Characteristics analysis of hybrid ZSM-5 zeolite catalyst with nano La2Zr2O7 for ammonia-selective catalytic reduction (NH3-SCR) of NOx

The characteristical effects of ZSM-5 by doping La2Zr2O7 nanoparticle was investigated based on the application of ammonia-selective catalytic reduction (NH3-SCR). The hybrid ZSM-5 zeolite catalyst was synthesized by the Ion exchange and wet impregnation method to develop Cu-ZSM-5 and 5%, 10%, &amp; 15% of La2Zr2O7 based Cu-ZSM-5. The characterization of hybrid catalyst was analysed by XRD, SEM, XPS, BET, FT-IR, &amp; UVVis. From the analysis of the characteristics, La2Zr2O7 doped Cu-ZSM-5 hybrid zeolite catalyst exhibits excellent properties towards the application of ammonia-selective catalytic reduction (NH3-SCR) for the reduction of oxides of nitrogen to achieve EURO VI norms</jats:p

Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound ecosystems

Ecosystem-level impacts of two hurricane seasons were compared several years after the storms in the largest lagoonal estuary in the U.S., the Albemarle–Pamlico Estuarine System. A segmented linear regression flow model was developed to compare mass-water transport and nutrient loadings to a major artery, the Neuse River Estuary (NRE), and to estimate mean annual versus storm-related volume delivery to the NRE and Pamlico Sound. Significantly less water volume was delivered by Hurricane Fran (1996), but massive fish kills occurred in association with severe dissolved oxygen deficits and high contaminant loadings (total nitrogen, total phosphorus, suspended solids, and fecal bacteria). The high water volume of the second hurricane season (Hurricanes Dennis, Floyd, and Irene in 1999) delivered generally comparable but more dilute contaminant loads, and no major fish kills were reported. There were no discernable long-term adverse impacts on water quality. Populations of undesirable organisms, such as toxic dinoflagellates, were displaced down-estuary to habitats less conducive for growth. The response of fisheries was species-dependent: there was no apparent impact of the hurricanes on commercial landings of bivalve molluscs or shrimp. In contrast, interacting effects of hurricane floodwaters in 1999 and intensive fishing pressure led to striking reductions in blue crabs. Overall, the data support the premise that, in shallow estuaries frequently disturbed by hurricanes, there can be relatively rapid recovery in water quality and biota, and benefit from the scouring activity of these storms