NONPURGEABLE TOTAL ORGANIC HALIDE ANALYSIS AND THE CHARACTERIZATION OF RIVER WATER-QUALITY ADJACENT TO THE DISCHARGE FROM A KRAFT MILL

Examination of river water quality downstream of the outfall from a kr aft mill has shown that the mill effluent water (bleach liquor) contai ns significant amounts of chlorinated organic compounds. These compoun ds, which appear to be polymeric in nature, may be indirectly detected in the river water using the nonpurgeable total organic halide (NPTOX ) test. Approximately 30% of the chlorinated organic content of the ri ver is contained in an acid insoluble material (Fenextract), which was separated from the other components in a river-water sample by pH adj ustment. Fenextract appears to be a macromolecular chlorinated thiolig nin that is formed in the kraft bleaching process when chlorine dioxid e is the primary oxidizing agent. Chemical and spectroscopic character ization of Fenextract has allowed some additional insight to be gained into the reaction mechanism occurring during the chlorine dioxide ble aching process. The other 70% of the organic chlorine content in the r iver, which cannot be precipitated from the river by pH adjustment, wa s also attributed to high molecular weight chlorinated lignin substanc es.