ALCHEMY Jurnal Penelitian Kimia
Vol 22, No 1 (2026): March

Preparation and Optimization of Coal Fly Ash-Based Geopolymer and Its Application as an Adsorbent for Basic Yellow 2 and Methylene Blue Dyes

Eddy Heraldy (Sebelas Maret University)
Edi Pramono (Sebelas Maret University)
Yuniawan Hidayat (Sebelas Maret University)
Khoirina Dwi Nugrahaningtyas (Sebelas Maret University)
Angel Maydeleine (Sebelas Maret University)
Intan Dwi Rahmadani (Sebelas Maret University)



Article Info

Publish Date
31 Mar 2026

Abstract

The preparation of geopolymer from coal fly ash (CFA) solid waste of Jepara PLTU has been carried out by activating CFA using a 10 M NaOH solution and Na2SiO3. Characterization of CFA and geopolymer using X-ray fluorescence (XRF), X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infra-Red (FTIR) spectroscopy. The adsorption process was studied under parameters including pH, geopolymer mass, contact time, and initial adsorbate concentration. The optimum conditions for the adsorption process of basic yellow 2 dye with fly ash-based geopolymer were optimum at solution pH of 11; adsorbent mass of 0.15 g; contact time of 120 minutes; and initial concentration of 80 ppm, while methylene blue adsorption was at solution pH of 11; adsorbent mass of 0.15 g; contact time of 120 minutes; and initial concentration of 60 ppm. Coal fly ash, a solid waste product from the Jepara PLTU, can be used to produce geopolymers through geopolymerization in the presence of activators such as NaOH and Na₂SiO₃. The adsorption capacities of these geopolymers for basic yellow 2 and methylene blue dye solutions are 26.55 and 19.825 mg/g, respectively.

Copyrights © 2026






Journal Info

Abbrev

alchemy

Publisher

Subject

Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Environmental Science Materials Science & Nanotechnology

Description

ALCHEMY Jurnal Penelitian Kimia is a chemistry journal published by Sebelas Maret University, Surakarta. ALCHEMY Jurnal Penelitian Kimia publishes original research articles or review articles in organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry, biochemistry, and ...