AOX contamination in Hangzhou Bay, China: Levels, distribution and point sources

The parameter AOX (adsorbable organic halogens) indicates the total amount of organic halogens in an environment. Seawater and surface sediment samples from 12 sample sites in the Hangzhou Bay (HZB), China, were analyzed for AOX to investigate its contamination status. In this study, the AOX concentration ranged from 140.6 ± 45.6 μg/L to 716.1 ± 62.3 μg/L in seawater of the HZB, and from 11.3 ± 2.4 mg/kg to 112.7 ± 7.2 mg/kg in the sediment. Ocean currents, fluvial currents and the Yangtze River exerted profound influences on the distribution of AOX in the HZB. The point sources around the HZB, represented by wastewater treatment plants, discharged at least 645.4 t AOX into the HZB every year, most of which was generated by industrial activities rather than the human daily activities. [Display omitted] •The Hangzhou Bay was polluted with AOX.•Distribution of AOX in the sediment highly depend on the source of sediment.•Industrial activities contributes more AOX than human daily activities. The Hangzhou Bay was polluted with AOX, of which the distribution and point sources were demonstrated for the first time.