Thermochemical treatment of mixed mandarin peel and algae via microwave and H3PO4 activation: process optimization and adsorption mechanism for methylene blue dye

• Published in: Biomass Conversion and Biorefinery
• Main Author: Jawad A.H.; Jumadi S.N.; ALOthman Z.A.; Wilson L.D.
• Format: Article
• Language: English
• Published: Springer Science and Business Media Deutschland GmbH 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85189921341&doi=10.1007%2fs13399-024-05598-y&partnerID=40&md5=776bccc569b416d3580726514b55e209

Herein, blended mandarin (Citrus reticulata) peel (MP) and algae (AG) biomass were thermochemically treated (TCTMPAG) to yield a cost-effective and renewable adsorbent for removal of methylene blue (MB), a known toxic cationic dye. The preparation included microwave irradiation, in conjunction with H3PO4 activation at 800 W for 15 min in a nitrogen atmosphere. The adsorption characteristics of TCTMPAG were studied by assessing its capacity to remove methylene blue (MB) dye from aqueous media. The Box-Behnken design (BBD) was used to optimize key adsorption factors, namely A: TCTMPAG dosage (0.02–0.12 g/0.1 L), B: pH (4–10), and C: contact period (30–420) min. The BBD model determined that the highest elimination of MB (98.4%) occurred for a TCTMPAG dosage of 0.12 g/0.1L, pH 10, and a contact time of 225 min. The MB dye adsorption rate profile conformed to a pseudo-second-order (PSO) model, while the Langmuir and Temkin model adequately represented the equilibrium adsorption profile (R2 = 0.97). The highest adsorption capacity (qmax) of TCTMPAG for MB dye was determined to be 48.5 mg/g. Various contributions to the adsorption mechanism include various contributions such as electrostatic forces, H-bonding, pore filling, and π-π stacking onto the TCTMPAG adsorbent surface. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.