The SBR sequentially selects multiple, individual processes in a single basin, based upon an activated sludge fill and draw wastewater treatment process. Combined with the latest in process and control technology, Ashbrook’s SBR incorporates equalization, aeration, clarification, etc. steps, enabling the treatment of wastewaters exhibiting a wide variation in composition, concentration and flow patterns.
The SBR enables removal of nutrients (nitrogen and phosphorus) as well, utilizing anaerobic/anoxic mixing during the FILL step and on/off cycling of the aeration blowers during the REACT FILL and REACT steps. All processes are easily programmed into the SBR operating control system.
The floating decanter utilizes a circular weir for decanting supernatant liquid and a flotation device for buoyantly supporting the weir within the basin. The floatation device also acts as a baffle to prevent scum from being withdrawn during the decant step. For the successful operation of an SBR, the decanter must be designed to prohibit Mixed Liquor Suspended Solids (MLSS) from entering the decanter during non-decant sequences as well. The Ashbrook weir is lifted out of the water and underwater seals are not required, allowing the Ashbrook decanter to make use of stainless steel V-notch weirs to significantly enhance flow control. Additionally, the Ashbrook design eliminates the need for expensive, actuated decant valves. A superior quality effluent is produced by lowering the v-notched weir into the water surface, starting with a slow, controlled decant rate which minimizes the disturbance of settled sludge. The weir position is adjusted by simultaneously operating three screw jacks with a single motor, which ensures proper control of the flow rate. The depth adjustment of the weir is controlled using electric actuators only, which allows for superior flow control.
The SBR is popular among wastewater treatment plant operators because the clarifier and sludge recycle are eliminated, and the entire operation of the process is controlled by a PLC, thereby simplifying the overall plant operation. Process components being controlled by the PLC include: process phase and sequence, motorized valves for influent wastewater, air valves, aeration blowers, mixers, waste sludge pumps (or waste sludge valves) and the liquid level control system. The automated operation of the SBR allows operators to concentrate on routine visual mechanical inspecting and critical laboratory sample analysis, rather than frequent hand-on adjustments. Key process adjustments can be made by simple keypad entries through the operator interface.
Ashbrook Simon-Hartley can design and engineer your SBR in various basin geometries and materials of construction. Geometries can be square, rectangular or circular, with construction materials of steel, concrete or earthen basins. Ashbrook Simon-Hartley SBR systems and services are employed most notably in municipal wastewater treatment applications, although parallel industrial water and wastewater applications are also served in the pulp and paper, mining, power generation, food processing, petrochemical and other associated industries.