Removal of Chloramphenicol from Aqueous Solution Using Low-Cost Activated Carbon Prepared from Typha orientalis

Yiran Li,Jian Zhang,Hai Liu

doi:10.3390/w10040351

Abstract

Low-cost and efficient activated carbon (AC) was prepared from Typha orientalis via phosphoric acid activation for chloramphenicol (CAP) removal. The adsorption capacity and mechanisms of CAP on AC were investigated. The physicochemical properties of AC were characterized by an N2 adsorption/desorption isotherm, elemental analysis, Boehm’s titration and X-ray photoelectron spectroscopy (XPS). The effects of experimental parameters were investigated to study the adsorption behaviors of CAP on AC, including contact time, initial concentration, ionic strength, and initial pH. AC had a micro-mesoporous structure with a relatively large surface area (794.8 m2/g). The respective contents of acidic and basic functional groups on AC were 2.078 and 0.995 mmol/g. The adsorption kinetic that was well described by a pseudo-second-order rate model implied a chemical controlling step. The adsorption isotherm was well fitted with the Freundlich isotherm model, and the maximum CAP adsorption capacity was 0.424 mmol/g. The ionic strength and pH had minimal effects on CAP adsorption. The dominant CAP adsorption mechanisms on AC were evaluated and attributed to π-π electron-donor-acceptor (EDA) interaction, hydrophobic interaction, in conjunction with hydrogen-bonding interaction. Additionally, AC exhibited an efficient adsorption performance of CAP in a realistic water environment.

Highlights

Chloramphenicol (CAP) as a broad-spectrum antibiotic is commonly used as a human antibiotic and veterinary drug due to its low cost and excellent antibacterial effects against many Gram-positive and Gram-negative bacteria [1,2]
Adsorbent porosity is an important factor of the adsorption capacity of activated carbon
The Typha orientalis (TO)-based activated carbon prepared in this study showed more efficient adsorption capacity of CAP compared with most of the reported adsorbents

Summary

Introduction

Chloramphenicol (CAP) as a broad-spectrum antibiotic is commonly used as a human antibiotic and veterinary drug due to its low cost and excellent antibacterial effects against many Gram-positive and Gram-negative bacteria [1,2]. CAP is banned for use in food production in many countries, including the European Union, United States, Canada, Australia, Japan, and China [1,8], the wastewater from antibiotic manufacturing, improper disposals of drugs or illegal usage in aquaculture still pollutes the water environment [8,9]. It is necessary and important to develop a sensitive and cost-effective strategy for extraction of CAP in contaminated waters. Only a few studies on CAP removal from water or wastewater have been reported, especially using porous carbon materials such as low-cost activated carbon

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Conclusion