Volume 6 Issue 1
Authors: Wankasi Donbebe; Ayawei Nimibofa; Inengite Azibaola Kesiye; Ebelegi Newton Augustus
Abstract: Batch adsorption experiments were conducted to investigate equilibrium, kinetic and thermodynamics of the sorption of Methylene Blue onto Fly Ash modified with various concentrations of hydrochloric acid (FAHC-4, FAHC-3, FAHC-2 and FAHC-1). Equilibrium data was best described by the Freundlich isotherm model which suggests adsorbents had heterogeneous surfaces therefore multilayer adsorption occurred in all cases. Fly Ash modified with 1M HCl exhibited the highest adsorption capacity (9.8 mg/L) and Fly Ash modified with 4M HCl had the least adsorption capacity (4.4mg/L). Kinetic data was best described by the pseudo-second-order kinetic model which means adsorption processes were controlled by chemisorption. Boyd kinetic model plots revealed that the rate determining step of each sorption process followed the film diffusion mechanism in which adsorbate ions travelled towards the external surfaces of adsorbents due to electrostatic interactions between chemically modified Fly Ash and adsorbate ions. All adsorption processes were spontaneous because Gibbs free energy of adsorption was negative in all adsorption processes.
Keywords: Adsorption; Langmuir; Freundlich; Intra-particle Diffusion; Boyd
Authors: Zina A.B. Al -Shadidi
Abstract: Energy is always exist in surroundings but it cannot be saved. Many sources of renewable energy were discovered, the problem is how to utilize it. One of the most usable energy sources is the solar energy. And one of the most difficulties is the absence of this source in the night, so it must be stored in the form of another kind of energy. This research focus on using the insulation materials in building hot water storage tanks supplied with solar power to save hot water. Theoretical comparison in terms of energy storage portability between the most two common materials are used in building these tanks. Matlab and Heat transfer equation used to compute properties for heat insulation and energy loss from the insulating material used to build the tank. Finite difference method used to solve heat equation for two kinds of insulating material (Alumina and fiberglass).
Keywords: Theoretical Study; Heat Equation; Renewable Energy; Matlab