Sonochemical degradation of azithromycin in aqueous solution

Background: The presence of pharmaceutical substances and their residual in water resources is an important environmental concern. Azithromycin, an antibiotic that is used for the treatment of infectious diseases, is a pollutant agent in the wastewater. The aim of this study was to investigate azithromycin degradation in aqueous solution through ultrasonic process in the presence of zinc oxide nanoparticles as catalysts. Methods: Sonocatalytic experiments were performed at variable conditions including pH (3- 8), temperature (20-60°C), time (3-21 minutes), catalyst dosage (0.25-2 g/L), hydrogen peroxide concentration (15-100 mg/L) and initial azithromycin concentration (10-100 mg/L). Results: The optimum values for pH (3), temperature (40°C), time (15 minutes), catalyst dosage (1 g/L), H2O2 concentration (50 mg/L) and initial azithromycin concentration (20 mg/L) were determined. The highest degradation efficiency of 98.4% was achieved after 15 minutes of ultrasonic irradiation under optimum condition. Conclusion: According to the results, ultrasonic irradiation is able to degrade azithromycin. In addition, ZnO and hydroxyl radical can successfully accelerate the reaction process in the shortest possible time. Keywords: Azithromycin, Catalysis, Wastewater, Ultrasonic

Adsorption of Nickel and Chromium From Aqueous Solutions Using Copper Oxide Nanoparticles: Adsorption Isotherms, Kinetic Modeling, and Thermodynamic Studies

The research was conducted with an aim to assess the efficiency of copper oxide nanoparticles as an adsorbent to remove Ni and Cr. The effect of pH, adsorbent dosage, contact time, initial concentration of metals (Ni and Cr) on the adsorption rate was evaluated and removal of these elements from aqueous solutions was measured using Atomic Absorption Spectrum System (Conter AA700). Moreover, the kinetic and isotherm besides thermodynamic adsorption models were assessed. The highest Ni and Cr removal rate occurred at an optimal pH of 7, and an initial concentration of 30 mg/L, a time period of 30 minutes, and 1 g/L of copper oxide nanoparticles. In fact, with the increase of adsorbent dosage and contact time, the removal efficiency increased and with initial concentration increase of Ni and Cr ions, the removal efficiency reduced. The correlation coefficient of isotherm models viz. Langmuir, Freundlich, Temkin, Redlich-Peterson, and Koble-Corrigan showed that Ni and Cr adsorption via copper oxide nanoparticles better follows the Langmuir model in relation to other models. The results showed that kinetic adsorption of Ni and Cr via copper oxide nanoparticles follows the second order pseudo model with correlation coefficients above 0.99. In addition, the achieved thermodynamic constants revealed that the adsorption process of metals (i.e., Ni and Cr) via copper oxide nanoparticles was endothermic and spontaneous and the reaction enthalpy values for these metals were 17.727 and 11.862 kJ/mol, respectively. In conclusion, copper oxide nanoparticles can be used as effective and environmentally compatible adsorbents to remove Ni and Cr ions from the aqueous solutions

The factors related to health administration with mediating role of organizational commitment

Background: A large company is a complex organization, in which the process of work and attention to users depends on the combination of knowledge from different professional categories. The purpose of this study was to examine administrative health in a company based on organizational variables with respect to the mediating role of organizational commitment. Method: This was a mixed method study including qualitative and quantitative methods. The statistical population consisted of two groups, namely experts (including 24 professors) and managers including deputies and employees (n = 820). The sample size was determined to be 262 people selected using the stratified simple random sampling method. In the first stage, collecting qualitative research data, meta-synthesis method was used to develop a model. To pursue the research purpose, four-step method was used: arrange the research questions, systematic search of texts, select the right articles, text Information Extractor. Data were analyzed using path analysis by AMOS software. Results: The results showed a significant predictive effect of factors related to administrative and mental health on administrative health with respect to the mediating role of organizational commitment (P-value <0.05). Conclusion: There is a relationship between factors related to administrative health with respect to the mediating role of organizational commitment in the selected company

Organizational culture and effective management: problems and challenges

Background: Managers are always trying to reduce the costs while improving the quality and efficiency of services. Thus, the aim of present study was to evaluate the status of organizational culture and to investigate the problems and challenges, to provide a developed and effective model of management. Methods: This research was a descriptive cross-sectional survey. The sample size was 344 clerks who were selected by stratified random sampling. A researcher-made questionnaire was used to collect data. The organizational culture questionnaire was designed in 9 factors and 42 sub-dimensions. The face and content validities of the questions were confirmed. To analyze the data, univariate t-test was used in SPSS software and structural equation modeling was used in AMOS software. Results: According to the results, the mean of organizational culture variable was above average (3) and was at the desired level (p-value <0.05). The status of identifying challenges and problems in the study population was measured below the average level. The results showed that more challenges and problems were identified by improving the implementation of organizational culture (0.486). Organizational culture also indirectly affects organizational effectiveness by identifying challenges and problems (0.214). Conclusion: based on our finding, the mediating effect of identifying challenges and problems on the relationship between organizational culture and identifying challenges and problems was confirmed

Análisis y examen de modelos de explicación del proceso de formulación de políticas: un enfoque para el paradigma posmodernismo

