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Pyrite, a naturally occurring mineral, can be found extensively in coal. The change in the pyrite structure that occurs during coaling process, the ability of the pyrite-derived α-Fe 2 O 3 to convert NO in the presence of NH 3 before catalyst bed and the kinetic study were investigated in this work. The pyrite-derived α-Fe 2 O 3 was obtained by calcining at 500, 600, 700, 800 °C and was characterized by the X-ray diffraction (XRD), N 2 physisorption, the X-ray photoelectron spectrometer (XPS), the scanning electron microscope (SEM), UV-visible near-infrared spectroscopy (UV-vis DRS), the temperature-programmed desorption of ammonia (NH 3 -TPD) and the in situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS). The results indicated that the α-Fe 2 O 3 derived from natural pyrite exhibited an affirmative effect on NO conversion in the presence of NH 3 at reaction temperatures of 200-450 °C, particularly at 350 °C, the pyrite-derived α-Fe 2 O 3 displayed the best efficiency for the NO conversion. In addition, the formed sulfate derived from the oxidation of pyrite enhanced the NO conversion at the temperature of 300-450 °C, while hinder the NO conversion at 200-275 °C. The in-situ DRIFTS and kinetic studies demonstrated that both the Eley-Rideal and Langmuir-Hinshelwood mechanism contributed to the selective catalytic reduction (SCR) of NO when the reaction temperature was over 200 °C, while selective catalytic oxidization (CO) happened over 300 °C. This study favored the understanding of the NO behavior in flue gas pipeline after sprawling NH 3 and the mechanism of NO conversion before the catalyst bed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The widespread use of nanomaterials has raised concerns about the potential impact of nanoparticles on human health and the natural environment. Although high doses of TiO 2 nanoparticles (NPs) are toxic to animals, low doses of TiO 2 NPs have been shown to benefit their growth and immune functions. Intestinal microorganisms are critical in maintaining the normal life activities and ensuring the health of their host. The intestinal microorganisms of lepidopteran insects can promote growth and development, foster insecticide resistance, and improve resilience against diseases. However, to date, there is no report on the effects of TiO 2 NPs on the intestinal microbiota of lepidopteran insects. In this work, we examined the effects of a low dose of TiO 2 NPs (5 mg/L) on the intestinal microbiota of silkworm (Bombyx mori). The results showed that the exposure to TiO 2 NPs did not alter the dominant species of intestinal microbiota significantly, but changed the abundance of individual species of intestinal microorganisms. Specifically, exposure to TiO 2 NPs increased the uniformity of intestinal microorganisms. The abundance of Lachnospiraceae_NK4A136_group, involved in the metabolism of nutrients, as well as the abundance of Pseudomonas and Sphingomonas, both involved in detoxification and disease resistance, was increased. Meanwhile, among the non-dominant species, the conditional pathogenic bacteria Serratia exhibited decreased abundance. In addition, exposure to TiO 2 NPs also increased the abundance of norank_f_Bacteroidales_S24-7_group, which could help relieve inflammation and regulate immune functions. The current study is the first to report the effects of TiO 2 NPs on the intestinal microbiota of lepidopteran insects. The results demonstrated that TiO 2 NPs could alter the composition of the intestinal microbiota of B. mori, and thus promote its growth and development, regulate its immune functions, and enhance its resistance to insecticide., (Copyright © 2019 Elsevier B.V. All rights reserved.)