Determination of Tetracycline, Oxytetracycline, Sulfadiazine, Norfloxacin, and Enrofloxacin in Swine Manure Using a Coupled Method of On-Line Solid-Phase Extraction with the UHPLC-DAD

Free water surface constructed wetlands: review of pollutant removal performance and modeling approaches

Free water surface constructed wetlands (FWSCWs) for the treatment of various wastewater types have evolved significantly over the last few decades. With an increasing need and interest in FWSCWs applications worldwide due to their cost-effectiveness and other benefits, this paper reviews recent literature on FWSCWs' ability to remove different types of pollutants such as nutrients (i.e., TN, TP, NH4-N), heavy metals (i.e., Fe, Zn, and Ni), antibiotics (i.e., oxytetracycline, ciprofloxacin, doxycycline, sulfamethazine, and ofloxacin), and pesticides (i.e., Atrazine, S-Metolachlor, imidacloprid, lambda-cyhalothrin, diuron 3,4-dichloroanilin, Simazine, and Atrazine) that may co-exist in wetland inflow, and discusses approaches for simulating hydraulic and pollutant removal processes. A bibliometric analysis of recent literature reveals that China has the highest number of publications, followed by the USA. The collected data show that FWSCWs can remove an average of 61.6%, 67.8%, 54.7%, and 72.85% of inflowing nutrients, heavy metals, antibiotics, and pesticides, respectively. Optimizing each pollutant removal process requires specific design parameters. Removing heavy metal requires the lowest hydraulic retention time (HRT) (average of 4.78 days), removing pesticides requires the lowest water depth (average of 0.34 m), and nutrient removal requires the largest system size. Vegetation, especially Typha spp. and Phragmites spp., play an important role in FWSCWs' system performance, making significant contributions to the removal process. Various modeling approaches (i.e., black-box and process-based) were comprehensively reviewed, revealing the need for including the internal process mechanisms related to the biological processes along with plants spp., that supported by a further research with field study validations. This work presents a state-of-the-art, systematic, and comparative discussion on the efficiency of FWSCWs in removing different pollutants, main design factors, the vegetation, and well-described models for performance prediction.

Impact of Polythiophene ((C4H4S)n; n = 3, 5, 7, 9) Units on the Adsorption, Reactivity, and Photodegradation Mechanism of Tetracycline by Ti-Doped Graphene/Boron Nitride (Ti@GP_BN) Nanocomposite Materials: Insights from Computational Study

This study addresses the formidable persistence of tetracycline (TC) in the environment and its adverse impact on soil, water, and microbial ecosystems. To combat this issue, an innovative approach by varying polythiophene ((C4H4S)n; n = 3, 5, 7, 9) units and the subsequent interaction with Ti-doped graphene/boron nitride (Ti@GP_BN) nanocomposites was applied as catalysts for investigating the molecular structure, adsorption, excitation analysis, and photodegradation mechanism of tetracycline within the framework of density functional theory (DFT) at the B3LYP-gd3bj/def2svp method. This study reveals a compelling correlation between the adsorption potential of the nanocomposites and their corresponding excitation behaviors, particularly notable in the fifth and seventh units of the polythiophene configuration. These units exhibit distinct excitation patterns, characterized by energy levels of 1.3406 and 924.81 nm wavelengths for the fifth unit and 1.3391 and 925.88 nm wavelengths for the seventh unit. Through exploring deeper, the examination of the exciton binding energy emerges as a pivotal factor, bolstering the outcomes derived from both UV-vis transition analysis and adsorption exploration. Notably, the calculated exciton binding energies of 0.120 and 0.103 eV for polythiophene units containing 5 and 7 segments, respectively, provide compelling confirmation of our findings. This convergence of data reinforces the integrity of our earlier analyses, enhancing our understanding of the intricate electronic and energetic interplay within these intricate systems. This study sheds light on the promising potential of the polythiophene/Ti-doped graphene/boron nitride nanocomposite as an efficient candidate for TC photodegradation, contributing to the advancement of sustainable environmental remediation strategies. This study was conducted theoretically; hence, experimental studies are needed to authenticate the use of the studied nanocomposites for degrading TC.

Excitation-depended fluorescence emission of boron-doped graphene quantum dot as an optical probe for detection of oxytetracycline in food and information encryption patterns

The boron-doped graphene quantum dot (HSE-GQD-B) was prepared by thermal pyrolysis of the mixture of citric acid, histidine, serine and ethylenediamine and boric acid. The resulting HSE-GQD-B is composed of tiny graphene sheets with an average sheet size of 4.2 ± 0.16 nm and exhibits an excitation-depended fluorescence emission behavior. The HSE-GQD-B produces the strongest blue fluorescence of 450 nm wavelength under the excitation of 365-nm ultraviolet light and the strongest yellow fluorescence of 550-nm wavelength under the excitation of 470-nm visible light. The interaction of HSE-GQD-B with oxytetracycline molecule induces a sensitive blue fluorescence quenching process. Based on this characteristic, a fluorescence method was established for optical detection of oxytetracycline. The analytical method offers a better sensitivity, selectivity, and repeatability compared with previously reported methods. The detection of oxytetracycline attains a wide linear range of 0.02-50 μM and a detection limit of 0.0067 μM. It has been successfully applied to fluorescence detection of oxytetracycline in food samples. In addition, the HSE-GQD-B was also used as a multicolor fluorescence probe for information encryption patterns.

