Purification of pulp and paper mill wastewater - aerobic bio-oxidation with ozonation in re-circulation systemKamenev, Inna; Roosalu, Kati; Vaks, Ursula; Viiroja, Andres; Kallas, JuhaInternational Conference on Ozone in Global Water Sanitation, Amsterdam, the Netherlands, October 1st to October 3rd 2002 : proceedings2002 / p. IV-6-1 - IV-6-18 : ill