Tetracycline Hydrochloride Solution Research Articles

Hollow TiO2/Bi2MoO6 Janus-nanofibers for photo-reforming of antibiotics into carbon monoxide

Photo-reforming is an environmentally friendly technology for converting organic wastewater into carbon monoxide (CO), a potential energy source and an important industrial material. Achieving efficient photo-reforming of CO production remains a challenge due to the limitation on fast photogenerated carrier recombination. Here, the TiO2/Bi2MoO6 hetero-nanofibers are well-designed to possess unique Janus interface and ingenious hollow structure. The photo-deposition experiments demonstrated that the Janus binary interface can realize the directional migration of interfacial charges and the spatial separation of redox sites. Moreover, the hollow framework allows full exposure of the bicomponent to reactants and provides excellent optical absorption through multiple light scattering inside the tube, as evidenced by theoretical simulations via COMSOL Multiphysics. The photo-reforming yield of CO from 6000 ppm tetracycline hydrochloride (TCH) solution reaches 2.69 μmol∙g−1∙h−1 (corresponding degradation rate of 44.55 % after 5 h), about 1.44-fold superior to that of the TiO2/Bi2MoO6 core-shell hetero-nanofibers. 13C isotope tracing experiments showed that the efficiency of CO production in the photocatalytic TCH oxidation process is superior to that in carbon dioxide reduction process. Furthermore, when oxygen was introduced into the photocatalytic system, the photo-reforming CO yield from the TCH solution was significantly increased to 60.45 μmol∙g−1∙h−1, which was 22.47 and 5.12 times higher than in carbon dioxide and air atmosphere, respectively. This work provides a promising interfacial engineering to design efficient photo-reforming catalysts for energy production and environmental remediation.

Designing Zn-MOF/AgCl composites for the photocatalytic degradation of rhodamine B dye and tetracycline antibiotic

The agglomeration tendency of AgCl, as a photocatalyst, hampers its advancement and practical application. In this paper, a simple composite method is designed based on the precipitation characteristics of AgCl. Ag+ ions introduced from outside combines with Cl− anions in complex [Zn(L)Cl]n (M1) [L = 2-(1-(carboxymethyl)-1H-benzo [d] imidazol-3-ium-3-yl)acetate)] to directly form Zn-MOF/AgCl composites (ZA-x, x = 0.5, 1 and 2), which may effectively prevent agglomeration of AgCl. The morphology and structure analysis displays a remarkable dispersity of AgCl. Further characterization and analysis of PL, UV–Vis, EIS, and TPC reveal that the composites have potential as excellent photocatalysts. The subsequent visible light catalytic degradation of Rhodamine B (RhB) and tetracycline hydrochloride (TC) has shown that the optimal composite ZA-0.5 with M1 to AgCl ratio of 1:0.5 exhibits the highest degradation efficiency in the 20 mg/L solution of RhB or TC, achieving 99.1 % for RhB within 20 min and 81.9 % for TC within 50 min. The free radical trapping test shows that ⋅O2− is the main catalytic species in the degradation process. In addition, the possible degradation mechanism was analyzed by VB-XPS and LC-MS. In a word, the in-situ combination of Cl− in M1 with Ag+ improves the dispersity of AgCl, enhances the interaction between M1 and AgCl, and leads to the effetive separation of electrons and holes, therefore improving the photocatalytic performance.

