Air contaminants in a submarine equipped with air independent propulsion

The Swedish Navy has operated submarines equipped with air independent propulsion for two decades. This type of submarine can stay submerged for periods far longer than other non-nuclear submarines are capable of. The air quality during longer periods of submersion has so far not been thoroughly investigated. This study presents results for a number of air quality parameters obtained during more than one week of continuous submerged operation. The measured parameters are pressure, temperature, relative humidity, oxygen, carbon dioxide, hydrogen, formaldehyde and other volatile organic compounds, ozone, nitrogen dioxide, particulate matter and microbiological contaminants. The measurements of airborne particles demonstrate that air pollutants typically occur at a low baseline level due to high air exchange rates and efficient air-cleaning devices. However, short-lived peaks with comparatively high concentrations occur, several of the sources for these have been identified. The concentrations of the pollutants measured in this study do not indicate a build-up of hazardous compounds during eight days of submersion. It is reasonable to assume that a substantial build-up of the investigated contaminants is not likely if the submersion period is prolonged several times, which is the case for modern submarines equipped with air independent propulsion.     

Ferronickel slag as free-draining rockfill dike material: a novel waste solution for mining regions

Journal of Material Cycles and Waste Management - Mining sites are vulnerable to erosion and siltation of rivers. While the construction of rockfill dikes can mitigate siltation, existing rockfill...     

Obtaining and characterization of catalytic materials from waste tires for the Fischer–Tropsch process

Journal of Material Cycles and Waste Management - In this contribution, the preparation of iron-based catalysts from waste tires is reported. Waste steel from disused tires was used as feedstock to...     

Spatial heterogeneity of greenhouse gas emissions from cereal crop production in China

Environmental Chemistry Letters - China is a major producer of wheat, maize and rice, which generates massive greenhouse gas emissions due to the consumption of elevated amounts of energy, land,...