Removal performance and inhibitory effects of combined tetracycline, oxytetracycline, sulfadiazine, and norfloxacin on anaerobic digestion process treating swine manure

Combined veterinary antibiotics (CVAs) belonging to different antibiotics classes could cause exacerbated impacts on the anaerobic digestion (AD) process of swine manure. Four different antibiotics "two tetracyclines: tetracycline (TC) and oxytetracycline (OTC), one fluoroquinolones: norfloxacin (Norf), and one sulfonamides: sulfadiazine (SDZ)" were combined to evaluate their removal performances and its inhibition effects on AD. Results indicated that CVAs removal decreased from 84.3 to 63.7 %, with an increase in the initial concentration from 12.5 to 50 mg L^-1, where the removal of CVAs occurring in the order OTC > TC > Norf > SDZ. An average of 9.5, 7.5, 9.5, and 32.1 % of the spiked TC, OTC, SDZ, and Norf were remained in the sludge, respectively. With 50 mg L^-1 of CVAs, a competitive adsorption phenomenon was found to have a notable impact on biodegradation microorganisms' activity leading a 73.1 % decrease in CH₄ production. CVAs caused a temporal inhibition to the acidogenic activity followed by partial inhibition to methanogenic by 66.8 %, and IC₅₀ was 38.5 mg L^-1. Moreover, CVAs resulted in acetate accumulation, while 26 % and 48 % lower in TS and COD removal, respectively, were observed. A significant reduction in the relative abundance of bacteria and archaeal genera was also mentioned. The findings of this research would provide a more in-depth understanding of AD's performance in treating swine manure contaminated with combined antibiotics.

Determination of Tetracycline Residues in Kidney and Muscle of Beef Cattle Slaughtered in Dire Dawa and Harar Municipal Abattoirs, Eastern Ethiopia

Background

Antibiotics are among the most widely used drugs in farm animals for therapeutic and prophylactic purposes. However, the antibiotic residues in meat are a serious public health concern due to their harmful effects on consumer health. Besides this problem, there is limited information on the level of the antibiotic residues, including tetracycline residues. Therefore, this study was aimed to determine the tetracycline residues in the kidney and muscle samples of beef cattle in Harar town and Dire Dawa city.

Methods

A study was conducted on 500 randomly selected carcass (250 kidney and 250 muscle samples) slaughtered at Dire Dawa and Harar municipal slaughterhouses between December 2018 and December 2019. The samples were collected aseptically and screened for tetracycline residues by thin layer chromatography. Then, presumptive positive samples were analyzed using high-performance liquid chromatography to get a quantitative outcome. Descriptive statistics were used to determine the frequency, mean, or standard deviation to determine the summary values and distribution of the outcomes. Finally, the data was analyzed using SPSS version 21 software.

Results

Out of 500 samples, oxytetracycline residues were detected in 84% of the samples. However, tetracycline and doxycycline were not detected in all samples. Among the kidney and muscle samples collected from Dire Dawa and Harar abattoirs, 109 (87.2%) and 101 (80.8%) were positive for oxytetracycline, respectively. Oxytetracycline residue levels in Dire Dawa ranged from 57 to 607 µg/kg for the kidney and 10.14 to 435 µg/kg for muscle samples. Among the samples collected from Harar, the concentration of oxytetracycline residues ranged from 16 to 433 µg/kg and 6 to 435 µg/kg for kidney and muscle samples, respectively, at Harar slaughterhouses. About 22.0% of muscle samples collected from Dire Dawa and 17.8% from Harar town had oxytetracycline residues above maximum residue limits.

Conclusions

In general, the study revealed that oxytetracycline residues were prevalent among tetracycline residues analyzed from kidney and muscle samples in the study areas. Thus, there is a risk of consumer exposure to these antibiotic residues that may have human health effects. Therefore, awareness creation and strict regulation is needed by the regulatory authorities for the use of antimicrobial drugs in the livestock industry.

Graphene Oxide Molecularly Imprinted Polymers as Novel Adsorbents for Solid-Phase Microextraction for Selective Determination of Norfloxacin in the Marine Environment

In this study, a novel sample pretreatment strategy of solid-phase microextraction using graphene oxide molecularly imprinted polymers as adsorbents coupled with high-performance liquid chromatography was developed to detect norfloxacin in the marine environment. As a carrier, the imprinted polymers were synthesized by precipitation polymerization with graphene oxide. Compared with graphene oxide non-imprinted polymers, the graphene oxide molecularly imprinted polymers exhibited higher adsorption capacity towards norfloxacin. The synthesized polymeric materials were packed into a molecularly imprinted solid-phase microextraction cartridge, and critical parameters affecting the extraction process were optimized. Under the optimized molecular imprinted solid-phase microextraction condition, the proposed method was applied to the analysis of norfloxacin for seawater and fish with satisfactory recovery (90.1–102.7%) and low relative standard deviation (2.06–5.29%, n = 3). The limit of detection was 0.15 μg L⁻¹ and 0.10 μg kg⁻¹ for seawater and fish, respectively. The study revealed that the proposed molecularly imprinted solid-phase microextraction represents an attractive sample pretreatment strategy for the analysis of norfloxacin in the marine environment.