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Background and aim: In co-word analysis, it is assumed that the most frequent words have a greater impact on a subject area compared to the less frequent words. The purpose of the current research is co-word analysis of review articles on the subject of "cloud computing" indexed in the PubMed database in 2009-2022 time period. Materials and methods: The current research is applied in terms of nature which utilized co-word analysis to analyze the data. The statistical population included 169 review articles on the topic of "cloud computing" indexed in the PubMed database in 2009 to 2022 period. The total of 57 articles lacked keywords which were excluded from the study. The required data was retrieved from the mentioned database by entering the word "cloud computing" in the subject field which were subsequently added to the Excel software. Voyant Tools software was used for co-word analysis. Findings: Based on the maps obtained from co-word analysis, keywords fog computing, data computing, cloud database, Internet of Things, cloud data, cloud challenge, cloud technology, cloud systems, health systems and cloud overlapped the most with the term cloud computing. Drawing maps of co-word at different time periods under investigation illustrates changes and stability in the concepts and words related to the field of informatics. New concepts emerged as a recombination of existing words interacting with developments and new technologies. Conclusion: The most frequent word in cloud computing review articles in all the texts indexed in PubMed among the words cloud computing, data computing, cloud database, Internet of Things, cloud data, cloud challenge, cloud technology, cloud systems , has been health and cloud systems in which the terms "data computing" and "fog computing" overlaped the most with cloud computing.

Abstract In this study, the NiFe2O4@ZnO nanocomposite was synthesized in a simple, accessible and affordable method using Pulicaria gnaphalodes plant extract as a reducing agent. The structural characteristics of this nanocomposite were determined by transmission electron microscopy (TEM), X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, X-ray energy diffraction spectroscopy and dynamic light scattering. TEM micrograph confirmed the formation of spherical and cubic spinel ferrite with average dimensions of 75–85 nm. Some parameters such as pH, dose of NiFe2O4@ZnO nanocomposite, concentration of penicillin G and reaction time to reach optimal conditions were investigated. According to the results of the present research, the photocatalyst process along with the use of NiFe2O4@ZnO nanocomposite as an oxidizing agent is an effective method in degradation of the penicillin G antibiotic from aqueous solutions.

Abstract In this study, the NiFe2O4@TiO2 magnetic nanocomposite was synthesized by the green synthesis method, which is an efficient and economical method. Pulicaria Gnaphalodes plant extract was used for nanocomposite synthesis because this method is suitable for the biosynthesis of nanocomposites on a large scale, and the nanocomposite produced by plants is more stable. The efficiency of the synthesized nanocomposite was investigated for the photocatalytic degradation of Penicillin G (PNG) under UVC light irradiation in aqueous solutions. The structural characteristics of this nanocomposite were determined by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, and dynamic light scattering. The effect of different parameters including pH, nanocomposite dose, penicillin G concentration and time were studied to reach optimum conditions. About 71% of PNG in optimal conditions (pH = 9, nanocomposite dose = 0.6 g/L, and penicillin G concentration = 10 mg/L) was decomposed. Generally, the NiFe2O4@TiO2 nanocomposite can be used as an efficient catalyst for the degradation of PNG in aqueous solutions.

In this research, the magnetic NiFe2O4 nanocomposite was synthesized using Pulicaria gnaphalodes methanolic extract and applied to remove penicillin G from aqueous solutions. The results of field emission scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared, Vibrating-Sample Magnetometer (VSM), and energy-dispersive spectroscopy-mapping analyses showed that this nanocomposite was well synthesized with a size of approximately 50–70 nm. The maximum adsorption capacity of the magnetic NiFe2O4 nanocomposite was 22.95 mg/g under optimal conditions. In addition, the experimental data of penicillin G adsorption by the magnetic NiFe2O4 nanocomposite showed that ΔH and ΔS values were positive and ΔG was negative and were following the Temkin isotherm model with R2 = 0.99 and follows the pseudo-second-order kinetic model. HIGHLIGHTS The adsorption of penicillin G by NiFe2O4 was maximum in optimal conditions (pH = 3, nanocomposite dose: 0.3 g/L, penicillin G concentration: 30 g/L, contact time: 20 min, and time temperature: 313 K).; The thermodynamic study of the adsorption process showed that the values of ΔH and ΔS are positive and ΔG is negative.; Penicillin G adsorption by NiFe2O4 nanoparticles conforms to Temkin isotherm with R2 = 0.99.;

