Facile synthesis of Cu-doped manganese oxide octahedral molecular sieve for the efficient degradation of sulfamethoxazole via peroxymonosulfate activation

Advanced processes for peroxymonosulfate(PMS)-based oxidation are efficient in eliminating toxic and refractory organic pol-lutants from sewage.The activation of electron-withdrawing HSO_(5)^(-)releases reactive species,including sulfate radical(·SO_(4)^(-)),hydroxyl radical(·OH),superoxide radical(·O_(2)^(-)),and singlet oxygen(1O_(2)),which can induce the degradation of organic contaminants.In this work,we synthesized a variety of M-OMS-2 nanorods(M=Co,Ni,Cu,Fe)by doping Co^(2+),Ni^(2+),Cu^(2+),or Fe^(3+)into manganese oxide oc-tahedral molecular sieve(OMS-2)to efficiently remove sulfamethoxazole(SMX)via PMS activation.The catalytic performance of M-OMS-2 in SMX elimination via PMS activation was assessed.The nanorods obtained in decreasing order of SMX removal rate were Cu-OMS-2(96.40%),Co-OMS-2(88.00%),Ni-OMS-2(87.20%),Fe-OMS-2(35.00%),and OMS-2(33.50%).Then,the kinetics and struc-ture-activity relationship of the M-OMS-2 nanorods during the elimination of SMX were investigated.The feasible mechanism underly-ing SMX degradation by the Cu-OMS-2/PMS system was further investigated with a quenching experiment,high-resolution mass spec-troscopy,and electron paramagnetic resonance.Results showed that SMX degradation efficiency was enhanced in seawater and tap water,demonstrating the potential application of Cu-OMS-2/PMS system in sewage treatment.

Preparation of Molecularly Imprinted Composites Initiated by Hemin/Graphene Hybrid Nanosheets and Its Application in Detection of Sulfamethoxazole

Molecularly imprinted polymers(MIPs)exhibit high selectivity resulting from imprinted cavities and superior performance from functional materials,which have attracted much attention in many fields.However,the combination of MIPs film and functional materials is a great challenge.In this study,hemin/graphene hybrid nanosheets(H-GNs)were used to initiate the imprinted polymerization by catalyzing the generation of free radicals.Thus,MIPs using sulfamethoxazole as the template was directly prepared on the surface of H-GNs without any film modification.Most importantly,the template could be absorbed on the H-GNs to enhance the number of imprinted sites per unit surface area,which could improve the selectivity of MIPs film.Thus,the composites could exhibit high adsorption capacity(29.4 mg/g),imprinting factor(4.2)and excellent conductivity,which were modified on the surface of electrode for rapid,selective and sensitive detection of sulfamethoxazole in food and serum samples.The linear range was changed from 5μg/kg to 1 mg/g and the limit of detection was 1.2μg/kg.This sensor was free from interference caused by analogues of sulfamethoxazole,which provides a novel insight for the preparation of MIPs-based sensor and its application in food safety monitoring and human exposure study.

Pharmacokinetics and acetylation of sulfamethoxazole in turbot Scophthalmus maximus after intravascular administration

The pharmacokinetic profi les and sulfamethoxazole(SMX) acetylation process in turbot reared at 18°C were investigated. Either SMX(parent drug) or its acetylized metabolite, N4-acetylsulfamethoxazole(Ac SMX), was administered intravascularly to turbot at a dosage of 50 mg/kg BW. Serum concentrations of the parent drug and its metabolite were both measured by HPLC, and the changes in concentration over time were analyzed in two- and non-compartment models because SMX treatment produced multiple peaks. The results demonstrated that the elimination half-life of the parent drugs, SMX and Ac SMX, were 159.2 and 5.9 h, respectively. The apparent volume of distribution was 0.2 and 0.8 L/kg, and the clearance was 0.038 and 0.222 L/(h·kg), for SMX and Ac SMX, respectively. SMX acetylation in turbot was 2.8%, and the deacetylation of Ac SMX was 0.2%. These fi ndings may be useful in optimizing SMX dosage regimens in turbot aquaculture.

