DIE-OFF PROCESSES OF INDICATOR BACTERIA IN THE MIXED-ALGAL REACTOR

Abstract

Die-off processes of coliform and enterococcus groups were investigated in the mixed-algal reactor with the retention time of 4 days. The results of this investigation indicated that both of coliform and enterococcus groups rapidly died off in the mixed-algal reactor.
The initial die-off rate coefficients of coliform group in the reactor were almost similar values to those of enterococcus group. The test of significant difference was applied between mean initial die-off rate coefficient of coliform group and that of enterococcus group. But there was no significant difference at the 10% level. However, compared with the results of the blank test at which no algae was existing in the reactor, die-off rates of E. coli, Klebsiella spp. and S. faecalis var.liquefaciens were much less than those of the blank test, respectively. Therefore, there is the possibility that the existence of algae proposes the preferable conditions for the survivals of E. coli, Klebsiella spp. and S. faecalis var. liquefaciens. The adsorption of coliform and enterococcus groups to the algae exerted no influence on estimating the die-off rate coefficients of them.