فهرست مطالب ghorban asgari

Tea holds a special place in Iranian culture, ranking as the most widely consumed beverage after water. A significant portion of Iran’s domestic tea production (approximately 70%) originates from the lush landscapes of Gilan province. The Iranian Tea Research Center (ITRC) claims that Iranian tea is pesticide-free. However, there is a concern that tea farms in the foothills may be exposed to pesticide spraying from nearby citrus gardens. This study aimed to investigate the presence of the 17 organophosphorus pesticides in tea leaf samples collected from tea plantation areas in Gilan province. Sample preparation was carried out using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method, followed by the determination of pesticide concentrations using the gas chromatography (GC) method. To assess the non-carcinogenic risk associated with the consumption of black tea due to pesticide residues, we followed the guidelines provided by the United States Environmental Protection Agency (USEPA). The results were striking, revealing the presence of pesticide residues in all tested samples, raising concerns about the purity of Iranian tea. Notably, the hazard quotient (HQ) for children (<15 years old) exceeded that for adults (>15 years old). Furthermore, spring-harvested tea samples demonstrated higher HQs compared to their autumn counterparts.

Metallic coagulants have been used for more coagulation and flocculation of flocs in many wastewater treatment plants (WWTPs) in all parts of the world. The integration of different methods to improve the wastewater treatment process has been considered in recent years. In this case-control study, the effects of four main coagulants (ferric chloride, ferric sulfide, alum, and poly-aluminum chloride) on sludge volume index (SVI) with and without exposure of static magnetic fields (SMFs) have been investigated. Both methods significantly reduced SVI (mL/g), but the combination of SMFs and coagulants was more effective. Ferric chloride could control bulking or reduce SVI to less than 150 mL/g at concentrations of 0.0625 to 2 g/L when the SMFs intensity of 15 mT was used. The control of bulking in other coagulants happened when SMFs were added to coagulants at 0.0625-0.125 g/L concentration of coagulants (P<0.05). With the application of SMFs, the highest reduction of SVI belonged to ferric sulfide (43.60%), followed by ferric chloride (18.40%), poly-aluminum chloride (PACl) (20.19%), and alum (19.80%). Without the application of SMFs, the highest reduction of SVI belonged to ferric chloride (38.36%), followed by alum (34.94%), PACl (25.43%), and ferric sulfide (6.69%).

In recent years, due to water shortages and rapid industrial growth, the treatment and reuse of industrial wastewater has become of great importance. Phenol and its derivatives can be mentioned as wastewater pollutants that have a destructive effect on the environment. Pentachlorophenol (PCP) is one of these derivatives that may be carcinogenic to humans, and wastewater treatment containing PCP is required. Therefore, the aim of this study was to remove PCP from aqueous media.

Effective operating parameters such as initial PCP concentration (25, 50, 100, and 150 mg/L), persulfate concentration (25, 50, 75, and 100 mg/L), solution pH (5, 7, 9, and 11), and reaction time (10, 20, 30, and 40 min) were investigated. After the removal of PCP, an experimental design based on an orthogonal array using the Taguchi method was proposed.

Based on the results, 98.78% of PCP in the optimal conditions (initial concentration of PCP of 25 mg/L, concentration of sodium sulfate (Na-PS) of 20 mg/L, pH = 11, and reaction time of 40 min) was removed. In this process, the COD and TOC removal rates were 82.3% and 61%, respectively. Analysis of variance (ANOVA) showed that persulfate is the most effective factor in the removal of PCP in the persulfate/UV process.

Persulfate/UV processes as an advanced oxidation process, powerful and environmentally friendly, can be used in wastewater treatment containing phenolic compounds, including PCP.

