There are provided methods and processes that employ a mercury-adsorbing granular material as a sorbent to remove mercury from fluids. The fluids can be waste fluids that result from manufacturing, processing, or other treatment processes or systems. The fluids can also be fluids that are treated in their natural state. The fluids to be treated may include water, air, sludge, slurries, gases from processing or furnaces flues, gaseous flows, liquid flows, and other gases and liquids. In one excellent form of the invention, the mercury-adsorbing material includes taconite tailings.