Distributions and Fate of Volatile Organic Compounds in Narragansett Bay, Rhode Island

Abstract

A wide range of volatile organic compounds (VOC) were measured in the water column along a north–south transect in Narragansett Bay, Rhode Island, during two summers and two winters. The dominant VOC are chlorinated C2-hydrocarbons, chlorobenzenes, and aromatic hydrocarbons. Major sources for these anthropogenic compounds are municipal and industrial wastewaters discharged into the upper bay. Concentration trends along the transect are variable depending on the compound class and the season of sampling, indicating that different processes control the distributions of different compounds. Volatilization apparently is a major removal process for all VOC. Calculations suggest water column residence times with respect to volatilization of 150–300 h in Narragansett Bay. Biodegradation, particularly in summer, is important for aromatic hydrocarbons, which are degraded in a few days. Sorption onto particulate matter and eventual sedimentation is minor, except for the higher molecular weight alkanes.