One of the most important problems in the process of wastewater treatment by the complete mix activated sludge method is the production of a large volume of sludge, which poses many problems in the management and conditioning of sludge. Since about 60% of the operating costs of wastewater treatment plants are related to sludge management, so any modified process that can produce less sludge can be effective in reducing costs and better sludge management. The use of magnetic fields to treat wastewater has been considered by researchers in recent years due to the lack of application of chemicals in these processes. This study considered the use of MFs strength in the range of 0.19 to 3.21 mT on diluted sludge volume index for 30 minutes. The rate of reduction of this index in the case samples compared to the control samples from 10 to 100 mL/g was different. During this period, the difference between the temperatures of the case samples compared to the control samples was statistically significant and was estimated from 0.4 to 20 °C. The difference between mean pH of the case and control samples was significant but the dissolved oxygen concentration of them, similar to other variables’ factors that affect the process, was not statistically significant (p> 0.05).

Considering the importance of alkalinity in pH regulation and its buffering role, in this study, the effect of inlet wastewater alkalinity on the efficiency of the anaerobic unit of the wastewater treatment plant. Moreover, a superior chemical compound in providing alkalinity to wastewater was investigated.

This study was performed in the treatment plant to determine the relationship between input alkalinity and removal efficiencies of COD, BOD5 and TSS. In order to determine the optimal alkali material for superb anaerobic wastewater performance, four common chemical substances including, NaOH, Na2CO3, Ca(OH)2 and MgO were selected and examined using One Factor At Time (OFAT) test method.

According to the results maximum removal efficiencies were obtained 62, 66.6 and 71.2% for COD, BOD5 and TSS, respectively under alkaline condition of 1260 mg/L CaCO3. Furthemore, the optimal dose to supply one unit of alkalinity by Na2CO3, Ca(OH)2 and MgO were 0.53, 0.54 and 0.3 mg/L, respectively. These values were obtained 5 min contact time and mixing rate of 150 rpm. However, for NaOH the optimal dose supply was obtained 0.35 mg/L for 3 min contact time and mixing rate of 100 rpm.

In conclusion, the performance of anaerobic baffled reactor is highly related to the supply of influent alkalinity to the reactor. In addition, the use of MgO can be considered as a suitable alkaline substance to neutralize acidic wastewater and provide alkalinity for ABR system.

Particulate or particle mattes in term of air pollution are particles with a diameter of 2.5 μm or less (PM2.5). PM2.5 is a natural source of air pollution and has harmful effects on citizens in Sanandaj City, located in the west of Iran. In this study, the hourly data of concentration of PM2.5 were taken from the Kurdistan Environmental Protection Agency. During the study period (2018-2019), the 24-hour concentration of PM2.5 exceeded 339 times the average level. By AirQ+ software, the relationship between data and Relative Risk (RR), Baseline Incidence (BI), and Attributable Proportion (AP) were estimated. Then chronic obstructive pulmonary disease, lung cancer, ischemic heart disease, and brain stroke in the range of over 30 years were estimated. The main target of this study was to survey the relationship between PM2.5 concentration and the death rate of citizens of this non-industrial city. The long-term health effect (more than 6 months) of PM2.5 caused 326 deaths on average (except for accidents and poisoning). Increase the concentration of PM2.5 is one factor that affects a high percentage of mortality rate.

Methylene blue (MB) dye is an environmental contaminant that has been mostly used in textile industry. Taguchi orthogonal array design was employed as an optimization method to reduce the number of experiments. In this research, bone char ash modified by MgO-Fe catalyst was applied for degradation of MB in catalytic ozonation process (COP) system and operational parameters including initial MB dosages, initial pH, catalyst dose, and contact time were optimized with Taguchi method. Accordingly, the best condition for the removal of MB obtained at initial MB concentration of 20 mg/L, reaction time of 15 minutes, initial pH value of 10, and catalyst concentration of 0.1 g/L. Additionally, optimization of experimental set-up showed that the MB concentration had a notable effect on MB degradation in COP process (55.6%), and reaction time had a negligible effect (1.98%). At this condition, total organic carbon (TOC) removal was determined to be 31% but in longer time, its removal increased to 65%.

