Evaluations of pH and High Ionic Strength Solution Effect in Cadmium Removal by Zinc Oxide Nanoparticles

For human and environmental health protection, it is necessary to remove excess cadmium in industrial wastewaters before discharging them to environment. Some laboratory experimental batch study was done to evaluate the effects of the initial cadmium concentration, adsorbent dose, pH, ionic strength, and contact time on the cadmium removal efficiency by zinc oxide nanoparticles. All tests were performed in 100 ml solution at constant temperature of 25\ub0C and mixing rate of 150 rpm. The residual cadmium concentration in the solution was determined using flame atomic absorption spectroscopy. Statistical analyses were performed on data using SPSS16 software by applying Mann-Whitney and Kruskal-Wallis tests and the result designing graphs were provided using Excel software. Finally, experimental data were analyzed using adsorption isotherm and kinetic equations. The results show that cadmium removal efficiency increases with an increase in the adsorbent dose and contact time and decreases with the increase in initial concentration of cadmium. Furthermore, it is observed that by raising the ionic strength of solution 30 fold, the adsorption rate is increased from 90.7% to 62.3%. Due to regression coefficient ( 650.99), the adsorption process follows Langmuir isotherms model and pseudo-second order equation. Attending to the outcomes, zinc oxide nanoparticles have proper efficiency in the removal of cadmium from aqueous solutions. So, they can be used in treatment of the wastewaters containing cadmium ions. However, its efficiency is deeply dependant on the ion strength and the interactions of other metals in wastewater

Removing Copper from Contaminated Water Using Activated Carbon Sorbent by Continuous Flow

Introduction: A major concern of human being is accumulation and toxicity of heavy metals in their body. Copper is a heavy metal ion that in concentration of 2 mg/l can cause numerous complications. Different treatment methods have been proposed for removing metals from contaminated water by researchers. Among these methods, sorption seems a better method with high removal efficiency. In this study, conditions for removal of copper ions by activated carbon sorbent were studied with continuous flow. Materials & Methods: This was a laboratory – experimental study. A 20mg/l solution of copper ions was prepared and passed through a 5 × 10 cm column with average output rate of 1.85 ml/min. Output of column was sampled every 30 minutes and the remaining amount of copper ion in each sample was measured by flame atomic absorption. Results: The empty bed volume (EBV) was equal to 138 ml. The highest removal efficiency was 99.7 percent at 127 minutes. From equilibrium time, the removal efficiency was constant with time. The adsorption capacity of activated carbon was 0.25mg.g-1. The isotherm study indicated that the sorption data can be obeyed by both Langmuir and Freundlich isotherms (R2>0.95) but Langmuir model had higher agreement with this experimental data (R2= 0.988). Conclusion: The binding of ions to the sorbent in the adsorption process is extremely important. For this column 62.5 minutes after filling was appropriate, so the highest removal efficiency was obtained. Equilibrium time was dependent on the speed of influent through the column in the continuous flow. For selected column, the rate of 1.85 ml/min is a good performance

Evaluations of pH and High Ionic Strength Solution Effect in Cadmium Removal by Zinc Oxide Nanoparticles

For human and environmental health protection, it is necessary to remove excess cadmium in industrial wastewaters before discharging them to environment. Some laboratory experimental batch study was done to evaluate the effects of the initial cadmium concentration, adsorbent dose, pH, ionic strength, and contact time on the cadmium removal efficiency by zinc oxide nanoparticles. All tests were performed in 100 ml solution at constant temperature of 25°C and mixing rate of 150 rpm. The residual cadmium concentration in the solution was determined using flame atomic absorption spectroscopy. Statistical analyses were performed on data using SPSS16 software by applying Mann-Whitney and Kruskal-Wallis tests and the result designing graphs were provided using Excel software. Finally, experimental data were analyzed using adsorption isotherm and kinetic equations. The results show that cadmium removal efficiency increases with an increase in the adsorbent dose and contact time and decreases with the increase in initial concentration of cadmium. Furthermore, it is observed that by raising the ionic strength of solution 30 fold, the adsorption rate is increased from 90.7% to 62.3%. Due to regression coefficient (≥0.99), the adsorption process follows Langmuir isotherms model and pseudo-second order equation. Attending to the outcomes, zinc oxide nanoparticles have proper efficiency in the removal of cadmium from aqueous solutions. So, they can be used in treatment of the wastewaters containing cadmium ions. However, its efficiency is deeply dependant on the ion strength and the interactions of other metals in wastewater

La información de Internet como señal de video y su editor

Based on some authors’ analyses of the terms video, virtual, and real, and the ways in which they converge in visual productions on the web, we examine what in actual fact constitutes a video in that space; Internet is considered a source of information which, in many cases, is visualized as video. It is assumed that such information presents many variables that, in the end, define the way in which it is to be presented; there are variables which can not be precisely assessed, thus turning the unpredictable factors into an actual editor of the information shown on Internet via a video signal.Partiendo del análisis de algunos autores de lo que significan los términos video, virtual y actual, y de la manera como ellos convergen en la producción visual en la red, se realiza un examen de lo que es el video en ese espacio; Internet se considera como una fuente de información que en muchos casos se visualiza como video. Se supone que esa información tiene muchas variables, que definen la forma como se va a mostrar; variables que no se pueden calcular con precisión, que hacen de lo impredecible un editor de esa información en Internet que se observa a través de la señal de video

Data on the attitudes of nurses and patient׳s family regarding the family presence in the intensive care unit in Birjand, Iran

The presence of the patient׳s family on the patient׳s bedside in the intensive care units (ICU) has been a challenging issue among nurses. Therefore, the aim of the data is to evaluate the viewpoints of nurses and the family of patients on the family attendance at the patient bedside in the intensive care units at the educational hospitals in Birjand City. A descriptive cross-sectional study was carried out on 70 nurses working in the intensive care units of the hospitals and 100 members of the family of patients admitted to the intensive care units in 2017. Statistical analysis was carried out by SPSS 16. The findings showed that the average score obtained by nurses and families were 0.46 ± 1.75 and 2.61 ± 0.50, respectively. The data showed that nurses have a negative opinion about the presence of the patients’ family regarding the family presence in the Intensive Care Unit ICU (P < 0.001). © 2018 The Author