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. This study examined the adsorption capacities of low-cost adsorbents that were created to extract methylene blue (MB) and malachite green (MG) from aqueous solutions. The fruits of Pyracantha coccinea (Red Firethorn), was the biomass that was used as biomass for biochar. The biomass was thermochemically converted into biochar using the slow pyrolysis procedure without oxygen. Pyrolysis was conducted in a traditional furnace. The final temperature for pyrolysis was determined to be 500°C, with a residence period of 30 minutes and a heating rate of 10°C per minute. FT-IR, SEM, EDX, and XRD were used to analyze the produced biochar. Each factor that affects the adsorption mechanism in batch experiments was thoroughly examined, including pH, adsorbent dosage, initial dye concentration, and duration. The pH of the solution had a major effect on the adsorption process; for both dyes, the pH range of 8 to 9 was found to produce the maximum adsorption efficiency. The adsorption mechanism for the dyes is based on the Langmuir isotherm model. It was discovered that biochar's highest adsorption capabilities for MB and MG were 32.7 mg/g and 55.0 mg/g, respectively. The experiment data demonstrates how well this method fits the pseudo-second-order kinetic model for both dyes when the relevant equations are applied. The results show that biochar is more effective at removing MG and MB, respectively, after 90 and 120 minutes of contact time.