One of the most important humic substances in water is humic acid. These substances enter water sources through soils, sediments of aquatic animals, plants and sewage. Therefore, removing them from water sources is very important. In this study, the photocatalytic removal of humic acid was investigated using zinc ferrite nanoparticles loaded with zinc oxide (ZnFe2O4@ZnO). This research was conducted in an experimental-interventional way in a batch reactor on a laboratory scale. A novel and facile method was applied for catalyst synthesis in different conditions, and it was structurally and morphologically characterized by XRD, FT-IR, SEM, DLS and EDS mapping techniques. The effects of pH (3–11), nanoparticle dose (0.005–0.1 g/L), and humic acid concentration (2–15 mg/L) were examined up to 120 min of time. The results showed that the efficiency of humic acid degradation by ZnFe2O4@ZnO reached 95% in optimal conditions. Also, it was found that this nanocomposite has an acceptable reusability and recovery after being tested in five stages. HIGHLIGHTS New magnetic ZnFe2O4@ZnO nanocomposite was synthesized and characterized.; FT-IR, SEM, EDS and XRD analyses showed successful synthesis of ZnFe2O4@ZnO nanocomposite.; In optimum conditions, 95% degradation efficiency of humic acid was observed.; Nanocomposite has an acceptable reusability and recovery after being tested in five stages.;

Nanocomposites with diameters of 1 to 100 nm have modified properties such as uniform size distribution, small size, high surface-to-volume ratio, high absorbability, porosity, and various potential roles, including in catalytic and biological activities. The purpose of this research study was to systematically review all research studies on the photocatalytic decomposition of pollutants by NiFe2O4-based nanocomposites and evaluate the optimal laboratory conditions and the results of these studies. The present systematic review was conducted by searching Scopus, PubMed and Web of Science databases until March 2022. The parameters of nano catalyst type and size, synthesis methods, pollutant type, optimal pH, optimal initial pollutant concentration, optimal catalyst concentration, optimal time, radiation and removal efficiency were investigated. 454 studies were screened and using the inclusion and exclusion criteria, in total, 31 studies met our inclusion criteria and provided the information necessary to photocatalytic degradation of pollutants by NiFe2O4-based nanocomposites. In the investigated studies, the percentage of photocatalytic degradation of pollutants by NiFe2O4-based nanocomposites was reported to be above 70%, and in some studies, the removal efficiency had reached 100%. From the results of this systematic review, it was concluded that the photocatalytic process using NiFe2O4-based nanocomposites has a high effect on the degradation of aqueous solution pollutants. HIGHLIGHTS 454 studies were screened and using the inclusion and exclusion criteria, in total, 31 studies met our inclusion criteria.; The percentage of photocatalytic degradation of pollutants by NiFe2O4-based nanoparticles was reported to be above 70%, and in some studies, the removal efficiency had reached 100%.;

In the process of sanitizing drinking water, humic acid present in drinking water sources reacts with chlorine disinfectant and forms mutagenic, defective, and carcinogenic disinfection byproducts such as trihalomethanes and haloacetic acids. In the present study, the methanolic extract of Elaeagnus angustifolia tree bark was used for the synthesis of ZnFe2O4@TiO2 nanocomposite and then properties and structural elements and diagnostic features of nanoparticles were analyzed. According to the results, the ZnFe2O4@TiO2 nanocomposites have an average crystalline size of ∼65–250 nm. Also, the effects of pH (3–11), nanoparticle dose (0.005–0.1 g/L), and humic acid concentration (2–15 mg/L) were examined up to 120 min of time. From the results, the highest removal percentages achieved about 100% at optimal conditions (pH = 3, nanocomposite dose = 0.05 g/L and humic acid initial concentration = 2 mg/L). The results of this research showed that the efficiency of nanocomposite at the highest concentration of humic acid that was investigated in this research (15 mg/L) was about 95.67%. Therefore, it can be concluded that this nanocomposite, while being cost-effective and environmentally friendly, is also very effective in removing humic acid from an aqueous solution. HIGHLIGHTS New magnetic ZnFe2O4@TiO2 nanocomposite was synthesized and characterized.; FT–IR, SEM, EDS, and XRD analyses showed the successful synthesis of ZnFe2O4@TiO2 nanocomposite.; In optimum condition, 100% degradation efficiency of humic acid was observed.;

