Papers by Keyword: Adsorption Process

Abstract: The paper presents a solution for modeling and simulation of the adsorption process of the sulfur dioxide in natural zeolites. The adsorption process is modeled as a distributed parameter process, its dynamics depending on three independent variables: time and two spatial variables. In order to simulate the adsorption process, an original form of the approximating analytical solution which describes the process work in dynamical regime is proposed and used. The coefficients of the approximating analytical solution are determined using experimental data obtained from the real plant. A direct practical application, resulted through the simulation of the obtained mathematical model, is the approximation of the time period in which the saturation of the zeolites of different dimensions occurs. Having the mentioned time period, the operators from the industrial field can decide with precision the moment when a zeolite block has to be replaced in order to avoid the environment pollution.

Abstract: Surface response optimization of adsorption process of neutral red dye wastewater by bamboo shoot hulls with the factors of pH value, amount of adsorbent, adsorption temperature, adsorption time and the response of adsorption rate were studied. The optimal parameters for adsorption process were of adsorbent concentration of 100 mg·L-1, adsorbent particle size of 60~80 mesh, pH 4.49, adsorbent amount of 3.65 g·L-1, adsorption time and temperature of 2.23 h and 39.70 °C, respectively. The maximal absorption rate got 98.37%. The adsorption follows the Langmuir and Freundlich isotherms, its dynamic behavior was consistent with the second-order reaction rate equations, the adsorption quantity was 179.3201 mg·g-1 at 30 °C. The apparent thermodynamic calculation of infrared spectroscopy showed that the adsorption process were of a spontaneous heat-emitting physical adsorption other than a simple chemical adsorption. Mechanical study showed that the functional groups were of hydroxyl and carbonyl groups on the pore and rough surfaces inside the hulls of bamboo shoots. Bamboo shoot hulls are good biological adsorption materials.

Abstract: Process of a silica cluster on a polyimide surface was simulated by atomistic calculations combining the semi-empirical molecular orbital method and algorithms that can find the optimal path of a chemical bonding process. Specifically, we estimated the activation and sorption energies in the process. From the simulations, we found that chemical bonding occurs between a silica cluster and the polyimide substrate surface. In the adsorption processes, those reactions between the silica cluster and the polyimide surface which involve Si-O bonding between the cluster and the polyimide are the most probable.