitrate in groundwater and its adverse impact on health have increased. This study aims to evaluate the efficiency of nitrate reduction from aqueous solution through modified Fenton process using Nano scale zero-valent iron. Material and Methods: This research was an experimental study and performed at laboratory scale. Nitrate reduction was conducted by advanced oxidation process of Fe°/FeІІ/FeШ/H2O2 at pH 2-10, contact time 10-90 min, nitrate concentrations of 50-300 mg/L, and the molar ratio of [H2O2]/[Fe] 0.5-5. The effect of adding H2O2, molar ratio of reagents, contact time, and pH on nitrate removal was examined and optimal conditions for each of these parameters were determined. Spectrophotometer Dr/5000 was used to measure nitrate in the effluent. Results: We found that the optimal parameters in our studywere pH 3, the molar ratio [H2O2]/[Fe°] of 0.5, and the contact time 15 min. By applying these conditions, nitrate removal efficiency at the retention time 15 min, initial nitrate concentration of 100 mg/L, iron concentration of 10 mg/L, and pH 4 for FeШ، FeІІ، Fe°، FeІІ/Fe°/H2O2 and FeШ/Fe°/H2O2 was 10.5, 27.6, 36.5, 62.3, and 74% respectively. Conclusion: According to the experimental results, it was determined that modified Fenton process using zero iron nano-particles can reduce nitrate under optimal conditions and this method can be used for the removal of similar compounds. [ABSTRACT FROM AUTHOR]