Tetracycline Concentration Research Articles

A 2D/2D (ZnO/InVO4) heterojunction and its Z-scheme photocatalytic degradation of tetracycline and potassium butyl xanthate

ZnO is a highly functional material with outstanding physical and chemical properties. Coupling with a suitable material can overcome the limitations and enhance its performance. In the study presented here, ZnO was coupled with InVO4, an emerging material attracting research attention. The as-prepared ZnO/InVO4 nanocomposite was successfully tested for its quality and characteristics. Its catalytic ability was determined for the removal of tetracycline (TC), an emerging threat leading to the development of antibiotic-resistant bacteria, and potassium butyl xanthate (PBX), the most commonly used collector in mineral processing plants, whose residuals adversely affect the selectivity to recycle water and poses a serious environmental impact if discharged. The synthesized ZnO had a hexagonal wurtzite structure, whereas InVO4 had an orthorhombic crystal structure. Their composite was found to be a 2D/2D heterojunction of ZnO nanosheets and InVO4 nanoflakes with a band gap energy of 2.65 eV. The as-prepared composite could reduce the TC concentration up to 96.41% in just 80 min, whereas 98.87% of PBX was removed in 110 min. It proved to be highly efficient and stable under repetitive usage.

Metal-organic framework modified molecularly imprinted polymers-based sensor for fluorescent sensing of tetracycline in milk

Tetracycline (TC) residues have a serious impact on human health, sustainable development of animal husbandry and aquaculture. Herein, a novel sensor (Cr-MOF@MIP) for TC detection was developed by modifying molecularly imprinted polymers (MIPs) on the surface of a luminescent metal-organic framework (MOFs). The sensor not only possesses excellent fluorescence stability and specific recognition sites, but also enables selective aggregation of the target. Subsequently, the physicochemical properties of Cr-MOF@MIP, such as morphological structure, crystal shape, surface area, pore size and functional groups, were characterized. Under the optimized conditions, the relative fluorescence intensity of the Cr-MOF@MIP fluorescent sensor decreased gradually and linearly as the TC concentration increased from 0.2 μg/mL to 50 μg/mL. The limit of detection (LOD) of TC was 0.032 μg/mL. In addition, the sensor has higher selectivity for TC compared to non-imprinted polymers (NIPs), with a bursting mechanism of Cr-MOF@MIP mainly attributed to the fluorescence resonance energy transfer. Remarkably, in the complex systems of milk, its specific detection of TC was demonstrated with satisfactory recoveries (90.06–104.34 %). It is expected that the development of Cr-MOF@MIP sensor will provide a new way of thinking for easy, rapid, highly selective and cost-effective analysis in complex samples.

Enhanced electrocatalytic degradation of tetracycline by ZIF-67@CNT coupled with a self-standing aligned carbon nanofiber anodic membrane

Due to the misuse and overuse of the antibiotic tetracycline (TC), as well as its refractory degradability, it has become a stubborn environmental contaminant. In this study, a self-standing polyacrylonitrile-based ZIF-67@CNT/ACF aligned anodic membrane was fabricated by innovatively incorporating ZIF-67@CNT nanoparticles into an aligned carbon nanofiber (ACF) membrane to treat the TC. The flow-through nanoporous construction of the ZIF-67@CNT/ACF membrane reactor can compress the diffusion boundary layer on the electrode surface to enhance mass transfer under microscopic laminar flow, which can further enhance the degradation rate. In addition, the enhanced degradation performance also benefited from the significant electrooxidation capacity of the ZIF-67@CNT/ACF membrane. At the optimal electrocatalytic condition of 3.0 V applied potential and pH 6, the degradation rate reached 81% in 1 h for an initial TC concentration of 10 mg l−1. The refractory and highly toxic TC was electrochemically degraded into small non-toxic molecules. Our results indicate that electrocatalytic TC degradation can be enhanced by ZIF-67@CNT/ACF membrane.

CS/CoFe2O4 nanocomposite as a high-effective and steady chainmail catalyst for tetracycline degradation with peroxymonosulfate activation: performance and mechanism.