Boosting solar-light photocatalytic activity of Ni2P-decorated ZnCr2O4 nanofibers for H2 evolution and tetracycline elimination

Photocatalysis is a promising route to convert solar light into chemical energy for H2 evolution and pollutants degradation. Hence, Ni2P decorated ZnCr2O4 (Ni2P/ZnCr2O4) nanofibers were prepared for boosting solar-light induced water splitting and tetracycline hydrochloride (TCH) degradation. For comparison to ZnCr2O4 nanofibers, Ni2P/ZnCr2O4 composites exhibited the better photocatalytic activities for water splitting and TCH removal. Owing to the co-catalytic effect of Ni2P for the efficient photon capture, the charge carriers were rapidly separated and migrated at the interface between Ni2P and oxygen-defected ZnCr2O4. H2 evolution rate of optimal C–Ni2P/ZnCr2O4 with a nominal Ni2P content of 9.0 wt% was 575.89 μmol g−1 h−1, and its apparent quantum yield at 420 nm was 15.25 %, while its H2 evolution decreased from 2815.13 to 2602.51 μmol g−1 after fifth cycle. In addition, the removal efficiency of C–Ni2P/ZnCr2O4 was 93.68 % within 90 min, and declined to 88.76 % after five cycles for solar-light driven degradation of 50 mg L−1 TCH solution. The deactivation of C–Ni2P/ZnCr2O4 was due to the photo-corrosion for the change in valence states of compositions.

Insights into the solar-light activated adsorption-photocatalysis of ZnLaxBi2−xO4 heterojunctions for tetracycline hydrochloride removal

Metal oxides-based heterojunction fabrication is a promising strategy to eliminate antibiotics from wastewater via adsorption-photocatalysis. ZnLaxBi2−xO4 hybrids with various La/Bi molar ratios were fabricated for enhancing the adsorption-photocatalytic elimination of tetracycline hydrochloride (TCH). Oxygen-defected ZnLaxBi2−xO4 composites provided the sufficient sites for photon capture and pollutants adsorption. In addition, the tight p-n-p type interface among oxygen-defected La2O3, ZnO, and spinel ZnBi2O4 favored the rapid transfer and migration of photo-excited e-/h+ pairs, enlarging the visible light utilization. Hence, ZnLaxBi2−xO4 samples had the better adsorption-photocatalytic activity than ZnLa2O4 and ZnBi2O4 for TCH removal. Langmuir and second-order models well described the adsorption isotherms and kinetics of ZnLaxBi2−xO4 samples, respectively. The adsorption capacity of optimal ZnLa1.75Bi0.25O4 with a La/Bi molar ratio of 7:1 was 406.85 mg g−1, and its removal efficiency of 210 mg L−1 TCH solution was 98.04 % within 150 min. The change in valence states of surface compositions induced to the declined removal efficiency of ZnLa1.75Bi0.25O4 to 91.95 % after five cycle times.

Nonthermal plasma induced NiS/UiO-66-NH2 for boosting visible-light photo-Fenton degradation of tetracycline hydrochloride

Heterojunctions constructed from metal organic frameworks (MOF) and metal sulfides are the potential candidates for solar-light driven photo-Fenton elimination of antibiotics from wastewater. To boost the solar-light induced photo-Fenton degradation of tetracycline hydrochloride (TCH) over UiO-66, NH2-functionlized UiO-66 (UiO-66-NH2) was in-situ loaded with NiS (NiS/NU-66) via the nonthermal plasma sulfurization. For comparison to UiO-66-NH2, NiS/NU-66 had the lower adsorption capacity while the higher photo-Fenton activity for TCH removal. The removal efficiency of NiS/NU-66 climbed and then declined with an increase in NiS content, and the best removal efficiency (84.92 ± 2.55 %) for 110 mg L−1 TCH solution was obtained by c-NiS/NU-66 in 150 min. The sulfur and oxygen defects as well as the plentiful functional groups over NiS/NU-66 were favorable for providing the abundant vacant sites of TCH adsorption and photons capture. In addition, the rapid separation and migration of photo-generated e−/h+ pairs were achieved at the tight junction interface between NiS and UiO-66-NH2, enlarging the visible-light absorption capacity. In NiS/NU-66-assisted photocatalytic system, H2O2 was efficiently convert to •OH by e− and Ni2+/Ni3+ couples in solar light region. Hence, •OH, •O2− and h+ played the vital roles in this photo-Fenton system.