Salt-tolerant Microbiota Enhancing Contaminants Removal from Mariculture Wastewater Containing Sulfamethoxazole in an A/O-MBBR

The wide application of antibiotics in aquaculture requires an efficient treatment of the wastewater before discharging it into the environment.During the wastewater treatment,the influence of antibiotics on the performance of bioreactor should be well revealed due to their toxicity to the functional microbial community.In this study,the effect of feeding 10-30 mg L−1 sulfamethoxazole(SMX)in influent on the performance of an anoxic/oxic-moving bed biofilm reactor(A/O-MBBR)treating mariculture wastewater and the responding change of biofilm microbial communities was investigated.The COD average removal rate remained at 94.61%-97.34%with the dosage of SMX.Compared with that,the nitrifying removals of NH4+-N and NO2−-N were violently inhibited by 30 mg L−1 SMX and denitrifying removal of the NO3−-N decreased obviously with 20 mg L−1 or more SMX.The microbial community in the successful startup bioreactor was relatively abundant,while the diversity of microbial community decreased with the increase of feeding SMX.The salt-tolerant and SMX-resistant genera Arcobacter,Thiothrix,Desulfuromusa and Nitrosomonas were gradually enriched and finally played a vital role in converting COD and recycling nitrogen and sulfur.Hence,the present A/O-MBBR reactor with the salt-tolerant functional microbiota achieved efficient removal of pollutants in the presence of low concentration(e.g.,10 mg L−1)SMX.

Non-covalent binding analysis of sulfamethoxazole to human serum albumin:Fluorescence spectroscopy,UV-vis,FT-IR,voltammetric and molecular modeling

This study was designed to examine the interaction of sulfamethoxazole （SMZ） with human serum albumin（HSA）. Spectroscopic analysis of the emission quenching at different temperatures revealed that the quenching mechanism of human serum albumin by SMZ was static mechanism. The binding constant values for the SMZ-HSA system were obtained to be 22,500 L/mol at 288 K, 15,600 L/mol at 298 K, and 8500 L/mol at 308 K. The distance r between donor and acceptor was evaluated according to the theory of Foster energy transfer. The results of spectroscopic analysis and molecular modeling techniques showed that the conformation of human serum albumin had been changed in the presence of SMZ. The thermodynamic parameters, namely enthalpy change （ΔH^0） - 36.0 kJ/mol, entropy change （ΔS^0） - 41.3 Jim01 K and free energy change （ΔG^0） - 23.7 kJ/ mol, were calculated by using van＇t Hoff equation. The effect of common ions on the binding of SMZ to HSA was tested.

Development of Surface Plasmon Resonance-Based Biosensor Immunoassay for Sulfamethoxazole

The illegal use of veterinary drugs has led to the occurrence of residues in food of animal origin.This is a hazard to people's health.In this paper,a sensitive and fast assay was developed to determine sulfamethoxazole (SMOZ) in PBS with a homemade surface plasmon resonance (SPR)-based biosensor which had a single flow channel and two references.The derivative of SMOZ was covalently immobilized to a carboxymethyldextran modified gold film.A recently developed monoclonal antibody against sulfamethoxazole was used to develop an inhibitive immunobiosensor assay in which the antibody was mixed with SMOZ of different concentrations prepared with PBS to construct a standard curve with a low limit of detection(LOD).The effect of matrix in milk was also studied.Calculating of the apparent concentration showed the cross-reactivity with other sulfonamides.

Biofilm formation in trimethoprim/sulfamethoxazole-susceptible and trimethoprim/sulfamethoxazoleresistant uropathogenic Escherichia coli

