Bisphenol A contamination in Canadian municipal and industrial wastewater and sludge samples

A large-scale study on bisphenol A (BPA) contamination in Canadian municipal and industrial wastewater and sludge has been completed. A total of about 200 samples were collected, including those from 31 sewage treatment plants and 15 pulp and paper mills across Canada, as well as 13 industrial facilities in the Toronto area. The samples were extracted by previously developed solid-phase and supercritical carbon dioxide extraction procedures and were analyzed by gas chromatography-mass spectrometry. BPA contamination was detected in all of the 72 sewage samples, with! concentrations ranging from 0.080 to 4.98 mu g/L (median 0.329 mu g/L) for the influent, and from 0.010 to 1.08 mu g/L (median 0.136 mu g/L) for the effluent. Of the 36 influent/effluent sample pairs studied, BPA in the influent is removed by the sewage treatment process at a median reduction rate of 68%. Levels of BPA accumulation in sewage sludge, for the 50 samples tested, ranged from 0.033 to 36.7 mu g/L, on a dry weight basis. A wide range of BPA concentrations, from 0.23 to 149.2 mu g/L were observed for the wastewater collected from selected industrial facilities in the Toronto area. The more contaminated samples came from the sectors of chemicals and chemical products, commercial dry cleaning, as well as packaging and paper products. Based on these data, on-site releases of BPA by industrial facilities seem to be much more widespread than the National Pollutant Release Inventory (NPRI) database has suggested. While relatively high levels of BPA were found in some of the primary treated effluent collected from the deinking mills, BPA concentrations in the secondary treated effluent of all pulp and paper mills were low, with a range from <0.005 to 0.406 mu g/L. Except for the samples derived from a few deinking mills, BPA contamination in pulp and paper mill sludge was either low or undetected.