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A novel SrWO4-poly(3,4-ethylene dioxythiophene) (PEDOT)-polypyrrole (PPy) nanocomposite was synthesized via chemically oxidative polymerization and considered by using numerous method of the techniques. The resulting SrWO4/PEDOT-PPy nanocomposite demonstrated remarkable electrochemical sensing capabilities for sulfadiazine (SFA). As a modified glassy carbon electrode (SrWO4/PEDOT-PPy/GCE) revealed for superior catalytic activity in the electrochemical oxidation of sulfadiazine, enabling sensitive detection with quantification and detection limits of 1.0936 × 10−9 M µA−1 and 2.2104 × 10−9 M µA−1, respectively. This technique effectively determined SFA content in real samples. Additionally, SrWO4/PEDOT-PPy demonstrated extraordinary photocatalytic ability, achieving a Methylene Blue (MB) degradation rate of up to 99.1% under halogen light irradiation within 80 min. Hybrid photocatalyst has exhibited to strong reusability and photocatalytic stability under frequent light exposure. A contrivance for the photocatalytic deprivation of MB by SrWO4/PEDOT-PPy is proposed. These results underscore the crucial role of SrWO4/PEDOT-PPy in practical environmental remediation analysis. The fluorescence investigations have betrothed to terephthalic acid radical formations of SrWO4/PEDOT-PPy hybrids, which were modulated by different approaches, and its mainly driven for higher illumination aptitudes. Meanwhile, this was more supporting for physio-chemical properties of the phenomenon, at this consequential with significantly well improved to the photocatalytic performances. Because of this, SrWO4/PEDOT-PPy hybrid materials were comprehended to deliver excellent kinetics, and better recyclable activities. [ABSTRACT FROM AUTHOR]

Nano TiO2 is an acclaimed photocatalyst, widely used in water treatment due to its remarkable performance. However, challenges in real production, such as the easy recombination of photogenerated carriers and recycling difficulties, limit its application. Heterojunction photocatalysts, with high efficiency of photogenerated carrier separation and large light absorption range, show great potential for efficient water pollution treatment. In this paper, a composite photocatalyst (ART-550) with a heterophase junction structure was developed using industrial submicron rutile TiO2 pigment as the carrier. This composite demonstrated excellent performance in the photocatalytic degradation of sulfadiazine, maintaining its performance over five cycles. Furthermore, it effectively degraded various representative organic pollutants present in water bodies. The construction of a heterophase junction boosted the efficient separation of photo-generated carriers, enabling more active species to participate in the reaction and thus enhancing the photocatalytic degradation performance. Additionally, the strong interfacial binding ensured the stability of the photocatalytic performance of ART-550. This research introduces a new strategy to broaden the application field of submicron rutile and produce nano-titanium dioxide catalysts that are easily accessible, scalable, and highly applicable. It offers promising prospects for advancing water treatment technologies. Highlights: Applying pigment rutile TiO2 in the field of photocatalysis. The highest photocatalytic performance occurred with a 15.7% ratio of the anatase phase. ART-550 demonstrates excellent performance in photocatalytic degradation and is easily recyclable. Sulfadiazine degradation route and photocatalytic mechanism predicted. [ABSTRACT FROM AUTHOR]

The equilibrium solubility of sulfadiazine (SD, 3) in several {acetonitrile (MeCN) + ethanol (EtOH)} mixtures at nine temperatures from T/K = (278.15 K to 318.15) has been determined by following the shake flask method. SD solubility increased with temperature-arising as well as with the MeCN proportion-increasing in the mixtures. Thus, x3 increased from 7.74 × 10−5 in neat EtOH to 6.20 × 10−4 in neat MeCN at T/K = 298.15. SD solubility was adequately correlated with a second-order multivariate equation as function of both mixtures composition and temperature. Moreover, two models including the Jouyban–Acree and Jouyban–Acree–van't Hoff models were applied to mathematical SD solubility data modeling in solvent mixtures. The accuracy of each model is investigated by the mean relative deviations (MRD%) of the back-calculated solubility. A full predictive model was provided by training the Jouyban–Acree–van't Hoff model with only seven experimental solubility data which provided excellent predictions with the MRD% of 3.7 %. All used models show a low MRD% values (< 4.0 %) for the calculated data indicating a good correlation of SD solubility data with the given mathematical models. By means of the van't Hoff and Gibbs equations, the apparent thermodynamic quantities relative to SD dissolution and mixing processes, namely Gibbs energies, enthalpies, and entropies, were calculated and reported. Apparent dissolution quantities of SD were positive in all cases indicating endothermic and entropy-driven behaviors. A non-linear enthalpy–entropy relationship was observed for SD in the plot of SD dissolution enthalpy vs. Gibbs energy. Observed trend exhibits negative slope in the composition from neat EtOH to the mixture of 0.05 in mass fraction of MeCN indicating entropy-driving mechanism for this SD transfer process. Moreover, variant but positive slopes were found in the composition interval of 0.05 < w1 < 1.00 indicating enthalpy-driving mechanism for these SD transfer processes. Furthermore, the preferential solvation of SD by MeCN or EtOH was analyzed by using the inverse Kirkwood–Buff integrals. Thus, SD is preferentially solvated by EtOH molecules in EtOH-rich mixtures but preferentially solvated by MeCN in MeCN-rich mixtures. In this way, this research expands the literature investigations about the solubility of SD in some non-aqueous cosolvent mixtures conformed by MeCN and other alcohols. [ABSTRACT FROM AUTHOR]

In this study, magnetic coconut shell biochar loaded with spherical Fe3O4 and γ-Fe2O3 particles was successfully synthesized using a chemical coprecipitation method. The magnetic biochar exhibited a good magnetic separability and environmental security. The maximum sulfadiazine (SDZ) and norfloxacin (NOR) removal efficiencies were 94.8% and 92.3% at pH 4 and 25 °C with adsorbent dosage of 2.5 g/L, respectively. When antibiotic concentrations ranged from 5 to 50 mg/L, the theoretical maximum adsorption capacities of SDZ and NOR were 16.7 mg/g and 25.8 mg/g, respectively. The Langmuir isotherm and pseudo-second-order kinetic models could better describe the adsorption process of both antibiotics, implying the monolayer chemical adsorption. The thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic. The ionic strength had no significant effect on the adsorption behavior of either antibiotic. Combined with BET, FTIR, and XPS results, the dominant mechanisms for SDZ and NOR adsorption were pore filling, π-π electron-donor–acceptor interaction, hydrogen bonds and surface complexation. Moreover, Lewis acid–base interaction also contributed to SDZ adsorption. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) were extensively employed for in-situ detection sulfadiazine (SDZ) residues, yet current synthesis methods suffer from complex procedures, reagent pollution of the environment, and low particle quality. This study presents a novel synthesis method using discarded longan seed extract as a reducing agent to synthesized high-quality AuNPs, and then can be used for in-situ SDZ detection. Response surface methodology (RSM) was employed to optimize synthesis parameters, which resulted in five optimal combinations that enhanced the flexibility of synthesis. These AuNPs, ranging in size from 18.26 nm to 33.8 nm with zeta potentials from − 29.5 mV to − 14.3 mV, were successfully loaded with functional groups from longan seed extract. In the detection of SDZ, the colorimetric aptasensor demonstrated excellent sensitivity and selectivity over other antibiotics with a limit of detection and quantification at 70.98 ng·mL−1 and 236.59 ng·mL−1 in the concentration range of 200–800 ng·mL−1. Recoveries of spiked SDZ samples ranged from 97.90% to 106.7%, with RSD values below 9.25%. Meanwhile, the aptasensor exhibited exceptional diagnostic efficacy (AUC: 0.976) compared to UV absorption methods in the ROC evaluation. In conclusion, this study highlights the potential of using AuNPs synthesized from longan seed extract coupled with aptamer technology as a straightforward detection method for SDZ in river water, offering promising applications in environmental monitoring. [ABSTRACT FROM AUTHOR]

