A new acridine-based photosensitizer with ultra-low light requirement efficiently inactivates carbapenem-resistant Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus and degrades their antibiotic resistance genes.

The spread of antibiotic resistant pathogens and antibiotic resistance genes (ARGs) in the environment poses a serious threat to public health. However, existing methods are difficult to effectively remove antibiotic resistant pathogens and ARGs from the environment. In this study, we synthesized a new acridine-based photosensitizer, 2,7-dibromo-9-mesityl-10-methylacridinium perchlorate (YM-3), by the heavy atom effect, which could photodynamically inactivate antibiotic resistant pathogens and reduce ARGs by generating singlet oxygen (O) in an aqueous environment.

MnO@N-doped carbon nanosheets derived from Mn-MOFs and g-CN for peroxymonosulfate activation: Electron-rich Mn center induced by N doping.

The fabrication of metal-carbon hybrids with heteroatom doping from manganese-metal organic frameworks (MOFs) has rarely been reported for peroxymonosulfate (PMS) activation. In this work, novel MnO@N-doped carbon (MnO@NC) nanosheets were prepared using 2D manganese-1,4 benzenedicarboxylic acid-based MOFs (Mn-MOFs) and different proportions of graphitic carbon nitride (g-CN, additional N source and carbon source) to activate PMS for sulfamethoxazole (SMX) removal. The polarization difference induced by Mn-N coordination during the carbonization process made C an electron-poor center and Mn an electron-rich center, thus providing more Mn(II) for PMS activation.

A ZIF-8-derived copper-nitrogen co-hybrid carbon catalyst for peroxymonosulfate activation to degrade BPA.

A series of copper-nitrogen co-hybrid porous carbon catalysts were prepared by pyrolysis of copper-doped ZIF-8 in argon atmosphere. Both the precursors and the corresponding pyrolysis products retained the polyhedral morphology of ZIF-8. The catalytic performance of the catalysts obtained at different Cu doping levels and pyrolysis temperatures for PMS activation was compared by bisphenol A (BPA) degradation experiment.

Pyridazine doped g-CN with nitrogen defects and spongy structure for efficient tetracycline photodegradation and photocatalytic H evolution.

In this study, with thiourea and 3-aminopyridazine as precursors, the graphite-phase carbon nitride (ACN-x) with nitrogen defects and sponge structure is prepared via the introduction of the benzene-like ring structure of pyridazine replacing a "melem" group through hydrothermal procedure combined with calcination. It is made possible by the attraction of three hydrogen bond receptors for 3-aminopyrazine to lone pair electrons on the "melem" molecule. The remarkable extensively photocatalytic activity can be attributed to three effects of the introduction of 3-aminopyridazine: (i)formation of nitrogen defects between adjacent tri-s-triazine groups; (ii)formation of effective charge transfer channels within the tri-s-triazine group; (iii)the spongy structure exposed abundant amino groups(-NH) at edge sites, combining with the internal amino group and as hole stabilizer to prolong the excited state life of photocatalyst.

Synergistic role of inherent calcium and iron minerals in paper mill sludge biochar for phosphate adsorption.

Phosphate adsorption using metal-based biochar has awakened much attention and triggered extensive research. In this study, novel Ca/Fe-rich biochars were prepared via a one-step process of pyrolyzing paper mill sludge (PMS) at various temperatures (300, 500, 700, and 800 °C) under a CO atmosphere for phosphate removal. Batch adsorption experiments showed that the biochar obtained at 800 °C (PB-800), which could be easily separated magnetically, exhibited the best phosphate adsorption capacity in a wide range of solution pH (5-11).

Removal of Sb(V) from wastewater via siliceous ferrihydrite: Interactions among ferrihydrite, coprecipitated Si, and adsorbed Sb(V).

Although ferrihydrite (Fh) exhibits good Sb(V) adsorption behavior, the instability of its amorphous structure limits its engineering applications. In this study, siliceous ferrihydrite (SiFh) was prepared via coprecipitation to resolve these limitations. X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and SiFh aging tests revealed that the growth of Fh particles covered with Fe-O-Si links was inhibited while maintaining their amorphous structure.