The discharge of a large volume of colored wastewater into receiving water sources has caused widespread concern around the world. The aim of this study was to investigate the efficiency of pumice as an adsorbent in removing methylene blue (MB) from aqueous solution. The adsorption process was also modeled and optimized by the methods as follows: central composite design-central composite design (RSM-CCD) and artificial neural network-genetic algorithm (ANN-GA).

Methods and Materials:

The independent variables in the study were included pH (3-11), contact time (10-50 minutes), adsorbent dose (0.1-2 g/L), and MB concentration (20-100 mg/l). The effect of these parameters on the efficiency of pumice in MB uptake was modeled and optimized by RSM-CCD and ANN-GA methods. A spectrophotometer at 620 nm was used to measure the residual MB concentration in solution.

The results showed that the RSM-CCD method has the ability to develop a quadratic polynomial model with high validity (R2 = 0.9997) for the adsorption process. Similarly, the ANN-GA method fitted well with experimental data to develop a model with high validity (R2 = 0.9978). The results of optimization process by RSM-CCD and ANN-GA methods obtained the highest adsorption efficiency at pH = 11, contact time = 50 minutes, adsorbent dose = 1 g/L, and concentration MB = 20 mg/L. Adsorption efficiency shows a direct relationship with pH, contact time and adsorbent dose and inversely with contaminant concentration. The linear effect of pollutant concentration and adsorbent dose variables had the greatest effect on adsorption efficiency.

In this study, it was observed that pumice as a cheap and available adsorbent can be considered as a suitable choice for absorbing dye pollutants from aqueous media. RSM-CCD and ANN-GA methods can also be used to model and optimize adsorption processes.

Some of the microorganisms such as Escherichia coli have the ability to migrate to areas in which the intensity of magnetic fields (MFs) is higher, which is called magnetotactic properties. Magnetotaxis is a process implemented by a group of gram-negative bacteria that involves orienting and coordinating movement in response to magnetic fields. This study was conducted to investigate these properties of Escherichia coli in laboratory conditions. By means of coated wires (30 rounds) placed in two parts of the reactor (with five zones and a volume of 250 mL) and direct current (DC), an intensity of 0.18 mT for 42 minutes has been prepared. The most probable number of E. coli per 100 mL (MPN/100 mL) in each zone of the reactor, before and after exposure, was estimated. According to the results of this study, E. coli has magnetotactic properties, and the mean density of these bacteria in higher MFs (0.18 mT) is higher compared to the other zones in the reactor.

 Nitrate can enter water bodies through using chemical fertilizers and discharging the effluents from municipal and industrial sewage treatment plants. As a superiority to the conventional statistical models, Grey models (GMs) require only a limited amount of representative data to estimate the behavior of unknown systems. In the current study, the nitrate concentration of the year 2023 in Babol groundwater resources was forecasted by using GM, namely GM (1, 1). 

 This descriptive-cross-sectional study was performed in the city of Babol. The data of 63 wells in urban and rural areas during the warm and cold seasons between 2007 and 2017 were supplied from the Health Center and Babol Rural Water and Sewage Company. In data set, the observed values between 2007 and 2015 were used to fit models, and the observed values between 2016 and 2017 were used to evaluate the accuracy of the model's predictions. To assess the efficiency of the model fitted and precision of the predicted values, we used indexes of forecast absolute error, small error probability, and the proportion of variance statistical metrics. 

 Simulated results showed that the accuracy of the model GM (1, 1) to predict and forecast both data sets is entirely appropriate and reliable. The forecasting values of nitrate concentration of the year 2023 and 8 years later, for urban and rural areas in warm and cold seasons, are 21.30 and 7.30 and 15.63 and 5.34 mg/L, respectively. 

 Although the predicted concentration of nitrate in the studied area is lower than that the standard concentration suggested by the World Health Organization, all water resources should be protected effectively.

