SYNTHESIS OF ACTIVATED CARBON FROM LONGAN PEEL AND SEED USING ZNCL₂ AS AN ACTIVATING AGENT

Nguyen Trong Nghia; Nguyen Thi Thuy Anh; Le Thanh Huy; Nguyen Thi Huong; Nguyen Hoang Dung

Nguyen Trong Nghia Hung Yen University of Technology and Education
Nguyen Thi Thuy Anh Hung Yen University of Technology and Education
Le Thanh Huy Hung Yen University of Technology and Education
Nguyen Thi Huong Hung Yen University of Technology and Education
Nguyen Hoang Dung Hung Yen University of Technology and Education

Keywords: activated carbon, longan peel and seed, ZnCl₂, chemical activation, adsorption, wastewater treatment

Abstract

In this study, activated carbon (AC) was successfully synthesized from longan peel and seed – an abundant agricultural byproduct – using chemical activation with ZnCl₂. The influence of activating agent concentration, activation temperature, and heating time on the adsorption capacity was investigated, revealing that these parameters significantly affect the quality of the final product. The optimal conditions were determined to be 50% ZnCl₂ concentration, activation temperature of 500 °C, and heating time of 90 minutes. The resulting activated carbon exhibited low moisture content (~4.36%), ash content below 6%, nearly neutral pH (~6.7), an iodine number of approximately 714 mg/g, a methylene blue adsorption capacity of ~236 mg/g, and a surface area of 896.52 m²/g. SEM, XRD, and N₂ adsorption–desorption isotherm analyses indicated a well-developed mesoporous structure and characteristic amorphous nature of the material. These results demonstrate that activated carbon derived from longan peel and seed holds great potential for wastewater treatment applications and highlights an effective approach to valorize agricultural waste into environmentally friendly adsorbent materials.

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