Efficiency evaluation of zeolite powder, as an adsorbent for the removal of nickel and chromium from aqueous solution: Isotherm and kinetic study

Heavy metals particularly nickel and chromium are recognized as threatening pollutants leaving serious adverse effects on human health and environment due to their toxicity, un-biodegradable properties and high concentration in industrial effluent. The present study aims to evaluate the zeolite powder efficiency, as an adsorbent, in removing nickel and chromium from aqueous solution. After preparing zeolite powder, batch experiments are performed in different times and adsorbent dosages (pH=7, heavy metals concentration=50 mg/L, and stirring/minute= 200rpm).Adsorption isotherm including Langmuir, Freundlich, Pseudo- first order and second-order model, Intra- particle diffusion and Elovich kinetics were applied to correlate the adsorption. Results indicate that nickel absorbs more than chromium and adsorption of both nickel and chromium obeyed the Freundlich model. Correlation coefficients obtained from Freundlich model and pseudo-second order kinetic are R2=0.995, R2=996 and R2=0.999, respectively, which shows that the Freundlich expression and the kinetics of pseudosecond order gave a better fit to the experimental data of zeolite powder. Also, removing Efficiency revealed significant increase after increasing the adsorbent dose and contact time (R2<0.001). According to obtained dimensionless constant separation term (RL) of Langmuir expression, the RL values for the adsorption of both nickel and chromium onto zeolite powder range of 1-0 indicates that the adsorption is a favorable process. © 2016, International Journal of Pharmacy and Technology. All rights reserved

Nonlinear dynamical analysis of carbachol induced hippocampal oscillations in mice

AIM: Hippocampal neuronal network and synaptic impairment underlie learning and memory deficit in Alzheimer's disease (AD) patients and animal models. In this paper, we analyzed the dynamics and complexity of hippocampal neuronal network synchronization induced by acute exposure to carbachol, a nicotinic and muscarinic receptor co-agonist, using the nonlinear dynamical model based on the Lempel-Ziv estimator. We compared the dynamics of hippocampal oscillations between wild-type (WT) and triple-transgenic (3xTg) mice, as an AD animal model. We also compared these dynamic alterations between different age groups (5 and 10 months). We hypothesize that there is an impairment of complexity of CCh-induced hippocampal oscillations in 3xTg AD mice compared to WT mice, and that this impairment is age-dependent. METHODS: To test this hypothesis, we used electrophysiological recordings (field potential) in hippocampal slices. RESULTS: Acute exposure to 100 μmol/L CCh induced field potential oscillations in hippocampal CA1 region, which exhibited three distinct patterns: (1) continuous neural firing, (2) repeated burst neural firing and (3) the mixed (continuous and burst) pattern in both WT and 3xTg AD mice. Based on Lempel-Ziv estimator, pattern (2) was significantly lower than patterns (1) and (3) in 3xTg AD mice compared to WT mice (P<0.001), and also in 10-month old WT mice compared to those in 5-month old WT mice (P<0.01). CONCLUSION: These results suggest that the burst pattern (theta oscillation) of hippocampal network is selectively impaired in 3xTg AD mouse model, which may reflect a learning and memory deficit in the AD patients