Tetracycline becomes a crucial measure for managing and treating communicable diseases in both human and animal sectors due to its beneficial antibacterial properties and cost-effectiveness. However, it is important not to trivialize the associated concerns of environmental contamination following the antibiotic's application. In this study, cobalt ferrate (CoFe2O4) nanoparticles were loaded into chitosan (CS), which can avoid the agglomeration problem caused by high surface energy and thus improve the catalytic performance of cobalt ferrate. And it can avoid the problem of secondary contamination caused by the massive leaching of metal ions. The resulting product was used as a catalyst to activate peroxymonosulfate (PMS) for the degradation of tetracycline (TC). To determine the potential effects on TC degradation, various factors such as PMS dosing, catalyst dosing, TC concentration, initial solution pH, temperature, and inorganic anions (Cl-, H2PO4- and HCO3-) were investigated. The CS/CoFe2O4/PMS system exhibited superior performance compared to the CoFe2O4-catalyzed PMS system alone, achieving a 92.75% TC removal within 120 min. The catalyst displayed high stability during the recycling process, with the efficiency observed after five uses remaining at a stable 73.1%, and only minor leaching of dissolved metal ions from the catalyst. This confirms the high stability of the catalyst. The activation mechanism study showed that there are free radical and non-free radical pathways in the reaction system to degrade TC together, and SO4•- and 1O2 are the primary reactive oxygen radicals involved in the reaction, allowing for effective treatment of contaminated water by TC.

Tetracycline removal from wastewater via g-C3N4 loaded RSM-CCD-optimised hybrid photocatalytic membrane reactor

In this study, a split-type photocatalytic membrane reactor (PMR), incorporating suspended graphitic carbon nitride (g-C3N4) as photocatalyst and a layered polymeric composite (using polyamide, polyethersulfone and polysulfone polymers) as a membrane was fabricated to remove tetracycline (TC) from aqueous solutions as the world's second most used and discharged antibiotic in wastewater. The photocatalyst was synthesised from melamine by ultrasonic-assisted thermal polymerisation method and, along with the membrane, was characterised using various methods, including Brunauer–Emmett–Teller analysis (BET), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), Field emission scanning electron microscopy (FESEM), and Ultraviolet–visible spectroscopy (UV–Vis). The PMR process was optimised, using Design-Expert software for tetracycline removal in terms of UV irradiation time, pH, photocatalyst loading, tetracycline concentration, and membrane separation iteration. It was revealed that a membrane-integrated reactor as a sustainable system could effectively produce clean water by simultaneous removal of tetracycline and photocatalyst from aqueous solution. The maximum removal of 94.8% was obtained at the tetracycline concentration of 22.16 ppm, pH of 9.78 with 0.56 g/L of photocatalyst in the irradiation time of 113.77 min after six times of passing membrane. The PMR system showed reasonable reusability by about a 25.8% drop in TC removal efficiency after seven cycles at optimal conditions. The outcomes demonstrate the promising performance of the proposed PMR system in tetracycline removal from water and suggest that it can be scaled as an effective approach for a sustainable supply of antibiotic-free clean water.

Novel Cerium (IV) Oxide -Ti3C2- titanium dioxide heterostructure photocatalyst for pharmaceutical pollutants removal: Photocatalyst characterization, process optimization and transformation pathways

Tetracycline (TC) is a widely applied antibiotic recognized for its potential negative consequences on human health and ecological balance. In this study, a novel photocatalyst, Cerium (IV) oxide -Ti3C2- titanium dioxide (CeMXT), was synthesized through sonochemical and impregnation techniques, subsequently subjected to comprehensive characterization employing diverse methods including XRD, SEM, TEM, HR-TEM, Raman, XPS, and BET. The optimization of TC degradation was pursued using the Response Surface Methodology (RSM), encompassing variables such as initial TC concentration, irradiation duration, photocatalyst dosage, and pH. The degradation efficacy was investigated through free radical trapping experiments, revealing the pivotal roles of OH and superoxide anion radicals. Remarkable degradation efficiency, reaching 94.70 %, was achieved under specific parameter conditions: 22.19 mg/L TC concentration, 104.13 min irradiation, 0.65 g/L photocatalyst dosage, and pH 4.72. This exceptional performance could be attributed to the elevated generation of oxidant species facilitated by the Z-scheme electron transfer heterojunction. Furthermore, LC-Mass analysis was employed to delineate the intermediates formed during TC photodegradation, culminating in proposing a conceivable degradation pathway. The impressive proficiency of the CeMXT photocatalyst underscores its potential application for effective large-scale treatment of persistent organic pollutants in wastewater treatment facilities. Additionally, comparative analysis with a recently developed photocatalyst highlights its promise as a viable alternative for the remediation of such contaminants in aquatic ecosystems.

