Silica Materials for Mercury Recovery From Wastewater

A number of industrial processes generate wastewater with mercury contamination. Existing cleanup processes have difficulties in achieving low mercury discharge limits, especially in the presence of competing metal ions already below their discharge limits. Commercial ion exchange media are not selective for mercury, so other metal ions compete with mercury for binding sites. Consequently, excessive amounts of ion exchanger are required. This Phase I project will develop two series of highly selective silica materials for removing mercury from contaminated wastewater. Relative to the low selectivity of state-of-the-art materials, up to four orders of magnitude less material will be required to achieve mercury discharge limits. In Phase I, the silica materials will be synthesized. Each will be evaluated for mercury capacity, selectivity relative to competing ions, ease of regeneration and reclamation of metal, and cost of production. If successful, the silica materials will be useful for the purification of wastewater generated in chloralkali manufacture, metal plating, battery recycling, and dentistry.