| Abstract: | Eighteen effluent types from seven thermomechanical (TMP), chemithermomechanical (CTMP), bleached chemimechanical (BCMP), and kraft pulp mills were treated in the laboratory with ozone alone or ozone in conjunction with aerobic biological treatment. Except for one mechanical pulp mill effluent, all effluents ozonized showed rapid and selective destruction of their acute toxicity, juvabiones (JB), and resin and fatty acids (RFAs) over biological and chemical oxygen demand (BOD and COD) by ozone. For acute toxicity and RFA/JB removal, aerobic biotreatment of mechanical mill effluent streams produced additive but not synergistic effects when combined with ozone treatment. Ozonation of biotreated kraft effluents yielded substantial decreases in the biologically recalcitrant residual adsorbable organic halogens (AOX), converted COD to BOD, and usually produced large decreases in color. |