Objective: To compare bioi lm formation in trimethoprim/sulfamethoxazole(SXT)-susceptible Escherichia coli(E. coli)(SSEC) and SXT-resistant E. coli(SREC) isolated from patients with urinary tract infections, and study the motile ability and physical characteristics of the isolates.Methods: A total of 74 E. coli isolates were tested for antimicrobial susceptibility with the disc diffusion assay. Based on the SXT-susceptibility test, the E. coli isolates were divided into SSEC(N = 30) and SREC(N = 44) groups. All E. coli isolates were examined for motile ability by using a motility test medium, and for checking bioi lm formation a scanning electron microscope was used. Bacterial colony size was measured with a vernier caliper and bacterial cell length was measured under a light microscope. The bacterial growth rate was studied by plotting the cell growth(absorbance) versus the incubation time. Results: The frequencies of non-motility and biofilm formation in the SREC group were signii cantly higher than that in the SSEC group(P < 0.01). The SREC bacterial cell length was shorter than that in the SSEC group [(1.35 ± 0.05) vs.(1.53 ± 0.05) μm, P < 0.05)], whereas the bacterial colony size and mid-log phase of the growth curve were not signii cantly dif erent. Conclusions: The present study indicated that bioi lm formation and phenotypic change of uropathogenic E. coli can be attributed to the mechanism of E. coli SXT resistance.

Imaging Array SPR Biosensor Immunoassays for Sulfamethoxazole and Sulfamethazine

A homemade array surface plasmon resonance （SPR）-based imaging biosensor was used to develop sensitive and fast immunoassays to determine sulfamethoxazole （SMOZ） and sulfamethazine （SMT） in buffer. Two conjugations of sulfonamide-bovine serum albumin （BSA） were separately immobilized on two different rows of the array chip with one row as reference. The immobilization was carried out in the instrument to monitor the quantity of the conjugations immobilized. The antibody mixed with the sulfonamide in the buffer was injected over the surface of the chip to get a relative response which was inversely proportional to the concentration of the sulfonamide in the PBS buffer. Two calibration curves were constructed and the limit of detection for sufamethoxazole in buffer was 3.5 ng/mL and for sulfamethazine 0.6 ng/mL. The stability and specificity of the antibody were also studied. The monoclonal antibody did not bind with BSA.

A novel indirect inhibitive immunoassay for sulfamethoxazole

A new indirect inhibitive immunoassay using surface plasmon resonance（SPR） coupled with molecularly imprinted polymer（MIP） was developed.A sulfamethoxazole（SMX） MIP coating capillary was produced and used as an in-tube solid phase extraction（SPE） device.The MIP coating formed a nanometer film on the inner wall of the capillary.The anti-SMX mono-antibody was inhibited by SMX extracted by the MIP coating in a dose-dependent manner.The calibration curve was generated by linear fit over the range of 0.04-10.00 ng/mL.The limit of detection was 0.01 ng/mL.This method has high sensitivity and can be performed automatically.

Degradation of sulfamethoxazole in water by dielectric barrier discharge plasma jet:influencing parameters,degradation pathway,toxicity evaluation

Sulfamethoxazole(SMX)is an antibiotic and widely present in aquatic environments,so it presents a serious threat to human health and sustainable development.A dielectric barrier discharge(DBD)plasma jet was utilized to degrade aqueous SMX,and the effects of various operating parameters(working gas,discharge power,etc)on SMX degradation performance were studied.The experimental results showed that the DBD plasma jet can obtain a relatively high degradation efficiency for SMX when the discharge power is high with an oxygen atmosphere,the initial concentration of SMX is low,and the aqueous solution is under acidic conditions.The reactive species produced in the liquid phase were detected,and OH radicals and O3were found to play a significant role in the degradation of SMX.Moreover,the process of SMX degradation could be better fitted by the quasi-first-order reaction kinetic equation.The analysis of the SMX degradation process indicated that SMX was gradually decomposed and 4-amino benzene sulfonic acid,benzene sulfonamide,4-nitro SMX,and phenylsulfinyl acid were detected,and thus three possible degradation pathways were finally proposed.The mineralization degree of SMX reached 90.04%after plasma treatment for 20 min,and the toxicity of the solution fluctuated with the discharge time but eventually decreased.

