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Photochemical oxidation of phenanthrene sorbed on silica gel

Article Abstract:

An examination of the photolysis of phenanthrene (PH) on silica gel in the presence of air revealed that PH does not repartition to the gas phase once it is sorbed onto the silica surface, even under vacuum. Dark reactions of PH were likewise not observed at the silica/air interface. Product yields from photolysis at 254 nm are 2,2'-biformylbiphenyl, 9,10-phenanthrenequinone, cis-9,10-dihydrodihydroxyphenanthrene, benzocoumarin, 2,2'-biphenyldicarboxylic acid, 2-formyl-2'-biphenylcarboxylic acid, 2-formylbiphenyl, 1,2-naphthalenedicarboxylic acid and phthalic acid. These photoproducts account for 85%-90% of the reacted PH.

Analysis, Oxidation-reduction reaction, Oxidation-reduction reactions, Polycyclic aromatic hydrocarbons, Absorption, Photochemistry

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Uptake and photodegradation of 2,3,7,8-tetrachlorodibenzo-p-dioxin sorbed to grass foliage

Article Abstract:

The utilization of grass foliage for the determination of plant uptake rates of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is discussed. Photodegradation and volatility were identified as the primary elimination mechanisms for 2,3,7,8-TCDD and were measured in natural sunlight, filtered sunlight with reduced UV-B radiation and in the dark. It was found that in the estimation of plant contamination from 2,3,7,8-TCDD, its rapid photodegradation should be considered as an elimination mechanism.

Environmental aspects, Leaves, Grasses

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Coupled transport and photodegradation of napropamide in soils undergoing evaporation from a shallow water table

Article Abstract:

A study was conducted on the influence of upward evaporative water flux on napropamide photolysis rates in soils. Sorption and retardation effects on transport and photolysis were also examined. Transport rates were found to be affected by sorption, with measured values of the distribution coefficient Kd of 0.4-0.72 in loamy sand and 6.6-7.2 mL/g in sandy clay loam soils.

Biodegradation, Herbicides, Soil mechanics

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