Abstract Contact dermatitis (CD) is an inflammatory skin disease of eczema that is elicited by chemicals or metal ions that have toxic effects without eliciting a T‐cell response (contact elicitation) or by small reactive chemicals that modify proteins and induce innate and adaptive immune responses (contact allergens). The clinical condition is characterized by localized skin rash, pruritus, redness, swelling, and lesions, which are mainly detected by patch tests and lymphocyte stimulation. Heavy metals such as palladium (Pd), platinum (Pt), and titanium (Ti) are ubiquitous in our environment. These heavy metals have shown CD effects as allergic agents. Immunological responses result from the interaction of cytokines and T cells. Occupational metal CD accounts for most cases of work‐related cutaneous disorders. In this systematic review, the allergic effects of heavy metals, including Pd, Pt, and Ti, and the mechanisms, clinical manifestations, prevalence, and therapeutic approaches are discussed in detail. Furthermore, the therapeutic approaches introduced to treat CD, including corticosteroids, topical calcineurin inhibitors, systemic immunosuppressive agents, phototherapy, and antihistamines, can be effective in the treatment of these diseases in the future. Ultimately, the insights identified could lead to improved therapeutic and diagnostic pathways.

Background: COVID-19 has become a global problem. In this case study, the experiences gained from disease control in rural areas are reported. Methods: An observational study was done in 2020 in Sistan and Balochestan, the largest province with most rural areas in the southeast of Iran. Results: After identification of the first patient of Covid-19 in a rural area, three measures were taken including: 1. Diagnosis, screening and treatment of the disease (Incident command post was established and the village was completely quarantined, etc.; 2. Intersectoral coordination for epidemiological management (limiting traffic for people and any gathering); and 3. Identification of any Covid-19 positive cases. The results of these measures showed that after quarantining the village and performing the mentioned actions, the number of patients decreased, and the disease was controlled. Conclusion: Quarantine of the contaminated rural area and people’s traffic routes is one of the most important measures in controlling Covid-19.

Introduction: Air pollution is the leading environmental risk factor for health. This study aimed to assess heavy metals in Particulate Matter (PM10, PM2.5) and their health impact assessment for a desert city in Iran, Birjand. Materials and methods: In this study, the concentrations of PM10 and PM2.5 were measured from September 2019 to March 2020. Measurements were performed once every six days for 24 h using high-volume samplers. Moreover, health-related effects attributed to the suspended particles were estimated using the AirQ2.2.3. Results: Mean and standard deviation of PM10 and PM2.5 concentrations were 97.5±38.7 μg/m3 and 36.3±19.1 μg/m3, respectively. The mean metal concentrations in PM2.5 were in the Co> Cd> Ce> V order, while the metal concentrations in PM10 were in the Cd> As> Ce>V order. The lowest and highest number of deaths attributed to PM2.5 per 100,000 persons were related to ischemic heart disease (1.73) and chronic respiratory disease (18.35). The highest number of deaths attributed to PM10 per 100,000 persons was related to chronic bronchitis in adults (35.74). Conclusion: This study revealed that particle-based air pollution negatively affects health as caused by heavy metals, whereas further research is required to determine the effects of bacterial and fungal bioaerosols on human health. Monitoring the elemental composition of atmospheric particles can contribute to better air quality management.

Background and Objective: In despite of the advancements and achievements regarding the control of the diseases, Leishmaniosis is still known as one of the basic health concerns. The objective of this study was to determine the effective factors in the follow-up delay among registered cases infected with Cutaneous Leishmaniosis from 2009 to 2014 in Sistan and Baluchestan province, Iran. Materials and Methods: Participants of this analytic descriptive study included 2410 people infected with Cutaneous Leishmaniosis from cities covered by Zahedan and Iran-Shahr Medical Universities from 2009 to 2014. Census sampling method was conducted and data were collected through the two-part questionnaire which included demographic variables and disease information. SPSS software version 20 was used for statistical analysis in order to determine the most important effective factors in patients’ follow-up delay by implementing logistic regression. Results: The mean (SD) patients’ age was 19.3 (16.4) years, the size of the wounds were identified as 2.7 (1.5) centimeter, and patients follow-up delay was 59.7 (52.5) days. As many as 1502 of patients (62.6%) were male, and 2014 (83.6%) were female. 730 patients (30.3%) were kids. Pakis compared with Iranians 70% (P