Phospholipid composition of bile and blood in rats under correction of experimental fatty hepatosis

To date, the aetiology and molecular mechanisms of the development of fatty hepatosis, which is quite common in mammals, have not yet been sufficiently explained. This pathology requires detailed study not only because of functional disorders of the liver and biliary system, but also because of the high probability of dangerous complications – fibrosis, cirrhosis, or hepatocellular carcinoma. The purpose of this study was to determine marker changes in the phospholipid composition of bile and blood in rats with experimental fatty hepatosis and with the use of corrective therapy. Hepatopathology was modelled in Wistar laboratory rats by intragastric administration of a 4% solution of tetracycline hydrochloride at the rate of 0.25 g/kg body weight for seven days. Using the method of thin-layer chromatography, the phospholipid components of animal bile and blood were studied. It was found that during experimental fatty hepatosis in rats, there was a decrease in the total phospholipid content in bile, mainly due to a decrease in the level of phosphatidylcholine (by 22.4-27.0%), the total fraction of inositol phosphatide and phosphatidylinositol (by 20.0-27.3%), and phosphatidylethanolamine (by 17.5-25.2%). Conversely, the introduction of milk phospholipids in the form of a dietary supplement “FLP-MD” in sick animals contributed to an increase in bile levels of phosphatidylserine by 67.1-99.8%, inositol phosphatide and phosphatidylinositol by 48.6-57.6%, phosphatidylcholine by 38.8-60.2%, phosphatidylethanolamine by 45.6-57.4%, and sphingomyelin by 30.4-46.3%. In the blood of such rats, a significant decrease in the content of phosphatidylcholine, phosphatidylserine, and sphingomyelin was found, which was not observed after administration of the “FLP-MD” dietary supplement to sick animals. In the case of using the supplement in healthy animals, only a 29.3% increase in the blood content of inositol phosphatide and phosphatidylinositol was noted. The determination of the most sensitive indicators in the phospholipid spectrum of blood and bile reveals the features of changes in molecular processes for the development of fatty hepatosis in animals, and also contributes to preclinical tests of the corrective effectiveness of newly created drugs according to established markers

Construction of petal-like MOF-derived C-TiO2/Caln2S4 with S-scheme heterojunction for boosted photocatalytic of antibiotics and organic pollutants

From the perspective of environmental protection, the highly efficient degradation of antibiotics and organic dyes in wastewater need to be tackled as soon as possible. Fortunately, the utilization of semiconductor photocatalysts with the Step-like scheme heterojunction (S-scheme) for their degradation has been currently considered as a very effective approach. In this paper, a novel S-scheme MOF-derived C-TiO2/Caln2S4 composites were synthesized to degrade antibiotics and organic pollutions. The FESEM and HRTEM images of as-fabricated samples indicated that the C-TiO2 nanoparticles were intimately grown on Caln2S4 surface and the morphology of C-TiO2/Caln2S4 exhibited petal-like structure. The experimental characterizations and density functional theory (DFT) calculation were utilized to expound the existence of S-scheme heterojunction. Additionally, the degradation rates of tetracycline hydrochloride (TC) and rhodamine B (RhB) solution catalyzed by 40 wt% C-TiO2/Caln2S4 (40 wt% TCLS) under 300 W Xenon lamp irradiation ran up to 83.4% and 95.1%, respectively. Moreover, the mineralizations of TC and RhB solutions were proved via total organic carbon (TOC) tests. The possible degradation pathway of TC was also conjectured via liquid chromatograph mass spectrometer (HPLC-MS). Response surface methodology (RSM) was applied to analyze the degradation condition of RhB over 40 wt% TCLS. Once more, the toxicity of TC and RhB solution catalyzed by 40 wt% TCLS were also assessed via biotoxicity tests. This work provides a new way for preparing novel S-scheme heterojunction photocatalysts to solve environmental pollution in the future.

