Methylene Blue Adsorption onto Cockle Shells-Treated Banana Pith: Optimization, Isotherm, Kinetic, and Thermodynamic Studies

Rosalyza Hasan (Faculty of Chemical and Natural Resources Engineering, Universiti Malaysia Pahang, Lebuhraya Tun Razak 26300, Gambang, Pahang, Malaysia)
Wong Jie Ying (Faculty of Chemical and Natural Resources Engineering, Universiti Malaysia Pahang, Lebuhraya Tun Razak 26300, Gambang, Pahang, Malaysia)
Chong Chi Cheng (Faculty of Chemical and Natural Resources Engineering, Universiti Malaysia Pahang, Lebuhraya Tun Razak 26300, Gambang, Pahang, Malaysia)
Nur Farhana Jaafar (School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia)
Rohayu Jusoh (Faculty of Chemical and Natural Resources Engineering, Universiti Malaysia Pahang, Lebuhraya Tun Razak 26300, Gambang, Pahang, Malaysia)
Aishah Abdul Jalil (School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia Centre of Hydrogen Energy, Institute of Future Energy, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Joh)
Herma Dina Setiabudi (Faculty of Chemical and Natural Resources Engineering, Universiti Malaysia Pahang, Lebuhraya Tun Razak 26300, Gambang, Pahang, Malaysia Centre of Excellence for Advanced Research in Fluid Flow (CARIFF), Universiti Malaysia Pahang, Lebuhraya Tun Raza)

Indonesian Journal of Chemistry
Vol 20, No 2 (2020)

Two low-cost wastes, banana pith (BP) and cockle shells (CS) were explored towards methylene blue (MB) removal. The performance of cockle shells-treated banana pith (CS-BP) in MB removal was compared with untreated BP and commercially Ca(OH)2-treated BP (Ca(OH)2-BP). The adsorption efficacy was following the order of BP < CS-BP < Ca(OH)2-BP, indicating the positive role of alkaline treatment towards MB removal and great potential of CS as a low-cost activation material. The optimization of MB removal onto CS-BP was executed by response surface methodology (RSM) with three independent variables (adsorbent dosage (X1), initial pH (X2) and initial MB concentration (X3)), and the optimal condition was achieved at X1 = 1.17 g/L, X2 = pH 7 and X3 = 214 mg/L, with 87.32% of predicted MB removal. The experimental data well-fitted the pseudo-second-order kinetic (R2 > 0.99) and the Langmuir isotherm (R2 = 0.999) models, demonstrating the chemisorption and naturally homogeneous process. Thermodynamics study discovered that the MB removal by CS-BP is endothermic, feasible, spontaneous and randomness growth at a solid-solute interface. It is affirmed that CS could be employed as a low-cost activation material and CS-BP as a low-cost adsorbent.