Removal of Tetracycline in Sewage and Dairy Products with High-Stable MOF.

Jing-Jing Li,Bin Di,Kan Li,Ying Ma,Ni Zhao

doi:10.3390/molecules25061312

Abstract

Serious environmental and human health problems caused by the abuse of antibiotics have attracted worldwide concern. Recently, metal–organic frameworks (MOFs) with high porosity have drawn wide attention for their effects in the adsorption and removal of pollutants from complex matrices. Herein, a high-stable metal organic framework (MOF), i.e., ((ZnCl2)3(L)2·DMF)n, where L=1,3,5-tris((pyridin-4-ylthio)methyl)benzene), MOF 1, was applied to adsorb and remove tetracycline from sewage and dairy products. The results showed that MOF 1 exhibited a strong performance in the adsorption of tetracycline. The effects of initial pH values, adsorbent dose, contact time and ionic strength of the adsorption performance of MOF 1 were investigated. The adsorption kinetics best fit the pseudo-second order model, and the adsorption isotherms matched the Langmuir adsorption model well. It was indicated that both chemical adsorption and physical adsorption play an important role in the adsorption process, and the adsorption of tetracycline was homogeneous and occurred on a monolayer on the surface of MOF 1. Additionally, the stability of MOF 1 and the details of the adsorption mechanism were also investigated. Thus, this study provides a new candidate for the application of MOFs-based adsorbents in the removal of antibiotics from sewage and dairy products.

Highlights

Tetracycline hydrochloride (Figure 1) is one of the most common broad-spectrum tetracycline-based antibiotics, which is widely used for treating bacterial infections and as a feed additive in a variety of animal husbandry and aquacultures, due to its advantages such as its low cost, obvious effects, low toxicity and wide antimicrobial spectrum [1,2]
The N2 adsorption–desorption isotherms were performed on a Quantachrome Autosorb iQ (Quantachrome, Florida, FL, USA) analyzer and the adsorption parameters of metal–organic framework (MOF) 1 were obtained by the Brunauer-Emmett-Teller (BET) method and the Density Functional Theory (DFT)
We have demonstrated that a water-stable MOF material, MOF 1, could serve as an excellent adsorbent for the removal of antibiotic tetracycline in sewage and milk

Summary

Introduction

Tetracycline hydrochloride (Figure 1) is one of the most common broad-spectrum tetracycline-based antibiotics, which is widely used for treating bacterial infections and as a feed additive in a variety of animal husbandry and aquacultures, due to its advantages such as its low cost, obvious effects, low toxicity and wide antimicrobial spectrum [1,2]. The abuse of antibiotics has become a major global issue since it causes serious environmental and food safety issues, due to their persistence and biological accumulation, and this abuse poses a latent threat to human health [3,4]. Excessive residual consumption or continual long-term intake with small doses of tetracycline can result in undesirable effects, such as gastrointestinal disturbance, anaphylactic reaction and hepatotoxicity, leading to a significant increase in antibiotic resistance of pathogenic microorganisms and a consequential increase in drug-resistant genes [10,11,12]. The tetracycline will eventually enter the human body through the food chain and poses a serious threat to human health.

Methods

Results

Conclusion