Organic compounds in paper-mill process waters and effluents

Paper-mill effluents are characterized by the presence of color and suspended solids, bad smell, high concentration of nutrients that cause eutrophication of receiving waters, and high toxicity overall. This study 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 included are natural products, such as resin and fatty acids (wood extractives), additives used during paper-making, such as biocides, surfactants and phenolic compounds and by-products generated during bleaching, such as dioxins and furans. Several extraction methods, such as liquid-liquid extraction (LLE) or solid phase extraction (SPE) followed by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS) with atmospheric pressure chemical ionization (APCI) or electrospray (ESP) are described and method performance is discussed for each family of compounds. This study contributes to the characterization of the organic fraction of paper-mill effluents and highlights elimination strategies.