Sustainable wastewater treatment: LDH@Fe3O4-Ag as a promising photocatalyst for tetracycline degradation

This study deals with the removal of pharmaceutical contaminants from wastewater, especially tetracycline (TC). For this purpose, calcium/aluminum-based nanolayered double hydroxide (LDH) was synthesized through the co-precipitation method. Subsequently, the pre-synthesized LDH was engineered with Fe3O4 and silver (Ag) nanoparticles to enhance the photocatalytic prowess and ease of use. The resulting LDH@Fe3O4-Ag composites were thoroughly characterized using various analytical techniques, including BET, FESEM, TEM, TGA, FT-IR, XRD, and DRS. The prepared LDH@Fe3O4-Ag composites were then employed as a photocatalyst for TC removal from water. Several critical parameters were methodically optimized, including reaction time, initial TC and LDH@Fe3O4-Ag concentrations, pH, and Ag loading amount. Under optimal conditions (90 min reaction time, pH 9, initial TC concentration of 35 ppm, and LDH@Fe3O4-Ag concentration of 0.05 g/L), an impressive TC removal efficiency of 96.4 % was achieved. Furthermore, the reusability of the photocatalyst, reaction kinetics, and the primary degradation site were investigated. This research presents LDH@Fe3O4-5Ag as a promising solution to address water contamination issues arising from pharmaceutical compounds.

L-arginine and 1,4-Butanediol conjugated highly ordered nitrogen doped carbon dots as photoluminescent probe for “turn off” based detection of organic pollutants in real sample matrices

Nitrogen doped carbon dots are emerging as efficient photoluminescent probes for wide range of sensing applications. A simple strategy of synthesizing highly ordered nitrogen doped carbon dots (named here as N-CDarg) is developed by thermal conjugation of 1, 4-Butanediol with L-Arginine. It led to formation of self-assembled transverse carbon chains through oligomerization of 1,4-Butanediol and conjugation with L-Arginine. The structural, morphological and compositional analysis of the N-CDarg is confirmed from 1H and 13C NMR, mass spectroscopy, FT-IR, higher resolution transmission electron microscopy and X-ray photoelectron spectroscopy. It exhibited bright bluish photoluminescence with PL quantum yield of 11 %. Under optimized pH and contact time, the probe solution of N-CDarg exhibited dual sensing for the detection of tetracycline (TC) and 4-nitrophenol (4-NP) via PL quenching proportional, which followed Stern-Volmer relation. The linear PL quenching response for TC is in the range of 0.5 μM to 60 μM with a limit of detection (LOD) of 103 nM; while the linear range for 4-NP is 0.4 μM to 20 μM, and the LOD is 77 nM. Selectivity of these species have been confirmed against several metal ions, anions, other antibiotics (for TC detection) and different structural analogues of phenols (for 4-NP detection). The ability of the probe to quantitatively detect trace concentrations of TC and 4-NP in real sample matrices like river water and milk has been demonstrated by spike analysis. The mechanism of PL quenching of N-CDarg by TC and 4-NP has been discussed using PL decay lifetime spectroscopy.

Effects of anaerobic soil disinfestation on antibiotics, human pathogenic bacteria, and their associated antibiotic resistance genes in soil

