Quaternary ammonium compounds in urban estuarine sediment environments--a class of contaminants in need of increased attention?
The distributions of wastewater-derived quaternary ammonium compounds (QACs) were determined in surficial sediments (n = 47) collected from the urbanized lower Hudson River basin. The most abundant class of QACs were dialkyldimethylammonium compounds (DADMACs, with C8 to C18 carbon chain lengths; median ΣDADMAC = 26 μg/g), followed by benzylalkyldimethylammonium compounds (BAC, C12-C18; 1.5 μg/g), and alkyltrimethylammonium compounds (ATMAC, primarily C16 and C18; 0.52 μg/g). The concentrations of total QACs are higher than those of other conventional organic contaminants determined on the same samples (e.g., median ΣPAH level of 2.1 μg/g). Comparatively high concentrations, correlations with sewage derived contaminants, and the relatively constant compositions of QACs observed over large areas suggest that many sediment-sorbed QACs can be relatively persistent in receiving waters. Unusually large concentration-dependent sorption is considered as a mechanism that likely affects persistence of these intrinsically biodegradable chemicals under field conditions. There has been comparatively little field-based research on these classes of cationic surfactants; given the levels of QACs observed here, it is suggested that further investigation is warranted.
Li
Xiaolin
X
School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York 11794, USA.
Brownawell
Bruce J
BJ
D005618:Fresh Water / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D012722:Sewage; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D000644:Quaternary Ammonium Compounds; D012722:Sewage; D014874:Water Pollutants, Chemical