Nitrogen Removal Performance of Denitrifying Ammonium Oxidation System in Treating Sulfamethoxazole-laden Secondary Wastewater Effluent

In this study,nitrogen removal performance of the denitrifying ammonium oxidation(DAO)process was investigated when treating sulfamethoxazole(SMX)-laden secondary wastewater effluent.The influent SMX concentration showed negligible effect on efficiencies for removal of nitrate and COD.However,the ammonium ions removal rate was moderately reduced,when the influent SMX concentration in wastewater reached 6 mg/L.Total nitrogen removal efficiency remained as high as 76.77%towards the day 158 at the end of experiment.Candidatus_Brocadia and Candidatus_Kuenenia were the functional anammox strains.The unclassified_f__Rhodobacteraceae sp.was predominant heterotrophic denitrifying strain in the studied reactor.The concentrations of soluble extracellular polymeric substances in sludge obviously increased from 16.76 mg/g VSS to 32.31 mg/g VSS,which might protect the nitrogen removal strains from high-concentration SMX.This result provides a theoretical and technical foundation for the application of denitrifying ammonium oxidation process in treating sulfamethoxazole-laden secondary wastewater effluent.

Antimicrobial therapy using sulfamethoxazole trimethoprim for Kawasaki disease patients unresponsive to intravenous immunoglobulin

Our previous study suggested that the production of superantigens and heat-shock protein 60 by small intestinal bacteria might play a role in Kawasaki disease (KD). We demonstrated that they were all resistant to commonly used antibiotics, except for sulamethoxazole trimethoprim (SMX-TMP). We used SMX-TMP for 7 cases of KD that were unresponsive to intravenous immunoglobulin (IVIG) and studied the antipyretic potency of this treatment. In 6 out of the 7 cases, we demonstrated that antipyretic potency was observed without side effects within 2 days of the initial administration. Antimicrobial therapy using SMX-TMP might represent a novel strategy for cases of KD that are unresponsive to IVIG.

Adsorption of Sulfamethoxazole on Nanoporous Carbon Derived from Metal-Organic Frameworks

Nanoporous Carbon (NPC) with high surface area of 1379 M2/G and high proportion of micropore and mesopore volume of 2.90 Cm3/G was prepared by carbonization of metal?organic frameworks ZIF-8. The adsorption of NPC towards the representative sulfonamide antibiotics sulfamethoxazole (SMX) from aqueous solutions was explored, in comparison with powder active carbon (AC). The adsorption kinetics and isotherms showed that the maximum adsorption capacity (Qm) of NPC toward SMX was 757 Mg/G, around 2 times than that of AC adsorption. The high adsorption affinity of NPC was related to the high surface area and special Mic/Mesopore structure. The pore-filling mechanism as well as electrostatic interaction had important influence on the high adsorption of NPC. The results implied that nanoporous carbon derived from mofs could remove the contaminants from aqueous solutions effectively, and would be a promising adsorbent for the removal of contaminants in the future.

A Patient with Acute Liver Injury after Sulfamethoxazole/Trimethoprim Treatment for Pyelonephritis

Background: Sulfamethoxazole/Trimethoprim is a commonly used drug in a variety of clinically indicated scenarios, but it is not without side effect. Case-reports have stated that adverse reactions secondary to Sulfamethoxazole/Trimethoprim can present very early in the course of treatment, especially in patients who have a higher predisposition. Thus, the burden is placed on the clinician to be wary of these side effects and be able to recognize them in the correct clinic scenario. Objective: To discuss the risk of developing cholestatic hepatic dysfunction secondary to treatment with sulfamethoxazole/trimethoprim. Methods: We present the history, physical findings, laboratory investigations, and clinical course of a 47-year-old African-American female who developed cholestatic hepatic dysfunction after treatment with sulfamethoxazole/trimethoprim for pyelonephritis. Results: Drug-induced liver injury is a rare complication of sulfamethoxazole/trimethoprim therapy and only 20% of cases are secondary to cholestatic hepatic dysfunction. Our patient, who had been on sulfamethoxazole/trimethoprim for 7 days for pyelonephritis, presented to our hospital with a clinical picture consistent with hepatic injury;her laboratory investigations were noteworthy for an elevated white blood cell count, platelet count, and elevated transaminases, along with alkaline phosphatase levels greater than 2 times the upper limit of normal. Promptly following the discontinuation of sulfamethoxazole/trimethoprim, our patient improved clinically and her liver enzymes down-trended during the course of her hospital stay. She returned to normal at her 4 month follow up, thus confirming the diagnosis of cholestatic hepatic dysfunction secondary to sulfamethoxazole/trimethoprim. Conclusion: Cholestatic hepatic dysfunction is a form of drug-induced liver injury and a rare complication of sulfamethoxazole/trimethoprim treatment. The majority of cases resolve following discontinuation of the offending medication. However, a small percentage of patients may progress to liver failure and ultimately require liver transplantation. Clinicians should be aware of these risks to avoid delaying the discontinuation of sulfamethoxazole/trimethoprim.