Despite the widespread use of anaerobic soil disinfestation (ASD) to improve soil health, its impact on soil antibiotics, human pathogenic bacteria (HPB) and antibiotic resistance genes (ARGs) remains unclear. To address this knowledge gap, we conducted an incubation study in manure-amended soil with three treatments: no treatment (CK), crop straw only (CS), and CS combined with water flooding and plastic covering (ASD). The results showed that ASD increased the concentrations of tetracycline by 27 % and β-lactam by 22 %, while depleting macrolide by 51 %. Furthermore, ASD increased the numbers of potential HPB species and genes by 4.1 % and 23 %, respectively. Co-occurrence network analysis demonstrated intensified cooperation and competition among HPB and HNPB (human non-pathogenic bacteria) species under ASD, favoring the prevalence of HPB species such as Escherichia coli, Streptococcus equi, Clostridium tetani, and Bacillus anthracis. Potential HPB species in Proteobacteria exhibited negative correlations with macrolide and β-lactam antibiotics, whereas those in Firmicutes showed positive correlations with tetracycline antibiotics, suggesting that specific bacterial taxa contributed to the production and degradation of antibiotics in response to ASD. Interestingly, CS mitigated the presence of ARGs in soil, while ASD further amplified this reduction, almost eliminating nalC, acrB, OXA-60, VIM-7, tetL, and tetQ. The variation in ARG profiles (91.7 %) could be explained by antibiotics, HPB, and HNPB species, indicating their collective contribution to reducing soil ARGs under ASD. Moreover, host prediction and network analysis revealed that, compared with CK, where potential HPB species were the main carriers of ARGs, soil ARGs were less frequently carried by potential HPB species after ASD, indicating a reduction in the collaborative dissemination of HPB and ARGs in manured soil. In conclusion, ASD provides a promising strategy for mitigation of soil biologic contamination, which can have profound significance for environmental safety and agricultural sustainability.

Tetracycline decontamination from aqueous media using nanocomposite adsorbent based on starch-containing magnetic montmorillonite modified by ZIF-67

In the present study, starch/zeolitic imidazole framework-67 (ZIF-67) modified magnetic montmorillonite nanocomposite adsorbent to remove tetracycline (TC) as an emerging antibiotic-based contaminant from aqueous media. The surface properties of the adsorbents were investigated using FTIR, XRD, SEM, EDX-Map, XPS, TEM, BET, and VSM analysis. The specific surface area of MMT, St/MMT-MnFe2O4, and St/MMT-MnFe2O4-ZIF-67 magnetic nanocomposite samples were found to be 15.63, 20.54, and 588.41 m2/g, respectively. The influence of pH, adsorbent amount, initial TC concentration, temperature, contact time, and coexisting ions on TC elimination was explored in a batch adsorption system. The kinetic and equilibrium data were well matched with the pseudo-second-order and Langmuir isotherm models, respectively. The maximum monolayer adsorption capacities of TC were obtained to be 40.24, 66.1, and 135.2 mg/g by MMT, St/MMT-MnFe2O4, and St/MMT-MnFe2O4-ZIF-67 magnetic nanocomposite adsorbents, respectively. Also, thermodynamic studies illustrated that the TC adsorption process is exothermic and spontaneous. Furthermore, the magnetic nanocomposite adsorbent St/MMT-MnFe2O4-ZIF-67 showed good reusability and could be recycled for up to five cycles. This excellent adsorption performance, coupled with the facile separation of the magnetic nanocomposite, gave St/MMT-MnFe2O4-ZIF-67 a high potential for TC removal from aqueous media.

An enzyme-free and label-free ratiometric fluorescence signal amplification biosensor based on DNA-silver nanoclusters and catalytic hairpin assembly for tetracycline detection

Sensitive and accurate in antibiotic detection is crucial for food security, environmental conservation, public health, and environmental protection. In this study, we developed an enzyme-free and label-free ratiometric fluorescence biosensor for highly sensitive detection of tetracycline (TET). This biosensor utilized a combination of target-triggered catalytic hairpin assembly (CHA) and DNA-silver nanocluster (DNA-AgNCs) dual-color fluorescent signal probes. Upon TET binding to the aptamer, it initiated the leakage of CHA initiator, resulting in the formation of numerous double-stranded DNA complexes. This process exposed the foothold sequence of hairpin-structured DNA-AgNCs (H3-AgNCs) that exhibit yellow fluorescence. Subsequently, the conformational changes in H3-AgNCs significantly reduced the yellow fluorescence intensity (FI) and reveal the auxiliary DNA-AgNCs (a-DNA-AgNCs) linkage sequence. The binding of a-DNA-AgNCs brought two dark AgNCs close, forming nanocluster dimers emitting red fluorescence. The results demonstrate that the variation in ratiometric signal is linear with TET concentration between 0.1 and 50 ng/mL, with a detection limit as low as 0.086 ng/mL. Additionally, this approach exhibited good recovery results with spiked milk samples. This enzyme-free and label-free combined signal amplification method with proportional signal output based on DNA-AgNCs provides valuable empirical reference for creating low-cost, stable, and highly-sensitive biosensors.

