Pollution prevention advances in pulp and paper processing

Data collected from a large number of pulp and paper mills across the U.S. show that although there has been a significant increase in pulp production during the last 20–25 years, discharges to the environment have gone down. Over this period total reduced sulfur (TRS) emissions have been reduced by 85%, SO2 emissions have gone down by over 40%, effluent flow has decreased by over 30%, and biochemical oxygen demand (BOD) and total suspended solids (TSS) have decreased by 75% and 45%, respectively. Paper recovery has increased from 20% to 50%. The recently promulgated Cluster Rule, which links air and water standards, will further reduce environmental releases of hazardous pollutants and chlorinated organics. New and emerging technologies, such as enzyme bleaching, black liquor gasification, cogeneration, production of ethanol from wastewater treatment plant sludges, and beneficial use—including land application—of solids residuals are expected to further reduce emissions.