Antibiotics are discharged into the aqueous environment in various ways. The disposal of wastewater containing antibiotics creates serious environmental problems. Today, given the necessity of using natural materials, natural-based adsorbents have been taken into consideration. Chitosan is a natural polysaccharide derived from the crust of crustaceans of the sea with many useful aspects such as hydrophilicity, biodegradability, and biocompatibility. In this study, after the preparation of chitosan, the effect of various parameters such as pH (3-11), adsorbent dosage (0.25-1g/L), penicillin G concentration (10-70 mg/L), and contact time (5-90 min) in the removal of antibiotic was investigated. Structural characteristics of synthesized chitosan were determined by Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). Also, the isotherm, thermodynamics, and kinetics of the adsorption process were studied. The results of this study showed that the maximum adsorption capacity of chitosan in optimum condition (pH=7, adsorbent dose: 0.25 g/L, the concentration of antibiotics: 70 mg/L, and contact time: 10 min) was 101.44 mg/g. SEM image showed that the size of chitosan was ranging from 700 nm to 5 microns. The results of XRD analysis showed the successful synthesis of chitosan. Experimental data indicate that the results are consistent with the Langmuir isotherm model and that the adsorption process was followed by a pseudo-second-order model. According to the results of thermodynamic studies, the standard entropy variations (∆S) were 20.68 (J/mol k) and standard enthalpy changes (∆H) were 5.69 kJ/mol and standard Gibbs free energy (∆G) values were negative and respectively indicates that adsorption process of penicillin G by chitosan is spontaneous and endothermic.

Background and Aim: Adding salt to foods including bread along with improving its taste can cause problems such as high blood pressure; therefore, considering the importance of the presence of salt in bread, the purpose of this study was to investigate the amount of bread salt in bakeries in South Khorasan province in 2014-2018. Materials and Methods: This descriptive-analytical and retrospective study was performed by random sampling method on bakeries in South Khorasan province in the period of 2014-2018. The measurement of the salt level was done according to the standards of the Iranian Institute of Standards and Industrial Research. The data were analyzed by using variance analysis tests and Tukey's post-hoc test. Results: 2577 loaves of bread were sent to the food laboratory of South Khorasan province during the years 2014-2018, which is the total average amount of salt In Lavash bread, it was equal to 1.63 ± 0.57 g, Taftoon was 1.51±0.53 g, and in Sangag bread, it was 1.42±0.56 g. The mean of salt levels in years had significantly various (p

Fluoride, a non-essential element, can enter water resources through several natural processes and human activities. The benefits and risks of fluoride depend on the concentration of this anion on drinking waters. In the present study, the performances of graphene and graphene oxide nanoparticles were investigated for the removal of fluoride from aqueous solution. In the present research, effects of pH, contact time, fluoride initial concentration, adsorbents dosage, as well as temperature in performance of graphene and graphene oxide nanoparticles in removal of fluoride from aqueous solution were examined. Also, isotherms and thermodynamics of the adsorption process were evaluated. For both adsorbents, the maximum adsorption capacities observed during the first 15 minutes at pH=3 and an initial fluoride concentration of 10 mg/L. The results also showed that adsorption of fluoride by graphene and graphene oxide fitted well with Freundlich and Langmuir isotherms, respectively. Furthermore, temperature increase resulted in the adsorption capacity decrease, indicating an exothermic adsorption reaction. According to the results of this research, graphene nanoparticles have higher adsorption capacity of fluoride than graphene oxide nanoparticles.

Considering the increasing incidence of fatal aluminium phosphide (ALP) poisoning and its toxicological aspects and also the paucity of our knowledge concerning the ALP effect on adipose tissue and adipokines, the present study aimed to assess the effect of acute and sub-chronic ALP inhalation exposure on adipose tissue characteristics and histological alterations in rats. This experimental study was performed on 40 male Wistar rats weighing 150–200 g. They were randomly divided into four groups (n = 10) including inhalation exposure groups to 5.67 mg/m3 (2.4 ppm) ALP for 6 h, one week and four weeks, respectively, and a control group. At the beginning and end of the study, body weight and fasting blood sugar (FBS) of animals were determined. Then, the animals were anaesthetized. The specimens of perirenal and visceral (perigonadal) adipose tissues by the routine histological process for haematoxylin and eosin (H&E) staining were determined. The results showed that the histopathological alteration of adipose tissue was significantly different between the study groups (p

