Potential application of biophysical interrelationships for faster evaluation of sequencing batch reactor effluent quality

Abstract

Conventional parameters for assessing effluent quality like the 5‐day biological oxygen demand, (BOD5), total suspended solids (TSS), and coliforms take from one to five days before the tests are completed. Simple, rapid, economical, and reliable methods to determine wastewater quality parameters are essential for the effective control of effluent discharges and the monitoring of process performance. If disinfection is necessary, these rapid methods may be used to quickly estimate the disinfection requirements and to ensure that the final effluent quality is microbiologically adequate. This is especially applicable to the sequencing batch reactor system, which treats wastewater in a batchwise manner. The 6‐h coliphage, 3‐h chemical oxygen demand (COD) and 1/2‐h total organic carbon (TOC) tests have been identified as rapid tests. Being microbiologically related, the coliphage test was shown to have a good degree of correlation with coliform levels in the effluent. Predictions of coliform numbers may be made by enumeration of the phages. The COD was also correlated and shown to produce a quick estimate of the total BOD5, TSS, and coliform values. Although the TOC test is based on the dissolved portion of the effluent, it may also be used as a rapid estimation of the total BOD5, TSS, and coliform values. © 1994 by John Wiley & Sons, Inc..

Coliphages as a rapid indicator of sequencing batch reactor (SBR) treatment performance

“…where FC is fecal coliforms/lOO mL and P is coliphages/100 mL. These equations represent trends similar to those found by Isbister et al (1983) for natural waters and Sim et al (1994) for SBR treated domestic sewage (Table I). These findings support the earlier view that a quick estimate of coliform numbers may be obtained by the enumeration of coliphages for a SBR treated effluent.…”

“…Considerable removals of BOD5, toxicity, coliforms, and coliphages by the pilot-scale SBR have been reported in Ng et al (1992), Ng et al (1993b), and Ng et al (1994). The results of our analyses have shown that the SBR is capable of removing coliphages from the wastewater in the course of the treatment cycle ( Fig.…”

“…Although a few investigators of wastewater have used coliphages as an indicator of treatment efficiency, none, except for Sim et al (1994), have tried to correlate coliphages with total coliforms or fecal coliforms for an SBR treated domestic sewage (Table I). Note that the MPN-BGB, MPN-EC, and modified ARCAT methods were used to enumerate total coliforms, fecal coliforms, and coliphages, respectively.…”

“…However, the intercepts were higher than those for natural waters. Since SBR effluent was a treated wastewater containing suspended solids and microbes, it may be expected to have a higher coliform count than natural waters (Sim et al, 1994). Based on coliphage counts, estimates of the total coliforms and fecal coliforms could be obtained for SBR treated domestic sewage.…”

“…Such SBRs are undoubtedly easier and cheaper to construct and operate, and the results obtained generally are easier to interpret, but there are limitations concerning the application of these results on the design and operation of full-scale systems. As a follow-up of an earlier study involving laboratory models of the SBR treating domestic sewage (Ng et al, 1993a;Sim et al, 1994), a pilot-scale SBR established at a full-scale combined (industrial and domestic) wastewater treatment plant was used to gain a better understanding of process performance.…”