Oxygen-containing groups and P doped porous carbon nitride nanosheets towards enhanced photocatalytic activity.

Metal-free polymer graphite carbon nitride (CN) is a promising photocatalyst that has garnered significant research attention. However, unmodified CN possesses several shortcomings such as low specific surface area, poor dispersibility in water, and rapid photogenerated electron-hole recombination, which have severely impacted its mass adoption. Here, this study proposed a two-step heat treatment method to incorporate P dopant and the containing-oxygen groups successively into CN.

Interface mechanisms of the catalytic ozonation of humic acids over siliceous ferrihydrite: Morphology, stability, and the catalytic process.

Ferrihydrite (Fh), a precursor of more crystalline Fe (hydr)oxides, exhibits decent catalytic behavior; however, the instability of its amorphous structure limits its engineering applications. Siliceous ferrihydrite (FhSi) was readily synthesized in this study by co-precipitation. The formation of Fe-O-Si linkages did not alter the amorphous state of pure Fh, but increased the surface area (S), reduced the point of zero charge (pH), and prevented the leaching of more iron.

Uracil-Doped Graphitic Carbon Nitride for Enhanced Photocatalytic Performance.

g-CN is a visible-light photocatalyst with a suitable band gap and good stability. Moreover, g-CN is considered to be earth-abundant, which makes it an appealing photocatalyst. However, due to its small specific surface area, low utilization of visible light, and high photogenerated electron-hole pair recombination rate, the photocatalytic activity of g-CN remains unsatisfactory.

[Removal of Antimony from Water by Nano Zero-Valent Iron/Activated Carbon Composites].

Nano zero-valent iron/activated carbon (nZVI/AC) composites were prepared via liquid phase chemical precipitation and then characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and Brunauer-Emmett-Teller theoretical methods for an analysis of the structure, morphology, physical and chemical characteristics of the composites. The effects of the reaction system, nZVI loading, initial pH, and dosage on antimony removal were investigated and the removal mechanisms were discussed. These results indicate that nZVI/AC can be successfully prepared via liquid phase chemical precipitation.

[Performance and Mechanism Study of Visible Light-driven CN/BiOBr Composite Photocatalyst].

Efficient visible light-driven CN/BiOBr composite photocatalysts were prepared via a facile hydrothermal method and characterized by X-ray diffraction, Fourier transform infrared, scanning electron microscopy, UV-Vis diffuse reflectance spectra and photoluminescence spectra for the phase composition and optical property. Taking rhodamine B (RhB) as the target pollutant, the photocatalytic activity and stability of photocatalysts were studied under visible light irradiation. Furthermore, the mechanism in the process of photocatalytic degradation was discussed by electron spin resonance spectroscopy analysis and the trapping experiment of generated radicals.

Adsorption characteristics of Bisphenol-A on tailored activated carbon in aqueous solutions.

The adsorption behavior of pharmaceuticals and personal care product, Bisphenol-A (BPA), according to four coal-based and four wood-based granular activated carbons modified using outgassing treatment, acidic treatment or alkaline treatment was studied. The adsorption isotherm results indicated that carbon surface acidity played a very important role in the adsorption of BPA. It was found that increasing surface acidity would increase the hydrogen bonding effects and increase adsorption of BPA on activated carbon.

Photodegradation of Orange II using waste paper sludge-derived heterogeneous catalyst in the presence of oxalate under ultraviolet light emitting diode irradiation.

A waste paper sludge-derived heterogeneous catalyst (WPS-Fe-350) was synthesized via a facile method and successfully applied for the degradation of Orange II in the presence of oxalic acid under the illumination of ultraviolet light emitting diode (UV-LED) Powder X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electronic microscopy and N2 sorption isotherm analysis indicated the formation of α-Fe2O3 in the mesoporous nanocomposite. The degradation test showed that WPS-Fe-350 exhibited rapid Orange II (OII) degradation and mineralization in the presence of oxalic acid under the illumination of UV-LED. The effects of pH, oxalic acid concentration and dosage of the catalyst on the degradation of OII were evaluated, respectively.

