- Mathematical models, simulation and parameter estimation for water/wastewater treatment by ozone in semicontinious, countercurrent and cocurrent columnsKallas, Juha; Munter, Rein; Viiroja, Andres; Kõrvits, Madis12th Ozone World Congress, May 15th to 18th, 1995, Lille, France : proceedings. Vol. 21995 / p. 229-240