Synthesis of type II heterojunction 2D/3D Bi2S3/MIL-88(A) with enhanced photocatalytic activity under visible-light irradiation

The aim of this article is to provide an effective catalyst for using photocatalytic technology to solve the antibiotic pollution. For this purpose, Bi2S3 was loaded on the surface of MIL-88 (A) to prepare rod-shaped composite photocatalyst via a combination of low-temperature hydrothermal and low-temperature water bath methods. The prepared composite photocatalysts were characterized by using SEM, EDS, XRD, FT-IR, UV–vis and XPS. Tetracycline hydrochloride (TC) degradation under visible light was used to gauge the photocatalytic activity of the composite as it was created. The results show that the degradation efficiency of the optimum sample Bi2S3/MIL-88 (A)-0.2 to TC within 120 min in a 10 mg/L TC solution is as high as 93%, which is 5.74 and 4.39 times as high as that of pure MIL-88 (A) and Bi2S3, respectively. The increased photocatalytic activity is ascribed to the type II heterojunctions that develop between Bi2S3 and MIL-88 (A), which contribute to increase the composite's specific surface area and separation efficiency of photogenerated carriers. Additionally, the possible photocatalytic mechanism of the composite photocatalyst is explored in detail by active species capture experiments, transient photovoltage electrochemical impedance spectroscopy and photoluminescence measurements. This research provides a new way to prepare MIL-88 (A)-based type II heterojunction photocatalysts.

Chitosan -based nanoniosome for potential wound healing applications: Synergy of controlled drug release and antibacterial activity

This study aims to develop a niosomal platform which can delivery drugs such as tetracycline hydrochloride (TCH) to treat bacterial infections in wounds. To this end, chitosan (CS) was used to obtain a controlled drug release and at the same time antibacterial activity. By design of experiments the niosome encapsulated TCH (TCH-Nio) were optimized for their particle size and encapsulation efficiency, followed by analysis of the release profile of TCH and stability of TCH-Nio and TCH-Nio@CS. The antibacterial activity and cytotoxicity of the fabricated nanoparticles were investigated as well. The release rate of TCH from TCH-Nio@CS in all conditions is less than TCH-Nio. In addition, higher temperature increases the release rate of drug from these formulations. The size, polydispersity index, and encapsulation efficacy of TCH-Nio and TCH-Nio@CS were more stable in 4 °C compared to 25 °C. TCH, TCH-Nio, and TCH-Nio@CS had MIC values of 7.82, 3.91, and 1.95 μg/mL for Escherichia coli, 3.91, 1.95, and 0.98 μg/mL for Pseudomonas aeruginosa, and 1.96, 0.98, and 0.49 μg/mL for Staphylococcus aureus, respectively. Coating of chitosan on niosome encapsulated TCH (TCH-Nio@CS) led to a reduced burst release of TCH from niosome (TCH-Nio), and enabled 2-fold higher antibacterial and anti-biofilm activity against the tested bacterial pathogens E. coli, P. aeruginosa and S. aureus, compared to the uncoated TCH-Nio, and 4-folder higher than the TCH solution, suggesting the synergetic effect of niosome encapsulation and chitosan coating. Moreover, the formulated niosomes displayed no in vitro toxicity toward the human foreskin fibroblast cells (HFF). Both TCH-Nio and TCH-Nio@CS were found to down-regulate the expression of certain biofilm genes, i.e., csgA, ndvB, and icaA in the tested bacteria, which might partially explain the improved antibacterial activity compared to TCH. The obtained results demonstrated that TCH-Nio@CS is capable of controlled drug release, leading to high antibacterial efficacy. The established platform of TCH-Nio@CS enlighten a clinic potential toward the treatment of bacterial infections in skin wounds, dental implants and urinary catheter.

