Efficiency of iron modified Pyrus pyrifolia peels biochar as a novel adsorbent for methylene blue dye abatement from aqueous phase: equilibrium and kinetic studies

Abstract

Herein, a magnetic biochar adsorbent based on Pyrus pyrifolia discarded peels impregnated with precursor FeCl3·6H2O was fabricated and probed as a low-cost adsorbent for toxic cationic dye methylene blue (MB). The textural characterization of Pyrus pyrifolia magnetic biochar (PMBC) obtained from BET analysis exhibited its mesoporous nature with SBET of 133.960 m2/g. The physicochemical characteristics of PMBC were elucidated using XRD, FTIR, SEM-EDX and TEM techniques. The impregnation of FeCl3 has a significant impact on the microstructure of Pyrus pyrifolia based biochar which resulted in enhancement in adsorption efficiency of PMBC. The sorption parameters adsorbent dosage, time, initial MB concentration, and pH were thoroughly elucidated using a batch methodology which were found to be 0.8 g/L, 40 min, 90 mg/L and 6, respectively. Temkin and pseudo-second-order rate equation respectively appropriated the equilibrium data than the rest of the models. The maximum adsorption capacity determined by the Langmuir model was found to be 967.80 mg/g. The adsorbent exhibited better regeneration up to 3 cycles validating its practical usage. The facile synthesis, economic, and environmentally benign characteristic of Pyrus pyrifolia magnetic biochar corroborated it as a highly efficient adsorbent to sequester MB from an aqueous phase.