Dyes are resistant organic matter because they have an aromatic rings. Sulfate radical (SO4●-) is a powerful oxidative radical. The design via CCD, cause the process was done by high accurate and low-cost. The aim of this study was modeling of UV-EPS process to degradation of Acid Blue 25 dye via the CCD from aqueous.

In this experiment study, used to a photoelectrochemical reactor with two iron electrodes as an anode and two titanium electrodes as a cathode and Low-pressure mercury lamp (254 nm). The pH (2-4), Direct Current (0.75-1/5 A), S2O82- concentration (0/5-1/5 mg/l), reaction time (20-40 min) and initial concentration of AB25 (50 -100 mg/l) as a main independed variables were chosen. Also, COD, synergist effect, presence of radical scavenger and kinetic of reaction were studied in optimum conditions. Dye concentration and COD were measured by spectrophotometer (DR5000).

The results illustrate that the efficiency of process is affected by the variables. Optimum condition obtained in pH=3/01, DC was 1/08 A, PS was 1/30 mg/l, reaction time was 34 minute and initial concentration equal to 50 mg/l. In this situation efficiency of process was 91 percent. The COD removal in these conditions was 69 percent. The correlation coefficient was 0.84 which indicates that the quadratic model is suitable for process design. The kinetics of reaction followed the first order kinetics. Reduce of efficiency of process in the presence of radical scavenger occur.

Optimizing via CCD reduces the number of runs and increases accuracy. This process has a high efficiency in dye and COD removal and this process can be used to reduce the pollutant loading form industrial wastewater, such as textile wastewater, before discharging into the environment.

4-chlorophenol (4-CP) is one of the seriously toxic chlorophenol compounds found in the effluent wastewater generated by oil refineries, pharmaceutical factories, and paper and leather producers which introduced into surface and ground water resources. This research aimed to study the feasibility of nZVI nanoparticles in activation of H2O2 and persulfate under UVA-LED irradiation based on Taguchi experimental design for 4-CP removal. This experimental study was conducted using a lab-scale batch reactor equipped with 18 ultraviolet light emitting diodes lamps with a wavelength of 390 nm. The effects of operating parameters such as pH of solution, contact time, dosage of nZVI, dosages of H2O2 and persulfate and different initial 4-CP concentration were evaluted by difiend factor of 4*4 using Taghuchi L-16 orthogonal array. Based on the results of the Taguchi method, the optimum conditions for removal of 4-CP in nZVI activated persulfate process included the initial 4-CP concentration of 25 mg/L, pH=3, reaction time of 60 min, nZVI and persulafte respective dosages of 2 and 2 mM. The highest removal efficiency and S/N values for this process were 51.83% and 34.29%, respectively. Also, optimum conditions for removal of 4-CP in nZVI activated H2O2 process were the initial 4-CP concentration of 25mg/L, pH=3, reaction time of 30 min, nZVI and H2O2 dosages of 0.75 and 1 mM. In this condition, the highest removal efficiency and S/N values were 81.76% and 38.25%, respectively. In both processes in this case, under acidic conditions, an increase in the active catalyst (Fe2+) activated more and more oxidants (radical hydroxide and radical sulfate) in both reactants, resulting in better efficiency of processes in these conditions. UVA-LED/H2O2/nZVI process could serve as a new and feasible approach for the degradation of 4-CP as well as other organic contaminants containing wastewater due to high efficiency, low contact time and need to the lowest oxidants agents. UVA-LED/H2O2/nZVI process could serve as a new and feasible approach for the degradation of 4-CP as well as other organic contaminants containing in wastewater due to high efficiency, low contact time and need to the lowest oxidants agents.

