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Among the pharmaceutical compounds, tetracycline is the second most common group of antibiotics in terms of production and consumption worldwide, which their entrance in to hospital, domestic and industrial wastewaters pollute water sources and environment and finally leads to antibiotic resistance. The aim of this study was to determine the efficiency of electrochemical processes, Fenton, electro-Fenton (EF) and sono-electro-Fenton (SEF) separately and using Graphite (G)/β-PbO2 anode to remove tetracycline from aqueous solutions. First, experiments for the electrochemical process by the response-surface methodology (RSM) using variables including pH (3–9), initial tetracycline concentration (20–100 mg/L), electrolysis time (4–45 min) and current density (0.5–4.5 mA/cm2) was designed and the optimal conditions of these variables were 3.5, 25.6 mg/L, 42.6 min, and 1.98 mA/cm2, respectively. Under the optimal conditions of the electrochemical process, the effect of FeSO4 with values of 0.02-0.08 g/250 mL in the Fenton process and the effect of H2O2 of 0.05–0.5 mg/L in the EF process were investigated, and the optimal values of 0.06 g/250 mL and 0.2 mg/L was obtained for FeSO4 and H2O2, respectively. Under optimal conditions, the removal efficiencies of SEF, EF, sono-electrochemical (SEC), electrochemical, Fenton and ultrasonic processes were 98.8%, 93.6%, 87.9%, 81.3%, 71.6%, and 11.5%, respectively. G/β-PbO2 anode had only 37.5% higher removal efficiency than graphite anode. Under the optimal conditions of SEF process, changes in toxicity reduction by bioassay with E. coli and Staphylococcus aureus bacteria were 86% and 58.4%, respectively, and the kinetic study showed that the removal of tetracycline by SEF process with R2=0.9975 followed the pseudo-first-order kinetics. Finally, intermediate compounds obtained from tetracycline analysis were identified using LC-MS analysis.

Background: Coronaviridae is a peculiar viral family with a vast ribonucleic acid (RNA) genome and characteristic appearance, endowed with an astonishing tendency to transfer from animals to humans. Various factors can affect preventing this emerging disease and controlling its severity. Objectives: This study aimed to evaluate the knowledge and attitude of students of Ardabil University of Medical Science (ARUMS) bout hygiene and food safety and their association with COVID-19 disease. Methods: This cross-sectional and descriptive study used an online questionnaire by random sampling, and the data were analyzed with SPSS software version 22. In this study, the statistical population was the students of ARUMS, and 100 (59 females and 41 males) students were selected from all the university students. A non-parametric test (Kruskal Wallis, Mann-Whitney), chi-square and Student’s t-test were used for statistical analysis. Results: There was a significant correlation between gender (male and female) and the level of understanding in three categories (weak, moderate, and good) (P = 0.048). However, there was no significant relationship with the variable of attitude. Determining the correlation between the variables of students’ knowledge and perspective with the Pearson correlation test revealed that the intersection between hygiene and food safety variables with the variables of awareness, attitude, and COVID-19 is significant. Conclusions: Having appropriate behaviors and knowledge about eating habits is essential for medical students who are constantly faced with high-risk environments regarding pathogens and need to strengthen their immune system and keep it at the desired level.

In this research, the efficiency of advanced oxidation processes (AOPs) including Fenton−Peracetic Acid (PAA) and photo-Fenton− PAA in the removal of the Rodamine B (RhB) dye from aqueous solutions were studied. Investigating the effect of operating parameters such as pH (3–9), contact time (2–30 min), PAA concentration (10–80 mg/L), FeCl3.7H2O concentration (10–100 mg/L), and dye concentration (25–500 mg/L) on the performance of AOPs in removal of RhB was considered. The results showed that by decreasing pH and dye concentration, RhB removal efficiency increased. The optimal conditions for removal of RhB using Fenton− PAA process were determined to be as follows: dye concentration = 50 mg/L, pH = 3, PAA concentration = 50 mg/L, contact time = 10 min, and FeCl3 = 50 mg/L; in these conditions, removal efficiency of the RhB was 99.9%. In contrast, the photo-Fenton− PAA process was able to remove this amount of dye in just 5 min. The high performance of the system in a short time is attributed to the synergistic effect of the photo-Fenton− PAA process in the presence of UV. Finally, RhB dye was completely degraded by the photo-Fenton− PAA process and converted into CO2 and H2O products. In general, the photo-Fenton− PAA process compared to other methods can be used as a suitable and reliable method for the treatment of effluents of the dyeing industry and discharge them to the environment.

Since 2019, the outbreak of coronavirus with acute respiratory symptoms has caused an epidemic worldwide. Transmission of the disease through respiratory droplets was announced as the main mode of transmission in 2020. But in this study, we discussed the method of indirect transmission of the virus through sewage. In this study, effluents related to urban and hospital wastewater treatment plants in 5 regions of Ardabil Province (northwest of Iran) were investigated. In this research, 120 samples were kept in pre-test conditions (temperature -20 degrees Celsius). To identify the viral genome, special primer and chain reaction probe targeting ORF1ab and N (nucleoprotein gene) genes were used. Out of a total of 120 samples, a total of 3 samples were positive. Wastewater epidemiology (WBE) can be considered as a cost-effective method in the diagnosis and prediction of pathogenic agents. And be considered an effective method for decision-making in order to protect the health of citizens.