Antibiotic contamination in soil has become a major concern worldwide. At present, it is not clear how two co-existed antibiotics with environmentally relevant concentrations would affect soil bacterial community structure, the abundances of antibiotic resistance genes (ARGs) and functional genes, and whether the effects of antibiotics would differ between rhizosphere and bulk soil. We conducted a greenhouse pot experiment to grow maize in a loess soil treated with oxytetracycline (OTC) or sulfadiazine (SDZ) or both at an environmentally relevant concentration (1 mg kg−1) to investigate the effects of OTC and SDZ on the rhizosphere and bulk soil bacterial communities, abundances of ARGs and carbon (C)-, nitrogen (N)-, and phosphorus (P)-cycling functional genes, and on plant growth and plant N and P nutrition. The results show that the effects of environmentally relevant concentrations of OTC and SDZ on bacterial communities and abundances of ARGs and functional genes differ between maize rhizosphere and bulk soil. The effects of two antibiotics resulted in a higher absolute abundances of accA, tet(34), tnpA-04, and sul2 in the rhizosphere soil than in the bulk soil and different bacterial community compositions and biomarkers in the rhizosphere soil and the bulk soil. However, OTC had a stronger inhibitory effect on the abundances of a few functional genes in the bulk soil than SDZ did, and their combination had no synergistic effect on plant growth, ARGs, and functional genes. The role of co-existed OTC and SDZ decreased shoot height and increased root N concentration. The results demonstrate that environmentally relevant concentrations of antibiotics shift soil microbial community structure, increase the abundances of ARGs, and reduce the abundances of functional genes. Furthermore, soil contamination with antibiotics can diminish agricultural production via phytotoxic effects on crops, and combined effects of antibiotics on plant growth and nutrient uptake should be considered. [ABSTRACT FROM AUTHOR]

Magnetite-functionalized biochar (MBC) is a promising engineered material for remediation of antibiotic-contaminated fields. However, sorption mechanisms of ionizable organic compounds such as sulfonamide antibiotics (SAs) on MBC are still unclear. This study employed four representative SAs including sulfamethazine (SMT), sulfamerazine (SMR), sulfadiazine (SDZ), and sulfamethoxazole (SMX), to compare the difference in sorption on MBC. Results showed that the sorption capacities and affinities of the four SAs varied with their substituents, hydrophobic properties, and dissociation constants (pKa). Synergistic effect during co-pyrolysis with Fe3+ enhanced the sorption performance of MBC towards SAs compared to original BC. Spectral methods confirmed structural changes of MBC such as the variance in oxygen-containing groups and defective/graphitized phases. Results of modeling pH-dependent sorption revealed that H-bonding or π-bond assisted H-bonding determined the sorption affinities and capacities of SAs. In particular, the SAs with lower pKa were thermodynamically favorable to form H-bonding with MBC via proton exchange with water molecules. Quantum calculation results quantified the contributions of H-bonding strengths and found that the energies of H-bonding were correlated with affinities of SAs. Moreover, contributions of oxygen-containing groups instead of minerals dominated the H-bonding energies. Mechanistic insights from this study can be valuable in exploring engineered BC composites for practical application in field remediation. Highlights: Sorption capacity and affinity of four SAs varied with substituents, Kow, and pKa Copyrolyzed carbon matrix and Fe3+ synergistically enhanced SA sorption performance H-bonding or π-bond assisted H-bonding determined SA sorption affinity and capacity Contributions of O-containing groups instead of minerals dominated H-bonding energy [ABSTRACT FROM AUTHOR]

In this work, two CdII-based coordination polymers, namely [Cd4(HL)2(H2O)5]n (1), and {[Cd2(HL)(2,2′-bpy)2(H2O)]·6H2O}n (2) (2,2′-bpy = 2,2′-bipyridine) have been designed and synthesized using 2,3-bis(3,5-dicarboxylphenxoy)benzoic acid (H5L). Coordination polymer 1 displays a layer structure, which was connected through C–H‧‧‧π interactions into 3D supramolecular network, while coordination polymer 2 shows a three-dimensional framework structure. In addition, the excellent fluorescence performance make them potential luminescent sensors for antibiotics. The results show that coordination polymer 1 exhibits high sensitivity for detecting of sulfadiazine (SDZ), while coordination polymer 2 can selectively detect nitrofurantoin (NFT). [ABSTRACT FROM AUTHOR]

The composite material based on N-, S-, and Fe-doped TiO2 (NSFe-TiO2) synthesized by wet impregnation was used as a photocatalyst to rapidly degrade sulfadiazine. The photocatalytic degradation behavior and mechanism of sulfadiazine on NSFe-TiO2 were investigated for revealing the role of degradation under ultraviolet light. The results showed that compared with TiO2, NSFe-TiO2 markedly improved the efficiency in photocatalytic degradation of sulfadiazine: more than 90% of sulfadiazine could be removed within 120 min by NSFe-TiO2 dosage of 20 mg L−1. The process conformed to first-order reaction kinetics model. The parameters such as loaded amount of NSFe-TiO2, solution pH value, humic acid concentration and recycle numbers on removal efficiency were also studied. Compared to neutral and alkaline conditions, acidic condition was not conducive to the photocatalysis. HA, Ca2+, Cu2+ and Zn2+ in the actual water body had mild inhibition on sulfadiazine degradation in UV/NSFe-TiO2 system. Fragments screened by high-resolution mass spectrometry were conducted to explore the oxidation mechanism and pathways of sulfadiazine degradation. On the whole, UV/NSFe-TiO2 photocatalysis has a good effect on sulfadiazine removal. [ABSTRACT FROM AUTHOR]

Toxoplasmosis is an infection that prevails all over the world and is caused by the obligate intracellular protozoan parasite Toxoplasma gondii (T. gondii). Promising novel compounds for the treatment of T. gondii are introduced in the current investigation. In order to test their in vitro potency against T. gondii tachyzoites, six 1,2,3-triazoles-based sulfonamide scaffolds with terminal NH2 or OH group were prepared and investigated as sulfadiazine equivalents. When compared to sulfadiazine, which served as a positive control, hybrid molecules showed much more anti-Toxoplasma activity. The results showed that the IC50 of the examined compounds 3(a–f) were recoded as 0.07492 μM, 0.07455 μM, 0.0392 μM, 0.03124 μM, 0.0533 μM, and 0.01835 μM, respectively, while the sulfadiazine exhibited 0.1852 μM. The studied 1,2,3-triazole-sulfadrug molecular conjugates 3(a–f) revealed selectivity index of 10.4, 8.9, 25.4, 21, 8.3, and 29; respectively. The current study focused on the newly synthesized amino derivatives 3(d–f), as they contain the more potent amino groups which are recognized to be essential elements and promote better biological activity. Extracellular tachyzoites underwent striking morphological alterations after 2 h of treatment as seen by scanning electron microscopy (SEM). Additionally, the intracellular tachyzoite exposed to the newly synthesized amino derivatives 3(d–f) for a 24-h period of treatment revealed damaged and altered morphology by transmission electron microscopic (TEM) indicating cytopathic effects. Moreover, compound 3f underwent the most pronounced changes, indicating that it had the strongest activity against T. gondii. [ABSTRACT FROM AUTHOR]

A 3D-supramolecular nickel integrated Ni-SDZ complex was synthesized using sodium salt of sulfadiazine as the ligand and nickel(II) acetate as the metal salt using a condensation process and slow evaporation approach to growing the single crystal. The metal complex was characterized for its composition, functional groups, surface morphology as well as complex 3D structure, by resorting to various analytical techniques. The interacting surface and stability as well as reactivity of the complex were carried out using the DFT platform. From ADMET parameters, human Intestinal Absorbance data revealed that the compound has the potential to be well absorbed, and also Ni-SDZ complex cannot cross the blood–brain barrier (BBB). Additionally, the complex's DNA binding affinity and in-vivo and in-vitro cytotoxic studies were explored utilizing UV–Vis absorbance titration, viscosity measurements, and S. pombe cells and brine shrimp lethality tests. In visible light radiation, the Ni-SDZ complex displayed exceptional photo-degradation characteristics of approximately 70.19% within 70 min against methylene blue (MB). [ABSTRACT FROM AUTHOR]

