Performance of activated carbon loaded fibrous filters on simultaneous removal of particulate and gaseous pollutants.

Activated carbons are used for the removal of volatile organic compounds (VOCs) from contaminated air carriers. Various arrangements, including fixed and fluidised layers, are employed to meet air quality standards for industrial and domestic applications. Filters are commonly used for the removal of small particles from gas streams. The selective performance of these devices can be high for the removal of either particles or VOCs. However, none of them can be used solely for the simultaneous removal of both contaminants, as their performance for the removal of the alternate group of pollutants is usually very poor. The scope of this project is to combine the above control technologies by loading fibrous filters with activated carbon powder and to investigate the performance of such a single-stage technology on the simultaneous removal of VOCs and particles from the gas stream under controlled laboratory conditions. It was found that the efficiency of the carbon loaded filter was about twice as high as the efficiency of the clean filter with respect to the removal of particles (monodisperse polystyrene latex spheres were used for the measurements) with a corresponding increase of the pressure drop across the filter by around 25-35%. Also, carbon loaded filters were capable of purifying VOC (toluene) concentrated air streams over quite substantial time periods.

Prediction of the partition coefficient of lipophilic compounds in the air-mammal tissue system.

A theoretical bioconcentration model for predicting the air-mammal tissue partition coefficient of lipophilic compounds has been developed. The tissue was considered to consist of three compartments, i.e. lipid, protein and water, in different proportions depending on the tissue considered. The model is based on equilibrium partitioning of the chemicals between the compartments and the atmosphere and requires the octanol-water partition coefficient (K(ow)), Henry's Law Constant (H) and the phase composition of the animal tissue as input information. The model was evaluated using experimental partition coefficients for 19 volatile chlorohydrocarbons and aromatic hydrocarbons. Predicted partition coefficients (Kba) for human blood and olive oil systems are in good agreement with the experimentally determined values. The model gave a lower level of precision with rat blood, rat muscle and rat liver systems and fairly consistently underestimated the experimental values by 22-62%.