Preparation of reusable UHMWPE/TiO2 photocatalytic microporous membrane reactors for efficient degradation of organic pollutants in water

A photocatalytic membrane reactor is an effective method to degrade organic pollutants in water and air. This method has many advantages, such as a complete degradation of organic pollutants, no secondary pollution to the environment, environmental protection, and high efficiency. Thus, how to efficiently manufacture membrane reactors with high catalytic efficiency is essential. In this study, ultra-high molecular weight polyethylene (UHMWPE)/inorganic particle photocatalytic microporous membrane reactors with high porosity and high loading capacity were prepared using a melt-blending method. In the preparation process, UHMWPE, liquid paraffin (LP), and nanoparticles, which acted as a binder, porogen, and photocatalyst, respectively, were completely dispersed and mixed in a self-developed pulsating tensile stress mixer. Then, the LP was extracted to obtain a microporous membrane reactor with high porosity and high loading of inorganic particles. This reactor had the advantages of excellent catalytic efficiency, industrial manufacture and application, recyclable and reusable, and environmental protection. In this study, inorganic titanium dioxide (TiO2) nanoparticles were used as photocatalysts to prepare the microporous membrane reactor. The effects of the ratios of UHMWPE to LP, the contents and sizes of inorganic particles, the thickness of the membrane, and biaxial tension treatment on the structure of the membrane reactors and the catalytic efficiency of organic dyes and hormone pollutants in water were studied. Results showed that the photocatalytic microporous membrane reactor with 75% porosity and 80 wt% of TiO2 had the best photocatalytic performance. Under ultraviolet photocatalysis, the degradation rate of the 20-mg/L methyl orange solution reached 98.5% within 60 min. Moreover, the degradation rate of the methylene blue solution reached 98.4% within 60 min, and that of the 20-mg/L Congo red solution reached 100% within 40 min. Furthermore, the degradation rate of the 50-mg/L tetracycline hydrochloride solution exceeded 96.6% within 80 min.

Supramolecular enzymatic membranes comprising of β-cyclodextrin and laccase for efficient removal and desalination of small molecules

Nanofiltration (NF) is regarded as a great potential technique for efficient treatment of industrial dyes and pharmaceutical effluents, however, its application still faces the challenges due to the trade-off among permeance, selectivity and anti-fouling property. Herein, a novel supramolecular enzymatic membrane was designed and successfully fabricated based on β-cyclodextrin (CD) and laccase (Lac), with the former providing supramolecular transport channels and the latter offering the pollutant degradation property. Specifically, after the host-guest complexation of CD with polyethylene glycol (PEG), the generated CD@PEG supramolecules were introduced into interfacial polymerization (IP) via reacting with terephthaloyl chloride (TPC) to fabricate supramolecular membrane with “bead-like” channels. Furthermore, the laccase was immobilized onto the modified polysulfone (mPSf) surface to generate CD@PEG@Lac-TPC/mPSf supramolecular enzymatic membrane for high-efficiency catalytic degradation of membrane foulants. The CD@PEG-TPC/mPSf supramolecular membrane displayed excellent performance and operation stability for removal and desalination of small molecules, with pure water permeance up to 26.8 L·m−2·h−1·bar−1, and satisfactory NaCl/dye and NaCl/medicine separation factors. Moreover, CD@PEG@Lac-TPC/mPSf supramolecular enzymatic membrane showed an effective anti-fouling property with only 8.0 % permeance decline rate after 24 h continuous separation of tetracycline hydrochloride solution, suggesting its potential application for removal and desalination of small molecules.

