Removal of Organic and Inorganic Mercury from Pharmaceutical Wastewater


Funded by: Wyeth Pharmaceutical Company & Villanova Center for Environment, Villanova University

Thimerosal (a benzene mercury sodium salt: C9H9HgO2SNa ) and trace amounts of Hg2+ are present in wastewater from the manufacture of certain pharmaceutical drugs and quality analysis/control procedures. The scope of this study was to examine the technical feasibility of using adsorption technology for removing thimerosal and inorganic mercury from the pharmaceutical wastewater. Several adsorbents were selected based on their physical and chemical properties and their adsorption affinity for mercury. Batch isotherm and column studies were conducted to determine the most suitable adsorbent for removal of mercury. A pilot plant was designed, constructed, and tested successfully for treatment of wastewater from a pharmaceutical manufacturing facility. The pharmaceutical company is currently sending their wastewater to be treated off site. By treating the water on site with the pretreatment system, the cost is reduced by 95% (a factor of about 20). The system also reduces the amount of waste by a factor of 400. About 8400 gallons of wastewater could be treated by 120 lbs of adsorbent. Treating the wastewater on site also reduces the liability risk associated with transportation of hazardous waste. The pharmaceutical company plans to put the system in operation.