A process, system and sorbent for removal of mercury from a combustion exhaust gas stream in a combustion exhaust gas purification scheme that includes a combustion exhaust scrubber system that uses an aqueous liquid to remove acid gases from the combustion exhaust gas. A powdered mercury sorbent is used. The sorbent is introduced into the aqueous scrubber liquid in the scrubber system. After introduction of the mercury sorbent into the scrubber liquid, at least some of the mercury sorbent is separated from the scrubber liquid.