N-(4-aminophenyl)aniline

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Additional information

Although 4-ADPA is not readily biodegradable with only 8% biodegradation observed in 20 days, it is inherently biodegradable with more than 70% DOC removal observed in 7 days independent from adsorption. 4-ADPA is abiotically stable without presence of light and oxygen. At 25°C the hydrolysis half-lives of 4-ADPA of 42 days at pH 7.0 and 75 days at pH 4 with light excluded were observed. In nutrient medium same as the one used in algal inhibition test, the half-life of 4-ADPA decreased to 3.5 d in presence of light and oxygen. 4-hydroxydiphenylamine and aniline were observed as main metabolites. The obtained half-life of 3.5 d was used to estimate the effective concentrations from nominal concentrations in ecotoxicity studies. On the other hand, 4-ADPA can be completely photocatalytically oxidized in water using TiO2 and/or SnO2 in 3.5 hours. 4-ADPA is not bioaccumulative with an estimated BCF of 7, which is far below 100. Simultaneously, 4-ADPA has a low adsorption potential in soil/sludge with the adsorption coefficient (log Koc) of 2.72. 4-ADPA is essentially non-volatile with an estimated Henry’s Law Constant of 2.8*10-5 Pa m³/mol at 20°C. Meanwhile it has a calculated half-life of 1.92 hours in air due to the reaction with hydroxyl radicals with a rate constant of 2 *10-10 cm3/(molecule*sec). The estimated half-life in air of 4-ADPA is much shorter than 48 hours; and hence no potential for long-range transport of 4-ADPA in air is expected. The distribution of 4-ADPA in a "unit world" was calculated according to the Mackay fugacity model level I based on the physico-chemical properties. The main target compartment for 4-ADPA is water of 98.96 %.