Adsorption Ni(II) on Magnetic Fulvic Acid-Chitosan: Kinetics and Isotherm Study

Raihansyah Raja Hutama (Department of Chemistry, The Republic of Indonesia Defense University, Kawasan IPSC Sentul, Bogor 16810, Indonesia)
Audrey Nur Aisyah (Department of Chemistry, The Republic of Indonesia Defense University, Kawasan IPSC Sentul, Bogor 16810, Indonesia)
Azzahra Sandri (Department of Chemistry, The Republic of Indonesia Defense University, Kawasan IPSC Sentul, Bogor 16810, Indonesia)
Mayang Fauziah Putri Kuntjahjono (Department of Chemistry, The Republic of Indonesia Defense University, Kawasan IPSC Sentul, Bogor 16810, Indonesia)
Sultan Napoleon (Department of Chemistry, The Republic of Indonesia Defense University, Kawasan IPSC Sentul, Bogor 16810, Indonesia)
Yusuf Bramastya Apriliyanto (Department of Chemistry, The Republic of Indonesia Defense University, Kawasan IPSC Sentul, Bogor 16810, Indonesia)
Nugroho Adi Sasongko (Research Center For Sustainable Production System and Life Cycle Assessment, National Research and Innovation Agency (BRIN), KST Prof. BJ Habibie, Building 720 Puspiptek Area, South Tangerang, Banten 15314, Indonesia Energy Security Graduate Program)
Rahmat Basuki (Department of Chemistry, The Republic of Indonesia Defense University, Kawasan IPSC Sentul, Bogor 16810, Indonesia)

Sorption Studies
Vol. 1 No. 1 (2025): Sorption Studies, Vol. 1 No. 1 June 2025

Indonesia, as one of the most populous countries in the world, requires clean water sources. Industrial waste that is improperly discharged pollutes water bodies with hazardous metals. Adsorption is one of the effective methods for reducing the concentration of harmful metals in water. This study utilized fulvic acid extracted from goat manure compost and combined it with chitosan and magnetite as an adsorbent material for Ni(II). The FTIR results for the magnetite-fulvic acid-chitosan composite showed a peak at 1627 cm⁻¹, indicating the presence of aromatic C=C, aromatic ring -OH, and quinone C=O groups, which confirm the binding of fulvic acid. BET analysis was performed on magnetite and magnetite-fulvic acid-chitosan, and the pore volume and pore size were found to be 0.177488 cm³/g and 6.5394 nm, respectively. The composite exhibited magnetic behavior due to the attraction between the magnetite-fulvic acid-chitosan and an external magnet. Adsorption tests using isotherm and kinetic models revealed that Ni(II) adsorption followed a multilayer mechanism and pseudo-second-order kinetics, with a b value of 121.68 mg/g and an experimental qe of 6.28 × 10⁻⁵ mol/g. This shows that the magnetite-fulvic acid-chitosan composite is a promising, sustainable, and magnetically separable adsorbent for the effective removal of nickel ions from contaminated water.