Removal Of Tetracycline Antibiotics Research Articles

Fabrication of zirconium-based metal-organic frameworks@tungsten trioxide (UiO-66-NH2@WO3) heterostructure on carbon cloth for efficient photocatalytic removal of tetracycline antibiotic under visible light

Designing recyclable photocatalysts with high activity and stability has drawn considerable attention in the fields of sewage treatment. Herein, a series of heterojunctions constructed by zirconium-based metal–organic frameworks (UiO-66-NH2) and tungsten trioxide (WO3) is immobilized on carbon cloth via a facile solvothermal method, resulting in highly recyclable photocatalysts. Multiple characterization techniques, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy, verify the successful synthesis of UiO-66-NH2 nanospheres on the surface of needlelike WO3 modified carbon cloth. Results show that the optimal heterojunction photocatalyst exhibits excellent photocatalytic degradation efficiency for the removal of tetracycline (TC) from water, for which nearly 100% of TC is degraded within 60 min under visible light. Trapping experiments and electron spin resonance (ESR) spectra analyses demonstrate that the superoxide radicals O2– and photogenerated hole h+ play a dominant role in the degradation process. Excellent photocatalytic activity is dominantly attributed to the effective separation of photoinduced carriers in this type-Ⅱ heterostructure system. Moreover, the possible photocatalytic oxidation degradation pathway is confirmed by analyzing intermediates using liquid chromatography mass spectrometry (LC-MS). This study offers a highly efficient strategy to design recyclable heterojunction photocatalysts for the degradation of refractory antibiotics in sewage.

Effective removal of tetracycline antibiotics from wastewater using practically applicable iron(III)-loaded cellulose nanofibres.

The non-toxic and completely biodegradable cellulose within bamboo is one of the most abundant agricultural polysaccharide wastes worldwide, and can be processed into cellulose nanofibres (CNFs). Iron(III)-loaded CNFs (Fe(III)@CNFs) derived from bamboo were prepared to improve the adsorption of tetracycline (TC), chlortetracycline (CTC) and oxytetracycline (OTC) from an aqueous solution. The preparation conditions of Fe(III)@CNFs suitable for the simultaneous adsorption of three tetracycline antibiotics (TCs) were investigated. Various analyses proved the abundance of oxygen-containing functional groups and the existence of Fe(III) active metal sites in Fe(III)@CNFs. In batch experiments, Fe(III)@CNFs were applied under a wide pH range and the maximum adsorption capacities were 294.12, 232.56 and 500.00 mg g−1 (for TC, CTC and OTC, respectively). In addition, different concentrations and types of coexisting anions have a weak effect on TCs adsorption. The original TCs adsorption capacities of Fe(III)@CNFs remained stable (greater than 92%) after five cycles when UV + H2O2 was used as the regeneration method. Four adsorption mechanisms (surface complexation, hydrogen bonding, electrostatic interaction and van der Waals force) were obtained for the endothermic adsorption of TCs, among which surface complexation between Fe(III) and TCs always dominates. The practically applicable Fe(III)@CNFs adsorbents are promising for TCs enrichment and remediation in engineering applications.

Reducing tetracycline antibiotics residues in aqueous environments using Tet(X) degrading enzymes expressed in Pichia pastoris

Tetracycline antibiotics (TCs) are massively produced and consumed in various industries resulting in large quantities of residuals in the environment. In this study, to achieve safe and efficient removal of residual TCs, a Pichia pastoris (P. pastoris) was gained to stably express glycosylated TCs degrading enzyme Tet(X) followed codon and expression parameter optimization of tet(X4). As expected, glycosylated Tet(X) still maintains efficient capacity of degrading TCs. The expressed Tet(X) maintained efficient TCs degrading ability over a pH range of 6.5 – 9.5 and temperature range of 17 – 47 °C. We tested this recombinant protein for its ability to degrade tetracycline in pond water and sewage models of tetracycline removal at starting levels of 10 mg/L substrate. 80.5 ± 3.8% and 26.2 ± 2.6% of tetracycline was degraded within 15 min in the presence of 0.2 μM Tet(X) and 50 μM NADPH, respectively. More importantly, the direct use of a Tet(X) degrading enzymes reduces the risk of gene transmission during degradation. Thus, the Tet(X) degrading enzyme expressed by P. pastoris is an effective and safe method for treating intractable TCs residues.

