Abstract
Experiments were run in a batch reactor on samples of wastewater from pulping processes and paper making after biological treatment (secondary effluent). The samples then were treated in the following technological systems: ozonation alone, ozonation with alum or lime coagulation as a prior step, and ozonation with chlorination as a prior step. Of these, the coagulation-ozonation system was found to be the most effective, yielding high removal efficiencies.