Optimization of methylene blue removal by H3PO4 thermochemically treated mixed pineapple peel and algae adsorbent and insight on the adsorption mechanism

• Published in: Biomass Conversion and Biorefinery
• Main Author: Jawad A.H.; Jumadi S.N.; Wilson L.D.; ALOthman Z.A.
• Format: Article
• Language: English
• Published: Springer Science and Business Media Deutschland GmbH 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85195186093&doi=10.1007%2fs13399-024-05787-9&partnerID=40&md5=febf0896cf37d7bf3d1ac3ac7865dd03

In this study, a mixture of pineapple peel (Ananas comosus) and algal biomass was subjected to a thermochemical treatment to develop a sustainable adsorbent based on thermochemical-treated mixture of pineapple peel and algae (TCTPPALG) for removal of a harmful model cationic azo dye (methylene blue (MB)) pollutant. The production process involved microwave irradiation, along with H3PO4 activation under microwave at 800-W irradiation for 15 min in a high-purity nitrogen atmosphere (99.99%). The physicochemical properties of TCTPPALG were characterized using various analytical techniques, including XRD, BET, FTIR, pHpzc, and FSEM-EDX. The adsorption properties of TCTPPALG were investigated by evaluating the ability to remove MB dye from water. The Box-Behnken design (BBD) was employed to optimize key adsorption variables: A: TCTPPALG dose (0.02–0.1 g/100 mL); B: pH (4–10); and C: variable contact time (10–130 min). According to the BBD model, the most effective removal of MB (98.8%) occurred while using a dosage of 0.06 g of TCTPPALG at pH 10 with a contact time of 130 min. The adsorption kinetics of MB dye followed a pseudo-second order (PSO) model, whereas the equilibrium adsorption profile was described by the Langmuir model. The maximum adsorption capacity (qmax) of TCTPPALG with MB was 108.7 mg/g. Several factors contribute to the dye adsorption mechanism with TCTPPALG, including electrostatic forces, hydrogen bonding, pore filling, and π–π stacking on the adsorbent surface. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.