Determination of fluorochemicals in waste-dominated aqueous systems.

摘要

While fluorochemicals have been detected all over the world and in wastewater treatment plants, the effect of wastewater effluent on the receiving waters has not been evaluated. In the first study, the mass flow of fluorochemicals emanating from wastewater treatment plants along the Glatt River in Switzerland was evaluated. The fluorochemical concentrations in daily composite samples of river water and wastewater were measured using LC/MS/MS. On average, the seven wastewater treatment plants proved ineffective in completely removing fluorochemicals from the influent and in some individual cases, the effluent concentrations of fluorochemicals were elevated when compared to the influent. Fluorochemical concentrations in wastewater were dominated by PFOS followed by PFHxS and PFOA; PFOS was detected in 100% of the samples. In the Glatt River, PFOS, PFOA and PFHxS were detected in all samples. Mass flows were determined and showed that the mass loading from the treatment plants is additive and that the mass flow along the river is conserved. Per capita discharges for the plants along the Glatt River were calculated and found to account for the upstream concentrations of fluorochemicals at the headwaters of the Glatt River.; In the second study, a method for the quantitative analysis of fluorochemicals in landfill leachates was developed to assess the amount of fluorochemicals emanating from landfills. The method employed solid phase extraction with EnviCarb cleanup prior to analysis by large volume injection LC/MS/MS. Perfluorocarboxylates (C4-C10) were the dominant species observed in landfill leachates. PFBA concentrations ranged from 63--1800 ng/L and PFOA concentrations ranged from 130--1100 ng/L. The most abundant perfluorosulfonate measured in leachate was perfluorobutane sulfonate (110-2300 ng/L), which was measured in all samples. PFOS was also detected in all samples at concentrations from 38--160 ng/L, including in leachates obtained from sites which received waste only after the 2002 phase out of PFOS. Fluoroalkyl sulfonamides, which was are precursors to PFOS and PFBS were also detected in leachate, often in concentrations exceeding that of their degradation product. Concentrations of MeFOSAA, which is indicative of the chemicals used in textile and carpet treatments, ranged from ND--290 ng/L, while concentrations of EtFOSAA, which is associated with polymeric paper coating applications, ranged from 7 to 480 ng/L. The analogous C4 sulfonamide, MeFBSAA, was observed at concentrations ranging from 11--540 ng/L including at sites that have been closed since before the phase out of PFOS and subsequent introduction of PFBS as a substitute. The distribution of fluorochemicals in landfills that operated under leachate recirculation conditions were not different from landfills that did not circulate leachate.