In the current work, the hybrid process potential of ultrasound (US) and electro-Fenton (EF), named sono-electro-Fenton (SEF), was fully investigated for sulfadiazine (SDZ) degradation. The decontamination in the integration approach was revealed to be greater than in individual procedures, i.e., EF process (roughly 66%) and US process (roughly 15%). The key operating process factors (i.e., applied voltage, H2O2 content, pH, initial concentration of SDZ, and reaction time) affecting SDZ removal were evaluated and optimized using Box-Behnken Design (BBD). In addition, an adaptive neuro-fuzzy inference system (ANFIS) as an efficient predictive model was applied to forecast the decontamination efficiency of SDZ through the SEF process based on the same findings produced from BBD. The results revealed that the predictability of SDZ elimination by the ANFIS and BBD approaches exhibited an excellent agreement (a greater R2 of 0.99%) among the both models. Density functional theory was also employed to forecast the plausible decomposition elucidation by the bond-breaking mechanism of organic substances. Plus, the main side products of SDZ degradation during the SEF process were tracked. Eventually, the non-carcinogenic risk assessment of different samples of natural water containing SDZ that was treated by adopting US, EF, and SEF processes was examined for the first time. The findings indicated that the non-carcinogenic risk (HQ) values of all the purified water sources were computed in the permissible range. [ABSTRACT FROM AUTHOR]

In this research study an eco-friendly approach is utilized to synthesize the green g-C3N4 based nanocomposites by employing Zingiber officinale as stabilizer and mediator. Our results proved that the green g-C3N4 have good performances and exceptional visible light photocatalytic activities as compared to the chemically synthesized g-C3N4. The small surface area, and low charge separation of g-C3N4 is upgraded by coupling with TiO2 nanoparticles. Our experimental results have confirmed that Zingiber officinale worked as stabilizer and mediator, while the coupling of TiO2 worked as facilitator and photoelectron modulator to enhance the charge separation. Compared to pristine green g-C3N4 (GCN), the most active sample 5Ti/GCN showed ~ 2.5-fold improvement in photocatalytic activities for sulfadiazine and bisphenol A degradation. The degradation pathways of sulfadiazine and bisphenol A showed the mineralization steps and production of less hazardous and small molecules (CO2 and H2O). Finally, our current novel research work will provide a new gateway to synthesize the plant assisted and eco-friendly green nanomaterials and its employment for pollutants degradation and environmental purification. Graphical abstract representing the Zingiber officinale mediated synthesis of TiO2 coupled g-C3N4 green nanocomposites [ABSTRACT FROM AUTHOR]

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Active Principal Ingredient (API) encapsulation through adsorption and physical entrapment onto TEMPO-oxidized cellulose nanofibrils (toCNFs) is possible, but challenges such as burst release and use of low water-soluble API such as sulfadiazine (SD) are yet to be addressed. The objective of this study is to assess the release property and antibacterial activity of toCNF/β-Cyclodextrin (β-CD)/SD materials in the form of films. Release in sink conditions was achieved with result highlighting the importance of the toCNF network structure, which is tightened at acidic pH for toCNFs due to its carboxylic content, reducing the burst effect phenomena. Antibacterial activity against Staphylococcus aureus and Escherichia coli was assessed and the results showed a clear beneficial impact of using β-CDs. An antibacterial effect for toCNF/SD films is confirmed for 3 successive applications whereas an antibacterial effect for a toCNF/CMβCD/SD film is prolonged up to 7 successive applications. The improvement of the topical release of a prophylactic agent with these materials are making them promising for biomedical applications such as wound dressing. [ABSTRACT FROM AUTHOR]

Metal-free porous biochars are popularly utilized as catalysts for peroxydisulfate (PDS) activation. The enhancement effect of PDS activation of porous biochars fabricated by employing both hard template and alkali metal activating agent has not been explored completely. In addition, the role of the inherent carbon defect in PDS activation has not been clearly elucidated. Hence, a series of carbonaceous catalysts were fabricated using a sole template (KCl), a sole activating agent (Na2S2O3) or a combination of template and activating agent (KCl/Na2S2O3, KCl/KHCO3, KCl/NaHCO3, and KCl/Na2C2O4), to systematically investigate the effect of specific surface area (SSA) and intrinsic defect of porous biochar on its PDS activation ability. The biochar synthesized by KCl and Na2S2O3 (SK-C) exhibited the optimum degradation performance. The SK-C was found to possess an interconnected hollow cage with three-dimensional mesh structure showing the largest surface area, pore volume and C-sp3 edge defect content among all the catalysts, which explained its paramount catalytic ability. The SSA and C-sp3 content together can determine the catalytic performance in a quantitative relationship. The single electron transfer pathway from SDZ to inner-sphere bound SK-C/PDS* was the protagonist of pollutant oxidation. The degradation intermediates were detected and recognized and their toxicities were evaluated. This study for the first time comprehensively identified the synergistic effect between the SSA and inherent defects on improving the catalytic performance of biochar for PDS activation to removal contaminants. Highlights: Several porous biochars with various surface area and defect degree were fabricated. These catalysts were used for peroxydisulfate activation to degrade sulfadiazine. The catalyst made by employing Na2S2O3 and KCl exhibited the optimum performance. The surface area and C-sp3 together determined quantitatively the catalytic effect. The single electron transfer from organic to inner-sphere catalyst/peroxodisulfate* was dominant. [ABSTRACT FROM AUTHOR]

Key message: We extended the applicability of the BY-2 cell line as a model by introducing two new selection systems. Our protocol provides guidelines for optimising Basta selection in other recalcitrant models. Tobacco BY-2 cell line is the most commonly used cytological model in plant research. It is uniform, can be simply treated by chemicals, synchronised and easily transformed. However, only a few selection systems are available that complicate advanced studies using multiple stacked transgenes and extensive gene editing. In our work, we adopted for BY-2 cell line two other selection systems: sulfadiazine and phosphinothricin (PPT, an active ingredient of Basta herbicide). We show that sulfadiazine can be used in a wide range of concentrations. It is suitable for co-transformation and subsequent double selection with kanamycin or hygromycin, which are standardly used for BY-2 transformation. We also have domesticated the sulfadiazine resistance for the user-friendly GoldenBraid cloning system. Compared to sulfadiazine, establishing selection on phosphinothricin was considerably more challenging. It did not work in any concentration of PPT with standardly cultured cells. Since the selection is based on blocking glutamine synthetase and consequent ammonium toxicity and deficiency of assimilated nitrogen, we tried to manipulate nitrogen availability. We found that the PPT selection reliably works only with nitrogen-starved cells with reduced nitrate reserves that are selected on a medium without ammonium nitrate. Both these adjustments prevent the release of large amounts of ammonium, which can toxify the entire culture in the case of standardly cultured cells. Since high nitrogen reserves can be a common feature of in vitro cultures grown on MS media, nitrogen starvation could be a key step in establishing phosphinothricin resistance in other plant models. [ABSTRACT FROM AUTHOR]

This paper reports the degradation of the sulfadiazine (SDZ) drug with a hybrid advanced oxidation process (AOP) of heterogeneous α-Fe2O3/persulfate coupled with hydrodynamic cavitation. The major objectives of the study are parametric optimization of the process and elucidation of the chemical mechanism of degradation. The optimum conditions for maximum SDZ degradation of 93.07 ± 1.67% were as follows: initial SDZ concentration = 20 ppm, pH = 4, α-Fe2O3 = 181.82 mg/L, Na2S2O8 = 348.49 mg/L, H2O2 = 0.95 mL/L, inlet pressure = 0.81 MPa (8 atm), orifice plate configuration: hole dia. = 2 mm and number of holes = 4. Density functional theory (DFT) calculations revealed that the atoms of SDZ with a high Fukui index (f0) were potentially active sites for the attack of •OH and SO 4 · - radicals. Fukui index calculation revealed that atom 11 N has a higher value of f0 (0.1026) for oxidation at the α-amine group of the sulfadiazine molecule. Degradation intermediates detected through LC–MS/MS analysis corroborated the results of DFT simulations. Using these results, a chemical pathway has been proposed for SDZ degradation. [ABSTRACT FROM AUTHOR]

