kaolinite and manganese-dioxide

Persulfate (PS)-based in situ chemical oxidation (ISCO) has been widely used for pollutant remediation in soil and groundwater. However, the underlying mechanism of interactions between mineral and PS was not fully explored. In this study, several soil model minerals including goethite, hematite, magnetite, pyrolusite, kaolin, montmorillonite, and nontronite were selected to investigate their potential effects on PS decomposition and free radical evolution. It was found the decomposition efficiency of PS by these minerals varied significantly, and both the radical and non-radical decomposition processes were included. Pyrolusite has the highest reactivity for PS decomposition. However, PS decomposition is prone to form SO

Topics: Bentonite; Environmental Pollutants; Ferrosoferric Oxide; Kaolin; Minerals; Oxidation-Reduction; Phenols; Soil; Sulfates; Water Pollutants, Chemical

Adsorption and fractionation of Pt, Pd and Rh (defined here as platinum group elements, PGEs) onto the representative inorganic microparticles, including Fe

Topics: Adsorption; Ferric Compounds; Humic Substances; Inorganic Chemicals; Kaolin; Manganese Compounds; Metal Nanoparticles; Minerals; Organic Chemicals; Oxides; Palladium; Platinum; Rhodium; Seawater; Silicon Dioxide

Improvised explosive devices (IED) are responsible for a significant proportion of combat and civilian deaths around the world. Given the ease with which IEDs can be made, the large quantity of explosive which can be contained within or on a vehicle, and the use of VBIED in the past (for example the 2002 Bali bombing) in terrorist activities, VBIED are an ongoing concern for Defence and law enforcement agencies. Fingermark and DNA analyses are routinely used by police and forensic analysts to identify suspects involved in illegal activities. There is limited information available on the feasibility of obtaining fingermarks, fibres, hair and DNA samples following an explosive incident, or a situation whereby an IED has been rendered safe following the utilisation of an appropriate defeat or render-safe tool. The main objective of this study was to determine if fingermarks and/or DNA (from saliva and hair samples) placed on the interior and exterior of road vehicles, and on inanimate objects (such as plastic or glass bottles), are able to be obtained and analysed following the use of a vehicle-borne IED (VBIED) render-safe tool on a vehicle containing simulated explosives. The identification of fingermarks on the exterior (67.2±8.5%) and interior (43.8±17.8%) of the vehicles was possible following the use of the render-safe tool, though this was more challenging in the latter than the former. Fingermarks were also able to be identified from both plastic and glass bottles placed inside the vehicles. Polymerase chain reaction (PCR) techniques yielded DNA profiles that were able to be identified from saliva and hair samples. These preliminary results suggest that both fingermarks and DNA profiles, obtained from vehicles that have been subjected to a VBIED render-safe tool, may be used to identify persons of interest.

Topics: Bombs; Coloring Agents; Cyanoacrylates; Dermatoglyphics; DNA; DNA Fingerprinting; Glass; Hair; Humans; Kaolin; Manganese Compounds; Motor Vehicles; Oxides; Plastics; Polymerase Chain Reaction; Powders; Saliva; Titanium; Volatilization

The photodebromination of decabromodiphenyl ether (BDE-209) adsorbed onto six different solid matrixes was investigated in sunlight and by irradiation with 350 +/- 50 nm lamps (four lamps at 24 W each). After 14 days of lamp irradiation, BDE-209 degraded with a half-life of 36 and 44 days, respectively, on montmorillonite or kaolinite, with much slower degradation occurring when sorbed on organic carbon-rich natural sediment (t1/2 = 150 days). In late summer and fall sunlight (40.5 degrees N, elevation 600 ft), the half-lives of BDE-209 sorbed on montmorillonite and kaolinite were 261 and 408 days, respectively. Under both irradiation schemes, no significant loss of BDE-209 occurred when sorbed to aluminum hydroxide, iron oxide (ferrihydrite), or manganese dioxide (birnessite). Upon exposure to both lamp and solar light and in the presence of montmorillonite and kaolinite, numerous lesser brominated congeners (tri- to nonabromodiphenyl ethers) were produced. Nearly identical product distribution was evident on montmorillonite and kaolinite. Dark control experiments for each mineral showed no disappearance of BDE-209 or appearance of degradation products. These results suggest that photodegradation of BDE-209 on mineral aerosols during long-range atmospheric transport may be an important fate process for BDE-209 in the environment.

Topics: Adsorption; Aerosols; Aluminum Hydroxide; Aluminum Silicates; Bentonite; Biodegradation, Environmental; Clay; Ferric Compounds; Geologic Sediments; Halogenated Diphenyl Ethers; Kaolin; Kinetics; Manganese Compounds; Minerals; Oxides; Phenyl Ethers; Photochemistry; Polybrominated Biphenyls; Water Pollutants, Chemical