Postmodernity has crossed the boundaries of art and philosophy very quickly, and by challenging the philosophical foundations of the social sciences, it has a great influence on mastering the theorizing of these fields. Consequently, the science of policymaking in general, and theories of policymaking in particular, have not remained immune to postmodern doctrines. Having said this, the objective of this essay is the analysis and examination of the models of explanation of the policy formulation process based on an approach of the postmodern paradigm. To this end, the issues of rationality in postmodernism, rationality in policymaking, and approaches that follow various types of rationality are discussed. The main models for explaining the policy-making process that have drawn much attention from thinkers are outlined. Studies suggest that notions such as objectivity criticism, escaping rationality, superficial, and negation of origin, and notions such as improvement, development, and justice, are among the characteristics of the postmodern paradigm that influence the policy formation ideas. The influence of the aforementioned notions in the policymaking process should be seen as a reminder of issues such as the chaotic model in policymaking, power centers, pressure groups, the mechanism for including marginal and insignificant issues on the agenda, the lack of universal models and insistence on national models of development and public decision-making, pluralism and participation.La posmodernidad ha cruzado las fronteras del arte y la filosofía muy rápidamente y al desafiar los fundamentos filosóficos de las ciencias sociales, ejerce una gran influencia en el dominio de la teorización de estos campos. En consecuencia, la ciencia de la formulación de políticas en general, y las teorías de formación de políticas en particular, no han permanecido inmunes a las doctrinas posmodernas. Dicho esto, el objetivo del presente ensayo es el análisis y examen de los modelos de explicación del proceso de formulación de políticas basados ​​en un enfoque del paradigma posmodernista. Con este fin, se analizan los problemas de la racionalidad en la posmodernidad, la racionalidad en la formulación de políticas, y los enfoques que siguen varios tipos de racionalidad. Se esbozan los principales modelos de explicación del proceso de formulación de políticas que han llamado mucho la atención de los pensadores. Los estudios sugieren que nociones tales como la crítica de la objetividad, la racionalidad que se escapa, el superficialismo y la negación de origen y nociones como el mejoramiento, el desarrollo y la justicia, se encuentran entre las características del paradigma posmoderno que influyen en las ideas de formación de políticas. La influencia de las nociones antes mencionadas en el proceso de formulación de políticas debe considerarse como un recordatorio de temas como el modelo caótico en la formulación de políticas, los centros de poder, los grupos de presión, el mecanismo para incluir los temas marginales e insignificantes en la agenda, la falta de modelos universales y insistencia en modelos nacionales de desarrollo y toma de decisiones públicas, pluralismo y participación

Evaluation of polyethylene microplastic bio-accumulation in hepatopancreas, intestine and hemolymph of freshwater crayfish, Astacus leptodactylus

Microplastics (MPs) are one of the biggest environmental problems threatening aquatic life. The accumulation of MPs in the body of aquatic animals can play a role in transferring these pollutants into the food chain. These pollutants can significantly affect the physiology of aquatic animals. In this study, the bioaccumulation capability of MPs in the body of freshwater crayfish, Astacus leptodactylus has been evaluated. For this purpose, crayfish were exposed to 0, 500, and 1000 µg L-1 of polyethylene MPs (PE-MPs) for 28 days. Then, the accumulation of MPs in hemolymph, hepatopancreas, and intestine of crabs was investigated by Fourier transform infrared spectroscopy (FTIR). Bioaccumulation of PE-MPs in the hemolymph, hepatopancreas, and intestines was observed in the crayfish exposed to PE-MPs. This study showed that FTIR is a suitable method for identifying and measuring MPs in aquatic organisms

The ultrasonic process with titanium magnetic oxide nanoparticles to enhance the amoxicillin removal efficiency

The widespread use of antibiotics and their subsequent release into the environment has caused concern around the world. Incomplete metabolism releases these chemicals into the environment, and traditional purification systems are unable to remove them. As a result, it lingers in the environment and is one of the most serious environmental issues confronting public health. The goal of this study was to investigate the possibility of using ultrasonic and titanium dioxide nanoparticles as catalysts for the removal of amoxicillin from aqueous solutions, as well as to figure out the optimal conditions to maximize the efficiency of removal efficiency. Decomposition of amoxicillin in water in the presence of titanium magnetic catalyst with concentrations of 0.1, 0.25, 0.5, 1, and 2.5 g/L and amoxicillin concentrations of 1, 10, 25, 50, and 100 mg/L at different times of 10 to 180 minutes, pHs of 3, 4, 5, 7, 9 and 11, temperatures of 10 to 60 ºC and frequencies of 35, 300, and 700 kHz were examined. At a concentration of 1 g/L catalyst, a concentration of 10 mg/L amoxicillin, a standstill duration of 60 minutes, an acidic pH, a temperature of 40 °C, and a frequency of 35 kHz, the maximum removal of amoxicillin (91.7%) occurred. The use of an ultrasonic method in conjunction with titanium magnetic nanoparticles as an oxidizing agent proved to be a successful tool for lowering amoxicillin concentrations in aqueous media. As a result, advanced oxidation processes, particularly ultrasonic, can reduce pharmaceutical and organic contaminants in the environment