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A full-scale pilot plant using SBR process was experimented with an actual wastewater emanating from a recreational center. The main purpose of this investigation was to evaluate applicability in the field and process removal efficiencies in terms of BOD, SS, TN and TP and its corresponding kinetic parameters. It was found that removal efficiencies were comparable with results of other studies reported in the literature. BOD removal was observed to be 95% on average while SS removal to be 89% on average. Removal rate of nitrogen was 70% in terms of total nitrogen and that of phosphorus was 77% in terms of total phosphorus. Effluent concentrations were 7.3 mg/??? BOD, 10.4mg/??? SS, 13.6mg/??? TN and 0.9mg/??? TP. Effluent quality was maintained consistently stable by controlling decantation quantity and operating cycles. Denitrification/nitrification were accomplished during anaerobic/aerobic processes and the conversion rates were 4.5mg/kgMLSS/hr and 1.5mg/kgMLSS/hr, respectively. The sludge yield coefficient was 0.32 whereas sludge phosphorus luxury uptake was as high as 5.6wt% at the end of aerobic cycle. Microscopic examination revealed that microcytes that were observed predominantly in sludge were Vorticella, Epistilis, Aspidisca (protozoa) and Philodina (rotatoria). This experiment may prove that SBR process is one of the most promising technologies that can be employed to treat organic matter as well as nutrients in wastewaters that are generated from such sources as recreational facilities because of fluctuations of wastewaters in terms of quality and quantity.

There have been several recent drinking water incidents in connection with detection of water borne pathogens in Korea. This has led to the need for research to find microorganisms that will indicate the stability of pathogenic removal in water treatment plants (WTPs). We investigated seven microorganisms as potential indicators: four for bacteria [E. coli, fecal coliform (FC), total coliform (TC) and heterotrophic plate counts (HPC)], two for protozoan [aerobic spore formers (ASF) and Clostridium perfringens (CP) spore], and one for viruses (F-specific RNA coliphage). Source water, treated water from each process, and finished water were analyzed periodically from three WTPs, chosen in view of the source water quality and plant size. This study concludes that HPC and ASF appeared to be good indicators of the stability of pathogenic removal. Although this study supports ASF as the best indicating microorganism, the potential use of HPC as an indicating microorganism was demonstrated in this study. From this study, the regrowth problem of HPC in water plants was shown to be negligible depending on the characteristics of the chlorination practice at the WTPs, and temperate climate conditions. The relative importances of each treatment process, for the removal of suggested indicating microorganisms, were found to be as follows: combined process of coagulation and sedimentation with prechlorination > filtration » disinfection, with emphasis on the necessity for the optimization of whole water treatment processes for effective microbial removal.

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