Urban sewage treatment method and device in normal temperature operating mode and low temperature operating mode

Abstract

The invention discloses an urban sewage treatment method and device in a normal temperature operating mode and a low temperature operating mode, and belongs to the technical field of water treatment. The device is composed of a grid, a desilting tank, a primary settling tank, a three-section tank, secondary settling tanks, a contact tank and sludge collecting wells, wherein two groups of secondary settling tanks and sludge collecting wells are provided; each secondary settling tank is composed of a tank body, a water inlet pipe, a central pipe, a water outlet pipe, a sludge suction pipe and a sludge discharging main pipe; a sludge collecting hopper is arranged in the middle of the bottom; an inner end is connected with the central pipe; the central pipe is vertically mounted in the middle of the tank body; a bottom opening is located at a position of the sludge collecting hopper; one sludge suction pipe is mounted on each of four sides in the tank body close to an inner wall of the tank body; a bottom end of each sludge suction pipe is connected with the sludge discharging main pipe; the sludge discharging main pipe is connected with the sludge collecting wells. The treatment method comprises the following steps: the concentration of winter sludge in the three-section tank is controlled in 6000-8000 mg/L; and the two secondary settling tanks operate alternately and intermittently, namely, when one operates, the other performs static settling. The urban sewage treatment method and device provided by the invention increases the concentration of reflux sludge, increases dissolved oxygen transferring efficiency, and adds a static settling link, so that a clear interface is present between sludge and water, and the quality of water discharged from the secondary settling tanks is improved.

Description

technical field [0001] The invention belongs to the technical field of water treatment, and in particular relates to a method for treating urban sewage and an adopted device. Background technique [0002] At present, the basis standard for the water quality design of urban sewage treatment plants is the pollutant discharge standard for urban sewage treatment plants (GB18918-2002). Most of the biochemical treatment units in urban sewage treatment plants use anaerobic-anoxic-aerobic activated sludge process (A 2 O method), the design is based on the specifications for outdoor drainage design (GB50014-2006) and the technical specification for anaerobic-anoxic-aerobic activated sludge sewage treatment engineering (HJ 576-2010). Specifically, the treatment device is composed of a grille, a grit chamber, a primary sedimentation tank, and a three-stage pool (A 2 O reaction tank), secondary settling tank, contact tank and mud collection well, the urban sewage passes through the gr...

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Problems solved by technology

However, due to the currently built sewage treatment plant and the specification requirements, the mixed solution of the high-concentration reaction tank enters the secondary settling tank, which ha

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