Distribution and behaviour of arsenic in the Huang He (yellow river) estuary and Bohai sea

Dissolved and particulate As were measured in the Huang He (Yellow River) estuary and in the Bohai Sea in order to investigate the behaviour of this element in one of the most turbid estuarine systems in the world. The elevated dissolved and particulate concentrations found in the Huang He River (27 nM and 10-14 μg g ^-1 respectively) are attributed to the high As content of of loess deposits, the main source of the suspended material. The estuarine behaviour of As was quite different for the two sampling periods carried out in May 1985 (low water stage) and in August 1985 (flood stage). As behaved conservatively during the low water discharge but it exhibited a mid-estuarine maximum during the high water discharge. The slight seaward decrease of As concentrations in particulate matter suggests that this maximum is the result of remobilization processes, either from suspended matter or temporarily resuspended bottom sediments where reducing conditions occur in interstitial and/or overlying waters.