Studies of Oxyanion Removal from Aqueous Solution Using Zeolite and HDTMA-Br Surface Modified Organo-Zeolite

Abstract

In the present study, the Jordanian zeolite was modified with cationic surfactant, hexadecyltrimethylammonium bromide (HDTMA-Br), and this organo-zeolite was used to remove the nitrate ion (oxyanion). Batch experiments were carried out using zeolite at different parameters; isotherms equilibrium models Langmiur, Freundlich, Dubinin-Radushkevich and Redlich-Peterson were investigated at different temperature values 25, 30, 35, 40 and 45°C. Redlich-Peterson, Freundlich and Dubinin-Radushkevich models showed that the experimental equilibrium data followed these models better than that of Langmuir model. The calculated energy  Zeolite and organo-zeolite were used as adsorbents for the investigation of the kinetic studies using column reactor. Kinetic models, a pseudo-second-order, intraparticle diffusion and Elovich were used to analyze the results. The calculated qmax values using second-order model for both organo-zeolite and zeolite are (1.720-2.074) and (0.916-1.274) respectively, the values of qmax for organo-zeolite are higher than that of zeolite. The normalized standard deviation (%SSE) showed a good agreement between the experimental capacity and the calculated one at different temperature values for both zeolite and the organo-zeolite. The intraparticle diffusion model showed deviation from linearity when zeolite is used and showed one line when the adsorbent is organo-zeolite. The calculated activation energies (Ea) in kJ/mol for both zeolite and the organo-zeolite, are 90.7 and 13.7 respectively, the value of the activation energy gives us evidence that the organo-zeolite is better than the zeolite as an adsorbent because it has lower activation energy than the zeolite.