SEQUENCING BATCH REACTOR AND CLOTH-MEDIA FILTRATION TECHNOLOGY FOR WATER REUSE

The Sequencing Batch Reactor (SBR) process is combined with cloth-media filtration technology to achieve high quality effluent with nutrient removal for the purpose of water reuse. This paper will feature the capabilities of the AquaSBR® process to achieve biological phosphorus removal, nitrification and denitrification with tertiary solids removal via AquaDisk® filtration.The discussion will detail the methods employed to attain an effluent less than 5 mg/l biochemical oxygen demand (BOD) and total suspended solids (TSS), less than 10 mg/l total nitrogen (TN), less than 1 mg/l phosphorus (P) and less than 1 nephelometry turbidity unit (NTU). Specific discussions will detail the various process phases employed within each cycle, targeting aerobic, anoxic and anaerobic biological environments. The biological capabilities, limitations and the implication of tertiary filtration will be investigated as they pertain to attaining the specified biological nutrient removal requirements.The manuscript will provide a case history of the Dick Creek Water Reclamation District wastewater treatment facility. This facility is designed to treat an ultimate flow of 1.1 million gallons per day (MGD) through a process train which includes SBRs, equalization, filtration and UV disinfection. This particular system employs a dual basin Sequencing Batch Reactor with coarse bubble retrievable diffusers, independent anoxic mixers, and floating subsurface decanting devices. The SBR system discharges into an effluent equalization basin which pumps flow to a pair of tertiary cloth-media filters. Each AquaDisk Filter processes flow through a series of four vertically mounted disks which provide the skeleton for the polyester filter media.The operational requirements for the SBR system and cloth-media filters will be reviewed, with their implications on the process and mechanical design selection. A comparison of the SBR and cloth-media filter technology will be drawn versus conventional methods.The paper will cover the growing need for nutrient removal and water reuse, and the benefits offered via Sequencing Batch Reactor and cloth-media filtration technologies. The advantages provided through biological nitrification, denitrification and phosphorus removal will be examined with a discussion of the cost implications necessary to achieve such objectives.