Resin acid compounds in a kraft pulp and paper mill effluent and their distribution in bottom sediments near the outfall

Kraft pulp and paper mill effluents (KPPME) collected on three occasions were analyzed for resin acids, aliphatic hydrocarbons, and aromatic hydrocarbons. The maximum total concentrations of these compounds found in secondary effluents were 8 mg/L resin acids, 4.0 mg/L resolved aliphatic hydrocarbons, and 0.2 mg/L resolved aromatic hydrocarbons. Abietic acid and dehydroabietic acid were the two major components in resin acid fractions and were responsible for \u3e 70% of the total concentration. Analyses of estuarine water and sediments collected from the outfall and nearby areas showed that dehydroabietic acid was the major resin acid in either water or sediment. Concentrations of dehydroabietic acid ranging from 0.4 (mu)g/L to 3.6 (mu)g/L were found in water samples collected during high water slack and up to 5.8 (mu)g/g dry sediment were found in sediments. This indicates that dehydroabietic acid is persistent in the estuarine environment. Most of the resin acids identified in the KPPME were present in sediments taken near the outfall. Concentration-station profiles of the major resin acids showed maximum concentrations near the outfall which indicates that the KPPME is a major source for these acids. The concentration-depth profiles of the resin acids in core samples appear to reflect the major events occurring in the mill. If this is true, average sedimentation rates after 1973 are estimated to be 2-3 cm/year near the outfall and 1 cm/year in the nearby areas. Sediment hydrocarbon concentrations also peaked near the outfall area. Discharge of the KPPME and the use of fuel oil in the mill are among the contributors of petroleum hydrocarbons in the sediments. Cordgrass (Spartina cynosuroides) in the adjacent marsh areas is likely to be the major source for high MW n-alkanes to the sediments. Retene was identified in the sediments. The concentration-station and concentration-depth profiles of retene in river sediments, however, suggests that it is unlikely to be derived primarily from resin acids near the discharged area. Retene was found to be predominant in one sample taken from the marsh area in March 1981, but it was a minor component in the sample taken in November 1982. Further study is needed to understand production process of this compound