An Eu-doped Zr-metal-organic framework for simultaneous detection and removal of antibiotic tetracycline

Due to the widespread use of tetracycline (TC), there is an increasing demand for rapid detection as well as effective removal of residual tetracycline for environment and food safety. Herein, we report an Eu/Zr-MOF material that combines the high adsorption performance of water-stable Zr-MOF and the unique emission characteristics of Eu3+, which enables both sensing and adsorption functions for TC. Eu/Zr-MOF can be achieved facilely by doping Eu3+ into Zr-MOF via the traditional hydrothermal method. In aqueous medium, the Eu3+ preferentially coordinate with TC molecules, which in turn acts as an antenna for UV–Vis absorbance to enhance the characteristic fluorescence of Eu3+. In such way, TC can be specifically detected in a wide dynamic range (0.001–0.5 µg/mL) with a low detection limit (0.00092 µg/mL). Moreover, by taking advantage of the unsaturated character of ZrO centers, the Eu/Zr-MOF has a TC loading capacity as high as 289 mg g-1. As a consequence, based on the Eu/Zr-MOF, rapid detection and efficient removal of TC from food and environment was realized at once. The principle of design proposed in this work may find more applications to synthesize new platforms for simultaneous sensing and removal of specific pollutants.

Adsorption of Tetracycline Antibiotic from Aqueous solutions using Natural Iraqi Bentonite

Natural Iraqi bentonite was employed in this study as inexpensive adsorbent for the removal of Tetracycline antibiotic from aqueous solutions. The removal of about 90% of the Tetracycline was achieved under the optimum adsorption conditions of 2 h equilibrium time, 0.2 g bentonite dose, 20 mg/L initial Tetracycline concentration, and at a pH between 6 and 7. The thermodynamic investigation was carried out at various temperatures ranging between 20-40 °C. The resulted thermodynamic parameters emphasize a decrease of the randomness, an exothermic, and a spontaneous nature of the adsorption process arising from the negative values of the entropy change, the enthalpy change, and the Gibbs free energy change, respectively. The kinetic studies showed that the pseudo-second order model could fulfill a better fit of the experimental data, and more than one process would influenced the diffusion of tetracycline from the solution into the bentonite. The Isotherm studies reveals that Langmuir model provided a best fit to the isotherm curve, with a maximum adsorption capacity of 23.69 mg g-1. The results suggest that Natural Iraqi bentonite can be used as a cost-effective adsorbent for the removal of Tetracycline from aqueous mediums.

A mild and one-pot method to activate lignin-derived biomass by using boric acid for aqueous tetracycline antibiotics removal in water

A mild and one-pot activation approach of activated carbon was found. The feasibility of boric acid as the activated reagent which was used for the adsorption of four tetracyclines antibiotics (TCs) in water. Boric acid activated carbon (BAC) from bioresource has a much higher removal efficiency than currently reported biochar. The maximum adsorption capacity of BAC is 173.9 mg/g for TCs. BAC is an ecofriendly, nontoxic, and low-cost absorbent from sawdust waste. BAC and TCs could keep coalescing at least 55 days on the surface without stable release. BAC was fully characterized by using scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Raman, zeta potential, and Brunauer–Emmett–Teller analysis; the large surface area and rich pore structure were proved. The interaction between BAC and TCs are hydrogen bond interaction, π-π interaction, and electrostatic interaction. These interactions are also related to the surface charge of BAC and the TCs’ species of ions in different pH. Furthermore, the adsorption kinetics and adsorption isotherm of BAC were studied thoroughly. The pseudo-first-order, pseudo-second-order, intra-particle diffusion, Elovich Langmuir, Freundlich, and Dubinin–Radushkevich models were fitted and the physical adsorption process was proved. After the study on adsorption thermodynamics, adsorption exhibits a spontaneous and favorable process.

