Reduction of Crystal Violet Dye from Water by Pomegranate Peel-Derived Efficient Biochar: Influencing Factors and Adsorption Behaviour

摘要

This work aimed to prepare a potential biochar from pomegranate peels (PP) and investigate its sorption ability toward a cationic dye, namely, crystal violet (CV). Adsorbent was obtained via a direct pyrolysis of precursor at 700 ℃ for 3 h. The biochar (PP-biochar) was characterized using FTIR, XPS, BET, SEM., and pH_(PZC) analysis, and used as adsorbent for the aqueous CV dye via batch experiments. Results showed that PP-biochar exhibits highly porous structure (S_(BET) = 508.9 m~2/g), V_T = 0.19 cm~3/g) with even distribution between micropore (50.8) and mesopore (49.2 ) volume. The pH_(PZC) value of the prepared biochar was 6.42. The uptake of CV dye occurred rapidly, and the adsorbed amount reached 83.4 after only about 15 min of stirring time. It was also found that the adsorption kinetic mechanism was well described by the pseudo-second order and Avrami models. The maximum adsorption capacity of Langmuir (Q~0_(max)) was found to be 201.2 mg/g at 50 ℃. Adsorption of CV dye involved mainly π-π interaction with contribution of other mechanisms (i.e., pore filling, hydrogen bonding, and electrostatic attraction). The finding suggest that the developed biochar is of promising potential to be applied as eco-friendly material for removing dyes from wastewater.