The aim of this study was to determine the toxicity of cefixime in the inlet solution and effluent treated with the sono-electro-Fenton process using standard strains of microorganisms. This research was performed as an experimental study, which was conducted on a laboratory scale. The standard strains of Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) were used for bioassay. First, the stock solution of 1000 mg/L containing Cefixime was prepared, and for each bacterium (gram-positive and gram-negative), 5 samples from the inlet solution of the reactor and 5 samples from effluent treated with the sono-electro-Fenton process were collected under optimal conditions. Finally, each sample was transferred to 10 mL of sterile lactose broth, and a loop of E. coli or S. aureus was dissolved in each sample. Toxicity changes were investigated by calculating the percentage of growth inhibition. The results showed that after 10 hours, the growth rate of both bacteria in the control and the effluent samples was higher, while the growth of bacteria in the inlet solution was lower and had higher toxicity. Based on the results of the study, the toxicity rate for E. coli was reduced from 70% in the inlet solution to 9.3% in the effluent (86.7% reduction in toxicity), and in the case of S. aureus, it was diminished from 25.3% in the inlet solution to 7% in the effluent (72.3% reduction in toxicity) after 10 hours. Based on the results of the present study, bioassay using microorganisms is an effective and useful method to study changes in the toxicity of cefixime.

Treatment of colored wastewater is one of the important challenges of environmental engineers. Adsorption is one of the most efficient methods in dye removal. The aim of this study was to prepare a...

In December 2019, all nations learnt about the emergence of a pandemic of coronavirus disease (COVID-19), induced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is a member of the β-coronavirus group. As SARS-CoV-2 has the potentiality of leading to life-threatening respiratory failure, its transmission routes need to be characterized. Yet, the possibility of airborne transmission is still debated. This study was performed to evaluate potential hospital indoor air viral quality in order to detect SARS-COV-2. For this purpose, an impinger method was used to monitor the SARS-COV-2 virus in the air. Thus, 33 samples were collected from 8 different hospital locations. The sampling time was between 50 and 60 min with a sampling flow rate of 28 L/min. Air samples were taken from 2 to 5 m away from the patients’ beds. Temperature, relative humidity, and CO2 concentration were 28, 37, and 438 ppm, respectively. The results indicated that air samples which were 2 to 5 m away from the patients’ beds were negative for the presence of the virus. According to the obtained results, it is suggested that airborne transmission may not have much effect on this pandemic. However, as the patients with SARS-CoV-2 were hospitalized in rooms with negative air pressure, the results might have been negatively affected. Graphical abstract

Background: Coronaviruses are a large family of viruses that have symptoms ranging from the common cold to severe respiratory syndromes. Objective: The purpose of this study is to provide appropriate strategies to raise knowledge and health behavior of students of the University of Medical Sciences to prevent COVID-19. Methods: This study was conducted as a cross-sectional and descriptive study, and the online questionnaire was used by random sampling. Our sample size was 360 subjects and the statistical population was the students of the University of Medical Sciences. We used the nonparametric test (Kruskal Wallis, Mann-Whitney U) and (Chi-Square & t-test) for statistical analysis. Results: The test results were statistically significant for students’ health behavior (p

This study was performed to determine the efficiency of the electro/persulfate process to remove basic violet 16 (BV16) dye and COD from aqueous solutions. The present study was experimentally performed on a laboratory scale. The effect of pH on the process was investigated independently, and after performing the experiments, the effect of voltage (volts), the dose of persulfate (g/L), initial concentration of BV16 dye, and electrolysis time was investigated with the model presented by Box Behnken design, and optimal conditions for BV16 dye removal was obtained. Under optimal conditions, COD removal efficiency and toxicity changes during the process were calculated, and the effect of distance between electrodes and surface of electrodes on process efficiency was investigated. By-products of oxidative degradation were determined with LS-MS. The amount of electrical energy consumed by the process was investigated by voltage changes and then the kinetics of the process was investigated by a pseudo-first-order model. The results showed that the electro/persulfate process in optimal conditions including pH of 5, a voltage of 11.43 V, persulfate dose of 0.09 g/L, initial BV16 concentration of 45 mg/L, and electrolysis time of 48.5 min could provide BV16 dye removal efficiency of 95% and COD removal efficiency of 57.14%. Findings of electrical energy consumption showed that with increasing voltage, the efficiency of the process increased, but the amount of energy consumption also increased. Under optimal conditions, increasing distance between the electrodes was led to a decrease in removal efficiency, but the removal efficiency increased with the increasing surface of the electrodes. Based on the kinetic results, the electro/persulfate process followed pseudo-first-order kinetics with R 2 = 0.9956. The present study showed that the electro/persulfate process as a useful technique has high efficiency in removing BV16 dye and its toxicity from aqueous solutions and can be effective and useful in removing the COD of solution.