The dry-gel conversion method (DGC) is a promising synthesis protocol for preparing magnetic zeolite composites as it yields homogeneous composite particles with more rapid crystallization, smaller reactor volume, and less waste production than the conventional hydrothermal method. This work investigates the optimal conditions for preparing magnetic BEA-type zeolites using the DGC method, including the gel/water ratio, crystallization temperature and time. Precursor dry-gel incorporating well-dispersed magnetite was subjected to crystallization under water vapor atmosphere with a gel/water ratio of 0.5–2, crystallization temperature of 140–200 °C for 1.5–12 h, followed by characterization using X-ray diffraction and scanning electron microscopy. The optimum conditions were found to be gel/water ratio of 1 and crystallization at 180 °C for 12 h. Magnetic properties of collected samples were evaluated using a vibrating-sample magnetometer after calcination at 400–500 °C for 12 h. Products calcined below 450 °C showed good magnetic properties. Adsorption of sulfadiazine using the BEA and magnetic BEA-type zeolites was evaluated in a 10–50 mg/l range. Results revealed favorable multilayer-type adsorption of sulfadiazine onto both non-magnetic and magnetic BEA-type zeolites (Freundlich model). These indicate that DGC method is suitable for preparing high-silica magnetic BEA-type zeolites with potential for antibiotic removal. Highlights: Effect of dry-gel conversion synthesis conditions for magnetic BEA zeolite composites is studied. Homogenous BEA zeolite/Fe3O4 composite was successfully synthesized using the optimal conditions. The composite exhibits magnetic properties and could be easily collected using a magnet. The obtained product could effectively remove sulfadiazine, especially from acidic solutions. The adsorption was found to be of a multilayer type and followed the Freundlich model. [ABSTRACT FROM AUTHOR]

Electrochemical advanced oxidation processes (EAOPs) is considered to be an efficacious method to degrade antibiotics. However, the performance of the anode has become the main limiting factor of this technology. In this study, due to the electron-deficient characteristics and the improvement of OER performance of Mo, we chose to use thermal decomposition to incorporate Mo into IrO2 to prepare anodes with industrial applicability. Under the optimal ratio of Ir to Mo is 7:3, (Ir0.7Mo0.3)Ox electrode's particular pore structure can expose more active sites and create a channel for the transportation of electrons, thereby promoting the formation of free radicals and degrading pollutants more efficiently. (Ir0.7Mo0.3)Ox electrode also has a higher mass activity (6.332 A g−1, three times that of the IrO2 electrode) and a larger electrochemical active area (ECSA, 375.43 cm2, seven times that of the IrO2 electrode). In addition, the optimal conditions of (Ir0.7Mo0.3)Ox electrode for degrading sulfadiazine(SDZ) were explored, which achieved a higher removal than traditional electrodes (90% removal within 4 h) when the Ti plate was the substrate. Through the intermediate products of SDZ degradation and related literatures, two possible degradation pathways of SDZ were speculated. This research provides a new type of anode catalyst for the degradation of sulfonamide antibiotics, which is possible for industrial application. [ABSTRACT FROM AUTHOR]

In this work, the hydrothermal method was used to synthesize f-BN@Bi2S3 nanocomposite and used as an electrocatalyst for the detection of sulfadiazine (SD) drug. Various spectroscopic and voltammetric techniques were adopted to evaluate the morphological and structural features of the prepared materials. The modification of the electrode results in good electrocatalytic activity and excellent sensitive towards the oxidation of SD because of its huge active surface area, high sensitivity, and electrical conductivity provided by the synergistic effects of the f-BN@Bi2S3 nanocomposite. This modified electrode exhibited linearity in the range 0.01–62 µM at Epa = 0.93 V (vs. Ag/AgCl). Furthermore, according to the electrochemical reaction towards the SD, a modified electrode of f-BN@Bi2S3 has a LOD value of 0.0015 µM, sensitivity (8.42 μA·μM−1·cm−2), good anti-interfering ability, and good repeatability. The suggested electrochemical sensor has high detection performance for monitoring water and urine samples. Notably, relative standard deviations (RSD) and recoveries of the proposed sensor for spiked water and urine samples are in the ranges of 0.014–0.75% and 98.97–99.98% (n = 3), respectively. [ABSTRACT FROM AUTHOR]

Herein, novel composite materials were prepared by intercalating functional pillars, i.e., pentafluorobenzene (PFB) and sodium 2,3,4,5,6-pentafluorobenzoate (PFBS), into graphene oxide (GO) sheets. It led to forming size hives and increased availability of intrinsic area of GO. The synthesized materials (GO-PFB and GO-PFBS) were investigated as adsorbents to eliminate sulfadiazine (SD) from aqueous solutions. The adsorption capacities of GO-PFBS (1002.21 μmol/g) and GO-PFB (564.17 μmol/g) were 6.37 and 3.59 times higher than that of GO (157.21 μmol/g), respectively. The adsorption of SD onto GO-PFBS decreased with increasing solution pH. Density functional theory (DFT) results revealed that the SD adsorption onto the adsorbents was exothermic, and the introduction of the carboxylate groups showed lower binding energy. It was found that hydrophobic interaction fully participates in the adsorption process, and the electrostatic complementation of hydrogen bonding further enhances the SD adsorption. Obtained results showed that intercalating functional rigid molecules as pillars to support GO sheets could improve its adsorption behavior. [ABSTRACT FROM AUTHOR]

The increasing demand for high performance, environmentally sustainable products especially polymeric materials employed in outdoor industrial applications led to the search for new methods of stabilizing polymers against UV light and extreme weather conditions. The use of additives for enhancing photo-stability of polymers and overall long term performance and sustainability had proven to be a successful approach. In this study, Poly (methyl methacrylate) (PMMA) a synthetic polymer widely utilized in industrial applications was functionalized via two step aminolysis reaction then the modified PMMA films were blended with nanoparticles (Copper, Cobalt, Chromium and Titanium oxide), the effects of surface functionalization and the addition of nanoparticles were systematically investigated by many characterization techniques. The results of this study showed an enhancement that can be described as remarkable in photo-stability of weight loss from 3% of neat polymer to less than 1% for modified PMMA. As well as the thermal properties of functionalized PMMA films blended with nanoparticles compared with neat PMMA, the blended films were compared to a commercial photostabilizer, Tinuvin 622, to determine their efficiency, with copper oxide being the most efficient photo-stabilizer followed by cobalt oxide, chromium oxide and titanium oxide respectively. Significantly, the modified, Blended PMMA films can be used as a durable, sustainable alternative for neat PMMA due to their simple surface modification, mechanical and thermal stability and eco-friendly features. [ABSTRACT FROM AUTHOR]

Sulfadiazine (SDZ) is a typical persistent sulfonamide antibiotic, which has been widely detected in natural drinking water sources. The degradation of SDZ by UV/Oxone (potassium monopersulfate compound) was explored in this study. The results showed that Cl− can effectively activate PMS to promote rapid degradation of SDZ in the Oxone process by forming chlorine in the system. Radical quenching tests suggested that radical oxidation, including HO•, SO4•−, and reactive chlorine species (RCS), played an important role by UV/Oxone. It further verified that concentration and distribution of HO•, SO4•−, and RCS were pH-dependent; RCS act as a major contributor at pH 6.0 and pH 7.0 to degrade SDZ in this process. The SDZ degradation rate was firstly increased and then decreased by Cl− and HCO3− (0–10 mM); HA (0–10 mg L−1) exhibited insignificant influence on SDZ degradation. The degradation pathways of SDZ during UV/Oxone and formation pathways of five disinfection byproducts during subsequent chlorination were proposed. The possible DBP precursors formed by SO2 extrusion, hydroxylation, and chlorination of SDZ during UV/Oxone pre-oxidation. [ABSTRACT FROM AUTHOR]

