Organic Compounds in Paper Mill Wastewaters

Abstract

This chapter is focused on the problem caused by the effluent discharges from paper and pulp mills. At present, three aspects should be considered in paper and pulp wastewater management: (1) the toxicity and high BOD5 of whitewaters and effluents; (2) the lack of knowledge on specific compounds responsible for the toxicity of the liquid and solid residue (sludge) and (3) the difficulty of treating whitewaters, which are characterized by the presence of suspended solids, colour odour, a high organic content, and an overall high toxicity. This chapter attempts to give an overview of organic compounds that contribute to the toxicity of paper mill waters and effluents, their levels, toxicological characterization and the methodologies used for their analysis. Families of compounds that are included are natural compounds such as resin and fatty acids, lignins, lignans and carbohydrates, and additives used during paper making such as surfactants, biocides and slimicides. In addition, part of the chapter is devoted to describing the wastewater treatment strategies used to decrease the toxicity and BOD₅ of the effluents, which are used to indirectly phase out toxic organic pollutants from paper and pulp whitewaters (Table 1).