Effects of Mg2+ on the bivalent mercury reduction behaviors in simulated wet FGD absorbents

► Mg2+ would have promoting effect on mercury reduction in Ca-based FGD adsorbents. ► An inhibiting effect on mercury reduction by magnesium ion in Dual-Alkali FGD adsorbents. ► The enhanced dissolution of CaSO3 particles would lead to the promoted mercury reduction. ► The inhibition of mercury reduction was mainly due to the formation of the neutral MgSO30 ion pair.