Volatile Loss of PCB Aroclors from Subaqueous Sand

Abstract

A series of experiments were conducted to measure the rate of volatile loss of PCBs from subaqueous quartz sand spiked with Aroclors 1242, 1248, 1254, and 1260 under laboratory conditions (20 °C, 25% relative humidity). Volatilized PCBs were trapped on Florisil columns attached to a 1.5-L evaporation chamber through which 1.2 L/min of filtered air was drawn for a 24-h period. PCB losses ranged from 20 to 65% and were inversely correlated with the chlorine percentage of the aroclors (R 2 = 0.97). Congeners with the fewest number of chlorines in each aroclor were preferentially lost. In comparison, sediment from a Federal Superfund site along the St. Lawrence River, originally contaminated with Aroclor 1248, lost 19% of its PCB total during a similar experiment. Several orthochlorinated congeners, produced by anaerobic biodegradation, were preferentially lost, and four of these (2/2; 2/6; 2; 26/2) accounted for >55% of the total loss. This work suggests that under certain conditions the volatile loss of PCBs and other hydrophobic compounds from wet soils and sedi ments may be rapid and substantial. Further work is needed to elucidate the implications for analytical procedures, remedial actions, and the global mass balance of PCBs.

Temporal and Spatial Trends of Total Aliphatic Hydrocarbons of Diesel Range and Trace Elements in Sediments and Mussels of the Corral Bay Area, Valdivia, South Central Chile

“…To evaluate the effects of the pollution over these ecosystems is useful to determine the type of contamination (organic, inorganic, bacterial) as well as their potential sources to distinguish the specific origin of point or diffuse contamination since both are concentrated in the mouth of the estuaries and related areas. However, even thought all contributing sources would be known, it has been demonstrated that environmental investigations can be complex, because the composition of chemicals in the environment usually change over time by photolysis, biodegradation, volatilization and oxidation 3 . Among the most important pollutants, petroleum hydrocarbons and metals from industrial, municipal and sewage discharge and runoff coupled with aerial deposition are of particular concern due to their environmental persistence and wide range of toxicity effects over the aquatic biota, even for some of them at low concentrations 4 .…”

Do Large-Scale Remedial and Dredging Events Have the Potential to Release Significant Amounts of Semivolatile Compounds to the Atmosphere?

“…Recent experiments monitoring the loss of polychlorinated biphenyls (PCBs) from wet sediment (1,2) and subaqueous sand (3) have shown that a strong correlation exists between water evaporation and PCB volatile loss, implying that PCBs can be released during drying of contaminated solids. Similar relationships between the volatile loss of dibenzofuran, phenanthrene, and pyrene from dredged sediment and the relative humidity of air have also recently been described (4).…”

A preliminary investigation of the environmental impact of a thermal power plant in relation to PCB contamination

“…3a). This similarity is noteworthy in two respects: (1) PCBs in these surficial sediments are due to recent pollution since, on average, the effect of physicochemical (Chiarenzelli et al 1997;Bergen et al 1998) and/or biological weathering (Bedard and May 1996) on PCBs seems minimal. (2) Aroclor 1254 (late) represents <1% of the total Aroclor 1254 production by Monsanto (ATSDR 2000).…”