Abstract: Methods for reducing mercury content from a mercury-laden aqueous stream comprise contacting the aqueous stream with a tannin coagulant, a sulfide, such as a polyorganic sulfide, and an optional cationic flocculent. The invention is particularly well suited to reduce mercury content in mercury-containing wastewater streams of the type generated during oil and natural gas production.

Abstract: A method for reducing the amount of Mercury in a liquid stream, such as an aqueous wastewater or process water stream or a non-aqueous liquid hydrocarbonaceous stream is disclosed wherein the liquid stream is contacted with an effective amount of a Hg-complexing agent, the mercury contaminants in the liquid stream form insoluble complexes with the Hg-complexing agent, then the insoluble complexes are removed from the liquid stream via microfiltration or ultrafiltration techniques including the use of submerged hollow fiber ultrafilters or the like.