Background: Biological activities of Pistacia atlantica have been investigated for few decades. The fruit oil of the plant has been used for treatment of wounds, inflammation, and other ailments in Traditional Persian Medicine (TPM). Objectives: The main objectives of this study were to analyze the chemical composition of Pistacia atlantica fruit oil and to study wound healing and anti-inflammatory effects of oil-absorbed bacterial cellulose in an in vivo burn wound model. Method: Bacterial cellulose membrane was prepared from Kombucha culture and Fourier-transform infrared was used to characterize the bacterial cellulose. Cold press technique was used to obtain Pistacia atlantica fruit oil and the chemical composition was analyzed by gas chromatography. Bacterial cellulose membrane was impregnated with the Pistacia atlantica fruit oil. Pistacia atlantica hydrogel was prepared using specific Carbopol. Burn wound model was used to evaluate in vivo wound healing and anti-inflammatory effects of the wound dressings containing either silver sulfadiazine as positive control, Pistacia atlantica hydrogel or bacterial cellulose membrane coated with the Pistacia atlantica fruit oil. Blank dressing was used as negative control. Results: FT-IR analysis showed that the structure of the bacterial cellulose corresponded with the standard FT-IR spectrum. The major components of Pistacia atlantica fruit oil constituted linoleic acid (38.1%), oleic acid (36.9%) and stearic acid (3.8%). Histological analysis showed that bacterial cellulose coated with fruit oil significantly decreased the number of neutrophils as a measure of inflammation compared to either negative control or positive control (p < 0.05). Wound closure occurred faster in the treated group with fruit oil-coated bacterial cellulose compared to the other treatments (p < 0.05). Conclusion: The results showed that bacterial cellulose coated with Pistacia atlantica fruit oil can be a potential bio-safe dressing for wound management. [ABSTRACT FROM AUTHOR]

Antibiotics usage is a double-edged sword among the production promotion and environmental aggravation of aquaculture system. In this study, the effects of sulfadiazine addition on algal-bacterial-based aquaponic (AA) system were thoroughly investigated. Results showed that sulfadiazine addition increased the nitrogen (N) and carbon (C) recovery of AA system by 1.3 times and 2.9 times, respectively. Meanwhile, the global warming potential was increased by 63% due to aggravated nitrous oxide (N2O) emission. This was mainly because sulfadiazine increased the abundance of nirS genes and decreased the abundance of nosZ genes, which subsequently led to higher N2O accumulation. Furthermore, resistance gene (sul-1, sul-2, and intI-1) abundance in the treatment group was an order higher than that of the control group, which would give rise to the environmental risk for agroecological system. Key Points: • Sulfadiazine addition increased NUE at expense of aggravated GHG emissions. • Sulfadiazine disrupted the balance between the abundance of nirS and nosZ genes. • Sulfadiazine addition increased the resistance gene abundance of AA system. [ABSTRACT FROM AUTHOR]

Sulfadiazine (SDZ) was a persistent sulfonamide antibiotic with a potential risk to human health. The waste dipping syrup was considered useless and environmentally unfriendly solution. In this work, carbonyl-, hydroxyl-, and amino-functionalized microporous carbonaceous nanospheres were synthesized using waste dipping syrup with glucose, fructose, and nitrogen, which was used as precursor for hydrothermal and pyrolysis process. The products were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FTIR), the point of zero charge (PZC), Xray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). The carbonaceous nanospheres with large BET surface area (924.528 m2/g), micropores (2.127 nm), and high micro-porosity (89.54 %) allowed the rapid diffusion of SDZ (0.512nm×0.738 nm) into micropores of nanospheres. The majority SDZ (initial concentration = 20 mg/L) was removed (>96.8%) in the presence of 1.0 g/L nanoparticles after 40-min reaction at pH = 6.0. The adsorption capacity of SDZ onto nanospheres was 96.6 mg/g. The adsorption kinetic and equilibrium followed pseudo-first-order model and Langmuir isotherm, respectively. The intra-particle diffusion model indicated a three-step adsorption process. In addition, the regenerated nanospheres could be reused over four recycles. The optimal fabrication was realized at lower hydrothermal and pyrolysis temperature of 180 °C and 400 °C, respectively, which involved no additional chemical activating agent and had a high yield (70.8 %). Collectively, hydroxylation, carboxylation, amination, large specific surface area, and multi-microporosity may be responsible for improved adsorption performance of SDZ onto nanospheres. The findings provided a novel pathway for SDZ-loading wastewater treatment using waste syrup. [ABSTRACT FROM AUTHOR]

Dissolved black carbon (DBC) is regarded as an important part of the natural organic matter pool. However, it is unclear about DBC's photochemical activity and the relationships between reactive intermediates (RIs) and the molecular structure of DBC remain unclear. In this study, we investigate the photochemical formation ability of RIs and spectral parameters (E2/E3, S275–295) of DBC made from five types of plants at five pyrolysis temperatures. The results showed that there were good linear regressions between the RI quantum yields and the spectral parameters (E2/E3, S275–295), and this was indicative of the RI generation prediction from DBC under solar irradiation. The DBC-mediated photochemical experiment of sulfadiazine revealed that 3DBC* was the primary active species for the indirect photodegradation of sulfadiazine. Further studies indicated that a linear relationship was observed between the indirect photodegradation ability of sulfadiazine induced directly by 3DBC* at different pyrolysis temperatures and the 3DBC* quantum yields or E2/E3. These findings indicate that the simple models of the RI quantum yield as a function of spectral parameters can be used to evaluate the degradation of pollutants with known DBC spectral parameters. [ABSTRACT FROM AUTHOR]

Antibiotics are frequently applied in aquaculture to control infectious diseases and promote aquaculture production. The long-term application of antibiotics can lead to antibiotic resistance within an ecosystem. Herein, we assessed the ecological responses to two antibiotics (oxytetracycline (OTC) and sulfadiazine (SD)) at three concentrations (0 mg/kg (control), 10 mg/kg, and 1000 mg/kg) re-entering the aquaculture sediments of shrimp ponds with an approximately long-term drug application history (5, 15, and more than 30 years) for 2 and 4 months. For the newly reclaimed aquaculture ponds (approximately 5 years), the re-entered OTC significantly promoted urease activity (UA) and peroxidase activity (POA), while inhibited dehydrogenase activity (DHA) and fluorescein diacetate esterase activity (FDA). Meanwhile, the re-entered SD showed promotional effects on POA and DHA, and inhibitory effects on UA and FDA. For ponds with 15 years of aquaculture history, re-entered OTC promoted POA, inhibited FDA, and changed the influencing effects of UA and DHA with exposure time. The re-entered SD showed promotional effects on UA, POA and DHA, and inhibitory effects on FDA. For long-term aquaculture ponds (more than 30 years of aquaculture history), re-entered OTC promoted POA, DHA, and FDA, while it inhibited UA. Meanwhile, SD promoted all four enzyme activities. Pearson correlation analysis indicated that the variances of enzyme responses to the re-entry of antibiotics in the three sediment environments were related with the type, concentration, and exposure time of antibiotics, as well as the sediment properties and aquaculture history. The enzyme activities in the sediment environment from newly reclaimed aquaculture ponds were more sensitive to the re-entered antibiotics, while the enzyme activities displayed a clear tolerance in the sediment environment with more than 30 years of aquaculture history. However, in the sediment environment with 15 years of aquaculture history, the response of the enzyme activities to re-entered antibiotics demonstrated time processes of antibiotic adaptation during antibiotic resistance selection. This study has illustrated the effects of re-entered antibiotics on enzyme activities in the aquaculture environment with long-term antibiotic resistance/tolerance profiles, and further establishes the possible effects on ecosystem functioning in continuous antibiotic selection pressure. [ABSTRACT FROM AUTHOR]

