A full-scale test of a biological nutrients removal system using the sequencing batch reactor activated sludge process

Abstract

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.