Increasing Oceanic Carbon Fixation Through Fe Fertilization: Opportunity for Mine Water?

Approximately 30 % of the Earth’s oceans support low rates of primary production because of low Fe concentrations. The fertilization of these waters with Fe has been proposed as a tool for creating phytoplankton blooms, increasing carbon fixation, and sequestering carbon in deep ocean waters. This paper reviews the status of the ocean iron fertilization (OIF) concept and assesses the opportunity it may provide to mining companies and mine water professionals who regularly deal with large quantities of Fe. Using data produced by large OIF experiments, calculations are provided regarding the efficiency of Fe additions for carbon fixation and the quantities of Fe that would be needed if OIF became an accepted practice. The gross value of Fe used in OIF projects is calculated from the current value of carbon credits and salmon and tuna fisheries. If the OIF concept advances, the huge demand for Fe that will be created may justify reconsideration of mine water treatment practices that produce more pure Fe solids than is the case with conventional treatment technologies.