Distribution and elimination of polycyclic musks in three sewage treatment plants of Beijing, China

The two representative polycyclic musks, 1-(5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphthenyl)-ethanone (AHTN) and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopentag]-2-benzopyrane (HHCB), were measured in aqueous samples and sludge samples of three STPs in Beijing, China by GC/MS. HHCB and AHTN concentration range in the influents were 1251.4--3003.8 ng/L and 111.9--286.3 ng/L, respectively. Meanwhile, the range of 492.8--1285.3 ng/L for HHCB and 47.3--89.3 ng/L for AHTN were present in the effluents. The musks in the sludges were three to four orders of magnitude higher than those in aqueous sewages. The removal efficiencies of the two musks varied in the range of 41.7%--70.1% for HHCB, and 25.5%--68.8% for AHTN. Adsorption onto suspended particulate matter played an important role in removing the musks from the sewages. The HHCB/AHTN ratio along the treatment processes showed that the two musks had high similarity of removal from sewage by each reactor of a STP. The musks in the effluent sewages may pose a low potential risk to aquatic environment in terms of the predicted-non-effect concentration. Nevertheless, considering the possible additive and synergistic effects with other compounds emitted via STPs, their bioconcentration and bioaccumulation in aquatic organisms and so on, it is essential to monitor these compounds in various compartments, and to study their environmental fate.