Textile industries use large amounts of water and chemicals for finishing and dying processes. The chemical structures of dyes vary enormously, and some have complicated aromatic structures that resist degradation in conventional wastewater treatment processes because of their stability to sunlight, oxidizing agents, and microorganisms. The objective of this research is to compare the adsorption efficiency of two types of magnetic activated carbons derived from Banana peel and Salvia seed for the removal of basic blue 41 dye. The faculty of the produced activated carbons to remove basic blue 41 dye from aqueous solutions via batch adsorption has been examined under several operating conditions such as pH, adsorbent dose, initial adsorbate concentration and contact time. The cheap, non-toxic produced activated carbons (AC) were characterized by scanning electron microscope and Brunauer-Emmett-Teller analyses. The best conditions of dye adsorption with BPAC@ Fe3O4 equal to pH = 9, AC dose 0.5 g/L , dye concentration 50 mg/L and equilibrium contact time 30 min, optimal dye adsorption conditions for SSAC@Fe3O4 equal to pH = 9, adsorbent dose 0.75 mg/L , dye concentration 50 mg/L and equilibrium contact time is 30 min. This study followed the Langmuir isotherm model well with regression coefficient of R2= 0.9886 for BPAC@Fe3O4 and regression coefficient of R2= 0.9764 for SSAC@Fe3O4.

In this experimental study, the statistical response surface methodology (RSM) based Box-Behnken design (BBD) was selected for evaluation of the effect of different parameters (solution pH,H2O2 concentration, current density, and time) and their interactions on the degradation of the diazinon by electro Fenton process. The results showed that the quadratic model is suitable for the obtained data (P-value = 0.0001) and in optimal process performance conditions was set equal to 100%. Regression analysis with a high correlation coefficient (R2 = 0.9980) and the model value of 765.56 indicated the adequacy of the model. Based on the results, the electro-Fenton process is an efficient technique for removing diazinon from aqueous media.

The most important effect of humic acid (HA) as a natural organic matter in water is the reaction with disinfectants and the generation of toxic and carcinogenic byproducts. The aim of this study w...

In this study, the experimental data were collected in a laboratory-scale batch reactor equipped with a graphite electrode as anode and an SS316 electrode as a cathode. The central composite design...

Azo dyes are mostly toxic and carcinogenic and cause harm to humans and the environment. This study was conducted to investigate the degradation of azo dye acid red 14 (AR14) from aqueous solution using hydrogen peroxide (H2 O2) /nano zerovalent iron (nZVI) and persulfate (S2 O8 2- )/nZVI processes in the presence of ultraviolet (UV) irradiation. This experimental study was carried out in a laboratory-scale batch photoreactor with a useful volume of 1 L. The nZVI was synthesized by the sodium borohydride (NaBH4 ) reduction method. In these processes, the effects of parameters including initial pH, H2 O2 concentration, S2 O8 2- concentration, nZVI dose, concentration of AR14 dye, and reaction time were studied. The results showed that decolorization increased by increasing the nZVI dosage, H2 O2 and S2 O4 2- concentrations, and reaction time, or decreasing dye concentration and pH. However, a too high oxidant concentration (H2 O2 and S2 O4 2- ) could inhibit the degradation. The experimental conditions for degradation of AR14 by UV/S2 O8 2- /nZVI and UV/H2 O2 /nZVI processes were as follows: [H2 O2 ] = 10 mM, [S2 O8 2- ] = 8 mM, AB14 dye = 100 mg/L, pH = 3, and nZVI dose = 0.05 g. Under these conditions, the highest removal efficiencies of AR14, chemical oxygen demand (COD), and total organic carbon (TOC) for the UV/S2 O8 2- /nZVI process were 93.94%, 86.5%, and 81.6%, respectively, while these values were 89.3%, 79.57%, and 72.9% for the UV/H2 O2 /nZVI, respectively. Also, the average oxidation state (AOS) was decreased from 2.93 to 2.14 in the effluent of the UV/S2 O8 2- /nZVI process and from 2.93 to 2.2 for the UV/H2 O2 /nZVI process. The results showed that the ratio of biochemical oxygen demand (BOD5 ) to COD in the effluents of the UV/S2 O8 2 /nZVI and UV/H2 O2 /nZVI processes after 90 min was 0.63 and 0.74, respectively. These findings suggest biodegradability improvement. PRACTITIONER POINTS: Photocatalytic degradation of azo dye Acid Red 14 (AR14) was achieved using H2 O2 /nZVI and S2 O8 2- /nZVI processes in the presence of UV irradiation. Effects of operating parameters on photocatalytic degradation AR14 dye were evaluated in the UV/H2 O2 /nZVI and UV/S2 O8 2- /nZVI processes. Biodegradability and mineralization studies of AR14 dye photocatalytic degradation were performed for the UV/H2 O2 /nZVI and UV/S2 O8 2- /nZVI processes.

