Levels of contaminants in effluent, sediment, and biota from Bai Bang, a bleached kraft pulp and paper mill in Vietnam

Abstract

Chemical analyses of organochlorine compounds in effluents, sediment, and biota samples were done for the Bai Bang Paper Company (BAPACO), a bleached kraft pulp and paper mill in Vietnam. High chlorine consumption in the bleaching process resulted in a high specific discharge of adsorbable organic halogens (AOX), 4.7 kg/ton of air dried pulp (ADP), and polychlorinated phenolic compounds (31 g/ton ADP) in the effluent. The extractable organochlorine content in the accumulated fiber sludge of the sedimentation tank (70–100 μg/g) was more than 100 times higher than the sediment from the receiving river. Chlorinated compounds including dioxins were detected at low levels in sediment and rice, crab, mollusc and fish samples. Significant amounts of the chlorinated persistent compounds are probably transported by the Red River to the river mouth and coastal area. Heavy metal content was high in sediment and mollusc samples from the receiving rice field and fish pond. There may be a possible risk for human intoxication of the metals through the aquatic food chain via the mollusc but not via the rice.