CN-117534254-B - Method for promoting aerobic sludge granulation by combining coagulating sedimentation and double-zone sedimentation tank

Abstract

The invention discloses a method for promoting aerobic sludge granulation by combining coagulating sedimentation and a double-zone sedimentation tank, which relates to the technical field of wastewater treatment and comprises the steps of sequentially feeding sewage into the coagulating sedimentation tank and a biochemical tank, feeding effluent from the biochemical tank into the double-zone sedimentation tank, feeding heavy sludge in the double-zone sedimentation tank back into the biochemical tank, directly discharging light sludge in the double-zone sedimentation tank, discharging effluent from the double-zone sedimentation tank after reaching standards, and strengthening biological denitrification and dephosphorization by utilizing the mechanisms of synchronous nitrification and denitrification, biological mineralization and the like of the sewage.

Inventors

• BAO FANGBO
• GAO YONGQING
• ZHANG SHUJUN
• LI JUN
• LI DONGGE
• GUO DAO
• LIU WENLONG
• SU XUEYING

Assignees

• 北京城市排水集团有限责任公司

Dates

Publication Date

20260508

Application Date

20231219

Claims (4)

1. 1. A method for promoting aerobic sludge granulation by combining coagulating sedimentation and a double-zone sedimentation tank, which is characterized by comprising the following steps: Sewage sequentially enters a coagulating sedimentation tank and a biochemical tank; The effluent of the biochemical tank enters a double-zone sedimentation tank; the heavy sludge in the double-zone sedimentation tank is returned to the biochemical tank; the light sludge in the double-zone sedimentation tank is directly discharged; the effluent in the double-zone sedimentation tank is discharged after reaching the standard; The double-zone sedimentation tank comprises a front zone and a rear zone, wherein a first sludge outlet is formed in the bottom of the front zone and is connected with the biochemical tank, a second sludge outlet is formed in the bottom of the rear zone and is communicated with the upper part of the rear zone, a first water outlet is further formed in the upper part of the rear zone, the residence time of the front zone is 5-20min, and the residence time of the rear zone is 20-120min; The first sludge outlet is communicated with the front part of the biochemical tank; the coagulating sedimentation tank comprises a stirring region and a sedimentation region, wherein a water inlet and a coagulant adding port are arranged on the stirring region, the stirring region is communicated with the top of the sedimentation region, and a second water outlet of the sedimentation region is communicated with the water inlet of the biochemical tank.
2. 2. The method for promoting aerobic sludge granulation by combining coagulating sedimentation and a double zone sedimentation tank according to claim 1, wherein the sedimentation time of the coagulating sedimentation tank is 5-20min.
3. 3. The method for promoting the granulation of the aerobic sludge by combining the coagulating sedimentation and the double-zone sedimentation tank according to claim 1, wherein at least one group of aeration devices is arranged in the biochemical tank, and the organic load is controlled to be 0.03-0.15 (kgCOD)/(kgMLVSS x d).
4. 4. The method for promoting aerobic sludge granulation by combining coagulating sedimentation and a double zone sedimentation tank according to claim 1, wherein the heavy sludge in the double zone sedimentation tank is returned to the biochemical tank by means of steam stripping.

Description

Method for promoting aerobic sludge granulation by combining coagulating sedimentation and double-zone sedimentation tank Technical Field The invention belongs to the technical field of wastewater treatment, and particularly relates to a method for promoting aerobic sludge granulation by combining coagulating sedimentation and a double-zone sedimentation tank. Background The basic principle of the coagulation method is that coagulant is added into the wastewater, and as the coagulant is electrolyte, a micelle is formed in the wastewater, and the micelle and colloid substances in the wastewater are electrically neutralized to form fluff particle sedimentation. The coagulating sedimentation can remove not only fine suspended particles in the wastewater, but also nutrient-rich substances such as chromaticity, oil content, microorganisms, nitrogen, phosphorus and the like, heavy metals, organic matters and the like. After coagulant is added into the wastewater, colloid is reduced or eliminated due to potential, and the stable state (called destabilization) of particles is destroyed. The process of the destabilized particles agglomerating with each other into larger particles is called agglomeration. The non-destabilized colloid may also form large particles, a phenomenon known as flocculation. Different chemicals can destabilize, coagulate or flocculate the colloid in different ways. According to the mechanism, coagulation can be divided into four types of compression double layers, adsorption electric neutralization, adsorption bridging and sediment net capturing. As one of the most promising biotechnology in wastewater treatment, the aerobic granular sludge technology has the advantages of compact structure, good sedimentation performance, high biological residence time, high organic load and toxicity resistance, synchronous denitrification and dephosphorization realization and the like compared with the traditional activated sludge technology. In general, the formation of aerobic granular sludge is a complex process comprising physical, chemical and biological actions, and the main flow belief is that the process is described as biological agglomeration phenomenon formed by self-agglomeration of microorganisms under certain hydrodynamic conditions, and the conditions which are proved to have significant positive effects on the formation of aerobic granular sludge currently comprise selection pressure, organic load, addition of metal cations, addition of coagulants or inert carriers and the like. However, the disadvantages of long formation time, poor stability and the like of the aerobic granular sludge limit the application range. Therefore, the coagulant and the aggregated particulates remained in the coagulating sedimentation process are utilized to promote the formation of the aerobic granular sludge, and the method has important significance for overcoming the defect of long starting time of the aerobic granular sludge process and improving the quality of effluent. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a method for promoting aerobic sludge granulation by combining coagulating sedimentation and a double-zone sedimentation tank, which aims at the characteristics and defects of the coagulating sedimentation process and combines the advantages of the double-zone sedimentation tank, thereby being beneficial to improving the sludge-water separation efficiency and strengthening biological denitrification and dephosphorization by utilizing the mechanisms of synchronous nitrification and denitrification, biological mineralization and the like. In order to achieve the above object, the present invention provides a method for promoting aerobic sludge granulation by combining coagulating sedimentation and a double-zone sedimentation tank, comprising: Sewage sequentially enters a coagulating sedimentation tank and a biochemical tank; The effluent of the biochemical tank enters a double-zone sedimentation tank; the heavy sludge in the double-zone sedimentation tank is returned to the biochemical tank; the light sludge in the double-zone sedimentation tank is directly discharged; and discharging the effluent in the double-zone sedimentation tank after reaching the standard. Optionally, the double-zone sedimentation tank comprises a front zone and a rear zone, wherein a first sludge outlet is formed in the bottom of the front zone and connected with the biochemical tank, a second sludge outlet is formed in the bottom of the rear zone and communicated with the upper portion of the rear zone, a first water outlet is further formed in the upper portion of the rear zone, the residence time of the front zone is 5-20min, and the residence time of the rear zone is 20-120min. Optionally, the first sludge outlet is in communication with a front portion of the biochemical pond. Optionally, the coagulating sedimentation tank comprises a stirring region and a sedimentation