The presence of SARS-CoV-2 virus in water resources and the transmission of diseases caused by it is one of the factors threatening the quality of water resources. This study for the first time concentrates on the presence of SARS-CoV-2 in water resources an urban location. In the present study, the samples were collected from known depth (30–50 cm) of rivers, dams and lakes. In each sample of water collected, different parameters such as residual chlorine, pH (phenol red), turbidity, total dissolved solids and temperature were also measured. Out of 267 samples, two samples were detected to be positive which their Ct values were 34.2 and 35.67. The existence of viable form of this virus in water and wastewater may be associated with issues for providing public health and difficulties in implementation of pandemic control strategies, and this situation can be exacerbated in developing countries that do not have adequate access to sanitation and safe water.

The aim of the present study was to evaluate the efficiency of advanced oxidation processes (electrochemical, Fenton, and electro-Fenton) in the removal of oxytetracycline antibiotic from aquatic environments using SS316 and SS316/β-PbO2 anodes. This study was performed experimentally on a laboratory scale in a 250-mL reactor. First, experiments were designed for the electrochemical process using a central composite design (CCD), and the optimal conditions for the variables pH (3.53), current density (3.85 mA/cm2), initial concentration of oxytetracycline (20 mg/L), and electrolysis time (42.35 min) were obtained; then, under these conditions, the efficiency of Fenton process with FeSO4 variable without the presence of electrodes was evaluated, and its optimal value was 0.3 g/L, and then in the presence of optimal values ​of the above four variables, the efficiency of the electro-Fenton process with H2O2 changes was investigated and the optimal value of 0.12 mg/L was obtained for H2O2. The removal efficiencies of oxytetracycline in electrochemical, Fenton, and electro-Fenton processes were 84.7%, 73.4%, and 98.2%, respectively. Under optimal conditions, the SS316/β-PbO2 anode electrode enhanced the oxytetracycline efficiency by electro-Fenton process to 100%. The results of bioassay with microorganisms showed that the reduction of toxicity of the effluent treated by the electro-Fenton process for Pseudomonas aeruginosa and Staphylococcus aureus was 84.5% and 69%, respectively.

Background We sought to investigate people's beliefs, decision dynamics, and future consequences of the current COVID-19 pandemic. Methods The present cross-sectional study was conducted from January 10th to April 30th, 2020. The data collection tool was a researcher-made electronic questionnaire that was designed in Porsline.com. The test-retest reliability of the questionnaire was good, and consisted of three sections: introduction, demographic characteristics, and belief questions about COVID-19. Results In 17 of the 43 beliefs, more than two-thirds of the subjects chose the "correct belief", and less than one-third chose the "I have no idea" or "I disagree" options. There was a significant correlation between age, gender, education, residential area, occupational status and correct belief about COVID-19. Conclusions Accurate knowledge of policymakers, managers, health care workers, and the public, beliefs about COVID-19 is important in promoting community health and disease prevention.

A UV-assisted heterogeneous photo-Fenton process based on powder activated carbon (PAC)/Fe3O4 catalyst was investigated to degrade metronidazole (MTZ). Successful uniform synthesis of PAC/Fe3O4 has confirmed by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-Ray spectroscopy mapping (EDX-mapping), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR) techniques. The interaction of five independent variables in the MTZ degradation in the UV + $${P}{A}{C}/{{F}{e}}_{3}{{O}}_{4}$$ + $${{H}}_{2}{{O}}_{2}$$ photo-Fenton system was optimized by a three-level full-face-centered central composite design (CCD). Proposed model proved to have adequacy and validity in prediction of MTZ degradation (P value 0.95). High stability, reusability, and separation capability of PAC/Fe3O4 were confirmed by EDX and VSM analyses and iron leach investigation. This process could represent the MTZ degradation, DOC, and COD removal efficiencies of 96.12%, 93.67, and 94.87%, respectively. Also, increasing of the AOS value from -0.422 to 0.437 and increasing of the COS value from -0.422 to 3.773 indicate that the MTZ has been highly mineralized and the solution biodegradability has been improved. MTZ degradation intermediates, mechanism, and pathways were proposed. The abundancy of intermediates with m/z

The experiments were designed based on the central composite design (CCD) and were analyzed and modeled by response surface methodology (RSM) to demonstrate the operational variables and the interactive effect of four independent variables on two responses. The results showed that the adsorption rates of both phenolic compounds (bisphenol A and pentachlorophenol) were increased by increasing contact time and adsorbent dose. The highest phenolic compounds adsorption was obtained at a pH of 6. Based on the analysis of variance of the results obtained from different models, a quadratic model was chosen to estimate the removal of phenolic compounds by the adsorption process using modified sorbent. The linear regression coefficient (R2) between experiments and different response values in the model was 0.96 for bisphenol A and 0.75 for pentachlorophenol. The optimum values for the studied variables were the pH of 6, the adsorbent dose of 4.2 g/L, the contact time of 65 min, and the concentration of the phenolic compounds of 40 mg/L. Under the mentioned conditions, the removal efficiency of pentachlorophenol and bisphenol A by the adsorbent was 93.1% and 87.06%, respectively. According to the results, the modified adsorbent in the removal of phenolic compounds follows the Freundlich isotherm and pseudo-second-order kinetics. The results showed that the adsorption onto modified adsorbent was able to provide the relatively high removal efficiency of phenolic compounds. This method can also be used to treat wastewater from petroleum and petrochemical industries containing phenolic compounds.

