COLIPHAGES AS A RAPID INDICATOR OF SEQUENCING BATCH REACTOR (SBR) TREATMENT PERFORMANCE

Generally, conventional tests for total and fecal coliforms take from 1 to 4 days before the results are available. In contrast, the colipha ge method is a simple, rapid, economical, and reliable method that has been used as an additional indicator of potential pathogens whereby c oliform numbers present in natural waters can be estimated within 6-24 h. In this pilot-scale study, besides demonstrating that the 6-h coli phage test may be used to evaluate sequencing batch reactor (SBR) trea tment efficiency (up to 99% removal), predictions of coliform numbers were made by enumeration of the coliphages. Coliform-coliphage correla tionships similar to that for natural water (as proposed by the Americ an Public Health Association's Standard Methods, 1989) and SBR treated domestic sewage have been developed for SBR treated combined sewage: log TC = 0.798(log P) + 3.921 where TC is total coliforms/100 mt and P is the coliphages/100 mi, and log FC = 0.850(log P) + 3.501 where FC is fecal coliforms/100 mt and P is coliphages/100 mt. Comparison betwe en the logarithm of coliphages after 24 h incubation with the logarith m of coliphages after 6 h incubation yielded correlation coefficients of at least 0.91 suggesting that the 6 h coliphage detection test is s ufficient for use as a rapid test and may be correlated to coliform nu mbers in sewage. (C) 1995 by John Wiley and Sons, Inc.