Adaption strategy of up-flow anaerobic sludge blanket reactor on tetracycline stress during tetracycline antibiotic wastewater treatment

Tetracycline antibiotic wastewater with high chemical oxygen demand (COD) concentration and containing bio-refractory compounds was investigated in a lab-scale up-flow anaerobic sludge blanket (UASB) and anoxic-oxic (A/O) reactor. Specific methanogenic activity (SMA) was determined to reveal the inhibition levels of methane production and volatile fatty acid (VFA) accumulation. The results showed that microorganisms can adapt to tetracycline or oxytetracycline when the concentration of antibiotics is less than 400 mg/L. Acetic acid, propanoic acid, and n-butyric acid accounted for more than 90% of VFA with increasing antibiotic concentration from 50 mg/L to 600 mg/L. During the 215 d of operation, the concentration of tetracycline antibiotic increased from 0 to 95 mg/L, and the COD concentration from 3,500 to 6,500 mg/L. The average COD and tetracycline antibiotic removal rates of the reactors were maintained above 90%. The methane production of the UASB reactor achieved 0.32 L/g COD. VFA accumulation was observed when tetracycline antibiotic concentration increased to 47.5 mg/L. The sludge granule diameter increased from 0–300 μm to 300–1,500 μm during the operation. Rod-shaped and coccus-shaped organisms with pores and internal channels on the granule surface were observed using scanning electron microscopy. In the internal space, methanogenic filamentous bacteria constitute a rock-steady structure.

Removal of Tetracycline Antibiotic from Wastewater by Fenton Oxidation Process

This study aimed to remove the antibiotic tetracycline from a sample of synthetic wastewater using an advanced oxidation process by Fenton's reagent treatment. Central Composite Design (CCD) software was used to reduce the number of tests required to remove tetracycline. The independent variables identified in batch oxidation experiments are the concentrations of tetracycline (40–250 mg / L), hydrogen peroxide (20–600 mg / L), and Fe(II) (0–60 mg / L). The rate of tetracycline degradation was significantly influenced by the concentration of hydrogen peroxide and tetracycline. The reaction time required for tetracycline removal was determined to be 15 minutes. The optimal ratio of independent variants leading to complete degradation 100% of tetracycline was hydrogen peroxide / Fe2 + / tetracycline 310/30/145 mg / l.

Fabrication of BiOBr/MoS2/graphene oxide composites for efficient adsorption and photocatalytic removal of tetracycline antibiotics

Bismuth oxybromide/molybdenum disulfide/graphene oxide (BiOBr/MoS2/GO) heterojunction composites were fabricated to modulate the adsorption ability and photocatalytic degradation performance toward oxytetracycline (OTC). The flowerlike BiOBr/MoS2/GO composites demonstrated excellent photocatalytic activies for the OTC degradation. Specifically, OTC, tetracycline, chlorotetracycline, and doxycycline were simultaneously removed with degradation rates higher than 98% under visible light irradiation within 40 min. Radical trapping experiments indicated that photogenerated holes (h+), hydroxyl radicals (OH), and superoxide radicals (O2−) played crucial roles in photocatalytic OTC degradation. Further, Possible transformation pathway and photocatalytic mechanism were proposed by investigating the intermediates in OTC degradation process.

Computational and experimental assessment of pH and specific ions on the solute solvent interactions of clay-biochar composites towards tetracycline adsorption: Implications on wastewater treatment

Experimental and computational investigations have been conducted in this study to assess the influence of municipal waste pyrolyzed biochar impregnated clay composites on antibiotic removal as a material for wastewater treatment and simultaneous value-addition for waste. The surface potential (zeta potential) of the pristine biochar and composite samples are found to be within the range ~10 to ~ −40 mV in the pH range 2–10. The presence of different inorganic salt solutions influences the electrophoretic mobility of the dispersed phase in a suspension, as well as its zeta potential. In addition of Na+ salt solutions, the Na+ ions undergo electrostatic interaction with the negatively charged biochar samples and form a double layer at the interface of biochar and ionic salt solution. Molecular dynamics simulations have been employed to understand experimental findings, ions adsorption and solute-solvent interactions at the molecular level of two biochar B7 (seven benzene rings, one methoxy, one aldehyde and two hydroxyls groups) and B17 (seventeen benzene rings, one methoxy, two hydroxyls and two carboxylic acid groups) in salts aqueous solutions. The results confirm that hydroxyls and carboxylate groups of biochar are responsible for solute-solvent interactions. Successful removal of tetracycline antibiotics is observed with 26 mg/g maximum adsorption capacity with montmorillonite biochar composite. This study confirms that interactions between amide and hydroxyl groups of tetracycline with hydroxyl and carboxylate groups of biochar play the key role in the adsorption process. The solution pH and presence of different background electrolytes effectively influence the process of solute-solvent interactions as well as adsorption efficacy towards tetracycline adsorption.

