Sri Lestari, M. Muflihah, Ratna Kusumawardani, Mukhamad Nurhadi, Yuniati Mangesa, Fathur Insani Ridho, Robbiatul Adawiyah, Pristiningtyas Ambarwati, Siti Rahma, Sin Yuan Lai, Hadi Nur
Bledug Kuwu is one of the geological phenomena as a mud volcano that occurs in Kuwu, Purwodadi, Grobogan, Central Java, Indonesia. The evaluation of Bledug Kuwu's clay as one of the adsorbents for synthetic dyes has been carried out. The preparation of the adsorbent started with washing the clay with distilled water, followed by activation with a solution of hydrochloric acid (1 M) under mechanistic stirring for overnight. The C-H and O-H groups found on the clay adsorbent could attract methylene blue by dispersion forces and hydrogen bonding. Hy-drocloric acid activation process for clay can increase surface area from 49 to 70 m2.g-1, meanwhile, reducing the average crystal size from 48.3 to 43.4 nm. The dye removal capacity increased from 34 to 40 mg.g-1 in correspond-ing to the increase of the temperature from 30 to 50°C. The results showed that the equilibrium adsorption capac-ity of activated Bledug Kuwu's clay reached 99% in an adsorption time of 20 min. The kinetic models of methylene blue adsorption onto BKC and ABKC adsorbents follow the pseudo-second order and the adsorption process is spontaneous with free energy (ΔG) as -23.519 kJ.mol-1. © 2022 Diponegoro University. All rights reserved.
Department of Chemical Education, Universitas Mulawarman, Kampus Gunung Kelua, East Kalimantan, Samarinda, 75119, Indonesia; School of Energy and Chemical Engineering, Xiamen University Malaysia, Selangor Darul Ehsan, 43900, Malaysia; College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China; Center for Sustainable Nanomaterials, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, Johor Bahru, 81310, Malaysia; Central Laboratory of Minerals and Advanced Materials, Faculty of Mathematics and Natural Sciences, State University of Malang, Indonesia