Removal of amoxicillin, phenol, and diethyl phthalate using activated carbon from murici seeds (Byrsonima crassifolia L. Kunth)

Abstract

The growth of anthropogenic activities, particularly the intensive use of pharmaceuticals and industrial chemicals, has led to the emergence of toxic "emerging pollutants," posing risks to ecosystems and public health. This study introduces a novel approach by converting murici seed, an underutilized agro-industrial waste, into an effective adsorbent for removing amoxicillin, phenol, and diethyl phthalate from water. Murici seeds were activated with phosphoric acid and carbonized. The activated carbon was characterized using electron microscopy, zero-point charge, infrared spectroscopy, thermal and textural analysis, revealing a surface area of 556.97 m2.g−1 pore volume of 0.447 cm3.g−1, and a mesoporous structure with an average pore diameter of 2.47 nm. A zero-point charge of 6.3 favors selective adsorption based on pH. The adsorbent achieved removal efficiencies of 76 % for amoxicillin, 56 % for phenol, and 97 % for diethyl phthalate, with maximum adsorption capacities (qmax) of 28.3 mg.g−1 for amoxicillin, 74.9 mg.g−1 for phenol, and 43.5 mg.g−1 for diethyl phthalate. Most removal occurred within the first 60 minutes, attributed to the porous structure and oxygenated functional groups facilitating hydrogen bonding and π-π interactions. Compared to other agricultural waste-derived adsorbents, murici-activated carbon shows superior efficiency, particularly for diethyl phthalate, highlighting its potential for scalable environmental remediation. This study offers a sustainable alternative for water purification and contributes to the circular economy by valorizing agro-industrial waste. The implications extend to cost-effective water treatment solutions in industrial and rural settings. Future research should explore adsorbent regeneration, reuse, and application in real-world wastewater systems to optimize performance and environmental benefits.