Organic aromatic compounds as common environmental pollutants can be existing in the effluent of different industries in concentrations ranging from trace quantities to hundreds of milligrams per liter. Phenol compounds extremely have been used in pharmaceutical, wood industry and paper and dyes industries which introduced to environment via effluents. This study was done to evaluate the efficacy of persulfate activated by Fe2+ in the present of UV for removal of phenol from aqueous solutions. This photocatalytic degradation experiment was performed in batch mode using a 2.5 L cylindrical reactor equipped with low-pressure Hg vapor lamp of 55 W for wavelength production of 253.7 nm. The effects of operating parameters such as pH of the solution (pH: 3-10), different initial persulfate concentration (10-75 mmol/l), initial Fe2+ concentration (5-30 mmol/l) and initial phenol concentration (10-100 mg/l). Concentration changes of phenol were determined using UV–VIS spectroscopy at the wavelength of 500 nm. Degradation of phenol was significantly decreased with increasing of pH from 3 to 10, whereas the highest phenol removal rate was 82% at pH=3 in 45 min contact time. Also, the phenol removal rate is depending on initial persulfate and Fe2+ concentration. The degradation of phenol by this photocatalytic followed first order rate decay kinetics (R2>98%(. Under optimum operational conditions, the removal of TOC was obtained to be 61% in 45 min contact time. This study indicated that activation of persulfate by Fe2+ in the present of UV process could serve as a novel treatment technique for removal of phenol in aqueous solution.

The aim of the present study was to calculate and to assess the potential lifetime cancer risks for trihalomethanes from consuming chlorinated drinking water in Hamadan and Tuyserkan cities, western Iran in 2016-2017. Study design: A cross-sectional study. Seventy-two water samples were collected from the distribution systems and from the outlet of water treatment plants (WTPs) and the experiments were carried out to determine the desired parameters. All the sampling and measurement methods were according to Standard Methods. The obtained data were analyzed using SPSS software. The mean concentration of total THMs in the summer and winter was 42.75 and 17.75 μg/L, respectively, below the WHO and Iranian standard. The positive correlation was observed between temperature and THMs levels. Moreover, THMs concentration in Shahid Beheshti’s WTP was several times lower than in Ekbatan’s WTP. Chloroform, the dominant species of THMs, was identified at different sampling points. The highest cancer risk in Hamadan was 1.4×10-5 and 4.8×10-5 for male and female, respectively; and the cancer risk was obtained to be 5.6×10-7–2.26×10-6 in Tuyserkan. The drinking water obtained from the studied area is safe in terms of THMs concentration. Nevertheless, the highest cancer risk was higher than the EPA’s acceptable level of 10-6.

Background and purpose: In order to design an industrial-scale adsorption process, it is necessary to model exact simulation of the dynamic behavior of fixed bed adsorption system. This study aimed at evaluating the performance of fixed bed column using sucrose-modified pumice in removal of metronidazole from aqueous phase. In this experimental study, the adsorbent was prepared from pumice stone and sucrose was used to modify the pumice. The laboratory mode reactor was a cylindrical shape in 20 cm length and 2 cm diameter. Different parameters such as initial concentration, pH of the solution, flow and pumice height in bed were investigated to assess the performance of fixed bed column in removal of metronidazole. Thomas and the Adams–Bohart models were used to evaluate the breakthrough curves of metronidazole removal. According to findings, the BET of modified pumice per gram of adsorbent increased from 8.4 to 35. Decrease in pH and contaminant concentration resulted in increase in bed lifetime. The experimental data were found to fit well with the Thomas model. According to this study, the Thomas model could be used in designing and investigating the amount of adsorbent in real conditions. Also, the fixed bed column can be used as an effective method to remove antibiotics from water.

Using additives such as Balnkit, to increasing the quality color of food and for the fermentation and early preparation of bread dough, has increased in recent years. The purpose of this study was to investigate the concentration of Blankit in Hamadan breads production and risk assessment of food consumption during 2016. In this descriptive-analytical study, Balnkit, concentration in breads produced in Hamadan in 2016 was determined. A total number of 85 samples were randomly collected from all bakeries in two steps. The concentration of Blankit was determined according to ISIRI guideline using spectrophotometer in 560 nm. Then for the evaluation of risk assessment of food consumption, the value of target hazard quotients (THQ) was calculated. The Blankit was not found in 97% of samples and only 3% of samples (Lavash bread) have the Blankit. The calculation of the THQ index showed that value of THQ was 0.0041 whose value is less than 1 and the consumption of bread with this concentration will not endanger. The results of this study showed that the addition of Blankitin bread processing, with regard to the concentrations determined and eliminating it from bread due to the heat, does not pose a threat to the health of the people.

