Mercury Pollution Prevention at a Bleached Kraft Pulp and Paper Mill, 1996 Environmental Conference Proceedings

Mercury is a natural element, potent neurotoxin and bioaccumulative chemical of concern that has been targeted for virtual elimination from anthropogenic or human-related sources in the Great Lakes Basin. To answer the call for virtual elimination, the pulp and paper industry has joined many other industrial sectors in efforts to reduce the use of mercury-containing products and incidental releases of mercury from manufacturing processes. Potlatch Corporation’s pulp and paper manufacturing facility in Cloquet, Minnesota has demonstrated that pollution prevention is the preferable means of achieving reductions in mercury pollution from mercury-containing products and feedstock chemicals. Since 1992, approximately 267 kilograms of elemental mercury have been captured and recycled from mercury-containing devices such as flow meter transmitters, manometers, fluorescent light bulbs, thermostats, thermometers, pressure switches, and batteries. This paper also discusses a project that identified and eliminated a significant source of mercury to the pulp bleaching process. The source of mercury was shown to be the sulfuric acid necessitated by a process change in March 1994. This process change was required as the mill completed the conversion to elemental-chlorine-free (ECF) bleaching. As a result of this project, mill wastewater effluent mercury mass loading was reduced by over 90%. The Potlatch Cloquet mill has taken a number of pollution prevention steps to ensure that feedstock chemicals are...