Achieving simultaneous hydrogen evolution and organic pollutants degradation through the modification of Ag3PO4 using Cs2AgBiBr6 quantum dots and graphene hydrogel

The Ag3PO4/Cs2AgBiBr6 quantum dots/graphene hydrogel (ACGH) photocatalytic system was designed. The Cs2AgBiBr6 quantum dots (CABBQDs) and graphene hydrogel (rGH) solved the insufficient redox ability and easy photocorrosion of Ag3PO4, at the same time, the novel system achieved full-spectrum-driven photoreforming to use for efficient photocatalytic hydrogen evolution and simultaneous organic compounds photodegradation. The feasibility study of alternative sacrificial agents evaluated higher simultaneous photocatalytic activity in tetracycline hydrochloride (TC) compared to general sacrificial agents (methanol, Na2S/Na2SO3, acid orange and glucose). The yield of hydrogen production and simultaneous photodegradation efficiency of TC were 5965.8 μmol/g and 98.32 % respectively in 6 h. And the hydrogen production rate in TC solution was more than twice that of general sacrificial agents within 24 h. Meanwhile, the mechanism exploration elucidated the photogenerated charge transfer path to generate the water splitting and photoinduced oxidizing species (h+, OH, ·O2-). The Hirshfeld atomic charges on TC and methanol molecules were calculated by density functional theory to predict the initial attack sites. Results indicated that the CCO and CNC fragments on TC molecules were inferred as nucleophilic attack and radical attack sites. And more electrons on TC could give to ACGH constantly for hydrogen production than methanol. The yield of hydrogen production and simultaneous degradation efficiency of TC remained at 3683.24 μmol/g and 93.22 % respectively in six photocatalytic cycle experiments, showing the reusability of ACGH. The simultaneous hydrogen production and degradation of organic pollutants of ACGH could proceed in actual municipal wastewater.

Facile synthesis, in vitro biocompatibility, and antibacterial activity of porous hollow hydroxyapatite microspheres

AbstractIn this study, porous hollow hydroxyapatite (HAp) microspheres are prepared using chitosan microspheres as novel sacrificial templates and their microstructure, biocompatibility, and drug delivery properties are evaluated. Scanning electron microscope (SEM) observations show that HAp microspheres are spherical in morphology with a diameter of 100–300 μm and have a porous and core–shell structure. X‐ray diffractometer patterns show that HAp microspheres consist of apatite phase. MTT assay indicates that HAp microspheres are biocompatible and have no significant cytotoxicity. SEM observations show that HAp microspheres support attachment and proliferation of osteoblast MC3T3‐E1 cells. After being soaked in the solution of tetracycline hydrochloride (TH, model drug), HAp microspheres adsorb TH with an adsorption capacity of 47% to derive TH‐loaded HAp microspheres. When exposed to two types of representative bacteria: Escherichia coli and Staphylococcus aureus, TH‐loaded HAp microspheres maintain the biological activity of TH to inhibit the growth of bacteria.

Efficient adsorption-photocatalytic removal of tetracycline hydrochloride over La2S3-modified biochar with S,N-codoping

The adsorption instability and weak visible-light utilization of biochar restrain the industrial application in wastewater and soil remediations. Hence, S,N-codoped biochar is modified with La2S3 (La2S3/SN-biochar) via the one-pot sulfurization approach to boost the adsorption and photocatalytic activities for tetracycline hydrochloride (TCH) removal. Among the biochar-based composites, the optimal 3c-La2S3/SN-biochar with the La content of 15.43 wt% and the N content of 0.49 wt% exhibits the best removal efficiency of TCH. Its calculated adsorption capacity is 419.18 mg g−1, and the solar-light driven removal efficiency is 98.45 % for 200 mg L−1 TCH solution within 120 min. However, the long-term photo-corrosion induces to the declined adsorption-photocatalytic efficiency of 3c-La2S3/SN-biochar from 98.45 % to 93.26 % after 5 cycles, and the inadequate vacant sites result in the decreased adsorption capacity from 313.44 to 286.36 mg g−1 after 7 cycles. Langmuir isotherms and second-order kinetics well fit with the adsorption isotherms and kinetics of La2S3/SN-biochar composites, respectively. The Z-scheme junction between La2S3 and S,N-codoped biochar favors the rapid migration and separation of photoinduced electron-hole pairs. Meanwhile, the negative surface discharge is suitable for the efficient electrostatic attraction of TCH adsorption.

