Four phthalate ester products (three alkyl benzyl and one dialkyl phthalate) were monitored in industrial areas of the United States over 3 years (1980)(1981)(1982). Documented methodology and quality assurance practices for both sample collection and analysis assured validity of results. The geometric mean concentration (corrected for method losses) for the three benzyl phthalates was less than 0.6 &L in surface waters and less than 0.2 Fglg in sediments. Only 20 of 205 water samples (10%) and 13 of 122 sediment samples (1 1 %) had detectable levels of one of the benzyl phthalates. The geometric mean concentration (corrected for method losses) for C7,9,1 I dialkyl phthalate was less than 3 p g L in surface waters and less than 0.6 pglg in sediments. Only 13 of 138 water samples (9%) and I of 90 sediment samples (I 96) had detectable levels of C7,9,1 dialkyl phthalate.
Four phthalate ester products (three alkyl benzyl and one dialkyl phthalate) were monitored in industrial areas of the United States over 3 years (1980–1982). Documented methodology and quality assurance practices for both sample collection and analysis assured validity of results. The geometric mean concentration (corrected for method losses) for the three benzyl phthalates was less than 0.6 μg/L in surface waters and less than 0.2 μg/g in sediments. Only 20 of 205 water samples (10%) and 13 of 122 sediment samples (11%) had detectable levels of one of the benzyl phthalates. The geometric mean concentration (corrected for method losses) for C7,9,11 dialkyl phthalate was less than 3 μg/L in surface waters and less than 0.6 μg/g in sediments. Only 13 of 138 water samples (9%) and 1 of 90 sediment samples (1%) had detectable levels of C7,9,11 dialkyl phthalate.
The biodegradability of three aliphatic adipic acid diesters and a 1,3-butylene glycol adipic acid polyester was determined in acclimated, activated sludge systems. Rapid primary biodegradation from 67 to 99+% was observed at 3- and 13-mg/liter feed levels for di-n-hexyl adipate, di(2-ethylhexyl) adipate, and di(heptyl, nonyl) adipate in 24 h. When acclimated, activated sludge microorganisms were employed as the seed for two carbon dioxide evolution procedures, greater than 75% of the theoretical carbon dioxide was evolved for the three diesters and the polyester in a 35-day test period. The essentially complete biodegradation observed in these studies suggests that these esters would not persist when exposed to similar mixed microbial populations in the environment.
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