Fenton-like degradation of Methylene Blue using paper mill sludge-derived magnetically separable heterogeneous catalyst: Characterization and mechanism.

For the paper industry, the disposal and management of the yielded sludge are a considerable challenge. In our work, the paper mill sludge-derived magnetically separable heterogeneous catalyst (PMS-Fe-380) was prepared easily through a facile synthesis method. The morphology and structure of PMS-Fe-380 were fully characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer-Emmet-Teller analysis.

Assessment of a novel overflow-type electrochemical membrane bioreactor (EMBR) for wastewater treatment, energy recovery and membrane fouling mitigation.

A novel overflow-type electrochemical membrane bioreactor (EMBR) without ion exchange membrane, was developed for wastewater treatment and utilized electricity recovered by microbial fuel cell (MFC) for membrane fouling mitigation in membrane bioreactor (MBR). The maximum power density of 629mW/m(3) or 7.18mW/m(2) was obtained.

Paddy field--a natural sequential anaerobic-aerobic bioreactor for polychlorinated biphenyls transformation.

The environmental pollution and health risks caused by the improper disposal of electric and electronic waste (e-waste) have become urgent issues for the developing countries. One of the typical pollutants, polychlorinated biphenyls (PCBs), is commonly found in farmland in Taizhou, a major hotspot of e-waste recycling in China. This study investigated the amount of PCB residue in local farmlands.

Mechanistic study of ozonation of p-nitrophenol in aqueous solution.

Ozonlysis in the treatment of p-nitrophenol solution was studied in this paper. The results indicated that the decomposition of p-nitrophenol was accelerated as the gas flow rate or pH value increased. When gaseous ozone concentration was 20.

Study on US/O3 mechanism in p-chlorophenol decomposition.

Study on the effects of sonolysis, ozonolysis and US/O3 system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of US/O3 system, individual ozonolysis and sonolysis, the decomposition rate of p-chlorophenol reached 78.78%, 56.20%, 2.

Ozonation with ultrasonic enhancement of p-nitrophenol wastewater.

Synergetic effects for p-nitrophenol degradation were observed in the ozonation with ultrasonic enhancement. The enhancements of removal rate for p-nitrophenol and TOC were around 116% and 294% respectively in comparison with the individual ultrasound and ozonation systems. The synergetic phenomenon is attributed to two physicochemical mechanisms: (1) Ultrasound decomposes ozone causing augmentation of the activity of free radicals; (2) Ultrasonic wave increased the concentration of O(3) in solution because of ultrasonic dispersion.

Ozonation of Cationic Red X-GRL in aqueous solution: degradation and mechanism.

Ozonation of the azo dye Cationic Red X-GRL was investigated in a bubble column reactor at varying operating parameters such as oxygen flow rate, temperature, initial Cationic Red X-GRL concentration, and pH. The conversion of dye increased with the increasing of pH and oxygen flow rate. As the reaction rate constant and the volumetric mass transfer coefficient increase while the ozone equilibrium concentration decreases with the temperature, there is a minimum conversion of dye at 25 degrees C.

Modeling of mass transfer characteristics of bubble column reactor with surfactant present.

Danckwert's method was used to determine the specific interfacial area, a, and the individual mass transfer coefficient, k(L), during absorption of CO(2) in a bubble column with an anionic surfactant in the carbonate-bicarbonate buffer solution and NaAsO(2) as catalyst, the presence of which decreases the specific interfacial area and the individual mass transfer coefficient. The specific interfacial area and the individual mass transfer coefficient increase with increasing superficial gas velocity. The specific interfacial area decreases whereas the individual mass transfer coefficient increases with increasing temperature.