Twisted-chiral mesoporous silica from coconut husk waste designed for high-performance drug uptake and sustained release

With an annual production of 2.81 million tons, the coconut husk is an essential source of silica. Various advantages of silica as a drug carrier make it one of the most developed materials in drug delivery applications. To improve the drug delivery performance of a material, twisted chirality is also classified as a critical factor because the pharmacological activity depends on the interaction of the drug with the drug carrier material in the target area. In this study, the coconut husk-based mesoporous silica (MS) can be synthesized through a calcination and sol-gel method. With the help of anionic surfactant, MS is successfully modified to have a twisted-chiral structure (CMS). CMS is characterized by twisted rod-like morphology at a size of 1–2 μm, with a helical arrangement (mixed with the beta-sheet and random coil conformations). CMS's surface area and pore volume are obtained at 288.3 m2/g and 0.614 cm3/g, with an average pore size of 7.63 nm. The maximum adsorption of tetracycline (506.5 mg/g) is reached at pH = 4, with the initial concentration of tetracycline at 400 mg/g, temperature of 323 K, and adsorption time of 600 min. The loading of tetracycline follows the pseudo-first-order model with a monolayer mechanism. The bulk migration of tetracycline from the solution into the surface of CMS is deemed the primary adsorption mechanism. The in-vitro release study of tetracycline at pH = 7.4 follows the slow-sustained release model with the cumulative release at 72.3 %, showing better release performance compared with the common MS.

Stevia rebaudiana leaf extract mediated green synthesis of cerium oxide nanoparticles for antibacterial activity and photocatalytic degradation of tetracycline

Cerium oxide nanoparticles (CeO2-NPs) are multifunctional oxide metal nanoparticles that have been considered by many due to their unique properties, including antimicrobial, antifungal, semiconducting, and photocatalytic activity. In this research, CeO2-NPs were synthesized using a natural sweetener glycoside in the aqueous crude extract of Stevia rebaudiana that acted as an excellent bio-reductant. The prepared nanoparticles were further characterized by Raman spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and field emission-scanning electron microscopy (FE-SEM). The FE-SEM results confirmed that the CeO2-NPs were nano-size (10–50 nm). The antibacterial activity of CeO2-NPs against Pseudomonas aeruginosa and Enterococcus faecalis has shown that the Minimum Inhibitory Concentration (MIC) was 6.25 and 12.5 μg/mL and Minimum Bactericidal Concentration (MBC) were 12.5 and 25 μg/mL respectively. In the presence of CeO2-NPs (under optimal conditions: catalyst dosage = 0.75 g/L, TC concentration = 5 mg/L, pH=10), about 80.68% of tetracycline (TC) was degraded after 45 min UV-irradiation that it is indicative of the acceptable photocatalytic property of CeO2-NPs.

Toward Enhanced Antibiotic Efficacy: Exploring the Synergistic Potential of Marine-Derived Lectins Against Human Pathogenic Bacteria.

This study aimed to assess the combined antibacterial effect of lectins and antibiotics on S. aureus ATCC 25923, multidrug-resistant E. coli ATCC 11303 and S. aureus ATCC 700698. Using the checkerboard assay, we evaluated the antibacterial effects of eight lectins isolated from marine organisms combined with two common antibiotics, oxacillin and tetracycline, on three virulent bacterial strains. Initially, none of the tested lectins exhibited antibacterial effects when used individually. However, when combined with antibiotics, the lectins exhibited synergistic, additive, antagonistic, or no interaction. Overall, the tested lectins alone had no effect on the efficacy of oxacillin. On the other hand, different lectins in combination with tetracycline potentiated its antimicrobial effect. Lectins from red algae of the Bryothamnium genus, for example, exhibited the most significant synergistic effects, reducing the minimum inhibitory concentration (MIC) of tetracycline by up to 16 times. Lectins from the Hypnea genus also reduced the MIC of tetracycline. Our findings suggest that some lectins binding to complex carbohydrates containing fucosylated cores (α1-6) are excellent candidates to boost the efficacy of some antibiotics.

