Sewage treatment by controlled eutrophication: bacterial study.

Several groups of bacteria were isolated and identified in an evaluation of the microbiological properties of a sewage treatment system involving the process of controlled eutrophication in a marine setting (J. G. Songer, N. M. Trieff, R. F. Smith, and D. Grajcer, 1974). Fecal coliforms, enterococci, Salmonellae, Shigellae, Vibrio parahaemolyticus, and Vibrio alginolyticus were studied at three stages of the treatment process. Significant reductions in fecal coliforms (P < 0.01) and enterococci (P < 0.01) were noted from raw sewage to effluent. Salmonellae and Shigellae were not detected at any stage, nor was V. parahaemolyticus. V. alginolyticus was isolated from the effluent only, reflecting the halophilic nature of the organism; low concentrations in raw sewage increased in the more saline effluent. Brine shrimp (Artemia salina), the herbivores in this system, were tested and found to have extremely low numbers of the organisms under study associated with them. Findings point further toward the use of this system as a combined mariculture-sewage treatment facility.