Simultaneous Removal of NO and Hg⁰ from Flue Gas over Mn–Ce/Ti-PILCs

A series of Mn–Ce/Ti-PILCs (PILCs, pillared interlayered clays) catalysts were prepared via impregnation method in simultaneous removal of NO and elemental mercury in simulated flue gas. The physicochemical properties of these catalysts have been examined by some characterization methods, such as H₂-TPR, nitrogen adsorption, XRD and XPS. Mn(6%)–Ce(6%)/Ti-PILCs exhibited superior NO conversion (>95%) and Hg⁰ removal efficiency (>90%) at low temperature (250 °C). The results indicated that the elemental mercury had little impact on NO removal efficiency, while the presence of NH₃ and NO in SCR system inhibited the Hg⁰ removal. NO and Hg⁰ removal activity was strongly affected by the transform between surface adsorbed oxygen and lattice oxygen. The species ratio of Mn⁴⁺/Mn³⁺ and Ce⁴⁺/Ce³⁺ on the catalyst surface contributed to the NO conversions and Hg⁰ removal. Mn–Ce/Ti-PILCs displayed a broad prospect for controlling the emission of NO and mercury. On the basis of the results obtained, a mechanism for the simultaneous removal of NO and Hg⁰ was proposed for the Mn–Ce/Ti-PILCs catalysts: −NH₂ + NO → N₂ + H₂O, −OH + 1/2 Hg_(ad) →1/2 HgO + 1/2 H₂O

CO₂ Adsorption on N‑Doped Porous Biocarbon Synthesized from Biomass Corncobs in Simulated Flue Gas

This study was to develop a low-cost N-doped porous biocarbon adsorbent that can directly adsorb CO2 in high-temperature flue gas from fossil fuel combustion. The porous biocarbon was prepared by nitrogen doping and nitrogen–oxygen codoping through K2CO3 activation. Results showed that these samples exhibited a high specific surface area of 1209–2307 m2/g with a pore volume of 0.492–0.868 cm3/g and a nitrogen content of 0.41–3.3 wt %. The optimized sample CNNK-1 exhibited a high adsorption capacity of 1.30 and 0.27 mmol/g in the simulated flue gas (14.4 vol % CO2 + 85.6 vol % N2) and a high CO2/N2 selectivity of 80 and 20 at 25 and 100 °C and 1 bar, respectively. Studies revealed that too many microporous pores could hinder CO2 diffusion and adsorption due to the decrease of CO2 partial pressure and thermodynamic driving force in the simulated flue gas. The CO2 adsorption of the samples was mainly chemical adsorption at 100 °C, which depended on the surface nitrogen functional groups. Nitrogen functional groups (pyridinic-N and primary and secondary amines) reacted chemically with CO2 to produce graphitic-N, pyrrolic-like structures, and carboxyl functional groups (−N–COOH). Nitrogen and oxygen codoping increased the amount of nitrogen doping content in the sample, but acidic oxygen functional groups (carboxyl groups, lactones, and phenols) were introduced, which weakened the acid–base interactions between the sample and CO2 molecules. It was demonstrated that SO2 and water vapor had inhibition effects on CO2 adsorption, while NO nearly has no effect on the complex flue gas. Cyclic regenerative adsorption showed that CNNK-1 possessed excellent regeneration and stabilization ability in complex flue gases, indicating that corncob-derived biocarbon had excellent CO2 adsorption in high-temperature flue gas

Activation of T helper lymphocytes by melanoma-derived PAEP protein.

<p>(A-B) The percent of CD3⁺ T cells in unfractionated PBLs from healthy donors was assayed for by direct staining with anti-CD3-FITC followed by flow cytometric analysis. (A) Negative control, (B) Healthy donor. Flow cytometry was applied to confirm the purity of CD4⁺ T cells before (C) and after (D) MACS isolation. (E) Levels of cytokines secreted by PHA-stimulated T helper cells co-cultured with PAEP-rich 624.38-Mel shControl or PAEP-poor 624.38-Mel shPAEP supernatant were determined. Melanoma-derived PAEP significantly inhibited both IL-2 and IFN- γ secretion by T helper cells (* p<0.05, Student’s <i>t</i>-test). (F) Levels of cytokines secreted by PHA- or anti-CD3 antibody-stimulated Th1 cells co-cultured with PAEP-rich 624.38-Mel shControl or PAEP-poor 624.38-Mel shPAEP supernatant were determined. Melanoma-derived PAEP significantly inhibited both IL-2 and IFN-γ secretion by Th1 cells (* p<0.05, Student’s <i>t</i>-test) (G-H) There were no differences in number of CD4/CD8 cells before or after PHA stimulation in the presence of PAEP (1 μg/ml). (G) PBLs; (H) CD3⁺ T cells. (I-J) The number of CD69/CD44 cells before and after activation in the absence or presence of PAEP was determined by direct staining with antibodies and flow cytometry. The number of CD69 cells significantly decreased co-cultured with PAEP-rich 624.38-Mel shControl supernatant. The experiment was repeated at least three times.</p

PAEP gene knockdown in melanoma cells.

<p>Stable PAEP 624.38-Mel shRNA transfectant and its non-targeting negative control transfectant, shControl, were established with a corresponding shRNA lentivirus. PAEP gene expressions were assayed by semi-quantitative RT-PCR (A) and Western blotting (B). PAEP protein secreted by melanoma cells was quantitated by ELISA (C).</p

Proliferation and Apoptosis of lymphocyte affected by melanoma-derived PAEP protein.

<p>There was a significant difference of lymphocyte proliferation between PAEP-rich 624.38-Mel shControl group and PAEP-poor 624.38-Mel shPAEP group at concentrations of 1 μg/ml PAEP (A) and 2 μg/ml PAEP (B), indicating that proliferation of PBLs was significantly inhibited by PAEP (* P < 0.05, Student’s <i>t</i>-test). The early and late phase apoptosis of PBLs co-cultured with PAEP-rich 624.38-Mel shControl supernatant (equivalent to 1 μg/ml PAEP protein) for 36 h (C) was significantly increased compared with PBLs co-cultured with shPAEP supernatant (F). Similar results were obtained with purified CD8⁺ or CD4⁺ T cells (D vs. G, E vs. H). Results are presented from one representative experiment. The same experiment was repeated at least three times.</p