Diazinon is one of the most widely used organophosphate pesticides classified by the World Health Organization (WHO) as “moderately hazardous” Class II, and its removal from water is of unquestionable importance. The aim of this study was the optimization of diazinon biodegradation from synthetic wastewater by moving bed biofilm reactor (MBBR) using the response surface methodology (RSM). The variables such as initial diazinon concentration (10–50 mg/L), hydraulic retention time (HRT) (12–36 h) and a filling fraction (25–75) were studied according to the RSM. The highest diazinon removal efficiency using the biological process was 97.66, under the conditions, i.e. (HRT= 36 h, filling fraction= 75 and diazinon concentration = 10 mg/L). The quadratic model was well fitted with test results (R2 = 0.986). Moreover, the kinetics of the biological process showed that removal of diazinon from synthetic wastewater adhered to the second-order model (Grau) with a high correlation coefficient (R2 = 0.97). The results showed that the MBBR process can be effectively used as a biological process to remove diazinon and similar pesticides. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.

Antibiotics are non-biodegradable and can remain for a long time at aquatic environments and they have a big potential bio-accumulation in the environment. The antibiotics are broadly metabolized b...

Oil wastewater industries create big problems for receiving sources due to the presence of a variety of compounds including linear and cyclic hydrocarbons, recalcitrant materials and toxic compound...

Background & Aims of the Study: Exposure to formaldehyde in ambient air has attracted a great attention, due to harmful health effects. This study was aimed to determine formaldehyde concentration in winter and spring seasons, in Azadi square region, Tehran, and the relation of variations of CO, NO2, O3, temperature and humidity with formaldehyde concentration was modeled based on Response Surface Methodology. Materials & Methods: This cross-sectional study was conducted in 2014–2015 in Tehran. For measuring the formaldehyde concentration, NIOSH3500 method was employed. The concentration of formaldehyde was detected at 580 nm wavelengths by PerkinElmer LAMBDA spectrophotometer model of 25UV/Vis. Data of CO, NO2 and O3 concentration were attained from Tehran Air Quality Control Company. SPSS 16 and Design Expert (version 7) were used for analyzing data. Results: Results showed the concentration of formaldehyde in the spring was on average 4.7 ppb more compared to winter season. The Model fitted for the prediction of formaldehyde showed a significant p-value (

The aim of the present study was to evaluate the efficiency of advanced oxidation processes (electrochemical, Fenton and electro-Fenton) in the removal of oxytetracycline using SS316 and SS316/β-PbO2 anodes. This study was performed experimentally on a laboratory scale in a 250 mL reactor. First, experiments were designed for the electrochemical process using a central composite design, and the optimal conditions for the variables pH(3.53), electric current density(3.85mA/cm2), initial concentration of oxytetracycline (20mg/L) and electrolysis time (42.35min) was obtained; then, under these conditions, the efficiency of Fenton process with FeSO4 variable without the presence of electrodes was evaluated, and its optimal value was 0.3 g/L, and then in the presence of optimal values ​​of the above 5 variables, the efficiency of electro-Fenton process with H2O2 changes were investigated and the optimal value of 0.12 was obtained for H2O2. The removal efficiencies of oxytetracycline in electrochemical, Fenton, and electro-Fenton processes were 84.7%, 73.4%, and 98.2%, respectively. Under optimal conditions, the SS316/β-PbO2 anode electrode enhanced the oxytetracycline efficiency by electron-Fenton process to 100%. The results of bioassay with microorganisms showed that the reduction of toxicity of the effluent treated by electro-Fenton process for Pseudomonas aeruginosa and Staphylococcus aureus was 84.5% and 69%, respectively.