Antibiotics to treat an illness or as a growth promoter, to be consumed. A pharmaceutical composition in the form of original or metabolized in the aquatic environment, due to increased bacterial resistance is a concern. Various methods have been used to remove it. The advanced oxidation process due to the ease of use, economical and high performance have attracted a lot of attention. The purpose of this study was to investigate the role of cerium dioxide on process efficiency combined UV/AC晳 as an advanced oxidation process is the removal of cefazolin in the aquatic environment.
This experimental study was done in batch reactor that has a one Liter volume. In this study effect of parameters such as initial pH (3-9), initial concentration of Cefazolin (20-200 mg/L), Modified photocatalyst concentration (20-100 mg/L), reaction time (10-60 min) and CeO2 dose (20-200 mg/L) was investigated. In this study use of low-pressure mercury lamp with a power of 55 watts in stainless case. The kinetic of process according to zero order, first order and second order kinetic was evaluated.
The results showed that the highest removal efficiency of antibiotics cefazolin in the process at the pH = 3, concentration 0.1 mg/L of Modified photocatalyst, Retention time of 60 min and Cefazolin concentrations of 100 mg/L was 96%. When you change any of the parameters of about optimization, process efficiency was renamed. The results also showed that by increasing the concentration of CeO2, the antibiotic removal efficiency decreased, so that by increasing the concentration of CeO2 from 20 to 200 mg/L, the antibiotic removal efficiency of cefazolin decreased from 91 to 76%.
This process has shown high efficiency in removal cefazolin and the ability of this process to reduce the burden on hospital sewage and pollution-producing industries before entering the units and final discharge effluent also contains conventional treatment or used for cefazolin. This process, because of the lack of production waste such as sludge, a process persistent organic pollutants and significant in the treatment process is environmentally friendly.

In this experimental study, the performance of a fixed bed column containing a mixture of iron and aluminum modified with acid, as a reaction bed, was evaluated for the removal of heavy metals of cadmium, nickel, and copper. The tests were carried out by feeding the columns with aqueous solutions at the concentration of 100 mg/L using four iron/aluminum granular mixtures at various volume ratios (100/0, 50/50, 75/25, 25/75 and 0/100), and pH (3, 5, 7) for a total of 28 column tests. Results showed that metal ion removal was mainly accomplished via redox reactions that initiated the precipitation of mineral phases. At pH 5 and flow rate of 1 mL/min, the removal efficiency of cadmium, nickel, and copper at the 50/50 ratio of modified iron and aluminum was obtained higher than 99% and this removal efficiency could be kept about 50 hours. It seems that the column with the volume ratio of 75/25 of iron and aluminum mixture was the most efficient column for removing the heavy metals with the most suitable iron content and also high hydraulic performance due to the suitable aluminum content. It is therefore seen that the mixture of iron and aluminum can be used as an environmentally and economically viable remediation technology for the subsequent prevention of groundwater contamination.

