Chlorinated Anisols and Veratroles in a Canadian River Receiving Bleached Kraft Pulp Mill Effluent. Identification, Distribution, and Olfactory Evaluation

Pulp and paper mills using chlorine bleaching release chlorinated anisoles and veratroles to receiving waters. Water samples were collected downstream from a bleached kraft pulp mill effluent in the Athabasca River in Alberta, Canada, and analyzed for the presence of these chlorinated compounds using gas chromatography with flame ionization detection, and olfactory gas chromatography. Odor threshold concentrations were determined by a panel of two or three persons. The average concentration of 2,4,6-trichloroanisole was found to be near the odor threshold concentration. Concentrations of 4,5-dichloroveratrole, 3,4,5-trichloroveratrole, and tetrachloroveratrole were below their odor threshold concentrations. Volatility was not found to be the major determinant of odor threshold for the compounds, but rather their structural factors, since the veratroles lacked the 2,6-dichloro-1-methoxy structural feature of the potent anisoles.