A hybrid sorbent of α-iron oxide/reduced graphene oxide: Studies for adsorptive removal of tetracycline antibiotics

Tetracyclines antibiotics (TAs), a veterinary drug used widely, has greatly attracted the attention due to its potential threats. We report the nanocomposites of the α-Fe2O3 nanoparticles growth on reduced graphene oxide (RGO) by a one-pot method. The adsorptive amounts (216.2 mg g−1 for chlortetracycline, 180.8 mg g−1 for tetracycline and 98.4 mg g−1 for oxytetracycline) of the α-Fe2O3 @RGO nanocomposites was mainly correlated with the increasement of the uniform and well-dispersed α-Fe2O3 nanoparticles on RGO. The relatively low adsorptive amount of oxytetracycline is due to the synergetic effect of its relatively weak interactions with RGO and relatively slack complexation with α-Fe2O3, which also provides an experimental proof for the theoretical prediction previously reported. The TAs adsorption by the α-Fe2O3 @RGO nanocomposites is achieved for 20 min and strongly pH-dependent due to the enhanced repulsive interaction at low or high pH. The TAs adsorptions fitted well the Langmuir and the pseudo-second-order equations.

Investigating the removal of tetracycline antibiotic from aqueous solution using synthesized Fe3O4@Cuttlebone magnetic nanocomposite

Investigating the removal of tetracycline antibiotic from aqueous solution using synthesized Fe3O4@Cuttlebone magnetic nanocomposite

Study on the remediation of tetracycline antibiotics and roxarsone contaminated soil.

Antibiotics are commonly used in livestock and poultry breeding along with organic arsenic. Through long-term accumulation, they can enter into the surrounding soil through various pathways and contaminate the soil. In this paper, tetracycline antibiotics (TCs) and roxarsone (ROX) contaminated soil were used as the representatives of the two kinds of veterinary drugs contaminated soil, respectively, to study the thermal desorption behavior and arsenic stabilization process. Different parameters like heating temperatures, heat duration, stabilizer type and dosage were optimized for effective removal of TCs and ROX. Furthermore, TCs and ROX removal path and ROX stabilization mechanism were explored. Results of the study showed that over 98% of tetracycline antibiotics and roxarsone were effectively removed at 300°C for 60min. The heat treatment process of TCs contaminated soil was controlled by the first-order kinetics. Based on the detection of degradation products and thermogravimetric analysis, the possible thermal degradation path of TCs and ROX was proposed. Addition of FeSO4.7H2O (10% by weight) as stabilizer during the heat treatment process yielded 96.7% stabilization rate. Through the analysis of arsenic fractions, valence and the characterization of soil samples collected after the heat treatment, mechanism of arsenic stabilization in ROX was explored. The results show that thermal treatment combined with chemical stabilization technology can not only degrade TCs and ROX efficiently and completely, but also convert organic arsenic into inorganic state, which is conducive to better stabilization, and finally achieve effective and safe remediation of this kind of contaminated soil.

Differences in Tetracycline Antibiotic Resistance Genes and Microbial Community Structure During Aerobic Composting and Anaerobic Digestion.