Untreated wastewater disposal containing synthetic dyes produces serious problems in the environment. Industrial wastewater containing dye requires treatment by a suitable process before discharging into the environment. The present study has been performed as a batch experimental study. Nanochitosan was synthesized from the Persian Gulf shrimp shell. The effect of the various parameters including pH, initial concentration of the RB29 dye, the equation contact time, and the adsorbent dosage as well as isotherm, thermodynamic and kinetic of the adsorption process were evaluated. The results of this study demonstrated that the maximum adsorption capacity of the nano chitosan, which occurred in pH=4, adsorbent dosage of 0.2 g/L, the concentration of 50 mg/L of RB29 dye and during 90 minutes, was 113.22 mg/g. Temkin and Dubinin-Radushkeish isotherms and pseudo-second-order kinetic equations have shown better results for describing the adsorption process. The entropic changes (ΔS°) and enthalpy changes (ΔH°) were 36.65J/mole K and 6.43 kJ/mole respectively. Also, the Gibbs free energy (ΔG) was negative. Therefore nano chitosan can be used as a suitable low-cost adsorbent for the removal of RB29 dye from aqueous solutions

Existence of fungi and disinfection by-products (DBPs) in public swimming pools water are dangerous since it can seriously affect on health of swimmers. This data study aimed to determine the fungi contamination and DBPs concentration including trihalomethanes (THMs), haloacetic acids (HAAs), halamines and cyanogen halides and haloacetonitriles (HANs) of swimming pools (chlorine based) in Gonabad County, Iran. So, the fungal load and DBPs concentration were investigated in two swimming pools in the middle of spring of 2017 by collecting a number of 9 water samples and 9 samples of lateral facilities of each pool by membrane filtration technique and sterile carpet. The DBPs concentrations were measured by gas chromatograph technique. The results showed that the pools were contaminated with Dermatophyte (trichophyton mentagrophytes and epidermophyton flucosomes), yeasts, and more with opportunistic saprophytic fungi. 24.8%, 22.7%, 16.9%, and 11.4% saprophytic fungi were separated from pool side, locker room, pool water, and shower positions, respectively. 7.4% and 3.2% of yeast fungi as well as 0.23% and 0.2% of dentofacies of causative agents of tinea were separated from the pools water and showers as well as locker room and shower positions, respectively. According to the data, halamines and cyanogen halides had the highest concentrations, followed by HAAs, THMs and HANs respectively. Among the halamines and cyanogen halides, HAAs, THMs and HANs, trichloramine acid was the most dominant species, followed by trichloroacetic acid and dichloramine, respectively. Keywords: Swimming pools, Disinfection, Fungi contamination, DBPs, HAAs, THMs, HANs

The data was obtained from fluoride ion concentrations determined in groundwater sources of Gonabad. A number of 144 samples from 12 drinking groundwater wells located in different regions at the mid of spring, summer, autumn and winter from each regions, were collected from spring 2016 to spring of 2017. The fluoride ions in the samples were determined through the SPADNS colorimetric method at a wavelength of 580 nm. Dispersion of fluoride ions in terms of concentration in groundwater resources of Gonabad was planned using geographic information system (GIS) base on inverse distance weighted (IDW) method. The data showed that lowest and highest concentration of fluoride ions were determined 0.46 in winter and 1.56 mg/l in summer season, respectively. The average, max and min amount of fluoride concentration in groundwater resources of Gonabad were 0.67 ± 0.03, 1.56 and 0.46 mg/L, respectively. The average chemical parameters concentration of Potassium, Sodium, Magnesium, Calcium, Phosphate, Nitrate, Bicarbonate, Sulfate and Chloride were 6.61 ± 1.2, 281.17 ± 3.08, 26.75 ± 2.55, 68.14 ± 3.89, 0.2 ± 0.04, 10 ± 1.83, 275.02 ± 7.20, 282.08 ± 5.04 and 235 ± 5.83 mg/L, respectively. Keywords: Groundwater, Fluoride, Fluorosis, Gonabad, Water quality, GIS

Thermal energy storage is an important component in energy units to decrease the gap between energy supply and demand. Free convection and the locations of the tubes carrying the heat-transfer fluid (HTF) have a significant influence on both the energy discharging potential and the buoyancy effect during the solidification mode. In the present study, the impact of the tube position was examined during the discharging process. Liquid-fraction evolution and energy removal rate with thermo-fluid contour profiles were used to examine the performance of the unit. Heat exchanger tubes are proposed with different numbers and positions in the unit for various cases including uniform and non-uniform tubes distribution. The results show that moving the HTF tubes to medium positions along the vertical direction is relatively better for enhancing the solidification of PCM with multiple HTF tubes. Repositioning of the HTF tubes on the left side of the unit can slightly improve the heat removal rate by about 0.2 in the case of p5-u-1 and decreases by 1.6% in the case of p5-u-2. It was found also that increasing the distance between the tubes in the vertical direction has a detrimental effect on the PCM solidification mode. Replacing the HTF tubes on the left side of the unit negatively reduces the heat removal rate by about 1.2 and 4.4%, respectively. Further, decreasing the HTF temperature from 15 °C to 10 and 5 °C can increase the heat removal rate by around 7 and 16%, respectively. This paper indicates that the specific concern to the HTF tube arrangement should be made to improve the discharging process attending free convection impact in phase change heat storage.