CORRECTION OF TRIACYLGLYCEROLS AND FREE FATTY ACIDS IN RAT BILE IN EXPERIMENTAL HEPATIC STEATOSIS

The relevance of the scientific study is associated with a substantial spread of hepatic steatosis in domestic animals (up to 40%) and the development of health-threatening complications in the form of cirrhosis of the liver, liver failure, and cancer. The purpose of this study was to determine the corrective effectiveness of the “FLP-MD” dietary supplement based on milk phospholipids in relation to the content of triacylglycerols and free fatty acids in the bile of rats with tetracycline-induced hepatic steatosis. Modelling of the drug form of hepatic steatosis was conducted by intragastric administration of a 4% solution of tetracycline hydrochloride at the rate of 0.5 g/kg of animal body weight for seven days. As a corrective therapy, for nine days the animals were intragastrically administered a dietary supplement “FLP-MD” based on milk phospholipids at a dose of 13.5 mg/kg of body weight. At the end of the experiment, bile samples were taken from rats for three hours every 30 minutes, in which the content of triacylglycerols and free fatty acids was determined by thin-layer chromatography. It was determined that the concentration of triacylglycerols in the bile of sick rats at the third hour of its selection is 63.0% lower than the control indicators. In laboratory rats that received a phospholipid-containing supplement against the background of modelling drug-induced hepatosis, this indicator in bile corresponded to the values of the control group. Therewith, the concentration of free fatty acids in bile samples at the third hour of its selection in sick rats was marked by a decrease of 47.2% compared to the control. The use of the dietary supplement under study in sick animals caused an increase in the concentration of free fatty acids in bile by 2.85 times compared to the control, which reduces the intensity of their use for the synthesis of triacylglycerols and prevents the development of fatty liver infiltration. Therefore, the phospholipid-containing dietary supplement is a highly effective corrective agent for impaired metabolism of triacylglycerols and free fatty acids in rats with drug-induced hepatic steatosis. This gives grounds to recommend it as a corrective therapy and for the prevention of the development of hepatic steatosis, especially in the case of the use of tetracycline antibiotics in animals

Synthesis of ZnFe2O4/B,N-codoped biochar via microwave-assisted pyrolysis for enhancing adsorption-photocatalytic elimination of tetracycline hydrochloride

B, N-codoped biochar was modified by ZnFe2O4 (ZnFe/BN-biochar) via the one-pot microwave-assisted pyrolysis for enhancing the adsorption-photocatalytic elimination of tetracycline hydrochloride (TCH). The addition of ZnFe2O4 could enhance the adsorption and photocatalytic capacity of B,N-codoped carbon under solar light irradiation. Among these composites, the optimal 3-ZnFe/3b-BN-biochar could remove 98.19 % of 150 mg L−1 TCH solution within 120 min, and its adsorption capacity estimated by Langmuir was 244.34 mg g−1 for TCH removal. However, the removal efficiency of TCH over 3-ZnFe/3b-BN-biochar decreased to 89.45 % after seven cycles. The photocatalytic and adsorption kinetics of biochar-based composites for TCH removal were well descried with Langmuir-Hinshelwood and second-order models, respectively. In addition, Langmuir well fitted with the adsorption isotherms of biochar-based composites. The adsorption process of TCH over 3-ZnFe/3b-BN-biochar was a spontaneous and physisorption process. Hence, 3-ZnFe/3b-BN-biochar was a promising material for the adsorption and photocatalytic elimination of pollutants in wastewater.