Background and Imidacloprid (IM) is a systemic insecticide that is widely used to control a large number of pests in agriculture. It has toxic effects, therefore, it should be removed using appropriate methods. The aim of this study was to evaluate the efficiency of electrochemical degradation process to remove IM from aqueous solutions.
In this experiment, a glass reactor and different combinations of electrodes were used to assess process efficiency in batch mode. The effects of various parameters were studied to determine the optimum conditions. We used the combinations of lead and stainless steel electrodes as the anode and the cathode, respectively. Then, under optimum conditions, the efficiencies of other electrodes including copper, iron, aluminum, steel and graphite in removal of IM were simply compared.
The analysis showed that in the optimal conditions, the maximum removal efficiency of IM and COD were 97.2% and 88.57%, respectively. The data followed the pseudo first order reaction kinetics model. Among the electrodes investigated, lead followed by copper, iron, stainless steel, graphite, and aluminum showed the highest efficiency. Fourier transform infrared spectroscopy (FTIR) analysis showed that due to IM degradation, the functional groups have been changed, and the results of GC/MS analysis confirmed the degradation of the compound to the final products.
The results indicated that electrochemical process is an effective process in Imidacloprid removal which could remove ≈ 97% of IM.

Background and 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.
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.
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.
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 Furfural is a toxic chemical that is widely used in refinery and petrochemical industries. Wastewater containing furfural need appropriate treatments before being disposed to the environment in order to avoid the toxic effects of this compound on the environment and human. This study aimed to investigate the efficiency of electrocoagulation process in removal of furfural.
This experimental study was conducted using a Plexiglas reactor with an approximate volume of 500 ml equipped with four Al and Fe electrodes (Anode-Cathode) in monopolar-parallel mode. The effects of operating parameters such as electrodes connection, type of electrodes, pH of solution, applied voltage, furfural initial concentration, and reaction time were evaluated by defined factor of 4×4 using Taguchi L16 orthogonal array in a batch mode. Concentration of furfural was determined using HPLC wavelength of 254 nm. Data analysis was performed in Minitab 16TM software.
Based on the results of the Taguchi method, the optimum conditions for furfural removal included the initial furfural concentration of 100 mg/L, pH= 7, voltage= 10 V, and reaction time= 30 min. The contribution rate of each parameter was determined through ANOVA test. Accordingly, the most and least influential factors were found to be the initial furfural concentration and pH, respectively. Furthermore, in optimum conditions, the furfural removal efficiency of this model was 94.7%.
As the findings of the present study indicated, electrocoagulation process is believed to be an effective method in furfural removal which could remove 95% of furfural in optimum laboratory conditions.

Industrialization has led not only to an increase in water demand, but also to an increase in water pollution due to the discharge of polluted industrial wastewaters with high salt content, and the organic compounds such as phenol into the water bodies.
This study aimed to investigate the efficiency of electrocuagulation and electro-Fenton processes in phenol removal from saline wastewater using Taguchi exprimental design method.
Material and This experimental study was performed in a reactor (1 liter) with synthetic phenolic saline wastewater. In this study for electrocoagulation process, the effects of five operation parameters on phenol removal efficiency including reaction time (20-80 min), electrolyte (1-4%), pH (3-5-7-9), initial phenol concentration (500-1000-1500-250 mg/L) and current density (4-16 mA/cm2) were investigated in four levels by Taguchi L16 orthogonal array. Also for electro-Fenton process, the effects of six operation parameters on removal efficiency in five levels including reaction time (20-80 min), electrolyte (0-4%), pH (2-3-4-6-8), initial phenol concentration (250-500-1000-1500-2000), current density ( 0-16mA/cm2) and hydrogen peroxide (50-300mg/L) were evaluated by Taguchi L25 orthogonal array. The concentration of phenol was determined according to the estandard method in spectrophotometric wavelength of 500 nm.
Experimental data showed that the optimum phenol elimination condition in electrocuagulation process was initial phenol concentration of 250 mg/L, pH = 5, electrolyt = 3%, curent density of 8 mA/cm2 and reaction time of 60 min. The most influential factor in removal efficiency was the initial concentration (63.2%), and the lowest effect belonged to the electrolyt (4.2%).
The optimum phenol removal condition for electro-Fenton process was initial concentration of 250 mg/L, pH:3, electrolyt:2%, hydrogen peroxide:150 mg/L, current density of 8 mA/cm2 and 20 mine contact time. The most influential factor in elimination efficiency was the curent density (29.12%), and the lowest influence on response variable belonged to the reaction time (3.08%).
This study showed the electro-Fenton process was effective in the removal of phenolthat can be used as an appropriate process in wastewater treatment.

