Adsorption of methylene blue dye from aqueous solution using low-cost adsorbent: kinetic, isotherm adsorption, and thermodynamic studies

• Published in: Environmental monitoring and assessment Vol. 195; no. 6; p. 676
• Main Authors: Al-Asadi, Safaa Talib, Al-Qaim, Fouad Fadhil, Al-Saedi, Haider Falih Shamikh, Deyab, Issa Farhan, Kamyab, Hesam, Chelliapan, Shreeshivadasan
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2023; Springer Nature B.V
• Subjects: Activated carbon; Adsorbents; Adsorption; Analytical methods; Aqueous solutions; Atmospheric Protection/Air Quality Control/Air Pollution; byproducts; carbon; Cationic dyes; Cations; Charcoal; Color removal; Dyes; Earth and Environmental Science; Ecology; Ecotoxicology; Electron microscopy; Environment; Environmental Management; Environmental Monitoring; Environmental science; figs; Fourier transform infrared spectroscopy; Fourier transforms; fruits; Hydrogen-Ion Concentration; Infrared spectroscopy; Isotherms; Kinetics; Leaves; Low cost; Methylene blue; Methylene Blue - chemistry; Monitoring/Environmental Analysis; Scanning electron microscopy; sorption isotherms; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Water - chemistry; Water Pollutants, Chemical; X-ray diffraction; Fig leaf; Kinetics; Adsorption; Activated carbon; Methylene blue; Thermodynamic
• ISSN: 0167-6369; 1573-2959; 1573-2959
• DOI: 10.1007/s10661-023-11334-2

Fig leaf, an environmentally friendly byproduct of fruit plants, has been used for the first time to treat of methylene blue dye. The fig leaf-activated carbon (FLAC-3) was prepared successfully and used for the adsorption of methylene blue dye (MB). The adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and the Brunauer–Emmett–Teller (BET). In the present study, initial concentrations, contact time, temperatures, pH solution, FLAC-3 dose, volume solution, and activation agent were investigated. However, the initial concentration of MB was investigated at different concentrations of 20, 40, 80, 120, and 200 mg/L. pH solution was examined at these values: pH3, pH7, pH8, and pH11. Moreover, adsorption temperatures of 20, 30, 40, and 50 °C were considered to investigate how the FLAC-3 works on MB dye removal. The adsorption capacity of FLAC-3 was determined to be 24.75 mg/g for 0.08 g and 41 mg/g for 0.02 g. The adsorption process has followed the Langmuir isotherm model ( R 2  = 0.9841), where the adsorption created a monolayer covering the surface of the adsorbent. Additionally, it was discovered that the maximum adsorption capacity (Qm) was 41.7 mg/g and the Langmuir affinity constant (KL) was 0.37 L/mg. The FLAC-3, as low-cost adsorbents for methylene blue dye, has shown good cationic dye adsorption performance. Graphical Abstract