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Background: Ibuprofen is one of the most widely used non-steroidal anti-inflammatory drugs that enter the water resources through manufacturing plants and disposal of hospital effluents and even domestic wastewater. The aim of this study was to removal of ibuprofen using biodegradation process by Saccharomyces Cerevisiae yeast fixed on alginate substrate from aqueous solutions. Method: This research was an experimental-laboratory study. The effect of parameters including yeast concentration (0.1-0.3 g/100ml), Initial concentration of ibuprofen (50-350 mg/l), contact time (1-30 hours), initial pH (4-7) on the biodegradation of ibuprofen with stabilized yeast on alginate substrate was investigated. Experiments were designed and optimized using response surface methodology in Design Expert 7 software. Results: The findings of this study showed that the maximum removal of ibuprofen by fixed yeast on alginate at pH = 5.5, yeast concentration 0.2 (g /100ml), time 30 hours, and initial concentration of ibuprofen=50 mg/L was 93.5%. Conclusion: Based on the results of this study, it can be concluded that the fixed Saccharomyces cerevisiae is capable to biodegradation of ibuprofen at low cost and high efficiency and this cost-effective method can be used for the treatment of pharmaceutical wastewater.

Background & Objectives: Ceftriaxone is an antibiotic which is extensively used to treat a number of various infections. It is mainly accumulated in water and sewage resulting in the environmental and health problems. This study is centered on the evaluation of the efficiency of a photocatalytic process using Fe3O4@SiO2@TiO2 in the removal of ceftriaxone from aqueous solutions. Methods: This research was based on an experimental-practical study. Fe3O4 @ SiO2 @ TiO2 was initially synthesized via a sol-gel method and characterized by SEM, XRD and EDX analyses. The effects of variables such as pH, catalyst concentration, ceftriaxone concentration, contact time, reusability tests (n=7) and degree of mineralization were separately assessed in a laboratory scale. The concentration of ceftriaxone was measured by HPLC at 240 nm. Results: Based on the results obtained, the highest process efficiency of 96.7% was obtained under the following optimal conditions: concentration of ceftriaxone 10 mg/L, pH=3, the catalyst dosage of 2 g/L and a time contact of 120 min. At the end of the process, the degree of mineralization was determined to be 83.7%. Additionally, the data regarding the reusability of the nanocatalyst demonstrated that a 5.2% loss in the removal efficiency was observed after 7 times of reuse. Finally, the results revealed that the removal process of ceftriaxone follows the first-order kinetic model. Conclusion: The results demonstrated that the photocatalytic process using the magnetic nanocatalyst (Fe3O4 @ SiO2 @ TiO2) could be effectively used for the removal of ceftriaxone from aqueous media.

Introduction: Nowadays, due to the extended use of the high speed Internet, online games have become one of the most common interests among adolescents. Therefore, determining the advantages and disadvantages of these games are basically valuable. The purpose of this study is to investigate the relationship between online game addiction and family emotional climate, academic achievement, and academic adjustment in students. Materials and Methods: This was a descriptive correlational study with the statistical population consisting of all secondary school students in Ardabil City, Iran, who were studying at Ardabil schools during 2019. 216 individuals were selected through the convenience sampling method. Data were collected using the online game addiction questionnaire, family emotional climate questionnaire, academic craving questionnaire, and academic adjustment scale. The data collected were then analyzed using Pearson’s correlation coefficient and regression models. Results: There was a significant negative correlation between family emotional climate, academic achievement, and academic achievement with online game addiction (-0.27 ≤ r ≤ 0.54, P ≤ 0.001). With beta values of respectively -0.638, -0.409, -0.332, these values directly predicted addiction to online games. Conclusion: It seems that the family's emotional climate and adolescents' educational longing and adjustment may well predict addiction to online games. Therefore, it is recommended to consider these three factors to reduce the tendency of young people to play such games and to identify the damage caused as a result of excessive playing of these games.

Background and Objective: 2,4 dinitrophenol is observed in sewage produced from chemical and petrochemical industries. Contamination of drinking water with these pollutants causes toxicity, health problems and change in taste and odor. The present study was developed to evaluate the efficiency of removal 2,4-DNP through dried sludge adsorbent and modified calcium chloride sludge adsorbent. Materials and Methods: At first, sludge was dried at temperature of 60 °C. Next, CaCl2 was used to improve adsorption capacity. The removal efficiency of 2,4 dinitrophenol were determined by HPLC at wavelength of 360 nm. The effects of influencing factors including pH, initial pollutant concentration, contact time, and adsorbent dose were examined. Results: The optimum pH of adsorption for both adsorbents was found to be 7. The optimum concentration of 2,4-DNP was 10 ppm. The results obtained from the present research showed that the removal of the contaminant using dried and modified sludge sorbent was increased from 72.6% to 86% at a dosage of 1.5 g. The adsorption kinetics were fitted with the pseudo second order kinetics model for both adsorbents. The isotherm data also showed that the adsorption of this pollutant on both adsorbents is fitted with the Freundlich model. Conclusion: Results obtained from the present study indicated that the efficiency of the modified sludge ash is more than the non-modified sludge in 2,4 dinitrophenol removal. This can reduce adsorbent consumption in industrial treatment plants.

In this study, a novel, simple, high yield, and scalable method is proposed to synthesize highly porous MoS2/graphene oxide (M−GO) nanocomposites by reacting the GO and co-exfoliation of bulky MoS2 in the presence of polyvinyl pyrrolidone (PVP) under different condition of ultrasonication. Also, the effect of ultrasonic output power on the particle size distribution of metal cluster on the surface of nanocatalysts is studied. It is found that the use of the ultrasonication method can reduce the particle size and increase the specific surface area of M−GO nanocomposite catalysts which leads to HDS activity is increased. These nanocomposite catalysts are characterized by XRD, Raman spectroscopy, SEM, STEM, HR-TEM, AFM, XPS, ICP, BET surface, TPR and TPD techniques. The effects of physicochemical properties of the M−GO nanocomposites on the hydrodesulfurization (HDS) reactions of vacuum gas oil (VGO) has been also studied. Catalytic activities of MoS2-GO nanocomposite are investigated by different operating conditions. M9-GO nanocatalyst with high surface area (324 m2/g) and large pore size (110.3 Å), have the best catalytic performance (99.95%) compared with Co-Mo/γAl2O3 (97.91%). Density functional theory (DFT) calculations were also used to elucidate the HDS mechanism over the M−GO catalyst. It is found that the GO substrate can stabilize MoS2 layers through weak van der Waals interactions between carbon atoms of the GO and S atoms of MoS2. At both Mo- and S-edges, the direct desulfurization (DDS) is found as the main reaction pathway for the hydrodesulfurization of DBT molecules.