Responses of soil enzyme and microbial community under co-loading of different microplastics and sulfamethoxazole

Polyamide/polyethylene(PA/PE)microplastics were injected into soil containing sulfamethoxazole(SMX)to investigate their combined effects on SMX removal,soil enzyme activity,and microbial communities.The results show that both PA and PE transiently increase SMX removal and inhibite the stimulation of microbial species diversity by SMX.The effect of PE is more significant.Meanwhile,PE combined with SMX increases the relative abundances of Actinobacteria and Pseudomonas,while PA combined with SMX decreases the relative abundances of Nocardioides and Streptomyces.In addition,PA/PE combined with SMX can increase dehydrogenase,urease,ammonia monooxygenase,and nitrate reductase activities in the soil while inhibiting the activity of laccase.Compared with PA combined with SMX,the activities of dehydrogenase,urease,ammonia monooxygenase,and laccase of PE combined with SMX increase by 9.82%,10.41%,8.07%,and 5.47%,while the activities of nitrate reductase and neutral phosphatase decrease by 1.47%and 6.78%.

Selective removal of sulfamethoxazole by a novel double Z-scheme photocatalyst:Preferential recognition and degradation mechanism

Sulfamethoxazole(SMX)is a significant environmental concern due to its adverse effects and ecological risks.SMX elimination in aquatic environments via photocatalysis presents a viable solution,given its high oxidation potential.However,such a solution remains controversial,primarily due to a lack of selectivity.Here we introduce a molecularly imprinted TiO2@Fe_(2)O_(3)@g-C_(3)N_(4)(MFTC)photocatalyst designed for the selective degradation of SMX.To assess MFTC's selectivity,we applied it to degrade synthetic wastewater containing SMX alongside interfering species sulfadiazine(SDZ),ibuprofen(IBU),and bisphenol A(BPA).The results demonstrated a selective degradation efficiency rate of 96.8%,nearly twice that of competing pollutants.The molecularly imprinted sites within the catalyst played a crucial role by selectively capturing SMX and enhancing its adsorption,thereby improving catalytic efficiency.The degradation process involvedOH and·O_(2)^(-)free radicals,with a newly proposed double Z-scheme mechanism and potential pathway for SMX degradation by the MFTC photocatalytic system.This study enriches the application of photocatalysis using molecularly imprinted nanocomposite materials for treating complex pollutant mixtures in water.

Effects of environmental factors on sulfamethoxazole photodegradation under simulated sunlight irradiation: Kinetics and mechanism

To advance the knowledge of the environmental fate of sulfamethoxazole （SMX）, we systematically investigated the effects of natural water constituents and synthetic substances （i.e., TiO2 nanoparticles （nTiO2） and Ti-doped ^-Bi203 （NTB）） on the photodegradation kinetics of SMX under xenon lamp irradiation. The photolysis of SMX in aqueous solution followed first-order kinetics. Our results showed that higher concentrations of SMX, fulvic acid, suspended sediments, NTB and higher pH value decreased the photodegradation rates of SMX, whereas H202 improved the SMX photodegradation. TiO2 nanoparticles had a dual effect on pbotodegradation due to their photocatalytic activity and photoabsorption of photons. No intermediates more toxic toward Vibrio fischeri than SMX were produced after direct photolysis and photocatalytic degradation for 3 hr. The photolysis of SMX involved three pathways： hydroxylation, cleavage of the sulfonamide bond, and fragmentation of the isoxazole ring. This study lays the groundwork for a better understanding of the environmental fate of SMX.

