Removal of chlorophenolics and toxicity during high-rate anaerobic treatment of segregated kraft mill bleach plant effluents

The behavior of selected chlorinated phenols, guaiacols, catechols, and vanillins during the high-rate anaerobic treatment of segregated graft mill bleach plant effluents was investigated. Eleven of the 12 detected chlorinated catechols, guaiacols, and vanillins were removed at efficiencies of greater than 80% from an 80% v/v dilution of the wastewater, at a hydraulic retention time of 6 h when the influent was cosubstrate supplemented. The behavior of chlorinated phenol was influenced by the chlorine position and degree of chlorination. Supplementation of the reactor influent with a synthetic evaporator condensate containing methanol and ethanol improved the removal of a number of the compounds by greater than 80%