Nonthermal plasma sulfurized CuInS2/S-doped MgO nanosheets for efficient solar-light photocatalytic degradation of tetracycline

To enhance the adsorption-photocatalytic capacity of tetracycline hydrochloride (TCH) under solar light irradiation, ultrafine CuInS2 nanoparticles of 5 nm modified MgO with S doping (CIS/S-MgO) nanosheets were in-situ sulfurized in the nonthermal plasma. Compared with pure MgO, In2S3/S-MgO and CuS/S-MgO, CIS/S-MgO exhibited the better photocatalytic activity while worse adsorption capacity. The optimal 2-CIS/S-MgO could remove 98.4% of 200 mg L−1 TCH solution within 180 min, and declined to 92.3% after five cycles. The attenuated surface discharge and small BET surface area of CIS/S-MgO induced to the inferior adsorption capacity, while the Z-structured junction formed between CuInS2 and S-MgO was favorable for the charge transfer and separation of electron-hole pairs. •O2− was vital for enhancing the solar-light photocatalytic activity of 2-CIS/S-MgO.

Evaluation of the Influence of a Hydrogel Containing AMPD on the Stability of Tetracycline Hydrochloride.

Tetracyclines, as beneficial antimicrobial factors in both local and systemic therapy, are characterized by high instability. The aim of the study was the development of the influence of hydrogel formulation on the tetracycline hydrochloride (TC) level under varying storage conditions. The HPLC, XPRD as well as SEM and macroscopic observations were involved in the study. The TC concentration decreased within ca. two months from 9.37 µg/mL to 4.41 µg/mL in the case of the photoprotected TC solution stored at 23 °C, whereas the decrease in storage temperature did not improve the final level of TC. In the presence of AMPD, the TC level in aqueous solution decreased drastically to ca. 1 µg/mL. Application of a polyacrylic acid derivative enabled conservation of the TC level through the ca. two months. Thus, the use of alcoholamine in the preparation of the TC hydrogel may result in the development of a therapeutic product with a dual action against acne, including antimicrobial activity and saponification of free fatty acids deposited in the follicles.

Removal of organic contaminants from wastewater with GO/MOFs composites.

Graphene oxide/metal-organic frameworks (GO/MOFs) have been prepared via solvothermal synthesis with ferrous sulfate heptahydrate, zirconium acetate and terephthalic acid for the purpose of removing organic pollutants from wastewater. The composites were analyzed using scanning electron microscopy, infrared spectrometry, and XRD. Tetracycline hydrochloride and orange II were implemented as model pollutants to evaluate the efficacy of the GO/MOFs in water purification, in which 50 mg of Zr/Fe-MOFs/GO was mixed with 100 mL of 10 mg/L, 20 mg/L, 30 mg/L, or 50 mg/L tetracycline hydrochloride solution and 25 mg/L, 35 mg/L, 45 mg/L, or 60 mg/L orange II solution, respectively. The removal efficacy after 4 hours was determined to be 96.1%, 75.8%, 55.4%, and 30.1%, and 98.8%, 91.9%, 71.1%, and 66.2%, respectively. The kinetics of pollutant removal was investigated for both tetracycline hydrochloride and orange II and excellent correlation coefficients of greater than 0.99 were obtained. The high efficacy of these MOFs in pollutant removal, coupled with their inexpensive preparation indicates the feasibility of their implementation in strategies for treating waste liquid. As such, it is anticipated that Zr/Fe-MOFs/GO composites will be widely applied in wastewater purification.

Application of membrane filters in determination of the adsorption of tetracycline hydrochloride on graphene oxide

This paper shows the use of membrane filters in adsorption of solution of tetracycline hydrochloride on graphene materials. The adsorption process was monitored at different wavelengths, different pH values ​​at certain time intervals. The absorbances of the solutions were measured by UV-Vis spectrophotometry at two wavelengths (275 nm and 356 nm), and three pH values (pH 4, pH 7 and pH 10) every 90 minutes for 6 hours of monitoring, with constant stirring in an ultrasonic bath. The results showed decrease in absorbance at both wavelength and in all three pH values which proved the adsorption of tetracycline hydrochloride on GO and rGO. The largest decrease in absorbance was 98.1%. The most suitable pH value for adsorption was pH 4. This paper used a unique approach to filtration through membrane filters, which in the future could lead to the development of membrane filters based on graphene materials.