Background: Due to their widespread use, sulfonamide antibiotics (SAs) have become ubiquitous environmental contaminants and thus a cause of public concern. However, a complete understanding of the behavior of these pollutants in complex environmental systems has been hampered by the unavailability and high cost of isotopically labeled SAs. Results: Using commercially available uniformly [14C]- and [13C]-labeled aniline as starting materials, we synthesized [phenyl-ring-14C]- and [phenyl-ring-13C]-labeled sulfamethoxazole (SMX), sulfamonomethoxine (SMM), and sulfadiazine (SDZ) in four-step (via the condensation of labeled N-acetylsulfanilyl chloride and aminoheterocycles) or five-step (via the condensation of labeled N-acetylsulfonamide and chloroheterocycles) reactions, with good yields (5.0–22.5% and 28.1–54.1% for [14C]- and [13C]-labeled SAs, respectively) and high purities (> 98.0%). Conclusion: The synthesis of [14C]-labeled SAs in milligram amounts enables the preparation of labeled SAs with high specific radioactivity. The efficient and feasible methods described herein can be applied to the production of a variety of [14C]- or [13C]-labeled SAs for studies on their environmental behavior, including the fate, transformation, and bioaccumulation of these antibiotics in soils and aqueous systems. [ABSTRACT FROM AUTHOR]

Purpose: Sulfonamides with high mobility in the soil pose a significant threat to environmental ecology and human health. Organic matter is known to affect the sorption and transport of these antibiotics in soil, although the mechanism remains unclear. In this study, the effects of humic acid (HA) on the transport of sulfadiazine (SDZ) in soil were investigated to advance the understanding on the fate of SDZ in soil. Materials and methods: Column experiments were conducted in combination with batch sorption experiments. The sorption and transport of SDZ in soil were simulated by the convection–dispersion model coupled with a linear sorption isotherm and kinetic adsorption processes. Fourier transform infrared spectroscopy was used to evaluate the molecular interactions and mechanisms of sorption. Results and discussion: The sorption isotherms conformed to a linear model with low distribution coefficients (Kd = 9.84 L/kg). Increasing the HA content led to increased sorption and inhibited transport of SDZ in soil. The sorption of SDZ on HA decreased with increasing pH and decreasing ionic strength. The mechanisms mainly comprised hydrophobic partition, hydrogen bonding, complexation, and π-π interactions. Mineral clays also played an important role in the sorption of SDZ on soil. The sorption and transport of SDZ were adequately described by the model, which demonstrated that as the HA content of the soil increased, the sorption capacity for SDZ and proportion of the time-dependent kinetic adsorption process both increased. Retained SDZ could also release slowly into the surrounding medium posing a longer-term risk to the environment. Conclusions: Humic acid increases the retention of SDZ in soil due to its high sorption capacity for SDZ. The sorption of SDZ on HA is dependent on solution chemistry such as pH and ionic strength. However, the retained SDZ would release slowly into the soil solution later. Thus, time-dependent sorption should be prioritized over sorption capacity in studies assessing the environmental fate and eco-toxicity of SDZ. [ABSTRACT FROM AUTHOR]

Pharmaceutically active compounds (PhACs) released into the environment have an adverse impact on the soil and water ecosystem as well as human health. Sorption of PhACs by soils and its potential modification through introduced DOM in the applied animal manure or treated wastewater (TWW) determines the mobility and environmental relevance of PhACs. Sulfadiazine, caffeine and atenolol were selected as target PhACs to investigate their sorption behaviors by five selected arable soils in the absence and presence of pig manure DOM. Sulfadiazine was least sorbed, followed by caffeine and atenolol according to the Freundlich sorption isotherm fit (soil average Kf [μg(1−n) mLn g−1] 4.07, 9.06, 18.92, respectively). The addition of manure DOM (31.34 mg C L−1) decreased the sorption of sulfadiazine and especially of caffeine and atenolol (average Kf 3.04, 6.17, 5.79, respectively). Freundlich sorption isotherms of the PhACs became more nonlinear in the presence of manure DOM (Freundlich exponent n changed from 0.74–1.40 to 0.62–1.12), implying more heterogeneous sorption of PhACs in soil–DOM binary systems. Sorption competition of DOM molecules with sulfadiazine and caffeine mostly contributed to their decreased soil sorption when DOM was present. In contrast, the formation of DOM–atenolol associates in the solution phase caused the largely decreased soil sorption of atenolol in the presence of DOM. It is suggested that DOM concentration (e.g., ≥ 60 mg C L−1) and its interaction with PhACs should be taken into consideration when assessing the environmental impact of land application of animal manure or irrigation with TWW. [ABSTRACT FROM AUTHOR]

Current research is based on biology-oriented synthesis of sulphadiazine derivatives and determination of their urease inhibitory activity. In this regard, a series of (E)-4-(benzylideneamino)-N-(pyrimidin-2-yl)benzenesulfonamide was synthesized from sulphadiazine and substituted aromatic aldehydes. The structures of synthesized compounds were ascertained by spectroscopic techniques, such as, FTIR, NMR and HRMS analysis, and in-vitro and in-silico investigation were carried out for the inhibition of urease. Ureases are harmful for humans by producing by-products of urea (ammonia and carbon dioxide). The most active compound (3l) against urease exhibited IC50 value of 2.21 ± 0.45 µM which is 10 times more potent than the standard thiourea (20.03 ± 2.06 µM). It is noteworthy that most of our synthesized compounds showed significant to excellent activities against urease enzyme and most of them substituted by halogen or hydroxy groups at ortho and para positions in their structures. Inhibition of enzyme by the synthesized analogues was in descending order as 3l > 3a > 3b > 3q > 3e > 3o > 3s > 3t > 3g > 3k > 3r > 3f > 3m > 3p > 3n > 3j > 3i > 3h. Moreover, molecular docking studies were performed to rationalize the binding interactions of the synthesized motifs with the active pocket of the urease enzyme. The synthesized sulphadiazine derivatives (3a–u) were found to be non-toxic, and presented passive gastrointestinal absorption. [ABSTRACT FROM AUTHOR]

An electrocatalyst modified electrode has been investigated to develop the rapid detection of antibiotics. The modified electrocatalyst was intended for the determination of sulfadiazine (SFZ) in biological fluids by electrochemical methods. Nanocube of zinc manganite (ZnMn2O4-NC) is prepared by hydrothermal method and a glassy carbon electrode (GCE) has been modified with the zinc manganite. The ZnMn2O4/GCE exhibit enhanced detection performances towards SFZ drug owing to their selective adsorption ability and the combination of electrostatic attraction of nanocube with SFZ. The modified electrocatalyst shows excellent electrocatalytic interactions with antibiotic drug. Besides, the modified sensors exhibit nanomolar detection limit (0.0021 μM) in 0.05 M phosphate buffer (pH = 7.0) using differential pulse voltammetric method. The working range of the modified electrode is 0.008–1264 μM, and the sensitivity of the SFZ sensor is 11.44 μA μM–1 cm–2. The modified sensor stability and reproducibility performances have been examined by electrochemical method. In addition, the obtained results of real sample analysis with different concentrations of SFZ in biological fluids are satisfactory with good recovery. [ABSTRACT FROM AUTHOR]

Sulfonamide (or sulphonamide) functional group chemistry (SN) forms the basis of several groups of drug. In vivo sulfonamides exhibit a range of pharmacological activities, such as anti-carbonic anhydrase and anti-t dihydropteroate synthetase allowing them to play a role in treating a diverse range of disease states such as diuresis, hypoglycemia, thyroiditis, inflammation, and glaucoma. Sulfamethazine (SMZ) is a commonly used sulphonamide drug in veterinary medicine that acts as an antibacterial compound to treat livestock diseases such as gastrointestinal and respiratory tract infections. Sulfadiazine (SDZ) is another frequently employed sulphonamide drug that is used in combination with the anti-malarial drug pyrimethamine to treat toxoplasmosis in warm-blooded animals. This study explores the research findings and the work behaviours of SN (SMZ and SDZ) drugs. The areas covered include SN drug structure, SN drug antibacterial activity, SN drug toxicity, and SN environmental toxicity. [ABSTRACT FROM AUTHOR]