A three-dimensional electrochemical reactor with Ti/SnO

2,4-Dichlorophenoxyacetic acid (2,4-D) is a herbicide that is considered as a carcinogenic and highly toxic contaminant, and due to its biological and chemical stability, its degradation is very difficult. Therefore, this study aimed to investigate a hybrid system's efficiency of three-dimensional electrochemical (3DE) process and a moving bed biofilm reactor (MBBR) in removing 2,4-D herbicides from aqueous solutions. In this experimental study, the electrochemical degradation of 2,4-D herbicide in a 3DE process with a G/β-PbO2 anode was first investigated as a pretreatment process. Then, in the post-treatment stage, MBBR with continuous flow was used. The amount of aeration in the MBBR reactor was 4 L min−1, and the amount of dissolved oxygen (DO) was in the range of 3–5 mg L−1. The effect of various parameters such as hydraulic retention time (HRT) and filling ratio were investigated. The amount of sewage injection was set between 0.001–0.004 L min−1. Routine microbiological biochemical tests were used to detect bacteria. BOD5/COD, COD/TOC, AOS, and COS ratio parameters were used to determine the biodegradability of 2.4-D due to the effluent of the 3DE process. The results showed that with increasing current density, decreasing pH, decreasing herbicide concentration and increasing electrolysis time, the herbicide degradation efficiency increased by 3DE pretreatment process. Based on the results of MBBR post-treatment process efficiency, with increasing HRT and filling ratio, the herbicide removal efficiency increased. According to the results, the highest removal efficiencies of 2,4-D and COD herbicides were obtained during HRT of 24 h, and the filling ratio of 70% were 97.33% and 88.95%, respectively. The consortium of 2,4-D degrading bacteria identified in this study included E. coli, Enterobacter spp., Bacillus spp., Alcaligenes spp., Proteus spp., Acinetobacter spp., Pseudomonas spp., Arthrobacter, and Brevundimonas vesicularis. In the MBBR biological process, the reaction kinetics followed the Grau second-order model (R2 = 0.98). In general, the results showed that the combined process of 3DE with G/β-PbO2 anode and MBBR biological process has relatively high efficiency in 2,4-D herbicide degradation and can be used as a suitable complementary treatment method in wastewater containing non-degradable compounds such as phenoxy herbicides, e.g., 2,4-D should be used.

2,4-Dinitrotoluene (2,4-DNT) has been found to be an important petrochemical compound, which is primarily employed for the synthesis of tolylene diisocyanate and the production of dyes, rubber, and explosives. Since this compound has high toxicity and carcinogenicity, the cautions should be considered when wastewater contaminated with DNTs and their derivatives is released into the environment. Thus, the object of the present study was the investigation of the 2,4-DNT degradation efficiency using the three-dimensional electrocatalytic reactor (3DER) with two different types of particle electrodes (granular activated carbon (GAC) and magnetized clinoptilolite zeolite (MCZ)@Fe3O4 nanoparticles)). Preparation of the graphite (G)/β-PbO2 anode was done by electrochemically depositing PbO2 layers on graphite sheets. The prepared graphite sheet and a stainless-steel 316 sheet (with the same dimensions) were employed as the anode and the cathode, respectively. Field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), and energy-dispersive X-ray spectroscopy mapping (EDS-mapping) confirmed the successful preparation of G/β-PbO2 anode. The surface morphology, chemical composition of MCZ@Fe3O4 nanoparticles as a particle electrode were determined by scanning electron microscope (SEM) and XRD pattern. To determine the optimal conditions, we employed the response surface methodology-based central composite design (RSM-CCD) method. According to observed results, higher efficiency of 3DER was obtained by increasing the reaction time and current density and decreasing pH and the pollutant concentration. Studies highlighted the initial 2,4-DNT concentration of 23.5 mg/L, current density 4.8 mA/cm2, pH of 4.1, electrolysis time of 50 min, particle electrodes dose = 6 g/250 cc as optimum values of parameters. The 2,4-DNT degradation efficiencies using GAC and MCZ@Fe3O4 nanoparticles as particle electrodes under mentioned optimal conditions were 98.6% and 96.5%, respectively. Moreover, the chemical oxygen demand (COD) and total organic carbon (TOC) removal efficiencies were 88.5% and 80.9% at the end of 50 min, respectively. Furthermore, results were indicative of an enhancement in average oxidation state (AOS) (from 1.27 to 2.36) and carbon oxidation state (COS) (from 1.27 to 3.68) in the 3DER process and a reduction in the COD/TOC ratio (from 1.81 to 1.09); these signposts the effectiveness of 3DER system for providing the biodegradability of 2,4-DNT. Considering the results, the 3DER could lead to suitable results for the degradation of wastewater containing DNT and resistant contaminants as pretreatment and has remarkable applicability for enhancing the biodegradability of wastewater.

The staff of health and dentistry schools can play an important role in encouraging students and their clients to adopt health and preventive behaviors. The aim of this study was to compare health-promoting behaviors in staff and students of health and dental schools in Ardabil University of Medical Sciences (ARUMS).This cross-sectional descriptive-analytical study was conducted in 2021. The research population was staff and students of health and dental schools. Staff sampling was by census and students were sampled by simple random sampling. The data collection tool was a questionnaire whose validity and reliability had been confirmed in previous studies. Data analysis was performed using descriptive and analytical statistics tests using SPSS version 20 software. Linear regression was performed using stepwise method.The results showed that the mean score of the individuals was 99.2 ± 20.24. In the leveling, the behaviors of 33 people (17.55%) were appropriate, desirable and good, and the health-promoting behaviors, 154 people (82.45%), were moderate and low. The correlation between age, gender, marital status, and workplace of the individuals with health-promoting behaviors was not statistically significant (Health-promoting behaviors in20% of students and staff are desirable, and in more than 80% of them are moderate and poor. Therefore, educational administrators should use these results in curriculum planning to increase health-promoting behaviors of students and staff. The score of health-promoting behaviors is related to the above-mentioned areas, but the relationship may not be linear.

