Aerobic particle sludge method for treating town sewage and aerobic particle sludge thereof

Abstract

The invention provides an aerobic granular sludge method for treating city sewage and the aerobic granular sludge, characterized in that a reactor adopts 8-15 ratio of height-to-diameter and 50-80 percent of drainage rate; air is compressed and filled into the bottom of the reactor; after flocculent sludge is inoculated, the drainage rate increases from 40 percent to 60 percent to 80 percent with the increase of 5 percent to10 percent per month; the operation cycle time shortens from 4-6 hours to 2-3 hours with the shortness of 1 hour per mouth; the sedimentation time decreases from 30-40 minutes to 15-20 minutes with the decrease of 1-2 minutes per week; the stable operation is carried out until the aerobic granular sludge takes 50-85 percent of reaction region volume of the reactor; the obtained aerobic granular sludge has large-sized particle, rapid sedimentation speed, compact structure and strong resistance to the environmental change. The invention overcomes the defects of expanded sludge, floated sludge, giant structure of an aeration tank as well as large occupied area, high investment and operation cost and unstable system operation in the prior art.

Description

Technical field: [0001] The invention belongs to the technical field of wastewater biological treatment, in particular to an aerobic granular sludge method for treating urban sewage and the aerobic granular sludge. Background technique: [0002] The U.S. "Biological Wastewater Treatment" (Biological Wastewater Treatment, 1999, 2nd edition, 246-313 pages) mentioned that the activated sludge method was developed by Arden and Lockett in Manchester ( Massachusetts ) The development of sewage treatment plants is the most widely used treatment technology for urban sewage treatment. The activated sludge method uses the metabolic activity of activated sludge to treat wastewater in an aerobic state; activated sludge is a microbial group formed by aerobic microorganisms after a large number of reproductions, as well as some inorganic substances, undecomposed organic substances and Composed of the secretions of microorganisms' own metabolism, air or oxygen enters the mixed liquid in a...

AI Technical Summary

Problems solved by technology

The activated sludge method uses the metabolic activity of activated sludge to treat wastewater in an aerobic state; activated sludge is a microbial group formed by aerobic microorganisms after a large number of reproductions, as well as some inorganic substances, undecomposed organic substances and Composed of the secretions of microorganisms' own metabolism, air or oxygen enters the mixed liquid in a pressure state or atmospheric pressure state, and the liquid in the reactor is mechanically stirred or air-flow stirred, and the mixed liquid is divided into precipitated biological solids and The treated wastewater is divided into two parts, the sludge part of the secondary sedimentation tank is returned, and the remaining sludge is discharged from the system; due to the low sedimentation speed of the sludge flocs in the existing sludge sedimentation system, the sludge structure is loose and easy to float, and the sludge The output is high, which leads to the large volume of the sludge sedimentation system, a large area, and a large amount of residual sludge. The sewage treatment plant needs a larger infrastructure area, more sludge disposal costs, and structure construction costs. Therefore, the current The construction and operation costs of sewage treatment plants are high; the existing activated sludge method has loose sludge structure, and the cells and extracellular polymers in the flocs are mixed together, the particle size is only 0.05-0.2mm, and the density is only 1.002- 1.007g / mL, low microbial content and weak resistance to changes in environmental conditions, the sedimentation velocity of sludge flocs is only 18-31m / h, and the sedimentation velocity is relatively small. Therefore, the volume load of the existing activated sludge process system is low , poor sludge settling performance

The existing urban sewage treatment system occupies a large area and is prone to sludge bulking, so the investment and operation costs are high, and the system operation is relatively unstable

[0003] China's "New Technology of Wastewater Biological Treatment-Theory and Application" (China Environmental Science Press, 1999) mentioned that the existing sequencing batch reactor (SBR) and sequencing batch airlift reactor (SBAR) processes are based on The sewage biological treatment system operated by intermittent aeration, which integrates influent, anaerobic, aerobic, and sedimentation in one pool, can flexibly change the operation mode to meet the treatment requirements of different types of wastewater. The sewage enters the treatment system intermittently, and intermittently Discharge; the reactor is cylindrical, the aeration head is installed at the bottom of the reactor, and the air pipe is used to connect with the external air compressor for oxygen supply, and a diversion cylinder can be installed inside; water intake-aeration-sedimentation-drainage is used as the treatment The operating process cycle is controlled by a time controller for automatic cycle operation at each stage; however, the height-to-diameter ratio used in the existing SBR and SBAR reactors is less than 1, and the drainage ratio is 50%, which are relatively low, which is not conducive to the granulation of activated sludge

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