The large-scale development of animal husbandry and the wide agricultural application of livestock manure lead to more and more serious co-pollution of heavy metals and antibiotics in soil. In this study, two common feed additives, copper (Cu) and sulfadiazine (SDZ), were selected as target pollutants to evaluate the toxicity and interaction of antibiotics and heavy metals on ammonia oxidizers diversity, potential nitrification rate (PNR), and enzymatic activity in black soils. The results showed that soil enzyme activity was significantly inhibited by single Cu pollution, but the toxicity could be reduced by introducing low-concentration SDZ (5 mg · kg−1), which showed an antagonistic effect between Cu and SDZ (5 mg · kg−1), while the combined toxicity of high-concentration SDZ (10 mg · kg−1) and Cu were strengthened compared with the single Cu contamination on soil enzymes. In contrast, soil PNR was more sensitive to single Cu pollution and its combined pollution with SDZ than the enzyme activity. Real-time fluorescence quota PCR and Illumina Hiseq/Miseq sequencing results showed that ammonia-oxidizing archaea (AOA) was decreased in C2 (200 mg · kg−1 Cu treatment) and ammonia-oxidizing bacteria (AOB) was obviously stimulated in soil contaminated in C2, while in S5 (5 mg · kg−1 SDZ treatment), AOB was decreased; both AOA and AOB were significantly decreased at gene level in soils with combined pollutants (C2S5, 200 mg · kg−1 Cu combined with 5 mg · kg−1 SDZ). So, it can be concluded that combined pollution can cause more serious toxicity on the enzymatic activity, PNR, and ammonia-oxidizing microorganisms in soil through the synergistic effect between heavy metals and antibiotics pollutants. [ABSTRACT FROM AUTHOR]

The widespread existence of antibiotics has caused inevitable influence on ecology and humans. In this study, we screened the most commonly used antibiotics, and 64 antibiotics were detected in Shanghai, an international metropolis. Most of the target substances were detected in all 46 water samples including main rivers and districts in Shanghai, with concentrations ranging from 0.02 to 502.43 ng L−1. In particular, sulfadiazine (502.43 ng L−1) had the highest maximum concentration. Besides, risk quotients based on fish suggested that sulfonamides had a medium risk (0.12) in Shanghai. Correlation studies had shown that most compounds with frequencies exceeding 60% were significantly positively correlated with the total concentration. Based on further analysis, sulfadiazine, sulfamerazine, and sulfapyridine were screened as indicators to reflect the pollution status of antibiotics in Shanghai for a long time. The screening conditions for these indicators include detection rate (> 60%), maximum concentration (> 100 ng L−1), RQ (> 0.01), and correlation (> 0). In addition, population density may be the main factor for antibiotic pollution through regional comparison. In a word, this work can systematically reflect the overall situation of Shanghai antibiotics and provide support for global data comparison in the future. Meanwhile, we provided the potential indicators that can be applied in the long term and economical monitoring of antibiotics. [ABSTRACT FROM AUTHOR]

This study addresses the growing concern about the high levels of antibiotics in water, outlining an alternative for their removal. The adsorption of four representative antibiotics from commonly used families (fluoroquinolones, β-lactams, trimethoprim, and sulfonamides) was performed over vegetal powdered activated carbon. The evolution of the adsorption was studied during 60 min for different initial antibiotic concentrations, not only individually but also simultaneously to determine competitive adsorption. Moreover, this research studied the adsorption isotherms and kinetics of the process, as well as the pH influence; FTIR of the activated carbon before and after adsorption was carried out. Trimethoprim and sulfadiazine showed more affinity for the adsorbent than amoxicillin and enrofloxacin. This trend might be attributed to their structure, capable of stablishing stronger π-π interactions with the adsorbent, which showed high affinity for the active sites of the adsorbent via FTIR. In addition, the sorption isotherms of trimethoprim followed a Langmuir type isotherm, amoxicillin followed a Freundlich type isotherm, and enrofloxacin and sulfadiazine followed both. The antibiotics followed pseudo-second-order kinetics. Sulfadiazine and amoxicillin gave better performances in acidic conditions. By contrast, the sorption of trimethoprim was favored in basic environments. Variations of pH had a negligible effect on the removal of enrofloxacin. [ABSTRACT FROM AUTHOR]

A double strategy based on the removal of sulfonamide antibiotics by Pleurotus ostreatus and adsorption on spent mushroom substrate was assessed to reclaim contaminated wastewater. P. ostreatus was firstly tested in a liquid medium fortified with five sulfonamides: sulfamethoxazole, sulfadiazine, sulfathiazole, sulfapyridine and sulfamethazine, to evaluate its capacity to remove them and to test for any adverse effects on fungal growth and for any reduction in residual antibiotic activity. P. ostreatus was effective in removing sulfonamides up to 83 to 91% of the applied doses over 14 days. The antibiotic activity of the sulfonamide residues was reduced by 50%. Sulfamethoxazole transformation products by laccase were identified, and the degradation pathway was proposed. In addition, P. ostreatus growth on a semi-solid medium of spent mushroom substrate and malt extract agar was used to develop a biofilter for the removal of sulfonamides from real wastewater. The biofilter was able to remove more than 90% of the sulfonamide concentrations over 24 h by combining adsorption and biodegradation mechanisms. [ABSTRACT FROM AUTHOR]

The addition of Fe3+ to TiO2 is one of the effective methods to inhibit the recombination of photogenerated electrons and holes and thus improve the photocatalytic activity of TiO2. The effect of PVDF-PVP-TiO2-FeCl3 (PPTFe) membrane filtration-photocatalytic system on the removal of trace concentration of sulfadiazine (SD) in water was evaluated. A two-factor four-level experiment was established to optimize 16 self-made modified membranes. The optimal membrane was then characterized in seven tests (SEM, EDS, membrane pure water flux, contact angle, porosity, mean pore size, ATR-FTIR), resulting in the optimal ratio (PPTFe membrane with 1.2 wt%TiO2 and 0.8 wt%FeCl3). Compared with the original membrane, the pore number, pore size, permeability, and hydrophilicity of the PPTFe membrane were all enhanced. The removal efficiency (92.63%) of SD by PPTFe membrane filtration-photocatalysis system was investigated. The reaction rate (0.0214 min−1) of the removal SD of the system was determined according to the pseudo-first-order kinetic model. The removal performance of membrane type, pH, and water quality parameters (Cl−, SO42−, NO3−, HA) on PPTFe membrane filtration-photocatalytic system were also made a deep inquiry. The results reflected that acidic conditions (pH = 3) were beneficial to SD removal, the presence of Cl−, SO42−, and HA could inhibit SD removal, while the existence of NO3− was unaffected. Furthermore, the removal rate of SD in the actual water body was displayed well in this system. Finally, the possible photocatalytic degradation mechanism was proposed. Graphical abstract [ABSTRACT FROM AUTHOR]

To improve the high-value application of corn stalk, phosphorus-containing stalk cellulose (PFC) was prepared, characterized, and utilized for the adsorption of sulfamethoxazole (SMZ) and sulfadiazine (SD), with maximum adsorption capacities of 1.385 and 2.527 mg/g at pH 7. As expected, the adsorption efficiency of PFC was strongly affected by pH, and the preferential adsorption order of SMZ− (SD0) > SMZ0 (SD−) > SMZ+ (SD+) was obtained from the experimental results and due to the charges of PFC and the SMZ and SD species. Furthermore, these results were qualitatively linked to the adsorption mechanism, e.g., π+-π electron donor-acceptor (EDA), anion-π bond electrostatic, and hydrophobic interactions. In particular, the adsorption mechanism was further characterized in terms of structure and analyzed systematically using density functional theory (DFT), frontier orbital theory (FOT), and molecular dynamics (MD) simulation, with the aim to explain the theoretical calculation and experimental results. As a result, the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) orbitals revealed the key role of the rings and functional groups of PFC and SMZ (or SD) and validated the optimized structures of PFC+ sulfonamides (SAs)+, PFC− SAs0, and PFC− SAs−, in which their binding energy values, energy gaps, and relevant molecular lengths determined their stability. Additionally, the van der Waals (vdW) energy confirmed the effect of various interactions on adsorption. [ABSTRACT FROM AUTHOR]