Unveiling the Antibacterial Properties of Statins: An In Vitro Study on Helicobacter pylori

Background. Helicobacter pylori (H. pylori), a widespread bacterial pathogen, is associated with various gastrointestinal diseases, including gastric cancer. Statins, widely prescribed cholesterol‐lowering agents, have demonstrated pleiotropic effects, including potential antimicrobial properties. This in vitro study investigated the direct antibacterial effects of three clinically approved statins, simvastatin, atorvastatin, and rosuvastatin, against H. pylori isolates. Methods. H. pylori strains were isolated from gastric biopsies of dyspeptic patients and identified by microbiological techniques. The minimum inhibitory concentrations (MICs) of statins were determined using the agar dilution method, and their antimicrobial activity was evaluated by the disc diffusion method using different concentrations of simvastatin, atorvastatin, rosuvastatin, tetracycline, and amoxicillin. Scanning electron microscopy (SEM) was employed to examine the morphology of H. pylori cells. Results. The minimum inhibitory concentration (MIC) values (μg/mL) of atorvastatin, rosuvastatin, simvastatin, tetracycline, and amoxicillin against H. pylori were 240 ± 20, 450 ± 20, 460 ± 15, 155 ± 30, and 140 ± 20, respectively. In the disc diffusion assay, atorvastatin and rosuvastatin produced significantly larger inhibition zones compared to simvastatin at all concentrations tested (p < 0.05). The inhibition zone diameters (mm) increased with higher statin concentrations, ranging from 9 ± 1.4 to 13 ± 1.4 for atorvastatin, 8 ± 0.9 to 11 ± 0.6 for rosuvastatin, and 5 ± 1.3 to 6 ± 1.4 for simvastatin at the highest tested concentration (1200 μg/ml). SEM analysis revealed the characteristic spiral morphology of H. pylori cells. Conclusion. Statins demonstrated varying degrees of antibacterial activity against H. pylori isolates, with atorvastatin exhibiting the highest potency. While the observed effects were lower than those of conventional antibiotics, these findings suggest the potential of statins as adjunctive agents or alternative therapeutic options, warranting further investigation through in vivo studies and clinical trials.

Facile and green synthesis of recyclable, environmentally friendly, chemically stable, and cost-effective magnetic nanohybrid adsorbent for tetracycline adsorption

Antibiotic contamination of water sources, particularly tetracycline (TC) contamination, has emerged as one of the global issues that needs action. In this research, ZnCoFe2O4@Chitosan (Ch) as a magnetic nanohybrid adsorbent was synthesized using the microwave-assisted co-precipitation method, and their efficiency for the TC adsorption process was investigated. FESEM (Field Emission Scanning Electron Microscope), EDX (Energy Dispersive X-ray), Mapping and line Scan, XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Spectrometer), VSM (Vibrating Sample Magnetometer), Thermogravimetric analysis (TGA) and BET (Brunauer Emmett Teller) techniques were used to check and verify its physical and chemical properties. The removal of TC via the adsorption process from synthetic and real wastewater samples was investigated. The factors determining the TC adsorption process, comprising tetracycline concentration (5–30 mg/L), adsorbent dosage (0.7–2 g/L), contact time (2–45 min), and pH (3–11), were evaluated. The removal effectiveness for the synthetic sample and the real wastewater sample was 93 % and 80 %, respectively, under the ideal TC adsorption process parameters of pH 3, adsorbent dosage 1 g/L, TC initial concentration 5 mg/L, and contact time 30 min. According to kinetic and equilibrium studies, the adsorption of TC by ZnCoFe2O4@Ch follows pseudo-second-order kinetics and the Freundlich isotherm. Additionally, it was determined through the analysis of thermodynamic data that the process of exothermic adsorption is spontaneous and is followed by a decrease in disorder (ΔH = −15.16 kJ/mol, ΔS = −28.69 kJ/mol, and ΔG = −6.62 kJ/mol). After five cycles of recovery and regeneration, the ZnCoFe2O4@Ch magnetic nanocomposite was able to remove 65 % of the TC pollutant and had good chemical stability. The results showed that the magnetic nano-adsorbent ZnCoFe2O4@Ch is a novel magnetic nano-adsorbent with high adsorption capacity that can be utilized to eliminate pharmaceutical contaminants from aqueous solutions.

