RESPONSE TO OZONATION OF DIFFERENT CELLULOSE PULP BLEACHING EFFLUENTS

Ozonation of pulp bleaching effluents of Pinus radiata from the sequen ces C:D(90:10)/E, C:D(70:30)/E and Eucalyptus globulus from the sequen ces C:D(80:20)/E and D/E-p/D, was studied. The influence on the reduct ion of color, AOX, COD and pH, of the variables pH (2-10), temperature (10 - 40 degrees C), ozone flow (0.9 - 5.0 g h(-1)) and time (2 - 10 min), were evaluated using a factorial design. The results showed that for the alkaline extraction effluents, the pH is not an important par ameter in the organic matter degradation by ozone. On the other hand, for the chlorine dioxide stage effluent, the efficiency of the treatme nt was pH dependent, obtaining the best results at alkaline pH. In all the effluents, color was removed faster and more efficiently than COD and AOX. Multivariate analysis was used to find equations that estima te the efficiency of the treatment, depending on the initial color, AO X, COD and of the ozone charge.