Removal of Nickel (II) ions from Aqueous Solutions Using Chicken Feather Nanoparticles: Study of Kinetic, Isotherm and Thermodynamic Models

Nickel is highly toxic and directly associate with health risk such as damage to kidney, liver and central nervous system. This study evaluated the potential of a chicken feather for the removal of nickel from aqueous solutions. Freundlich, Langmuir and Temkin isotherm models were used to characterize the bio sorption of the mentioned metal onto the chicken feather. In the batch system, parameters of pH (4-8), adsorbent dosage (0.01- 0.06 g/l), contact time (15-120 min), nickel initial concentration (5-200 mg/l), and temperature (15-40 °C) were studied. Studies have shown that the maximum Nickel uptake efficiency occurred at pH = 6, concentration of 50 mg / g, contact time of 60 minutes, ambient temperature of 25 ° C and adsorbent mass of 0.03 g. The thermodynamic parameters such as Gibb's Free Energy (ΔG), Enthalpy (ΔH) and Entropy (ΔS) indicated that the adsorption of nickel ion were spontaneous and endothermic at 288–313 °K. Comparing the determination coefficients between measured data and obtained value from pseudo- second-order model (R2 = 0.95) and pseudo- first-order model (R2 = 0.65) showed that the pseudo- second-order model describes experimental data better. Also, comparing the Langmuir, Freundlich and Temkin isotherm for nickel adsorption by chicken feather nanoparticles showed that Freundlich isotherm (R2 = 0.87) was more proper than Langmuir isotherm (R2 = 0.82) and Temkin isotherm (R2 = 0.67) in describing adsorption process. According to the results of this study, chicken feather nanoparticles adsorbent with a high efficiency of 96.8% can be used to remove Nickel from aqueous solutions

Application of Chitosan and Activated Carbon Nano-composite in Removal of Nitrite, Phosphate, and Ammonia From Aquaculture Wastewater

Developing an adsorbent with natural components is one of the effective methods to reduce the amount of wastewater pollutants. Wastewater reuse can improve the quality of water prior to entering the natural environment. The aim of this study was to evaluate the efficiency of chitosan nano-composite and activated carbon adsorbent in the removal of nitrite, phosphate, and ammonia pollutants from fish farms of Aq-Qala. To prepare the adsorbents, the shrimp shells were converted to nano-chitosan. The date palm kernel was prepared and activated with oxalic acid in pyrolysis furnace by injecting nitrogen gas into activated carbon, then, the nano-composite was prepared from nanochitosan and activated carbon. A field-laboratory study was conducted during the winter of 2018, and then, batches of synthesized nano-composite were investigated and the effects of pH, initial effluent concentration, and adsorption time were investigated. The experiments were performed in the pH range of 5-8, effluent concentration of 25-100 mg/L, and contact time of 15-90 minutes. The results showed that at optimum conditions (pH of 7, effluent concentration of 50 mg/L, and contact time of 60 minutes), the highest removal percentage and adsorption capacity for nitrite, phosphate, and ammonia contaminants were 99.98%, 99.77%, and 65.65%, and 6.65, 6.14, and 7.32 mg/g , respectively. Due to the high removal percentage (99.98%) of the chitosan and activated carbon nano-composite, the adsorbent was highly capable of removing pollutants (nitrite, phosphate, and ammonia)

Efecto del Covid en la Hostelería Aragonesa

España es uno de los países más visitados de mundo. El turismo ha posibilitado un crecimiento económico importante durante los últimos años.La hostelería, que recoge las actividades económicas consistentes en la prestación de servicios ligados al alojamiento y la alimentación esporádicos, ligados al turismo se han visto afectados a nivel mundial por la pandemia y los trabajadores del sector se han sentido vulnerables como consecuencia de la misma. Este trabajo tiene como objeto analizar la actividad turística y hostelera aragonesa y el cambio que han sufrido como consecuencia de la pandemia por el Covid 19. Para el análisis nos apoyaremos en el índice de actividad IASS como índice de la actividad del Sector ServiciosSe concluirá que el índice de actividades IASS ha descendido y aportaremos luz en las variables que han influido en tal descenso. Además, podremos observar cómo ha evolucionado el sector de la hostelería a partir del estado de Alarma, tanto a nivel económico, como la repercusión en el mercado laboral.<br /

The Safety and Effectiveness of a Polysaccharide Extracted from Rosa Canina in Patients with NAFLD: A Randomized Trial

Objective: Non-alcoholic fatty liver (NAFL) is a common pathology of hepatocytes due to the accumulation of fat which is predominantly implicated in obesity. Due to the multifaceted characterization of fatty liver and no effective treatment, this study was aimed to assess the protective effect of a polysaccharide in NAFL patients. Materials and methods: Polysaccharide fraction was isolated from Rosa canina and administered to 33 NAFL patients for 90 days. Demographic information, liver ultrasonography, and the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzymes were studied. Data were analyzed with the use of SPSS version 21 (SPSS, Inc.) All data were shown as means ± SDs and p &lt; 0.05 was considered as significant. Results: After 90-day prescription, the weight loss, reduced activity of ALT and AST as well as changing the echogenicity of the liver from grades of 3, 2, and 1 to 2, 1 and normal, respectively, were observed in patients compared to the baseline (p ≤ 0.05). In addition, there were no visible side effects in patients during drug consumption. Conclusions: The data indicated that polysaccharide fraction with no obvious side effects is significantly able to protect the liver from steatosis in patients with NAFL disease. However, further information is required to better conclude on the effectiveness of the isolated polysaccharide as a promising fatty liver drug

Using Fe3O4-graphene oxide-modified chitosan with melamine magnetic nanocomposite in the removal and magnetic dispersive solid-phase microextraction of Cr (VI) ion in aquatic samples

An eco-friendly magnetic nanoparticle (MNPs)-based stir rod-assisted dispersive solid-phase extraction (SRMDSPE) method was proposed for the removal and extraction of Cr (VI) preceding its spectrophotometric determination. The magnetic melamine‐functionalized chitosan-modified graphene oxide (MCMGO) nanocomposites were synthesized as a biocompatible, effective adsorbent with admirable adsorption capacity, great magnetic property and excellent dispersion ability for the adsorption of the Cr (VI) ion. The prepared adsorbent was characterized by XRD, FTIR, TGA, VSM, EDX, and SEM. Different parameters affecting removal and microextraction efficiencies such as sample volume, pH, interferences, volume and type of eluent, and adsorbent dosage were investigated and optimized. The result of isotherm shows that Cr (VI) adsorption followed the Freundlich model. Thermodynamic parameters (i.e., change in the free energy (ΔG 0), the enthalpy (ΔH 0), and the entropy (ΔS 0)) were also evaluated. The overall adsorption process was endothermic and spontaneous. The sorbent elution with ability and reusability was used in dispersive solid-phase extraction. Under optimal conditions, the extraction efficiency was 78.0%, and the enrichment factor was 31.19. The SRMDSPE was successfully quantified in the 0.05–0.5 mg L−1 (R 2 = 0.9993) with a detection limit of 0.015 mg L−1. The proposed method was applied to leather wastewater, Tabriz, and some surface waters. The percentage of recoveries for spiked real samples were in the range of 91–101%, and the percentage of relative standard deviations were 2–6%