Artificial Neural Network [ANN] modeling for tetracycline adsorption on rice husk using continuous system

In this work, Tetracycline (TC) was dynamically adsorbed from aqueous solution using Raw Rice Husk (RRH). The removal of TC from various aqueous solutions was done continuously using a fixed bed column that was filled with RRH. It was investigated how various flowrates, bed heights, and TC concentrations impact the performance of the adsorption breakthrough. The dynamic TC adsorption process was modeled using an artificial neural network (ANN). Various error analysis techniques, such as the correlation coefficient, mean square error (MSE), and error histogram (R2) for the training, testing, and validation data, were employed to compare the model's predicted data with experimental data. The Artificial Neural Network (ANN) model that was utilized to predict TC adsorption using raw rice husk demonstrated a robust correlation coefficient of 0.999, This shows how well the trained model performed in predicting the TC adsorption process.

A heterogeneously activated peroxymonosulfate with a Co and Cu codoped bimetallic metal-organic framework efficiently degrades tetracycline in water

In the study presented in this paper, a cobalt and copper codoped bimetallic metal-organic framework (CoCu–MOF) was synthesized by a solvothermal method. The CoCu–MOF was then utilized to activate peroxymonosulfate (PMS) to degrade the tetracycline (TC) present in water. When the concentration of organic pollutants was 20 mg/L, the degradation efficiency of TC by the Co1Cu1–MOF/PMS system reached 98.17 % within 30 min, which was better than that of the PMS and Cu-MOF/PMS systems alone. The effects of catalyst addition, PMS usage, initial pH, temperature, coexisting ions and initial TC concentration on the degradation of TC by Co1Cu1–MOF were investigated. The sulfate radical (SO4•−), hydroxyl radical (•OH), superoxide radical (O2•−), and nonradical singlet oxygen (1O2) were identified as the primary reactive species through quenching experiments and electron paramagnetic resonance (EPR) analyses. Moreover, linear sweep voltammetry (LSV) analysis was used to determine the occurrence of an electron transfer-mediated nonradical pathway in the reaction system in addition to 1O2. The concentrations of the TC intermediates were determined using liquid chromatography‒mass spectrometry (LC‒MS), and potential degradation processes were proposed. This study showed that CoCu–MOF is a heterogeneous catalyst that activates PMS for efficient TC degradation.

Orange peel biochar/clay/titania composites: low cost, high performance, and easy-to-reuse photocatalysts for the degradation of tetracycline in water

New orange peel biochar/clay/titania nanocomposites (NCs) were studied for photocatalytic tetracycline (TET) degradation under both UV and natural solar irradiation by variation of NC dose, initial TET concentration, ionic strength,...

A low-cost iron mining residue catalyst employed in antibiotic degradation: Parameter optimization, influence of photogenerated species and the identification of main transformation products

The ubiquitous presence of antibiotics in aquatic ecosystems due to their frequent and indiscriminate use has become a major global health concern, leading to high environmental bacteria and resistance gene development. In this context, this study aimed to evaluate the degradation of three antibiotics, ciprofloxacin (CIP), sulfamethoxazole (SMX) and tetracycline (TET), employing a mining residue as the photocatalyst. The mining residue was characterized by the Brunauer-Emmett-Teller (BET), X ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X ray diffraction (XRD) techniques, and exhibited high iron content (∼70%) predominantly Fe+2. A rotatable central composite design (RCCD) employing catalyst concentrations, H2O2 and pH as variables was applied, resulting in optimal catalyst and H2O2 concentrations of 277.01 mg L−1 and 65.37 mg L−1, respectively, at pH 3.4. These conditions achieved 89% and 83% SMX and CIP degradation rates and the TET concentration at 60 min of treatment was lower than the instrumental LOD, confirming the predominance of catalyst photo-Fenton reactions. When applied to a real effluent sample, 71% and 79% SMX and CIP degradation rates were observed, respectively, while no degradation value changes were noted for TET at 60 min. The main reactive species involved in the antibiotic degradation reactions were HO• for SMX, O2•- and h+ for CIP, and O2•- for TET. In total, 12 antibiotic transformation products (TPs) were identified by LC-QTOF MS. The most frequent TPs observed during antibiotic degradation were formed by hydroxylation, dealkylation, defluorination and hydrolysis of the sulfonamide bond. The investigated mining residue is, therefore, a low-cost and efficient alternative for the photocatalytic degradation of CIP, SMX and TET, contributing to the United Nations Sustainable Development Goals (SDG 6) and follows circular economy principles.