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Enhanced removal of antibiotics from secondary wastewater effluents by novel UV/pre-magnetized Fe0/H2O2 process
摘要： Antibiotics have been frequently detected in the aquatic environment and are of emerging concern due to their adverse effect and potential of inducing antibiotic resistance. In this study, we developed an UV/pre-magnetized Fe0/H2O2 process (UV/pre-Fe0/H2O2) valid for neutral pH conditions, which could remove sulfamethazine (SMT) completely within only 30 min and enhance 1.8 times of SMT removal. Meanwhile, this process demonstrated outstanding mineralization capability with the TOC removal of 92.1%, while for UV/H2O2 and UV/Fe0/H2O2 system it was 53.9% and 72.1%, respectively. Better synergetic effect between UV irradiation and pre-Fe0/H2O2 system was observed, and the value of synergetic factor was 6.3 in the presence of both ions and humic acid, which was much higher than that in deionized water (4.4), humic acid (5.5) and ions (1.5). Moreover, the process could efficiently remove various antibiotics (800 μg L-1 oxytetracycline (OTC); 800 μg L-1 tetracycline (TC); 400 μg L-1 sulfadiazine (SD) and 400 μg L-1 SMT) in the secondary wastewater effluent. After optimization of Fe0 and H2O2 dosage, these antibiotics could be removed within 10 min (kapp (103) = 288.6 min-1) with a very low treatment cost of 0.1 USD m-3, and the EE/O value was only 1.22 kWh m-3. Compared with O3, UV/Fe2+/PDS, VUV/UV/Fe2+ and other US-based processes, the degradation rates by this process could enhance as high as 22.3 folds while the treatment cost or EE/O value could reduce greatly. Therefore, UV/pre-Fe0/H2O2 process is promising and cost-effective for the treatment of antibiotics in secondary wastewater effluents.
关键词： secondary wastewater effluents,synergetic effect,cost-effective,UV/pre-Fe0/H2O2 process,antibiotics
更新于2025-09-23 15:23:52
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A Fluorescent Cocktail Strategy for Differentiating Tumor, Inflammation, and Normal Cells by Detecting mRNA and H <sub/>2</sub> O <sub/>2</sub>
摘要： Accurately distinguishing tumors from noncancerous inflammation and normal tissues is hugely significant for tumor diagnosis and therapy. However, tumor and inflammatory tissues have similar pathologic characteristics in their microenvironment, making differentiation very difficult. Here, a fluorescent cocktail nanoparticle capable of simultaneously detecting intracellular mRNA and H2O2 was designed to differentiate tumors from nontumor cells. To detect targeted mRNA in living cells, a DNA probe was generated using the fluorescence resonance energy transfer (FRET) principle. A pH-responsive amphiphilic polymer was synthesized to realize the transportation of the DNA probe. In addition, the polymer was conjugated with a coumarin-boronic acid ester (Cou-BE) H2O2 probe. According to the change in the fluorescence of Cou-BE, tumor and inflammatory cells could be distinguished from normal cells owing to their high concentration of H2O2. Because of the different concentrations of tumor-related mRNA in tumor and nontumor cells, the fluorescence intensity of the DNA probe-loaded nanoparticles inside tumor cells was different from that inside inflammatory cells. Therefore, our fluorescent cocktail strategy could discriminate simultaneously tumor, inflammation, and normal cells through the cooperative detection of intracellular mRNA and H2O2, which demonstrated potential application value in biomedical research and clinical diagnosis.
关键词： H2O2,tumor,tumor-related mRNA,fluorescence imaging,inflammation
更新于2025-09-23 15:23:52
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Study of the relationship between metal-assisted chemical etching and direction of the applied electric field
摘要： Metal-assisted chemical etching (MACE) has been proposed as a promising alternative for the fabrication of micro/nano-structures on silicon with simple process and low cost. Electric field can be applied during the reaction to control the motion of charged particles so as to accelerate the reaction and form uniform vertical trenches with high aspect ratio. In this paper, boron doped p-type (100) silicon wafers with resistivity of 20～30 Ω·cm was used as substrates. After coated with layers of 5 nm Ti and 10 nm Au, the silicon substrate was immersed into the etchant containing hydrofluoric acid (HF) and hydrogen peroxide (H2O2) with high HF-to-H2O2 concentration ratio (ρ) and an applied voltage of 40 volts. It was found that the direction of the applied electric field had a great influence on morphologies of the trenches. Deeper trenches with vertical sidewalls and relatively smoother bottom were observed when silicon substrate was connected to cathode of the power supply. Possible interpretation to these phenomena was proposed, and the effect of the electric field intensity and doping concentration was further studied.
