TRACKING POLYBROMINATED DIPHENYL ETHERS (PBDEs) DURING CONVENTIONAL WASTEWATER TREATMENT

Polybrominated diphenyl ethers (PBDEs) are a class of synthetic brominated flame retardants added to combustible materials such as plastics, wood, paper and textiles in order to meet National and International fire safety regulations. They are an inexpensive way to improve fire resistivity and may constitute up to 5-30% by weight of consumer products. PBDEs are non-covalently bound and are an additive which tends to bleed and leach their way into the environment during use and disposal of these products. PBDEs have been found throughout the world in air, sediments, sewage sludge, fish tissue, bird eggs, whale, dolphin and seal fat, mussels, and in human serum, milk and tissue. They enter the environment through synthesis, incorporation into polymers or finished products, during use of products and disposal or recycling of products. Exposure pathways to humans and animals include consumption of contaminated food, inhalation of particles, and direct contact with materials treated with PBDEs. Current literature suggests major point-sources of PBDEs into the environment include municipal and industrial wastewater effluents. National studies reveal concentrations of PBDEs in raw influent as high as 392 ng/L , 413,000 ng/L in biosolids and 26.4 ng/L in treated effluent. Treated effluent discharged into the Charleston Harbor is of particular importance due to the significant findings of PBDE concentration in the blubber of bottle nosed dolphins which ranged 429–22,780 ng/g lipid. Studies to date regionally have not quantified PBDE concentrations from point sources. The objective of this study is to determine the occurrence and distribution of PBDEs in municipal waste streams of 11 PBDE congeners (BDE- 17, 28, 71, 47, 66, 100, 99, 85, 138, 153, and 154) throughout the treatment process and quantify the resulting mass loading of PBDEs into the Charleston Harbor based on daily flow rates. This study expects to see a direct correlation of efficient PBDE removal from municipal waste streams with total suspended solids removal based on the physiochemical properties of PBDEs.