7-1 Introduction to the Activated-Sludge Process Historical Development Experiments conducted at the Lawrence Experiment Station during 1912 and 1913 by Clark and Gage With air input into wastewater, growths of organisms could be cultivated in bottles and in tanks partially filled with roofing slate spaced about 25 mm (1 in) apart and would greatly increase the degree of purification
Production: Organization Films International in collaboration with Foreign Films Productions, some sources also credit Capitani Films; black and white, 35mm; running time: 117 minutes, originally 124 minutes; length: 4195 feet. Released 1946. Producers: Roberto Rossellini, Rod E. Geiger, and Mario Conti;
Production: Vermedia (Lisbon), Cooperativa Arco-Íris (Bissau), Eurocréation Production (Paris), and Rádiotelevisão Portuguesa (Lisbon); color, 35mm; running time: 90 minutes. Released 1992. Producer: Paulo de Sousa; screenplay: Flora Gomes, Ina Césair