Adsorption Characteristics and Mechanism of Methylene Blue in Water by NaOH-Modified Areca Residue Biochar

To solve the water pollution problem caused by methylene blue (MB), areca residue biochar (ARB) was prepared pyrolysis at 600 °C, and modified (M-ARB) obtained modifying ARB with 1.5 mol/L NaOH, they were utilized to adsorb eliminate MB from water. The structural characteristics of M-ARB examined, main influencing factors adsorption mechanism process investigated. outcomes demonstrated an increase in M-ARB’s specific surface area total pore volume 66.67% 79.61%, respectively, compared ARB, structure more abundant, content oxygen element also significantly increased. When reaction temperature 25 starting pH mixture 10, initial concentration 50 mg/L, dosages 0.07 g/L 0.04 g/L, equilibrium achieved about 210 min, elimination rate for exceeded 94%. behaviors on line Langmuir isotherm model (R2 > 0.95) quasi-secondary kinetic 0.97), which characterized single-molecule layer chemisorption. highest amount that may theoretically be absorbed ranging 136.81 152.72 mg/g 74.99–76.59% higher than ARB. a spontaneous heat absorption driven entropy increase, mainly involved electrostatic gravitational force, filling, hydrogen bonding, π–π complex containing multiple mechanisms action. NaOH modification can make have perfect properties functional group structures participate reaction, used as advantageous material removal