Behavior toxicity to Caenorhabditis elegans transferred to the progeny after exposure to sulfamethoxazole at environmentally relevant concentrations

Sulfamethoxazole （SMX） is one of the most common detected antibiotics in the environment. In order to study whether SMX can affect behavior and growth and whether these effects could be transferred to the progeny, Caenorhabditis elegans was exposed at environmentally relevant concentrations for 24, 48, 72 and 96 hr, respectively. After exposure, the exposed parent generation （P0） was measured for behavior and growth indicators, which were presented as percentage of controls （POC）. Then their corresponding unexposed progeny （F1） was separated and measured for the same indicators. The lowest POC for P0 after 96 hr-exposure at 100 mg/L were 37.8%, 12.7%, 45.8% and 70.l% for body bending frequency （BBF）, reversal movement （RM）, Omega turns （OT） and body length （BL）, respectively. And F1 suffered defects with the lowest POC as 55.8%, 24.1%, 48.5% and 60.7% for BBF, RM, OT and BL, respectively. Defects in both P0 and F1 showed a time- and concentration-dependent fashion and behavior indicators showed better sensitivity than growth indicator. The observed effects on F1 demonstrated the transferable properties of SMX. Defects of SMX at environmental concentrations suggested that it is necessary to perform further systematical studies on its ecological risk in actual conditions.

Simultaneous removal of cadmium and sulfamethoxazole from aqueous solution by rice straw biochar

The simultaneous sorption behavior and characteristics of cadmium (Cd) and sulfamethoxazole (SMX) on rice straw biochar were investigated. Isotherms of Cd and SMX were well modeled by the Langmuir equation (R2 >0.95). The calculated maximum adsorption parameter (Q) of Cd was similar in single and binary systems (34129.69 and 35919.54 mg/kg, respectively). However, the Q of SMX in a binary system (9182.74 mg/kg) was much higher than that in a single system (1827.82 mg/kg). The presence of Cd significantly promoted the sorption of SMX on rice straw biochar. When the pH ranged from 3 to 7.5, the sorption of Cd had the characteristics of a parabola pattern with maximum adsorption at pH 5, while the adsorption quantity of SMX decreased with increasing pH, with maximum adsorption at pH 3. The amount of SMX adsorbed on biochar was positively correlated with the surface area of the biochar, and the maximum adsorption occurred with d 250 biochar (biochar with a diameter of 150-250 μm). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) showed that the removal of Cd and SMX by rice straw biochar may be attributed to precipitation and the formation of surface complexes between Cd or SMX and carboxyl or hydroxyl groups. The results of this study indicate that rice straw biochar has the potential for simultaneous removal of Cd and SMX from co-contaminated water.

A comparative study and evaluation of sulfamethoxazole adsorption onto organo-montmorillonites

Three organo-montmorillonites were prepared using surfactants, and their adsorption behaviors toward sulfamethoxazole（SMX） were investigated. The surfactants used were cetyltrimethyl ammonium bromide（CTMAB）, 3-（N,N-dimethylhexadecylammonio） propane sulfonate（HDAPS） and 1,3-bis（hexadecyldimethylammonio）-propane dibromide（BHDAP）. The properties of the organo-montmorillonites were characterized by X-ray diffraction, scanning electron microscopy and N2adsorption–desorption isotherm measurements. Results showed that the interlayer spacing of montmorillonite was increased and the surface area as well as the morphology were changed. Batch adsorption experiments showed that the surfactant loading amount had a great effect on the adsorption of SMX. The adsorption process was p H dependent and the maximum adsorption capacity was obtained at p H 3 for HDAPS-Mt, while CTMAB-Mt and BHDAP-Mt showed a high removal efficiency at 3–11. The adsorption capacity increased with the initial SMX concentration and contact time but decreased with increasing solution ionic strength.Kinetic data were best described by the pseudo second-order model. Equilibrium data were best represented by the Langmuir model, and the Freundlich constant（n） indicated a favorable adsorption process. The maximum adsorption capacity of SMX was 235.29 mg/g for CTMAB-Mt, 155.28 mg/g for HDAPS-Mt and 242.72 mg/g for BHDAP-Mt. Thermodynamic parameters were calculated to evaluate the spontaneity and endothermic or exothermic nature. The adsorption mechanism was found to be dominated by electrostatic interaction,while hydrophobic interaction played a secondary role.