Livy Laysandra, Rizka Fabryanty, Yi-Hsu Ju, Jindrayani Nyoo Putro, Shella Permatasari Santoso, Felycia Edi Soetaredjo, Alfin Kurniawan, Suryadi Ismadji
Adsorption is an efficient process for removing contaminants from water by using adsorbent. In this work, bentonite, rarasaponin, and sodium alginate are used as raw materials to prepare new composite to be applied to the adsorption of crystal violet dye. The prepared adsorbent (benton-ite-rarasaponin-alginate composite) has a sponge-like appearance. The Fourier transform infrared (FTIR), X-ray diffraction (XRD), nitrogen (N2) sorption and scanning electron microscopy (SEM) methods were employed to characterize the prepared adsorbents. The adsorption experiments were conducted isothermally at 30,50, and 70°C. The Freundlich and Langmuir isotherm models were chosen to correlate the equilibrium adsorption data. Meanwhile, the adsorption kinetics was studied at 30°C, and the data were correlated by using the pseudo-first-order and pseudo-second-order. Based on the adsorption results, it was found that composite can adsorb crystal violet dye 3 times more than bentonite at all investigated temperatures, where at 70°C the adsorption capacity for acid-activated bentonite is 176.63 mg/g and for rarasaponin-bentonite-alginate composite is 476.04 mg/g. The adsorption of crystal violet dye onto the adsorbents increases with increasing temperature indicating that the chemisorption is dominant in this process. © 2019 Desalination Publications. All rights reserved.
Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya, 60114, Indonesia; Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, No. 43, Sec 4, Keelung Rd, Da’an District, Taipei City, 106, Taiwan; Department of Chemical Engineering, National Taiwan University of Science and Technology, No. 43, Sec 4, Keelung Rd, Da’an District, Taipei, 106, Taiwan