关键词： trench morphology,metal-assisted chemical etching,electric field,HF-to-H2O2 ratio,electrode connection
更新于2025-09-23 15:23:52
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Heterogeneous degradation of organic contaminants in the photo-Fenton reaction employing pure cubic β-Fe2O3
摘要： Pure cubic β-Fe2O3 crystal, which can absorb visible light (< 650 nm) on account of the bandgap of 1.9 eV as a direct bandgap semiconductor, was employed as a low-cost and non-toxic catalyst for photo-Fenton reaction in this article. Diverse organic contaminants including rhodamine B (RhB), methyl orange (MO), alizarin red (AR) and phenol can be effectively degraded. In particular, the degradation of RhB were investigated detailedly. As such, hydroxyl radicals (%OH) were verified to act as considerable active species for the process by using terephthalic acid as an indicator. Degradation mechanism and intermediates of phenol in the photo-Fenton reaction was discovered by virtue of liquid chromatography-mass spectrometry (LCeMS). Notably, hydroxylation of phenol generated some intermediates, which are converted into H2O and CO2 eventually.
关键词： Photo-Fenton,H2O2,β-Fe2O3,Degradation,Hydroxyl radicals
更新于2025-09-23 15:22:29
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Efficiency of sequential UV/H2O2 and biofilm process for the treatment of secondary effluent
摘要： In response to the shortage of water resources, multiple processes have been applied to turn wastewater secondary effluent (SE) into potable water. However, trace organic contaminants (TOrCs) and high concentrations of organic matter contained in SE pose a significant challenge to the reclamation. In this manuscript, combined UV-based and biofilm processes were used to treat the SE spiked with ibuprofen (IBU) and clofibric acid (CA). The efficiency of these sequential treatments was characterized in terms of changes in dissolved organic carbon (DOC), absorbance at 254 nm (A254), fluorescence excitation-emission matrix (FEEM), the concentration of IBU and CA, and molecular weight of SE. Parallel factor (PARAFAC) was applied as the analysis method for FEEM of the samples and two fluorescent components were successfully identified: humic-like substances (C1) and protein-like matter (C2). Large reductions in A254, C1, C2, IBU, and CA were observed during the UV-based processes, especially with the addition of H2O2. Nearly 50% of A254, 80% of the component C1 were decreased and almost complete removal of the component C2 and TOrCs was achieved by UV/2.0 mM H2O2 after 90-min treatment. During the oxidation processes, the formation of lower molecular weight (LMW) compounds was detected, and the biodegradability of the organic matters was greatly increased. Although no significant DOC reduction was obtained in UV-based processes, an obvious further DOC reduction (30~60%) was achieved by biofilm treatment following UV-based processes, especially after UV/H2O2 treatments. In the meantime, large amounts of LMW were removed in the biofilm treatment process. This manuscript provides an effective advanced treatment of SE for the removal of DOC and TOrCs, facilitating the wastewater reclamation.
关键词： Trace organic contaminants,Removal,Biofilm,Secondary effluent,Dissolved organic carbon,UV/H2O2
更新于2025-09-23 15:21:21
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Selective and Sensitive Sensing of Hydrogen Peroxide by a Boronic Acid Functionalized Metal–Organic Framework and Its Application in Live-Cell Imaging
摘要： A new boronic acid functionalized Zr(IV) metal?organic framework having the capability of sensing H2O2 in live cells is reported. The Zr-MOF bears a UiO-66 structure and contains 2-boronobenzene-1,4-dicarboxylic acid (BDC-B(OH)2) as a framework linker. The activated Zr-UiO-66-B(OH)2 compound (called 1′) is highly selective for the ?uorogenic detection of H2O2 in HEPES bu?er at pH 7.4, even in the presence of interfering ROS (ROS = reactive oxygen species) and other biologically relevant analytes. The ?uorescent probe was found to display extraordinary sensitivity for H2O2 (detection limit 0.015 μM) in HEPES bu?er, which represents a lower value in comparison to those of the MOF probes documented so far for sensing H2O2 using other analytical methods. Taking advantage of its high selectivity and sensitivity for H2O2 in HEPES bu?er, the probe was successfully employed for the imaging of intracellular H2O2. Imaging studies with MDAMB-231 cells revealed the emergence of bright blue ?uorescence after loading with probe 1′ and subsequent treatment with H2O2 solution.
关键词： Zr(IV) metal?organic framework,boronic acid,live-cell imaging,fluorescent probe,H2O2 sensing
更新于2025-09-23 15:21:21
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HCN emission by a Polydesmid Millipede Detected Remotely by Reactive Adsorption on Gold Nanoparticles Followed by Laser Desorption/Ionization Mass Spectrometry (LDI-MS)
摘要： Hydrocyanic acid (HCN) is a well-known defensive allomone in the chemical arsenal of millipedes in the order Polydesmida. The presence of HCN in the headspace vapor of adult Xystocheir dissecta (Wood, 1867), a common millipede from the San Francisco Bay Area, was traced by laser desorption/ionization-mass spectrometry (LDI-MS). To accomplish this, the headspace vapor surrounding caged, live millipedes was allowed to diffuse passively over gold-nanoparticle (AuNP) deposits placed at various distances from the emitting source. The stainless steel plates with AuNP deposits were removed and irradiated by a 355-nm laser. The gaseous ions generated in this way were detected by time-of-flight mass spectrometry. The intensity of the mass spectrometric peak detected at m/z 249 for the Au(CN)2? complex anion was compared to that of the residual Au? signal (m/z 197). Using this procedure, HCN vapors produced by the live millipedes could be detected up to 50 cm away from the source. Furthermore, the addition of H2O2, as an internal oxygen source for the gold cyanidation reaction that takes place in the AuNP deposits, significantly increased the detection sensitivity. Using the modified H2O2 addition procedure, HCN could now be detected at 80 cm from the source. Moreover, we found a decreasing intensity ratio of the Au(CN)2?/Au? signals as the distance from the emitting source increased, following an exponential-decay distribution as predicted by Fick’s law of diffusion.
