Gaseous effluents environmental effects

Fully contained gaseous effluent for effective environmental control. 

Two bioassays are employed to evaluate the effect of samples on terrestrial life forms. For gas samples, the plant stress ethylene test is presently recommended. This test is based on the well-known plant response to environmental stress release of elevated levels of ethylene (under normal conditions plants produce low levels of ethylene). The test is designed to expose plants to various levels of gaseous effluents under controlled conditions. The ethylene released during a set time period is then measured by gas chromatography to determine toxicity of the effluent. For liquid and solid samples, a soil microcosm test is employed. The sample is introduced on the surface of a 5 cm diameter by 5 cm deep plug of soil obtained from a representative ecosystem. Evolution of carbon dioxide, transport of calcium, and dissolved oxygen content of the leachate are the primary quantifying parameters. 

Owing to its high toxicity, phosgene waste-gas must be recycled, destroyed or, in some way, removed to prevent environmental contamination or hazards to personnel. This Section is concerned with the main methods for chemically removing phosgene from gaseous effluents, the extent to which phosgene is taken up and retained by various sorbents, and the effect of time, temperature, pressure and moisture on the sorption. 

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