Pyracantha Coccinea Biochar Synthesis, Characterization, and Use in the Removal of Cationic Dyes

Abstract

A variety of dyes are released into aquatic habitats, primarily as wastewater from textile companies. The purpose of this study was to evaluate the adsorption capabilities of inexpensive adsorbents designed to remove malachite green (MG) and methylene blue (MB) from aqueous solutions. The biomass used to produce the biochar was derived from the fruits of Pyracantha coccinea, also known as Red Firethorn. The biomass was thermochemically converted into biochar using the slow pyrolysis process in the absence of oxygen. Pyrolysis was conducted in a traditional furnace, with a final temperature of 500 degrees C, a residence time of 30 min, and a heating rate of 10 degrees C per minute. The produced biochar was analyzed using FT-IR, SEM, EDX, and XRD. Various factors affecting the adsorption mechanism in batch experiments were thoroughly examined, including pH, adsorbent dosage, initial dye concentration, and contact time. The pH of the solution significantly influenced the adsorption process; for both dyes, the pH range of 8 to 9 yielded the highest adsorption efficiency. The adsorption mechanism for the dyes follows the Langmuir isotherm model. The maximum adsorption capacities of the biochar for MB and MG were determined to be 32.7 mg/g and 55.0 mg/g, respectively. The experimental data demonstrates that this method aligns well with the pseudo-second-order kinetic model for both dyes when the relevant equations are applied. The results indicate that biochar is more effective at removing MG and MB after 90 and 120 min of contact time, respectively.