• Home
• Water
• Sox and Nox
• Energy
• ghgs
• compounds
• Nonwoodfiber
• BOD

The effects of paper recycling on the use or discharge of chlorine-containing compounds occur primarily in bleaching.

Several substances once associated with bleaching (e.g., dioxin and highly chlorinated phenolic compounds) are now below levels that can be detected in effluents at both virgin and recycling mills. Chloroform is generated in small amounts at virgin mills that use chlorine dioxide for bleaching and in larger and comparable amounts at virgin and recycling mills using sodium hypochlorite for bleaching or brightening. Polychlorinated biphenyls (PCBs), which in the past entered recycling mills in certain carbonless copy papers, are now seldom detected in mill effluents.

Total quantities of chlorinated organic compounds in effluents, measured as adsorbable organic halides (AOX), will often tend to be higher in virgin mill effluents because greater quantities of chemicals are required to bleach virgin pulp compared to the amounts applied to recovered fibers. Studies of the significance of the chemicals measured in the AOX test, however, suggest that they are not of particular environmental concern.

In cases where all chlorine-containing chemicals used for bleaching in virgin or recycling mills are eliminated (i.e., totally chlorine free (TCF) or process chlorine free (PCF) mills), the potential for generating chlorinated organic chemicals is also eliminated, but small amounts of chlorinated organic chemicals may continue to enter the mill as contaminants in recovered fiber or other raw materials.

Follow the links to the right for more information.

More information:

Pulp bleaching and brightening

PCBs in recovered fiber