Antibiotics are widely added to swine forage and are the main reason for the environmental accumulation of antibiotic resistance genes (ARGs) in swine manure-dwelling microorganisms. Aerobic composting (AC) and anaerobic digestion (AD) are efficient methods for converting swine manure to bio-fertilizer while degrading residual antibiotics. However, the influence of these methods on ARG accumulation and the difference in their efficiency have rarely been investigated. In this study, we explored the variations in four tetracycline antibiotics (TCs) and their associated ARGs and in microbial communities after AC and AD treatment. After full-scale manure AC and AD, the four TCs were removed effectively. AD had a higher TC removal efficiency than AC and a slower rate of TC-associated ARG accumulation. In addition, the community structure was more stable in the AC and AD manures than in untreated manure, and the relationship among microbial species also evolved into competition from mutualism after both AC and AD treatment. It was also speculated that the genera Acholeplasma and Arthrobacter were the possible hosts of tetO, tetW, and tetQ; the shift in the prokaryotic community composition and the alleviation of selective pressure by TC degradation led to decreased relative abundance of ARGs in AD- and AC-treated manure.

AgO/MgO/FeO@Si3N4 nanocomposite with robust adsorption capacity for tetracycline antibiotic removal from aqueous system

Present study has been designed to govern the usage of nanocomposite of Si3N4 with trimetallic oxide nanoparticles of Ag, Mg and Fe (AgO/MgO/FeO@Si3N4) for the tetracycline (TC) removal from aqueous solution. Characterization techniques such as SEM, TEM, XRD, FTIR, XPS and BET were employed for analysing the successful fabrication of AgO/MgO/FeO@Si3N4 nanocomposite. Adsorption process has been found to be dependent upon the surface properties of AgO/MgO/FeO@Si3N4 nanocomposite (such as charge, functionality, etc), concentration of TC, solution pH and contact time. As determined from the isotherm studies, surface of AgO/MgO/FeO@Si3N4 nanocomposite has been found to be energetically heterogeneous in nature as the data fitted well to Freundlich isotherm. Maximum adsorption capacity of AgO/MgO/FeO@Si3N4 nanocomposite has been found to be 172.41 mg/g. Pseudo-second order kinetic model successfully explained the rate studies of TC adsorption. Also, reusability study of AgO/MgO/FeO@Si3N4 nanocomposite has also been carried out. In short, the present study could determine an effective way for the removal of toxic pollutants from the wastewater system.

Copper carboxymethyl cellulose nanoparticles for efficient removal of tetracycline antibiotics in water.

Copper carboxymethyl cellulose nanoparticles were prepared and characterized by FT-IR, XRD, SEM, TEM, and EDX techniques. Removal of tetracycline was obtained at 90% with optimized parameters of 500μg/L concentration, 40min contact time, 7.5 pH, 1.5g/L dose, and 298 K temp. The adsorption followed Freundlich model very well in comparison to Langmuir. Tempkin model described good interactions between tetracycline and nanoparticles. Dubinin-Radushkevich isotherm confirmed the chemical nature of adsorption. The adsorption was pseudo-second order with a liquid film diffusion kinetics mechanism. The adsorption was endothermic and spontaneous as suggested by thermodynamics results. The supramolecular mechanism was developed for the process. Interestingly, the process was suitable at 7.5 pH with low contact time. These features of the adsorption made this process applicable at natural water conditions, making the process eco-friendly and feasible. Therefore, it may be an excellent method for the removal of tetracycline in any water system.

Removal of antibiotic tetracycline by metal-organic framework MIL-101(Cr) loaded nano zero-valent iron

Nano zero-valent iron (nZVI) is a highly reactive particle but easily to be aggregated. Porous materials support can improve the stability of nZVI. Materials of Institute Lavoisier Frameworks (MILs), a type of metal-organic frameworks (MOFs), have enormous surface areas, ultrahigh porosity, and good water stability. The combination between MILs and nZVI can provide an intensively “capture & destroy” effect to micro-pollutants in water. In this study, a novel composite, nZVI modified MIL-101(Cr), was prepared, characterized, and applied for tetracycline (TC) adsorption and degradation. The surface morphology and micropore structure of nZVI/MIL-101(Cr) were characterized. The TC adsorption performance of the composite was investigated via various parameters, adsorption kinetics, isotherms, and thermodynamics. Results showed that the TC adsorption followed pseudo-second-order kinetic equation and the maximum adsorption quantity (qm) was 625.0 mg/g. The catalytic property of nZVI/MIL-101(Cr) was also investigated via heterogeneous Fenton-like process, and nZVI/MIL-101(Cr) showed 90% TC removal efficiency in a wide pH range. Moreover, nZVI/MIL-101(Cr) displayed good stability and reusability. The developed composite is a potential adsorbent and heterogeneous catalyst for antibiotics pollution control in water.