In this study, degradation of p-chlorophenol (p-CP) was evaluated using persulfate (PS) activated zerovalent iron (ZVI) based ultraviolet (UV) in a bench scale photoreactor. The effect of operational parameters such as solution pH (3, 7, and 11), reaction time (0-60 minutes), ZVI dosage (0.15, 1.25, 0.5, 1, and 1.5 mM), PS concentration (0.5, 1.5, 2, 2.5, 3, and 4 mM), and initial p-CP concentration (0.22, 0.44, 0.88, 1.32, and 1.76 mM) were examined on the degradation of p-CP in batch experiments. The experimental results indicated that the p-CP removal rate significantly depends on operational parameters. The highest p-CP removal rate was achieved after 45 minutes (> 0.99%) in pH = 3, ZVI = 1 mM, and PS = 3 mM, and with initial p-CP concentration = 0.44 mM. The results revealed that excess amount of PS and ZVI could reversely affect p-CP removal efficiency. In addition, an increase in p-CP initial concentration from 0.22 to 1.76 mM significantly decreased its removal rate. This study indicated that PS activated ZVI based UV process is practically feasible for the effective degradation of p-CP in aqueous solution.

Background and Using catalysts to enhance the efficiency of the ozonation process (known as catalytic ozonation process) has received much attention in recent years. This study aimed at examining the overall feasibility of using catalysts ozone as catalyst in ozonation process for decolorization and mineralization of a real textile wastewater in presence of persulfate.
This experimental study was conducted on a laboratory scale reactor using a semi-batch mode. The effect of persulfate, ozone flow rate, reaction time and catalytic dose in dye and COD was investigated in an optimal state of textile wastewater. To obtain optimization test, the experiment was performed by fractional factorial method at three-level factorial (3k−p) with a high resolution (VI).
In this study, 15 min contact time (P = 0.006) and 0.5g/L dose of catalyst (P=0.029) had the best effect on color removal. Moreover, the interaction of these parameters were found to be significant (P= 0.025). The optimum condition for color removal was achieved at 15 min reaction time, ozone flow rate of 2 L/min, 1.5 mM persulfate and catalyst dosage of 0.5 g/L. Optimum efficiency removal for color and COD in textile wastewater were 96% and 75%, respectively.
Application of nano-magnesium oxide with ozone in presence of persulfate showed synergistic effect and buffering property in decolorization and mineralization of textile wastewater. It also increases the efficacy of color removal and improves mineralization so, there would be no need for pH adjustment.

Considering extensive applications of manganese tetroxide nanoparticles in various industries due to its special properties, conducting studies on how to achieve more suitable ways to produce smaller nanoparticles is of great importance. In this study, nanoparticles of manganese tetroxide (Mn3O4) were synthesized by a co-precipitation method. In order to determine the characteristics of the structure, size, and specific surface of the resulting nanoparticles, techniques such as XRD, BET, BJH, FESEM, and FTIR were employed. Also, the nanoparticles were quantified with EDS and their colony size was examined using DLS experiments. The findings revealed a production of crystalline manganese tetroxide nanoparticles with a space group of 141/amd (S.G.) (141) and a molecular weight of 228.81 with the international code of ICSD Card # 89 - 4837. The specific surface area was 32.147 m2/g with a pore volume of 0.1041 cm3/g. The XRD and EDX analyses verify the production of the Mn3O4 nanoparticles. The size of the nanostructures is approximately 19 nm. The method used in this study could produce the Mn3O4 nanoparticles in a much easier way without the need for surfactants. Compared to the nanoparticles produced in other studies, the size of the nanoparticles produced in the present study is remarkably smaller. Moreover, less amount of the metal salt was used.