Abstract: Water samples were collected from 48 main sewage streams and each process of 2 wastewater treatment plants in 5 regions of Zhongshan City. This study used Solid Phase MicroExtraction (SPME) for pretreatment and combined with Gas Chromatography/Mass Spectrometry (GC/MS) technique to detect the contents of three synthetic musks in the water samples. The three synthetic musks are Galaxolide (HHCB), Tonalide (AHTN) and Musk Ketone (MK). And the distribution characteristics of them were analyzed, as well as the change law of their concentrations along the water treatment processes of wastewater treatment plants, which had certain reference value for understanding the distribution of synthetic musks in sewage streams. The results showed: 1) Synthetic musks had been widely found in the sewage streams of Zhongshan City. Among them, the total contents of synthetic musks in 4 sewage streams, such as Yanqi Stream and Kuikui Stream, all exceeded 500 ng/L. The total contents of synthetic musks in 8 sewage streams, such as Huangpu Stream and Hengli Stream, were in the range of 200 – 500 ng/L. The total contents of synthetic musks in the remaining 36 sewage streams, such as Sulie Stream and Shijun Stream, were less than 200 ng/L. The total contents of synthetic musks from sewage streams in the Western and Southern regions of Zhongshan City were relatively the lowest as compared with other regions, due to their proximity to the outer river channels which could dilute and migrate pollutants, including synthetic musks. The Central Region also had low concentrations of synthetic musks in the sewage streams, which could be explained by that there were many wastewater treatment plants and the sewage collection rate was higher than that in other regions. 2) The major synthetic musk of different sewage streams was different. The main synthetic musk was HHCB, which accounted for more than 50% of total synthetic musks content in 28 sewage streams, such as Yanqi Stream and Kuikui Stream. The main synthetic musk was MK, which also accounted for more than 50% of total synthetic musks content in 13 sewage streams, such as Yilie Stream and Wusha Stream. And the main synthetic musks were HHCB and MK, which accounted for more than 35% of total synthetic musks content respectively in the other 7 sewage streams, such as Sulie Stream and Shijun Stream. 3) The Oxidation Ditch Process and Anaerobic/Anoxic/Oxic (A2/O) Process both could produce a certain removal effect on synthetic musks, due to activated sludge adsorption and microbial metabolic decomposition. In Wastewater Treatment Plant A, the ultimate removal rates of HHCB, AHTN and MK were 86.94%, 72.15% and 89.36%, respectively. In Wastewater Treatment Plant B, the ultimate removal rates of HHCB, AHTN and MK were 82.09%, 85.73% and 87.90%, respectively. 4) The secondary sedimentation tank of these two wastewater treatment plants and ultraviolet disinfection of Wastewater Treatment Plant A could produce further removal effects on synthetic musks. Both Wastewater Treatment Plant A and B could produce a higher removal rate on MK than HHCB and AHTN, which could be due to that MK contained nitrogen element and had a better removal effect.

Key words: synthetic musks, Zhongshan City, SPME-GC/MS, sewage streams, wastewater treatment