Dyeing wastewaters are one of the most common pollutants that cause many problems for public health and environment due to dermatitis and skin rashes, cancer production, mutagenesis, etc. Thus, treatment of these wastewaters is necessary. The purpose of this study was to investigate the efficiency of montmorillonite nanoparticles as an adsorbent in adsorption process of Reactive Yellow 15 (RY15) and Reactive Yellow 42 (RY42) dyes from aqueous solutions. In this study, montmorillonite nanoparticles were used to remove RY15 and RY42 dyes. The effect of different variables such as pH, contact time, dye concentration and adsorbent dosage was studied. Finally, the effect of process temperature and thermodynamic was studied. Also, pseudo-first and second orders of kinetics were studied. The results showed that 3 is the best pH for the removal of both dyes. As contact time increases to 15 minutes, adsorption capacity increases and then reaches an approximately constant value. Adsorption capacity was also increased with increased dye concentration. By changing the adsorbent dosage from 0.2 to 0.6 g/L, adsorption capacity for RY15 and RY42 was reduced from 142and 166 to 63 and 59 mg/g, respectively. The results also showed that both dyes had the highest correlation with pseudo-second-order kinetics. The results of analyzing the process thermodynamics and temperature showed that values of DH, DS and DG are negative for both dyes.

This study was aimed to investigate the amount of reactive blue 29 (RB29) dye removal from aqueous solution by Chitosan extracted from Persian Gulf shrimp shell. The effect of parameters such as pH, the concentration of reactive blue 29 dye, contact time, and adsorbent dosage in dye removal was studied. Isotherm, Thermodynamics, and kinetics of adsorption process were also investigated. The results of this study showed that the optimum condition of the adsorption process occurred in 50mg/L of RB29 dye concentration, pH=4, contact time of 90 minutes and adsorbent dosage of 0.2 g/L. The maximum adsorption capacity in optimum condition was estimated to 87.74 mg/g. Lab data displayed that the results were in compliance with Langmuir isotherm. According to the results of thermodynamic studies, standard entropy changes (ΔS°) was 66.67 J/mol K and standard enthalpy changes (ΔH°) was 19158.3 kJ/mol. Also, the standard Gibbs free energy (ΔG°) was negative and kinetics of adsorption process follows the pseudo-second-order model

Background and Aim: Humic substances include natural organic polyelectrolyte materials that formed most of the dissolved organic carbon in aquatic environments. Reaction between humic substances and chlorine leading to formation of disinfection byproducts (DBPs) those are toxic, carcinogenic and mutagenic. The aim of this study was investigation of isotherms, kinetics and thermodynamics of humic acid removal process by nano chitosan from aquatic environment. Materials and Methods: This practical research was an experimental study that performed in a batch system. The effect of various parameters such as pH, humic acid concentration, contact time, adsorbent dosage, isotherms, thermodynamics and Kinetics of humic acid adsorption process were investigated. Humic acid concentration measured using spectrophotometer at wave length of 254 nm. Results: The results of this research showed that maximum adsorption capacity of nanochitosan that fall out in concentration of 50 mg/l and contact time of 90 minutes was 52.34 mg/g. Also, the maximum adsorption was observed in pH = 4 and adsorbent dosage 0.02 g. Laboratory data show that adsorption of humic acid by nanochitosan follow the Langmuir isotherm model. According to result of thermodynamic study, entropy changes (ΔS) was equal to 2.24 J/mol°k, enthalpy changes (ΔH) was equal to 870 kJ/mol and Gibbs free energy (ΔG) was negative that represent the adsorption process is spontaneous and endothermic. The kinetics of adsorption has a good compliant with pseudo second order model. Conclusion: Regarding to results of this study, nano chitosan can be suggested as a good adsorbent for the removal of humic acids from aqueous solutions.