Green synthesized Fe/Pd and in-situ Bentonite-Fe/Pd composite for efficient tetracycline removal

The residual TC in the aquatic system is a major threat to human and animal lives. In this study, green synthesized bimetallic Fe/Pd and in-situ clay supported Fe/Pd was used for the efficient removal of tetracycline antibiotics from the aqueous system. Green synthesized bimetallic Fe/Pd nanocomposite and in-situ clay supported Fe/Pd (B-Fe/Pd) were characterized by SEM-EDX, FTIR, and XRD to confirm their size and surface functional groups. The batch removal processes were performed to examine the effect of operational parameters such as dopant Pd concentration (5−20 mM), sorbents: Fe/Pd (100−1000 mg/L) and B-Fe/Pd (100−300 mg/L), pollutant TC (20−60 mg/L) and pH (3–9) on the TC removal. At the optimized conditions, Fe/Pd (sorbent dosage 1000 mg/L, pH 7, TC conc. 20 mg/L), and B-Fe/Pd (sorbent dosage 300 mg/L, pH 7, TC conc. 20 mg/L) nanocomposite can remove 81 % and 97 % of TC from aqueous sample. Higher surface area and prolonged shelf-life of B-Fe/Pd with highest removal percentage make it more effective and efficient material for TC removal; further, the statistical optimization of TC removal by B-Fe/Pd was carried out by response surface methodology, and 95 % of TC could be eliminated from the aqueous solution. Reusability studies of B-Fe/Pd showed that the TC removal efficiency up to 3rd cycle with above 60 % TC removal and the validation on real water sample confirmed with above 75 % TC removal. Residual toxicity of B-Fe/Pd interacted TC solution on freshwater chlorella sp. showed less toxicity, which indicates the environmentally friendly and hazardous free nature of B-Fe/Pd.

Recycling of Fenton sludge containing Ni as an efficient catalyst for tetracycline degradation through peroxymonosulfate activation

Fe sludge containing heavy metal Ni was used as a catalyst to activate potassium peroxymonosulfate (PMS) after thermal treatment. The crystal structures of recycled Fe sludge samples occur in the form of α-Fe2O3 and γ-Fe2O3. The existence of Ni had minimal effect on the crystal structure, but it changed the surface morphology and the internal chemical bond. X-ray photoelectron spectroscopy result proved that Ni existed as Fe–O–Ni. Influencing factors, such as the Ni content, PMS dosage, pH level, and the structural characteristics of the recycled products were explored. All the recycled Fe sludge products with and without Ni possessed catalytic activity in the removal of antibiotic tetracycline from the water for PMS activation. The optimal application conditions and possible mechanisms were proposed in accordance with the physicochemical properties of recycled products and the experimental results. Electron spin resonance spectra showed that Ni-containing Fe sludge could activate more OH· and SO4·− than the product without Ni. OH· and SO4·− are probably the critical free radicals in tetracycline degradation, but Ni did not significantly affect the catalytic degradation of tetracycline. Based on the findings of this study, the new idea and direction for the utilization of Fenton sludge can provide reference for heavy metal sludge recycling.

Nanocomposites of zero-valent Iron@Activated carbon derived from corn stalk for adsorptive removal of tetracycline antibiotics

The hybrid nanocomposites of zero-valent iron loaded the activated carbon derived from the corn stalk (ZVI@ACCS) was prepared and used to remove the antibiotics of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) from aqueous solution. The adsorption amounts of three antibiotics (103.1 mg g−1 for CTC, 72.9 mg g−1 for OTC and 81.5 mg g−1 for TC) were sensitive to the temperature and independent of pH in the range of 4.2–7.1 at 298 K through the synergistic interactions of the electrostatic attraction, the bridging complexation and the surface complexation. The equilibrium was performed within 20 min at 298 K. The spontaneous (ΔGo<0) and endothermic (ΔHo>0) adsorption of three antibiotics onto the ZVI@ACCS nanocomposites gave a better matching (r2 > 0.99) with Langmuir and pseudo-second-order models.