Proceedings [of] 10th Asian chemical congress: Sessions. 5. Physical & theoretical chemistry. Hanoi, 2003

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Catalytic air oxidation-an on-line treatment and/or an end-of-pipe alternative pre-treatment method for pollution abatement

Material production always is the main pollution resource, particularly pulping (PI) and textile industries (TI). Among all pollution abatement technologies wet air oxidation (WAO) is a promising alternative. In the one hand it can be applied as an in-plant measure to mineralize organics in wastewater (WW), therefore remained inorganic chemicals can be recovered and/or reused, on the other hand it can also be used as a WW pretreatment before popular biological treatment to get discharge demands. The best, and may be the most economical way to widen application of conventional WAO process is application of catalysts. Conventional oxidation catalysts contain precious metals, they also require stable to hydrothermal conditions supporting materials that bring additional high cost. The utilization of solid wastes (SW) from some industries for catalysts production can get multi-purpose goal: in one side reduction of SW in some industries, in the other side their use in CWO can reduce pollution in the other industries. Besides, due to low pressure and temperature required it can make application of WAO much easier and widened. With pretreatment prior to biological treatment purpose it can partially degrade persistent and toxic compounds that make following biological treatment more efficient. First application trials of CWO were made with black liquor from PI and dyeing WW from TI showed possibility of such idea. ]

Kinetics of antimony oxides catalyzed dehydrogenation of isobutane at low pressures

Kinetics of p-xylene deep oxidation on CuO/gamma-Al2O3 and CuO/ZSM-5

Semi-quantum molecular dynamics simulation of chemical reactions

The paper introduces the semi-quantum molecular dynamics simulation (SQMD) of chemical reactions. The theoretical background, algorithm and computer code have been introduced. The calculated results for the rearrangement and elimination reaction of HNC, H2CNH, H3CNC and addition reactions of N02 and NH2 as well have been presented. The calculation shows that SQMD simulation could give detail information about molecular structure and energy change during reaction, and therefore, makes possible to study on non-catalytic reaction dynamics, mechanism, kinetics and the effects that could not be determined experimentally. The order effect, the chemical equilibrium movement of rearrangement reaction, the mechanism, and the optimized attack position of addition reaction as well has been also illustrated using data collected during simulation.

The application of zeolites synthesized from kaolin taken in Yen Bai, Vietnam for NH4+ and Pb2+ removal from aqueous solutions

This article reports the application of Zeolites with different structure (NaP1, NaP, NaA, NaX) synthesized from kaolin taken in Yen Bai-Vietnam to separate NH4+ and Pb2+ from aqueous solutions. Experimental results showed that the exchanging and the holding capability of Zeolites with different structure with NH4+ and Pb2+ were diferent. NaP zeolite with uniform and narrow micropores had the best exchanging and the holding capability with NH4+ and Pb2+, equipvalent to 44.07 mg/g (after 3 hours exchanged at 25°C in the solution with Pb2+ concentration of 240 mg/l) and 139.05 mg/g (after 2.5 hours exchanged at 30°C,pH=7, in the solution with Pb2+ concentration of 450 mg/l). NaX zeolite with larger miropores had good exchanging ability but its holding capability was worse than narrow micropores zeolites.