Sequencing Batch Reactor
COMPARISON OF SBR AND CONTINUOUS FLOW ACTIVATED SLUDGE FOR NUTRIENT REMOVAL
Alvin C. Firmin CDM Jefferson Mill, 670 North Commercial Street Suite 201 Manchester, New Hampshire 03101
ABSTRACT Sequencing batch reactors (SBR) are a flexible configuration of the activated sludge process, capable of providing low effluent nutrient levels. The SBR is fundamentally the same as any other variation of the activated sludge process, except that it operates in a batch draw and fill mode. The nuances of a batch operation must be understood and applied. This paper presents design considerations unique to the SBR and a design comparison of a continuous flow system and SBR, demonstrating that the total volume in a SBR system is not less than a comparably sized continuous flow system and that the total number of diffusers and installed blower horsepower is greater for the SBR system. KEYWORDS
Sequencing batch reactor, SBR, activated sludge, aeration
INTRODUCTION Sequencing batch reactors (SBR) have become a popular means of providing activated sludge treatment. With proper design and configuration, SBRs will provide very low effluent nutrient levels. The SBR is fundamentally the same as any other variation of activated sludge—the same concepts, design procedures, and biological kinetics are applicable. However, the batch operation of the process and impacts on design aspects must be understood and correctly applied to achieve optimum results. In particular, the batch operation has a significant impact on sizing of the aeration system. This paper presents a sizing comparison between conventional flow activated sludge and a SBR system with varying numbers of reactors, demonstrating the impact of the number of reactors on the sizing of the aeration system. The paper also discusses the impacts of alkalinity control, decanting, the necessity of scum removal and advantages of the SBR compared to continuous flow systems. SEQUENCING BATCH REACTOR – DESCRIPTION AND DESIGN SBRs are
Alvin C. Firmin CDM Jefferson Mill, 670 North Commercial Street Suite 201 Manchester, New Hampshire 03101
ABSTRACT Sequencing batch reactors (SBR) are a flexible configuration of the activated sludge process, capable of providing low effluent nutrient levels. The SBR is fundamentally the same as any other variation of the activated sludge process, except that it operates in a batch draw and fill mode. The nuances of a batch operation must be understood and applied. This paper presents design considerations unique to the SBR and a design comparison of a continuous flow system and SBR, demonstrating that the total volume in a SBR system is not less than a comparably sized continuous flow system and that the total number of diffusers and installed blower horsepower is greater for the SBR system. KEYWORDS
Sequencing batch reactor, SBR, activated sludge, aeration
INTRODUCTION Sequencing batch reactors (SBR) have become a popular means of providing activated sludge treatment. With proper design and configuration, SBRs will provide very low effluent nutrient levels. The SBR is fundamentally the same as any other variation of activated sludge—the same concepts, design procedures, and biological kinetics are applicable. However, the batch operation of the process and impacts on design aspects must be understood and correctly applied to achieve optimum results. In particular, the batch operation has a significant impact on sizing of the aeration system. This paper presents a sizing comparison between conventional flow activated sludge and a SBR system with varying numbers of reactors, demonstrating the impact of the number of reactors on the sizing of the aeration system. The paper also discusses the impacts of alkalinity control, decanting, the necessity of scum removal and advantages of the SBR compared to continuous flow systems. SEQUENCING BATCH REACTOR – DESCRIPTION AND DESIGN SBRs are
References: EPA 932-F-99-073 (Sept 1999) Wastewater Technology Fact Sheet, Sequencing Batch Reactors Wilderer, Irvine, and Goronszy; Sequencing Batch Reactor Technology; Scientific and Technical Report No. 10, IWA Publishing.