There is a critical need for new efficient solutions to purify and disinfect water from source to point-of-use, especially for the water contaminated by pathogenic microbes. Traditional disinfection technologies are chemically intensive and limited, either by biofouling or by the irreversible consumption of disinfectants. Herein, we present a scalable methodology to create biocidal and rechargeable nanofibrous membranes (BNF membranes) by combining N-halamine antimicrobial agent with electrospun nanofibers. Our method allows intrinsically rechargeable N-halamine moieties to covalently incorporate into nanofibers with high biocidal activity and durability. The resulting BNF membranes exhibit integrated properties of high porosity, large surface area, robust mechanical strength, super hydrophilicity, rechargeable chlorination capability (>3000 ppm), and high bactericidal efficacy (99.9999% contact-killing), which enabled the BNF membranes effectively disinfect bacteria-contained water by direct filtration, with promising high durability and fluxes (10000 L m −2 h −1 ). The successful synthesis of BNF membranes also provides a versatile platform for exploring the antimicrobial N-halamine materials in a self-supporting, structurally adaptive, and nanofibrous form.

The formation mechanism of ammonium bisulfate (ABS) in the process of SCR flue gas denitrification and some research progresses on ABS are reviewed in the paper. The main factors affecting the formation of ABS are investigated, the formation temperature of ABS is in the range of about 190°C−240°C; ABS exists in vapor phase at temperature between 320°C and 345°C, and begins to decompose when the temperature is higher than 345°C; the formation of the ABS can be reduced by reducing the amount of NH3 slip and SO3, in the flue gas. The adverse effects of ABS on catalyst and air preheater are discussed: ABS will cover the surface of catalyst and Bronsted acid sites, decreasing denitrification efficiency; it will deposit in the air preheater, fouling and corroding the air preheater and reduce its operational effectiveness; it also can reduce the resistivity of fly ash and the quality of the fly ash as well. The methods to control ABS formation and the measures to reduce its negative effects are proposed: Select appropriate operating temperature to reduce the ABS deposition over the SCR catalyst; replace the material of the air preheater components from steel to ceramic coating type and change the structure of the air preheater; Take proper methods to reduce NH3 slip and the oxidation rate of SO2, etc. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1664–1672, 2016

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Titanium dioxide gel monoliths were synthesized using an organic precursor and 0-30 vol % ethanol in water. The visible-light-activated proton pump, bacteriorhodopsin, in its native purple membrane form, was successfully encapsulated within the titanium dioxide gels. Absorption spectra showed that the folded functional state of the protein remained intact within gels made with 0 and 15 vol % ethanol and retained the ability to make reversible conformational changes associated with the photocycle within the gel made with 0 vol % ethanol. The photocatalytic activity of gels made with no ethanol was significantly detectable and gels made with 0-30 vol % ethanol were comparable to commercial crystalline nanoparticles in similar solution conditions when irradiated with UV light. Our results show that sol-gel-derived photocatalytic titanium dioxide can be made biocompatible for a membrane-associated protein by minimizing the amount of ethanol and maximizing the amount of water in the synthesis procedure. The entrapment of the membrane protein, bacteriorhodopsin, in sol-gel-derived titanium dioxide provides the first step in future explorations of this bionanocomposite for visible light photocatalysis, including hydrogen production.

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