Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: the influence of zeolite chemical surface characteristics.

In this study, the effect of zeolite chemical surface characteristics on the oxidative regeneration of toluene saturated-zeolite samples is investigated. A Chilean natural zeolite (53% clinoptilolite, 40% mordenite and 7% quartz) was chemically modified by acid treatment with hydrochloric acid and by ion-exchange with ammonium sulphate. Thermal pre-treatments at 623 and 823K were applied and six zeolite samples with different chemical surface characteristics were generated.

Natural zeolite reactivity towards ozone: the role of compensating cations.

Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied.

Catalytic ozone aqueous decomposition promoted by natural zeolite and volcanic sand.

Chemical oxidation using ozone in the presence of appropriate catalysts offers an attractive option for removing poorly biodegradable pollutants. However, the effect of such catalysts on ozone aqueous decomposition is not well documented. This study compares experimental results on ozone aqueous decomposition promoted by zeolite and volcanic sand.

Heterogeneous and homogeneous catalytic ozonation of benzothiazole promoted by activated carbon: kinetic approach.

Ozone oxidation combined with activated carbon adsorption (O(3)/AC) has recently started to be developed as a single process for water and wastewater treatment. While a number of aspects of aqueous ozone decomposition are well understood, the importance and relationship between aqueous ozone decomposition and organic contaminant degradation in the presence of activated carbon is still not clear. This study focuses on determining the contribution of homogeneous and heterogeneous reactions to organic contaminants removal in O(3)/AC system.

Analysis of aerosol particles and coarse particulate matter concentrations in Chillán, Chile, 2001-2003.

Daily particle samples were collected in Chillán, Chile, at six urban locations from September 1, 2001, through September 30, 2003. Aerosol samples were collected using monitors equipped with a Sierra Andersen 246-b cyclone inlet on Teflon filters. Average concentrations of coarse particulate matter (PM10) for the 2001-2003 period ranged from 43.

A study of the particulate matter PM10 composition in the atmosphere of Chillán, Chile.

Inhalable particulate matter (PM10) concentrations were measured over 24-h intervals at six different urban sites in the city of Chillán from September 2001 to April 2003. Sampling locations were selected to represent central city, commercial, residential, and industrial portions of the city. Chemical composition of PM10 was performed to samples of 47 mm diameter Teflon membranes within the city of Chillán.