Background and Objective: Fluoride is one of the essential elements of water that introduce to water resources through several natural and human activities ways. The benefits and risks of fluoride depend on concentration of this anion on drinking waters. In this research, defluoridation of aqueous solution with graphene nanoparticles was studied. Methods: In the present study, effects of pH, contact time, fluoride initial concentration, adsorbent dosage, temperature as well as presence of sulfate anion in performance of graphene nanoparticles in removal of fluoride from aqueous solution were investigated. Langmuir and Freundlich isotherms also were evaluated. Results: Maximum adsorption capacity occurred in first 15 minutes in pH=3 and initial fluoride concentration of 10 mg/L. The results also show that adsorption of fluoride on graphene well fitted with Freundlich isotherms. In presence of the sulfate anion, the adsorption capacity decreased. Furthermore, Increasing of temperature led to reducing the adsorption capacity that indicative of exothermic adsorption reaction. Conclusion: According to results of this research, graphene have good adsorption capacity in removal of fluoride from aqueous solution.

Background and Aim: Fluoride is one of the essential elements of water that is introduced into water sources through several natural and human activities. Maximum contaminant level for fluoride in drinking water is set at 1.5 mg/L by WHO. In the present research, defluorination of aqueous solutions using graphene oxide nanoparticles is discussed. Materials and Methods: In the present study, effects of pH, contact time, fluoride initial concentration, adsorbent dosage, temperature as well as presence of sulfate anions in the performance of graphene oxide nanoparticles in removing of fluoride from aqueous solutions were investigated .Besides, investigation of thermodynamic, synthetic, and Langmuir and Freundlich adsorption isotherm were employed for the process. Results: Maximum adsorption capacity occurred in the first 15 minutes .for the adsorbent with pH=3 and initial fluoride concentration of 10 mg/L. The results also showed that adsorption of fluoride by graphene oxide was well in accord with Langmuir isotherm. . .Furthermore, increasing of temperature led to reducing the adsorption capacity that was indicative of exothermic adsorption reaction. Moreover, it was found that the process followed the pseudo- second order kinetic. Conclusion: Graphene oxide nanoparticles have higher removal capacity for fluoride in acidic conditions, ambient temperature and higher fluoride concentration.

Copper and hexavalent chromium are heavy metals that are harmful to human health. Natural adsorbent chitosan, due to its considerable properties such as the presence of functional groups of –NH2 and -OH, non-toxicity, low cost, and biocompatibility, has gained much attention in pollutant removal. Therefore, in the present study, adsorption of chromium (VI) and copper (II) ions was conducted in a batch system using magnetic chitosan/Fe-Zr nanoparticles. In addition, the effect of different variables such as contact time, pH, adsorbent dose, initial concentration of heavy metals, and temperature were investigated. The results of the present study indicated that the highest efficiency in removal of chromium (VI) and copper (II) in pH of 4 were 99.52% and 97.72%, respectively. Moreover, adding 0.4 g of the composite at concentration of 5 mg/l can result in up to 97.43% removal of copper (II) and adding 1 g of this composite at the same concentration can result in more than 91% removal of chromium (VI). In addition, it was concluded that increasing the density of the heavy metals did not have a remarkable effect on the removal efficiency. The equilibrium related to adsorbent capacity and the amounts of nanoparticles were obtained using the plots of Langmuir and Freundlich adsorption isotherms for chromium (VI) and copper (II), respectively. The studied adsorbent had a high level of efficiency in the removal of heavy metals from aqueous solutions.

Background and Aim: One of the notorious air pllutants on which air quality is determined is carbon monoxide (CO). The aim of the present study was to measure the concentration of CO outdoor and indoor urban environments and compare it with air quality standards within buildings and open spaces. Materials and Methods: This research was a descriptive-analytical study of CO estimation in outdoor and indoor air of Birjand. Concentration of CO at the height of 150 cm and in the closest street leading to the specific building and also, inside the building (i.e.drawing room)-at the hight of 75 cm was measured using a CO meter. For data analysis, statistical softwares SPSS (V:18) and Excel were used applying Mann-Whitney, Friedman, and Wilcoxon statistical tests. Results: It was found that the highest concentrations of CO in the outdoor air in Birjand were 11 and 10 ppm in December and March, respectively. And highest concentrations of CO in indoor air were 11 and 9 ppm in February, respectively. But, in general, the average concentration of CO measured in outdoor and indoor air quality in both months were less than the standard measure air pollution outside (9ppm) and the quality of indoor air pollution (25ppm). Conclusion: Regarding to results of the present study, concentrations of indoor and outdoor CO of Birjand air were in standard ranges.

