Preparation and Characterization of Activated Carbon Prepared from Pomegranate Peel for Efficient Removal of Rhodamine B and Acid Red ۱۱۴ Dyes

This study aims to valorize pomegranate peels to remove two ubiquitous dyes in industrial waste, Rhodamine B (Rh-B) and Acid Red ۱۱۴ (AR-۱۱۴), from their aqueous phases. Pomegranate peels were chemically activated with potassium hydroxide (KOH) and heat-treated to obtain an Activated Carbon (AC) activated with KOH (AC-K). Burn-off, iodine number, Methylene blue index, BET, TGA, DTG, TEM-EDX, SEM, pHPCZ, Boehm titration, IRTF, and XPS spectroscopy were used to characterize AC-K. Discontinuous adsorption tests were carried out to examine the impact of major operational parameters: contact time, adsorbent dose, solution pH, initial solute concentration, and temperature. N۲ adsorption-desorption analysis revealed a specific surface area of ۱۰۷۰ m۲/g, microporosity of ۹۸.۸۱%, and a yield of ۲۲.۸%. Moreover, the methylene blue index and iodine number were evaluated to be ۲۹۹.۹۳ and ۹۵۱.۹۸ mg/g, respectively. The equilibrium between adsorbate and adsorbent was attained after ۶۰ minutes for Rhodamine B (Rh-B) and ۱۲۰ minutes for Acid Red ۱۱۴ (AR-۱۱۴), while the corresponding maximum adsorption uptakes amounted to ۱۸۲.۶ and ۱۶۹.۰ mg/g at pH ۲ for both dyes. Modeling of the experimental data using kinetic and isotherm models indicated that the adsorption process was satisfactorily described by the pseudo-second-order kinetic and the Langmuir isotherm models. Thermodynamic parameters revealed the favorability, spontaneity, and exothermicity of both dyes' adsorption by AC-K. Overall, the results confirm the feasibility of using pomegranate peels for the treatment of dye-polluted wastewater.

کلیدواژه ها:

Pomegranate peel ، Preparation of activated carbon ، Valorization ، Adsorption ، Dyes ، Characterization