Biological oxidation in anaerobic digestion of sulfate rich wastewaterBlonskaja, Viktoria; Menert, Anne; Kurissoo, Tõnu; Vilu, Raivo9th World Congress Anaerobic Digestion 2001 : September 2-6, 2001, Antverpen, Belgium : proceedings. Part 12001 / p. 713-718 : ill Comparison of some physical and chemical pre-treatment methods for excess sludgeMenert, Anne; Blonskaja, Viktoria; Vaalu, Tarmo; Sokk, Olev; Mölder, Heino9th World Congress Anaerobic Digestion 2001 : September 2-6, 2001, Antverpen, Belgium : proceedings. Part 12001 / p. 61-66 : ill