During the aeration process of the desulfurization wastewater discharged from the seawater wet flue gas desulfurization unit

some reducing ions (SO_3~(2–)

Fe~(2+)

Mn~(2+)

etc.) are present in the desulfurization wastewater

which will reduce the mercury and arsenic ions captured during the desulfurization process to gaseous mercury and gaseous arsenic to be released to the atmosphere again

reducing the mercury and arsenic removal efficiency of the wet desulfurization system.An aeration reactor is used to simulate the actual aeration process of desulfurization wastewater

the effects of temperature

Cl~–concentration

SO_3~(2–)concentration

SO_4~(2–)concentration and aeration flow rate on the re-emission characteristics of mercury and arsenic are investigated in detail.The results show that

as the temperature and aeration flow increase

the reduction of mercury and arsenic ions will be accelerated

and the re-emission of mercury and arsenic will be promoted.The increase of the concentration of SO_3~(2–)will significantly promote the re-emission of mercury

but has a weak effect on re-emission of arsenic.The re-emission rate of mercury and arsenic shows a trend of first increasing and then decreasing.Cl~–and SO_4~(2–)can form stable complexes with mercury ions in the solution

and can also be combined with arsenic ions in a more stable chemical state

thereby effectively inhibiting the re-emission of mercury and arsenic

and the inhibitory effect of Cl~–is more significant than SO_4~(2–).