Background and Aim: Currently, several methods are used to remove heavy metals from aqueous solutions one of which is the adsorption process. Graphene oxide nanoparticles, due to their high adsorption capacity, have caused major concerns. The current study aimed at assessing the role of these particles in removing Chromium and Lead from aqueous solutions. Materials and Methods: This empirical study investigated the effect of the initial concentration of pollutants, their PH, adsorbent dose, time and temperature on graphen oxide nanoparticles capacity in removing Chromium and Lead from aqueous solutions. Results: Maximum adsorption efficiency occurred at PH=9 with initial concentration of 4 mg/L and at PH=3 with initial concentration of 3 mg/L for Lead and chromium, respectively. Maximum efficiency of Lead and Chromium adsorption by graphen oxide occurred at 0.01 g dosage of the adsorbent and after 15 minutes of contact time i.e. 90% and 42.33%, respectively. Results showed that adsorption of the two metals was better in accord with Freundlich isotherm. Thermodynamic reaction results revealed that Cr adsorption reaction was exothermic and that of Pb was endothermic. Conclusion: The adsorbent Graphen Oxide has got a favorable role in removal of the two contaminants Lead and Chromium from aqueous solutions and waste waters.

Over the last few years, a number of investigations have been conducted to explore the low cost sorbents for the decontamination of toxic materials. Undoubtedly, agricultural waste mass is presently one of the most challenging topics, which has been gaining attention during the past several decades. Wastes are very cheap and easily available material in production of sorbent. Therefore, the Reactive Red 198 (RR198) removal efficiency from aqueous solutions by potato peel powder based sorbent (PP) was examined in this study. The Taguchi method was used in combination with full factorial methods to design the experiments. Based on the design of experiment outputs, 18 experimental sets were designed and the experiments were done in accordance with the experimental design. The sorption handmade batch reactor consists of a 200 ml beaker, 100 RPM magnetic stirrer, and a sampling port. Then, the experimental data were collected under desired conditions. In each sample sorbent was separated using a centrifuge (3000 rpm and 5 minutes). Then, dye concentrations were determined based on Beer’s law and calibration plots using a UV-visible spectrophotometer. The wavelength resolution and the bandwidth were, respectively, 1 and 0.4 nm. The length of the optical path in glass cell was 1 cm. The maximum absorption wavelength was determined in each run to compensate the matrix effects. The results revealed that PP is effective for the sorption of RR198 from aqueous solutions. The maximum sorption of PP from RR198 solution was determined as 93 mg/g. Artificial neural network (ANN) model of dye removal efficiency (DR%) was developed based on the experimental data sets. The ANN model was strongly validated using statistical tests. The R2 and RMSE of the test set were 0.98 and 4.3, respectively. The results demonstrate that PP can be successfully used as sorbent for RR198 removal from aqueous solutions. The results revealed that experimental parameters strongly influence the DR% and different experimental conditions cause different DR% (from 0 to 93).

زمينه و هدف: یکی از مهمترین مسائل دنیای امروز، کمبود آب و آلودگی محیط زیست به فلزات سنگین است. این مطالعه با هدف بررسی میزان حذف یون‌های سرب و کبالت توسط نانو‌لوله‌های کربنی تک دیواره عامل‌دار و بدون عامل از محلول آبی انجام گردید. مواد و روش‌ها: مطالعه حاضر به صورت تجربی و در مقیاس آزمایشگاهی به منظور بررسی حذف سرب و کبالت از محلول آبی توسط نانو‌لوله‌هاي كربني تک دیواره عامل‌دار و بدون عامل در سيستم جريان ناپيوسته صورت گرفت. در این مطالعه، متغیرهای آزمایش شامل pH، جرم جاذب، غلظت اولیه سرب و کبالت، زمان واکنش و دمای واکنش مورد بررسی قرار گرفت. غلظت یون‌های سرب و کبالت با استفاده از دستگاه جذب اتمی اندازه گیری شد. يافته‌ها: با عامل‌دار کردن نانو‌لوله‌های تک دیواره، افزایش دما، pH و افزایش غلظت اولیه سرب و کبالت و کاهش جرم جاذب ظرفیت جذب افزایش یافت. راندمان بهینه حذف یون‌های سرب و کبالت در جرم جاذب 25میلی‌گرم، غلظت 2 میلی‌گرم در لیتر سرب و کبالت، دمای 25 درجه سانتیگراد و همچنین زمان 15 دقیقه برای کبالت و 10 دقیقه برای سرب بدست آمد. نتایج بدست آمده با ایزوترم لانگمویر مطابقت بیشتری نشان داد. نتيجه گيري: در این مطالعه مشخص شد که نانو‌لوله‌های عامل‌دار نسبت به نانو‌لوله‌های بدون عامل ظرفیت جذب و درصد حذف بالاتری را دارا می‌باشند.