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The coexistence of heavy metals and antibiotics in the environment always results in greater toxicity compared to the individual precursors. Therefore, efficient and economic technology for the simultaneous removal of antibiotics and heavy metals is essential. Herein, litchi leaves biochar carbonized at 550 °C (L550) demonstrated high efficiency in co-removal of CTC (1838.1 mmol/kg) and Cu (II) (1212.9 mmol/kg) within wide range of pH (pH 4-7). Ionic strength obviously enhanced the Cu (II) removal but showed no significant effect on CTC removal. Although Al 3+ and HPO 4 2- decreased the adsorption capacities of CTC and Cu (II) on L550, the coexistence of Na + , K + , Mg 2+ , Cl - , NO 3 - , CO 3 2- and SO 4 2- showed a negligible effect on the simultaneous removal of CTC and Cu (II). Moreover, the adsorption capacities of CTC and Cu (II) on L550 were excellent in the river water, tap water, and lake water. In addition to electrostatic interactions, ion exchange governed Cu (II) adsorption, while surface complexation played a key role in CTC adsorption on L550. Our results demonstrated that litchi leaves biochar could be a promising adsorbent for remediating multi-contaminated environments., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The presence of large amounts of antibiotic residues can potentially threaten environmental sustainability and human health. Thus, it is imperative to develop convenient and effective technologies for eliminating antibiotics from aquatic environments, which are major contaminant reservoirs. Herein, based on Zn/Fe-MIL-88B, we designed and synthesized a magnetic nanocomposite (MC) that contains hierarchical pores and as an effective and regenerative adsorbent for the removal of chlortetracycline (CTC) from water. The characteristics of the MC and its CTC adsorption performance were investigated systematically. The synthesized MC sample pyrolyzed at 800 °C (MC-800) consisted of metallic iron and N/O-doped graphitic carbon along with cluster-like particles with a mesoporous structure. Further, the adsorption of CTC on MC-800 (maximum adsorption amount of 1158.0 mg/g) could be described using the Freundlich isotherm model and a pseudo-second-order model, indicating that the surface of MC-800 was heterogeneous. The adsorption is likely driven by weak chemical forces, including hydrogen bond formation, cation-π electron donor-acceptor (EDA), and π-π EDA interactions. Finally, MC-800 could be recovered readily through facile magnetic separation and regenerated such that its adsorption rate remained higher than 85% even after five cycles., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The environmental and human health risk posed by veterinary antibiotics is of global concern. Antibiotic uptake by herbal plants has been studied, but little is known about perennial woody fruit crops. Litchi (Litchi chinensis Sonn.), a longevial fruit tree, is routinely fertilized with animal manure and, therefore, may be at risk of antibiotic uptake into its fruits. This study investigated the degradation of chlortetracycline and doxycycline present in manure used to amend orchard soil, and their subsequent assimilation by litchi plant, as affected by manure application rate. The results show that half-lives of chlortetracycline and doxycycline in soil were decreased by increased manure rate, with an average of 27 and 59 days, respectively. Chlortetracycline was readily transported to litchi shoots and increased with the growth of litchi plants. Doxycycline predominantly remained in the roots, and underwent growth dilution in the plants. The two tetracyclines could not be detected in fruits from litchi trees when applied with manures, at various rates, over 2 years. For litchi, chlortetracycline may pose human health risk through manure application, but doxycycline is unlikely to do so. Long-term field experiments are required to monitor antibiotic accumulation in fruits of perennial fruit trees fertilized with animal manure.

A magnetic composite of nano-iron wrapped by graphitic carbon in the carbonaceous matrix with hierarchical pores is an efficient, regenerative, and versatile adsorbent to remove antibiotics from water. [Display omitted] • The magnetic composite of nano-iron wrapped by graphitic carbon in the carbonaceous matrix with hierarchical pores (Fe in /C-700) was synthesized through one-step thermolysis of Fe in /Zn-MOF. • Excellent chlortetracycline adsorption performances maintained with respect to various coexisting ions and actual water. • Fe in /C-700 exhibited highly effective adsorption capacities for chlortetracycline, ciprofloxacin, and sulfamethoxazole in the mixed antibiotic system. • Fe in /C-700 showed perfect reusability via magnetic recovery. The stability, versatility, and reusability of an adsorbent are of great significance to its practicability to remove antibiotics from water due to their universal residual. Herein, a magnetic composite of nano-iron wrapped by graphitic carbon in the carbonaceous matrix with hierarchical pores (Fe in /C-700) was constructed by one-step pyrolysis using Fe in /Zn-MOF as a precursor. Fe in /C-700 exhibited a core–shell structure and superparamagnetism behavior, which showed excellent chlortetracycline (CTC) adsorption with the maximum adsorption capacity of 546.5 mg/g. The adsorption process matched well with the pseudo-second-order kinetics model and Langmuir model, indicating chemisorption was likely contributed to the CTC adsorption. Electrostatic interaction, surface complexation, hydrogen bond, and π-π EDA interaction were the dominant driving forces. Cl- and SO 4 2- significantly enhanced the CTC adsorption due to the electrostatic attraction or hydrogen bond formed among Fe in /C-700, anions, and CTC. Fe in /C-700 maintained high adsorption capacities in the mixed antibiotic system (255.1, 143.3, and 169.6 mg/g for CTC, ciprofloxacin, and sulfamethoxazole), in actual water (372.9, 383.3, 390.6, and 366.7 mg/g for CTC in Pearl River water, lake water, tap water, and ultrapure water), and regeneration (366.7, 354.2, 360.4, 314.6, and 301.0 mg/g for CTC in five runs), indicating a promising reusable adsorbent for the remediation of antibiotics in water. These findings provide a feasible and straightforward strategy to synthesize high stable magnetic nanoparticles derived from MOFs. [ABSTRACT FROM AUTHOR]