In this work, the degradation of sulfamethazine (SMT), sulfadiazine (SMD), and sulfamethoxazole (SMX) by using UV light, UV/H2O2, and UV/S2O8−2 was analyzed. Direct photolysis was studied by varying the lamp power and the solution pH. DFT calculations were carried out to corroborate the efficiency of the degradation as a function of the solution pH. The variation of the apparent rate constant, kap, was determined in the indirect photolysis by employing an experimental Box-Behnken-type response surface design. The results evidenced that SMX can be efficiently degraded by applying UV radiation independent of the operating conditions. Nevertheless, the quantum yields for SMT and SMD were close to zero, indicating a low energy efficiency for their photochemical transformation. The effect of the solution pH showed that the photodegradation of sulfonamides depends both on the amount of radiation absorbed as the electronic density. Calculations based on density functional theory and supported by the quantum theory of atoms in molecules allowed to describe fragmentation patterns in the systems under study, proving the lability of S14-C2, N17-C18, and N22-O22 bonds, for SMT, SMD, and SMX, respectively. From response surface methodology, four statistically reliable equations were obtained to determine the kap value as a function of the system operating conditions. Finally, SO4•− radicals proved to have a higher reactivity to degrade SMT and SMD compared with HO• radicals regardless of the operating conditions of the system. [ABSTRACT FROM AUTHOR]

The development of efficient solar driven catalyst for the degradation of antibiotics has become increasingly important in environmental protection. However, the reported efficient photocatalysts for antibiotic degradation are limited. In this work, porous Fe3+-doped graphitic carbon nitride (g-C3N4) with outstanding photocatalytic ability is synthesized and then used as the photocatalyst for the efficient degradation of sulfadiazine (SDZ) under visible light. A series of characterization results indicate that Fe3+ is successfully doped into the interlayer of g-C3N4 and is stabilized in g-C3N4 by Fe-N coordination bond. The SEM, DRS and ESI and transient photocurrent results demonstrated that Fe3+-doped g-C3N4 has a porous structure, a low band gap, improved separation efficiency of photogenerated electron and holes as well as a wider light absorption range. Such improved physical and chemical properties greatly enhanced the photocatalytic ability. Using Fe3+-doped g-C3N4 for photocatalytic degradation of SDZ under white light, almost complete degradation of SDZ was achieved with a degradation efficiency as high as 99.8% (whereas only 52.1% for bulk g-C3N4) within 90 min. The degradation was mainly ascribe to 1O2 during the irradiation, and also a small amount of •O2−, OH• and h+ are involved in the degradation process. The Fe3+-doped g-C3N4 was applicable for the degradation of a wide range of antibiotic pollutants. [ABSTRACT FROM AUTHOR]

Sulfadiazine (SDZ) was effectively removed by the heterogeneous catalytic sulfate radical (SO4•−) oxidation using a novel composite material of mesoporous carbon (MC) loaded nano zero-valent iron (nZVI). Possessing larger specific area (433.3 m2 g−1) and high mesopores volume (2.537 cm3 g−1), the composite material (nZVI/MC) was used as the activator to activate persulfate for the degradation of SDZ. The results of degradation experiments indicated that the removal efficiency of SDZ in nZVI/MC+ persulfate (PS) process reached the highest, due to good dispersing property of MC for nZVI. The removal of SDZ was further enhanced by the increase of nZVI loading as well as the nZVI/MC composite content. Quenching experiments showed that SO4•− acted a crucial role in the degradation process of SDZ. Both the FT-IR and XPS analyses showed that the FeO contents decreased after degradation reaction, which indicated the occurrence of active oxidation reaction between SO4•− and Fe2+ from the breakage of the Fe–O bond. The LC-MS analysis indicated that the cleavages of C–N bond in the heterocyclic ring and N–S bond were the major degradation pathway of SDZ, attributing to the attack of SO4•− and •OH. These results demonstrated that the novel nZVI/MC composite with excellent stability could be used for the effective degradation of SDZ through activating PS to produce SO4•−. [ABSTRACT FROM AUTHOR]

Sulfadiazine (SDZ) residues have been detected in manured soils as well as their adjacent water resources, but its behavior is still poorly understood in acidic tropical soils. This research aimed to evaluate sorption, leaching, and biodegradation of 14C-SDZ in four acidic soils from Brazil, using OECD guidelines. Except for the sand soil (Kd = 2.6 L kg−1), SDZ sorption tended to be higher (Kd > 8.4 L kg−1) and more hysteretic (ΔH >> 1) in acidic soils. When freshly applied, SDZ leaching was low (< 0.11% of applied radioactivity (AR)) and could not always be predicted by Kd values; but leaching was restricted when SDZ was aged for 62 days. SDZ mineralization was low (< 3%) but its dissipation was fast (DT50 < 2.3 days and DT90 < 6.3 days) due to fast initial degradation (an unknown metabolite was immediately formed, likely 4-hydroxysulfadiazine) and mainly to fast formation of non-extractable residues (NER) (> 78% of AR up to 7 days). For certain acidic soils, the abrupt breakdown of the SDZ suggests that degradation should be initially chemical and then followed by enzymatically driven reactions. The fast formation of NERs was attributed mostly to chemical bounding to soil humic substances (Type II-NER), but SDZ sequestration cannot be ruled out (Type I-NER). NERs represent a long-term environmental reservoir of SDZ that may cause deleterious effects on non-target organisms as well as promote antibiotic resistance to soil microbes. [ABSTRACT FROM AUTHOR]

Sulfadiazine is an antibiotic used in animals and humans, this molecule is being released increasingly into the aquatic environment, which is why the depletion of this molecule in rainbow trout (Oncorhynchus mykkis) was studied using radiometric techniques with 14C, for which a specific activity of 3.5171 MBq mg−1 was used, during 14 days in semi-static conditions. The study found accumulation in trout on day four 5.10 × 10−4 mg g−1 after the exposure phase, and 1.0 × 10−4 mg g−1 after the purification phase, indicates that the concentration used puts human health at risk because exceed the maximum residual limits. [ABSTRACT FROM AUTHOR]

Healing of injuries caused by exposure to heat has been discussed in many studies, although a few drugs have been shown to produce satisfactory results. In this study, 100 healthy mice randomly allocated into four categories (each = 25 mice) were analyzed. A deep second-degree burn on the back of each mouse was created. The burns were dressed daily with either AgNPs or silver sulfadiazine over 28 days of treatment. Safety evaluation of the AgNP treatment was performed by measuring the deposition rate of silver in the liver, brain, and kidney of treated mice. In the murine burn model, the speed of wound healing and the antibacterial effect of AgNPs were better than those in the silver sulfadiazine group. Burn wounds treated with SSD appeared to display a greater degree of inflammation as notable by the three clinical signs of the inflammatory process such as redness and swelling which appeared to be less after wounds treated with AgNPs. Also, AgNP treatment modified leukocytic infiltration and reduced collagen degeneration in treated mice and enhanced healing processes that were confirmed by morphological and histological investigations. Beside the potential significant effects of AgNPs on reduction of some microorganism counts that routinely isolated from burn wounds included aerobic organisms as Staphylococcus aureus and Escherichia coli when compared to both SSD and control groups. The deposition kinetics of AgNPs revealed lower distribution in the liver, brain, and kidney than that in silver sulfadiazine-treated mice with respect to both SSD and control groups. [ABSTRACT FROM AUTHOR]