Infection with COVID-19 has resulted in considerable mortality all around the world. This study aimed to investigate the effect of convalescent plasma on the treatment of hospitalized patients with COVID-19 in Imam Khomeini Hospital at Ardabil, Iran.In this quasi-experimental clinical trial, patients over 18 years of age with polymerase chain reaction-positive COVID-19 were admitted based on the clinical criteria of respiratory distress with hypoxia (OAnalyses revealed that length of stay in hospital was significantly lower in the CPT group as compared to the control group (It seems that CPT can be used as an alternative treatment at the early stages of COVID-19 to prevent the progress of the disease, reduce the need for intubation and consequently the length of stay in hospital, and finally, decrease mortality.

In this experimental study, an electrochemical cell (100 cc) equipped with anode electrodes of SS316 and graphite and the cathode electrode of SS316 in parallel form at a distance of 1 cm f...

Nowadays, the presence of antibiotics in the environment has been identified as an important concern for the various life cycle. Thus, this study was conducted to evaluate ciprofloxacin (CIP) adsorption efficiency onto the multi-walled carbon nanotube (MWCNTs) and magnetic multi-walled carbon nanotube (MMWCNTs). In this experimental study, the characteristics of the studied adsorbents were determined using SEM, FTIR and XRD methods. The effects of operational parameters including contact time (10–120 min), initial concentration of CIP (10–100 mg/L), adsorbent dosage (0.1–1 g/L) and pH (3–9) were evaluated. The isotherm and kinetics studies of the CIP adsorption onto the studied adsorbents were also carried out. The adsorption efficiency increases by increasing the contact time and adsorbent dosage, while it increased by increasing the CIP initial concentration. The results showed that higher CIP adsorption efficiency was observed at pH = 7, adsorbent dosage of 0.5 g/L, CIP concentration of 30 mg/L and contact time of 120 min. The isotherm and kinetics studies revealed that the CIP adsorption data were better described by the Langmuir isotherm model and pseudo-second-order kinetics equation model. It can be concluded that both of these adsorbents have suitable potential to remove the CIP from aqueous solution but this ability is greater in MMWCNTs.

Insufficiencies and deficiencies in slaughterhouses could adversely affect public health. Wastewater from slaughtering, along with high microbial pollution, results in serious pollution to the surrounding environment if not treated. This study sought to investigate the efficiency of the electrocoagulation process using copper electrodes in the disinfection of poultry slaughterhouse wastewater without any initial controlling. The physical and chemical properties of samples of wastewater taken from a poultry slaughterhouse were first analyzed. Then the samples were subjected to the electrocoagulation process using copper electrodes in potential differences of 10, 20, and 30 V over a period of 60 min. Then the removal efficiency of total coliforms was examined in accordance with standard methods found in textbooks. The results obtained from this study indicated that the efficiency of the electrocoagulation process increased by an increase in process time as well as in electric potential difference. The maximum removal efficiency of total coliforms was 100% in potential difference, equal to 30 V in the reaction time of 10 min. Moreover, the results of this study revealed that the electrocoagulation process using a copper electrode was fully able to remove total coliform from poultry slaughterhouse wastewater. © 2018, HARD Publishing Company. All rights reserved.

Colloidal particles are the main cause of turbidity in an aquatic environment. Water turbidity maintains pathogenic microorganisms against disinfection. In addition to increasing the consumption of antiseptic substances, mainly it causes a lot of aesthetic and non-sanitary problems such as the formation of toxic and carcinogenic side constituents in the treatment of water. In this study we investigated the efficiency of the use of tragacanth of Astraglus gossypinus (Catira) on the effectiveness of the electrocoagulation process in the removal of turbidity from brackish water. In this descriptive-analytic study, direct bentonite injections of 2 to 8 g/L were used to provide opacity. In the following, the effect of applying coagulant aid of Tragacanth of Astraglus gossypinus plant with values of 0.25 to 1.5 g/L on the efficiency of the electro-coagulation process equipped with iron electrodes in the removal of opacity from brackish water samples were examined in potential difference from 5 to 30 volts, and pH from 2 to 9 over a period of 60 min. Variation of turbidity was determined using the turbidity sensor in accordance with standard reference methods. The results showed that the highest opacity removal efficiency is about 99 for each 1 kg of opacity due to the addition of 7 g/L bentonite under neutral pH conditions, Tragacanth dose of 1.5 g/L, 8 g/L dose of NaCl, and voltage of 30 V for 30 min, along with the average consumption of iron and electrical energy of 0.18 kg and 0.53 Kwh, respectively. Thus, the use of Astraglus gossypinus tragacanth for removing turbidity as a natural coagulant aid dramatically improves the electrocoagulation process efficiency in the removal of turbidity from brackish water samples and reduces current costs of the electro-coagulation process.

