Adsorption Analysis of Fluoride Removal Using Graphene Oxide/Eggshell Adsorbent

Norhusna Mohamad Nor (Faculty of Chemical Engineering, Universiti Teknologi MARA, Cawangan Pulau Pinang, 13500 Permatang Pauh, Pulau Pinang, Malaysia)
Nur Hidayahtul Nazrah Kamil (Faculty of Chemical Engineering, Universiti Teknologi MARA, Cawangan Pulau Pinang, 13500 Permatang Pauh, Pulau Pinang, Malaysia)
Amirul Izan Mansor (Faculty of Chemical Engineering, Universiti Teknologi MARA, Cawangan Pulau Pinang, 13500 Permatang Pauh, Pulau Pinang, Malaysia)
Hawaiah Imam Maarof (Faculty of Chemical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia)

Indonesian Journal of Chemistry
Vol 20, No 3 (2020)

Graphene oxide with eggshells (GO/ES) adsorbent has been studied for fluoride ions (F–) removal. An adsorption study was conducted in batch experiments at different adsorption parameters, which are initial F– concentration, contact time, and temperature. The effects of these adsorption parameters towards F– removal by using GO/ES adsorbent were investigated. The adsorption parameters were then analyzed with adsorption isotherms (Langmuir and Freundlich), kinetics (pseudo-first-order and second-order) and thermodynamic studies. Under various parameters, GO/ES is proven as an effective adsorbent with an adsorption capacity of F– are up to 48 mg/g. The experimental data were satisfactorily fitted with Langmuir isotherm, which illustrated the monolayer pattern of F– adsorption into GO/ES adsorbent. The adsorption kinetic analysis indicated that the adsorption data could be well described by Pseudo-second-order kinetic model, which indicated the chemisorption process, while thermodynamic studies revealed that the adsorption of F– was an exothermic process.