Synthesis of mg/al layered double hydroxide (LDH) nanoplates for efficient removal of nitarate from aqueous solutions

Leaching of nitrate is an important issue on the losses of nitrate from agriculture soils in temperate zone. Decomposition of plants and other organic residues in the soil and improper discharge of sewage lead to the presence of nitrates in the sources of surface and groundwater and flowing water drainage in agricultural drainage networks and their pollution. This study aimed to study the potential use of chloride layered double hydroxide (LDH) nanoplates to remove nitrate from aqueous solutions. The nano-material of chloride-LDH was made by hydrothermal technique and then, its characteristics were specified through scanning electron micrograph and removal of nitrate from aqueous solution by the minerals was investigated in terms of pH, time, speed of shaker, different concentrations of adsorbent and surface adsorption isotherm. Microscopic images of built nanoplates were examined using FESEM and SEM electron microscope with two magnifications. The thickness of nanoplates was about 20nm and their diameter was about 250 nm. Magnified image of the synthesized nanostructures shows squamous-shape. Surface adsorption isotherm of nitrate by chloride- LDH nanoplate was explained with Langmuir model shown with the values greater than 2R. In surface adsorption of nitrate, the optimal values were measured as following: pH = 7, speed = 250 rpm, time = 45 min, concentration of adsorbent = 0.1gr.  This material could adsorb nitrates from aqueous solutions efficiently and effectively.Keywords: pollution, nitrate, layered double hydroxide, hydrothermal, surface adsorptio

Application of experimental design for extraction of BHA and BHT from edible vegetable oil and their determination using HPLC

The optimal conditions of liquid–liquid extraction of two synthetic phenolic antioxidants, BHA and BHT were investigated in five Iranian edible vegetable oil samples using the central composite design. Stepwise multiple linear regression method was used for construction of different models based on the experimental data. Optimum conditions for BHA and BHT were achieved using 3 ml of ethanolic solution containing (0.25% v/v) of glacial acetic acid, three extractions and a mixing time of 10 minutes

Fabrication of novel TiO2 nanoparticles/Mn(III) salen doped carbon paste electrode: application as electrochemical sensor for the determination of hydrazine in the presence of phenol

Hydrazine and phenol are two important environmental pollutants. In this work, an electrochemical sensor for the selective and sensitive detection of hydrazine in presence of phenol was developed by the bulk modification of carbon paste electrode (CPE) with TiO2 nanoparticles and Mn(III) salen. Large peak separation, good sensitivity, and stability allow this modified electrode to analyze hydrazine individually and simultaneously along with phenol. Applying square wave voltammetry (SWV), a linear dynamic range of 3 × 10(-8)-4.0 × 10(-4) M with detection limit of 10.0 nM was obtained for hydrazine. Finally, the proposed method was applied to the determination of hydrazine and phenol in some real samples

In vitro analysis of antifungal effects of acrylic resin modified by zinc oxide nanoparticles on candida albicans

Background and purpose: Removable prostheses made of polymethyl methacrylate are susceptible to Candida-dependent denture stomatitis and Candida albicans is considered to be the first common cause. The aim of the present study was to investigate the antifungal effect of acrylic resin modified by zinc oxide nanoparticles. Materials and methods: In this laboratory study, 72 disks (10*4 mm) made of polymethyl methacrylate (Acropars, Marlic, Iran) were divided into three groups (n= 24). Concentrations of zinc oxide nanoparticles (ZnO NPs) were 1 (group A), 0.5 (group B), and 0 (group C, control) mg/ml. Samples were studied in laboratory using Candida albicans strains (ATCC 10231) according to CLSI M27-A3 and M27-S4 documents. For data analysis, one-way ANOVA and Scheffe's post-test were performed using SPSS V24. Results: There were significant differences in mean numbers of fungal colonies in study groups. The amount of fungal colonies in group A was lower than those in group B and in group B was lower than those in group C (P<0.05). Conclusion: Considering the limitations of this study, findings showed that zinc oxide nanoparticles have antifungal activity, which increases by increase in concentration of nanoparticles. © 2021, Mazandaran University of Medical Sciences. All rights reserved

Green Synthesized Silver Nanoparticles Using Feijoa Sellowiana Leaf Extract, Evaluation of Their Antibacterial, Anticancer and Antioxidant Activities

Biogenic synthesis of silver nanoparticles (SNPs) has great attention of scientists, as it provides clean, biocompatible, non-toxic and inexpensive fabrication. In this study, F. sellowiana leaf extract was used for synthesizing SNPs which reduces silver nitrate into silver zero-valent. SNPs were characterized by UV, FTIR, XRD, SEM-EDS, and TEM analysis. They were also examined for their biological activities. The presence of biosynthesized SNPs was characterized by UV–visible spectroscopy and also crystal nature of SNPs was identified with XRD analysis. FT-IR spectrum was used to confirm the presence of different functional groups in the biomolecules which act as a capping agent for the nanoparticles. The morphology of SNPs was explored using SEM and the presence of silver was confirmed by elemental analysis. The size of the nanoparticles was in the range of 20–50 nm determined by TEM. The green synthesized SNPs showed good antibacterial activities against both gram-negative and gram-positive bacteria and also in resistant clinically isolated pathogens. Furthermore, the green synthesized SNPs showed reliable anticancer activity on the gastric adenocarcinoma (AGS) and breast (MCF-7) cancer cell lines with little effect on normal (HFF) cells. The in-vitro antioxidant activity of SNPs showed a significant effect on the scavenging of free radicals and iron chelating activity