Background & Aims of the Study: Methylene blue (MB) is a risk for human and environment. Adsorption process is one of the removal mechanisms of MB. The purpose of this research was the evaluation of low cost adsorbent of walnut bark granule for MB dye removal from aqueous environments. Materials & Methods: In this experimental research, the effect of various operating parameters such as dose of dye (100-500 mg/L), contact time (10-50 min), adsorbent dosage (1-5 g/L) and pH (3-8) was investigated. Color concentration was measured by spectrophotometer (Shimadzu Model UV-120-02) at 663 nm wavelength and pH was analyzed through pH meter (Digimed model DM-20, Digicron AnaliticaLtda, Sao Paulo, Brazil). Results: The findings of this research were showed that the walnut bark granule was able to remove up to 41% of MB dye (100 mg/L) from solutions at initial pH 7. Removal efficiency was increased by adsorbent dosage and contact time. MB concentration has a reverse effect on removal. Also, the equilibrium data were also fitted to the Freundlich equilibrium isotherm model (R2=0.95). Conclusions: Present study showed that use of walnut bark granule, as an absorbent, could be utilized in methylene blue removal. Therefore, considering the production wastes of this compound, utilization the essence of this substance as inexpensive absorbent with inexpensive and available raw material is clear.

International audience; The link between the concentration of biodegradable organic matter and the rate of phenol removal in anaerobic conditions was examined in this work. This study was undertaken using a laboratory scale anaerobic stabilization pond and five closed reactors at two retention times, 2 and 5 days. The initial concentration of phenol and soluble COD decreased in the anaerobic pond effluent and the reactors with increasing hydraulic retention time; 98.6 % phenol removal was observed in reactors after 50 days and in the presence of 1000 mg/L COD, while 98.8 % removal was obtained after 5 days in the anaerobic stabilization pond system in the presence of 500 mg/L COD. Two-way ANOVA test with Scheffe post-hoc confirmed that phenol removal was optimal for 1000-2000 mg/L biodegradable COD and 50 days retention time in the reactors and with 500 mg/L biodegradable COD and 5 days retention time in the anaerobic pond.

This study aimed to investigate the electro-degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solution using two and three-dimensional electrode (2D and 3D) reactors with graphite(G)/β-PbO2 anode. To increase the degradation efficiency, affecting parameters on the electro-degradation process were investigated and optimized by adopting the Taguchi design of experiments approach. The structure, morphology and electrochemical properties of the electrodes were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), linear sweep voltammetry and cyclic voltammograms. The controllable factors, i.e., electrolysis time, 2,4-D initial concentration, solution pH and current density (j) were optimized. Under optimum conditions, the 2,4-D degradation efficiency was 75.6% using 2D and 93.5% using 3D electrode processes. The percentage contribution of each controllable factor was also determined. The pH of the solution was identified as the most influential factor, and its percentage contribution value was up to 39.9% and 40.4% for 2D and 3D electrode processes, respectively. Considering the parameters of the kinetics, it was found that the degradation of 2,4-D and removal of COD using the G/β-PbO2 electrode obey the pseudo-first order kinetics. In addition, the mineralization pathway of 2,4-D at G/β-PbO2 electrode was proposed. The results also demonstrated that the 3D electrode process with G/β-PbO2 anode can be considered as a useful method for degradation and mineralization of 2,4-D herbicides from aqueous solution.

Bisphenol A (BPA) is one of the endocrine disrupting compounds that has significant estrogenic effects and if it is not treated, it will enter into water resources and will cause irreparable environmental problems. Thus, this study aims at determining the efficiency of heterogeneous Fenton-like process using modified magnetic nanoparticles with sodium alginate in removing BPA from aquatic environments. In this experimental research, the effects of environmental factors including pH (3–9), contact time (10–180 min), initial concentration of catalyst (0.5–20 g/L), initial concentration of hydrogen peroxide (50–300 mg/L) and the initial concentration of BPA (10–60 mg/L) were studied in removing efficiency of BPA using processes of heterogeneous Fenton-like, alginate sodium and hydrogen peroxide. Results of present study showed that during heterogeneous Fenton-like process, the highest removal efficiency (BPA) is achieved (95) at pH 5, catalyst concentration 5 g/L, initial concentration of hydrogen peroxide 100 ppm and BPA concentration 20 ppm in 120 min in a way that the processes of sodium alginate and hydrogen peroxide had smaller removal efficiency. Also, studies of kinetic reaction revealed that removal of BPA in heterogeneous Fenton-like process followed a second-order kinetic model (R2 = 0.98). Results demonstrated that heterogeneous Fenton-like process is able to remove BPA effectively from aquatic environments using modified magnetic nanoparticles with sodium alginate as a catalyst under optimal conditions and this process could be used to remove other similar compounds. © 2018 Desalination Publications. All rights reserved.