Bacterial Dieoff in Ponds

Abstract

Quantitative data have been obtained which demonstrate the effect of representative algal species on selected enteric bacteria. The data show that individual algal species exert little influence on the dieoff of enteric bacteria; however, as the environment becomes more complex with the involvement of a greater variety of algal species, the dieoff rates increase. Laboratory and pilot-scale field tests provided similar results. The dieoff coefficients for enteric bacteria were similar for tests conducted in the laboratories using mixtures of axenic algal cultures and in the field using pilot-scale waste stabilization ponds. Tests conducted with pathogenic bacteria and algal cultures yielded results similar to those found when enteric bacteria were used. Escherichia, Pseudomonas, and Serratia exhibited aftergrowth potential while Proteus, Alcaligenes, Enterobacter, Salmonella, Shigella, and Vibrio did not. Both laboratory and field tests showed that anaerobic pretreatment in combination with facultative and maturation ponds, as compared to facultative and maturation ponds in series, resulted in higher dieoffs of enteric bacteria.