Carbon dioxide (CO2) is a compound responsible for the greenhouse effect. One of the methods of CO2 capture from the gas stream is adsorption process. In this paper, the adsorption equilibrium isotherms of CO2 on zeolite 13X were measured at different temperatures (293.15 K, 303.15 K, 313.15 K, 323.15 K, 333.15 K, 348.15 K, 373.15 K, 393.15 K) and under pressures up to 2 MPa. These data were obtained using an Intelligent Gravimetric Analyzer (IGA-002, Hiden Isochema, UK). Selected multitemperature adsorption isotherm equations, namely Toth, Langmuir–Freundlich, and, Langmuir were correlated with experimental data.
This paper discusses the adsorption of Direct Orange 26 azo dye on sunflower husk - an agricultural waste product. During the study, sorption kinetics and equilibrium as well as sorption capacity of the husk were investigated. The adsorption kinetics was analyzed using pseudo-first and pseudo-second order equations, which indicated a chemical sorption mechanism. The sorption equilibrium was approximated with the two-parameter Freundlich and Langmuir equations and the three-parameter Redlich-Peterson equation. The main experiments were carried out in a laboratory adsorption column under different process conditions. Experimental data were interpreted with the Thomas model, based on the volumetric flow rate, initial composition of the feed solution and mass of the adsorbent. The results of modeling the adsorption equilibrium, adsorption kinetics and adsorption dynamics were evaluated statistically.
The adsorption of lead ions onto a zeolite bearing tuff (stilbite) from synthetic acid aqueous solution and acid mine drainage taken from Sasa mine, Macedonia, is elaborated in this paper. The results present that adsorption occurs effi ciently in both of cases. The physical and chemical properties of the used natural material, zeolite bearing tuff, are characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy. The concentration of metal ions in solution before and after treatment is obtained by AES-ICP. The effectivity of zeolite bearing tuff is determined through a series of experiments under batch conditions from single ion solutions, whereby the main parameters are the effects of initial pH of solution, mass of adsorbent, initial metal concentration in solution, contacting time and competing cations. The maximum capacity of zeolite bearing tuff for removal of lead ions from solution is determined by equilibrium studies. The experimental obtained data are fi tted with Freundlich and Langmuir adsorption models. The experimental data are better fi tted with Langmuir adsorption isotherm. Zeolite bearing tuff is effective adsorbent for treating acid mine drainage. The results showed that 99% of lead ions are removed from acid mine drainage, i.e. the concentration of lead ions from 0.329 mg/dm3 decrease to 0.002 mg/dm3 . The pH value of acid mine drainage from 3.90 after treatment with zeolite bearing tuff increases to 5.36.