关键词： Gold nanoparticles (AuNP),Polydesmida,Laser desorption/ionization (LDI),Millipedes,Hydrogen cyanide (HCN),Hydrogen peroxide (H2O2),Allomones
更新于2025-09-23 15:19:57
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Hydrogen Peroxide-Assisted Photocatalysis under Solar Light Irradiation:Interpretation of Interaction Effects between an Active Photocatalyst and H <sub/>2</sub> O <sub/>2</sub>
摘要： In this work, the combination of H2O2 and an active visible-light-driven photocatalyst (Ag-S/PEG/TiO2) was utilized under natural solar radiation for the degradation of 2-nitrophenol (2-NP), and interaction effects between the photocatalyst and hydrogen peroxide were analyzed. For this purpose, experiments were designed using the response surface methodology based on the central composite design. The resulting data was utilized to obtain a model for the prediction of response (the degradation efficiency) as a function of two independent factors (H2O2 concentration and the photocatalyst loading). The statistical analysis indicated that optimum values of each of the two independent factors decreased by increasing the other one and vice versa. Moreover, it was found that adding the optimal amount of H2O2 to the solution, which contained just the photocatalyst, can enhance the degradation significantly (up to 45 %). However, using higher concentrations of H2O2 may decrease the efficiency. The global optimum condition was found to be 545 ppm and 316 mM for Ag-S/PEG/TiO2 loading and H2O2 concentration, respectively. In this condition, the degradation efficiency of 2-NP reached 92.4 % after only 45 min of solar light irradiation.
关键词： photocatalysis,2-nitrophenol,Ag-S/PEG/TiO2,solar degradation,H2O2-assisted
更新于2025-09-19 17:15:36
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Enhanced photoelectrocatalytic degradation of bisphenol A and simultaneous production of hydrogen peroxide in saline wastewater treatment
摘要： The degradation of organic pollutants in saline wastewater has been a challenge for environmental remediation. In this study, a two-chamber cell was structured to simultaneously degrade organic contaminants (bisphenol A, BPA) from saline wastewater and produce hydrogen peroxide (H2O2). In the anode chamber, a new solar-light-driven system was devised using chloride ions (Cl?) as a medium and WO3 photoanode as a radical initiator. Under solar light irradiation, photogenerated holes yielded at the WO3 photoanode promoted the conversion of Cl? to reactive chlorine species, which could oxidize BPA more rapidly. The results indicated that the BPA removal can be significantly enhanced by increasing pH to 10.8 or increasing the Cl? concentration to 200 mM. At these conditions, 92% BPA was degraded into CO2 and H2O in 120 min. In the cathode chamber, a new dopamine modified carbon felt (CF-DPA) cathode was employed to produce H2O2, obtaining a high concentration of 5.4 mM under optimum conditions. The electrochemical analyses for CF-DPA revealed that dopamine modification promoted electron transfer and enhanced the two-electron oxygen reduction to increase H2O2 yields.
关键词： WO3,H2O2,Photoelectrocatalysis,Dopamine,Organic pollutant,Saline wastewater
更新于2025-09-19 17:15:36
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Clinically Colorimetric Diagnostics of Blood Glucose Levels based on Vanadium Oxide Quantum Dots Enzyme Mimics
摘要： The environmental vulnerability of the natural enzyme have always been the most concerned issue in the diagnosis of blood glucose levels, which could be settled by the discovery and application of nanozyme mimics. However, the nanozyme still encountered with the problem of complex preparation process or low enzymatic activities. Herein, peroxidase-like vanadium oxide quantum dots (VOxQDs) were synthesized via a one-step bottom-up solvothermal method using vanadium (Ⅲ) trichloride (VCl3) powder as the precursor. Besides, the most favorable temperature and solvent for VOxQDs synthesis were confirmed. Due to the inherent properties of quantum dots, including larger specific surface areas and more active sites, the as-prepared VOxQDs exhibited 43 times lower value of Km and 32 times higher one of Vmax than those of natural peroxidase using H2O2 as the substrate, indicating the higher affinity and stronger peroxidase-like activity of the VOxQDs nanozymes. Accordingly, a facile and sensitive colorimetric sensor to detect glucose was designed via the integrated enzyme system of VOxQDs and glucose oxidase, which showed wider linear range of 0.005 - 2 mM glucose and lower limit of detection of 1.7 μM compared with those of many other peroxidase-like nanozymes. Especially, the colorimetric sensor was demonstrated with reliable and satisfactory performance in detection of glucose in human serum, which was in good accordance with the clinical results provided from the domestic hospital.
关键词： Peroxidase-like activity,Vanadium oxide quantum dots,Kinetic study,Detection of H2O2 and glucose
更新于2025-09-19 17:13:59