阅读说明：本技术 一种污泥循环调理脱水的方法 (Method for circularly conditioning and dehydrating sludge ) 是由 施钦 谭学才 刘绍刚 刘宇川 黄政邦 敬康 于 2021-09-01 设计创作，主要内容包括：本发明的一种污泥循环调理脱水的方法,将剩余污泥送入重力浓缩池进行初步的浓缩将易分离的泥水分开,较难脱水的污泥被输送到调节池中进行充分曝气之后,再送到电化学氧化装置通过电化学阴阳极耦合氧化作用对成层沉淀带的污泥进行调理,破坏污泥中絮凝体的结构,并使微生物的细胞壁发生溶胞作用,释放毛细水和结合水后送回重力浓缩池中再分离,改善污泥脱水性能。本方法将电化学氧化调理技术和重力浓缩技术有机结合,构建一种剩余污泥减量化循环处理过程,具有设备操作简单、处理费用低、无二次污染和污泥减量效果好等优点,是一种环境友好的工艺方法。(The invention relates to a sludge circulation conditioning and dewatering method, which is characterized in that residual sludge is sent into a gravity concentration tank for primary concentration to separate easily separated mud and water, the sludge which is difficult to dewater is sent into a regulating tank for full aeration, and then sent into an electrochemical oxidation device for conditioning the sludge in a layered precipitation zone through electrochemical cathode-anode coupling oxidation, so that the structure of floccules in the sludge is damaged, cell walls of microorganisms are subjected to cell lysis, capillary water and bound water are released and then sent back into the gravity concentration tank for re-separation, and the sludge dewatering performance is improved. The method organically combines the electrochemical oxidation conditioning technology and the gravity concentration technology to construct a circulating treatment process for reducing the excess sludge, has the advantages of simple equipment operation, low treatment cost, no secondary pollution, good sludge reduction effect and the like, and is an environment-friendly process method.)

1. A sludge circulating, conditioning and dehydrating system comprises a gravity concentration tank, and is characterized by also comprising a regulating tank and an electrochemical oxidation device, wherein the gravity concentration tank is provided with at least 2 sludge inlet pipes, at least one of the 2 sludge inlet pipes is a circulating sludge inlet pipe, at least one of the 2 sludge inlet pipes is a fresh residual sludge inlet pipe, and the pipe orifice of the circulating sludge inlet pipe is deeper than the pipe orifice of the fresh residual sludge inlet pipe; the middle part of the gravity concentration tank is provided with a circulating sludge discharge pipe which is positioned at 1/2-2/3 parts of the gravity concentration tank and is lower than the pipe orifice of the circulating sludge inlet pipe, and the bottom of the gravity concentration tank is provided with a sludge discharge pipe.

2. The system of claim 1, wherein the mouth of the sludge recirculation pipe is 30-80cm deeper than the mouth of the sludge fresh excess pipe.

3. The system of claim 1, wherein the conditioning tank is provided with a blender.

4. The system of claim 1, wherein the electrochemical oxidation apparatus is a mobile integrated electrochemical device with an input voltage ranging from 10 to 32V, the electrode module is a detachable structure, and the circulating sludge enters from the bottom and flows out from the top.

5. The method for sludge circulation conditioning and dewatering by using the system of claim 1, characterized in that the excess sludge is first subjected to gravity concentration, then to conditioning by sufficient aeration, and finally to oxidation treatment by electrochemical reaction; the gravity concentration is to feed the residual sludge into a gravity concentration tank from a fresh residual sludge feeding pipe; the full aeration is to send the sludge in the layered sedimentation zone into a regulating tank, add electrolyte and carry out aeration treatment; the electrochemical oxidation treatment is to carry out electrochemical oxidation treatment on the sludge after the aeration treatment by using an electrochemical oxidation device.

6. The method as claimed in claim 5, wherein the aeration treatment time is 10-60 min.

7. The method of claim 5, wherein the electrolyte is sodium sulfate.

8. The method of claim 5, wherein the electrochemical oxidation treatment is carried out for a treatment time of 10 to 40 min.

Technical Field

The invention relates to the field of excess sludge conditioning and dehydration, in particular to a method for sludge circulation conditioning and dehydration.

Background

The environmental pollution problem caused by the development of economy and the expansion of population size is quite serious worldwide. The activated sludge process is commonly used for the purification of municipal and industrial wastewater, and one of the technical disadvantages is the production of large amounts of excess sludge. The sludge has complex components and high water content, often contains a large amount of heavy metals, pathogenic bacteria and other substances harmful to human bodies and the environment, has loose and large volume and is difficult to transport and store. Most of the sludge after dehydration and drying is treated by landfill or incineration, but the existence of capillary water and bound water makes the dehydration very difficult. The sludge dehydration treatment is a key step of sludge innocent treatment. Sludge dewatering typically employs polymer addition and mechanical dewatering processes, such as by centrifugation, membrane filter presses, or vacuum filters, among others. The efficiency of sludge dewatering depends to a large extent on the amount, nature and properties of the polymer and the characteristics of the sludge. Mechanical dewatering, which allows the interstitial water in the sludge to be removed through a very narrow pore space, cannot remove bound water, has a very limited dewatering effect and requires a large amount of subsequent treatment work. Therefore, the development of an economical and effective sludge dewatering process is an important approach to solve the problem of sludge pollution.

The electrochemical technology is a sludge conditioning technology which is emerging in recent years. Under the condition of electrification, strong oxidant and reducing agent generated on the surface of the electrode perform electrochemical lysis on microorganisms, and release bound water. Meanwhile, the strong oxidant generated by the electrode reaction can also oxidize and degrade organic pollutants, so that the biodegradability of the sludge is improved. The electrochemical technology has the advantages of environmental friendliness, small volume of treatment equipment, no secondary pollution and the like, and has wide application prospect in the field of sludge dewatering.

After the single conditioning method is used for treatment, the sludge is still a mud-water mixture and does not realize real dehydration, which brings great difficulty to subsequent treatment. Therefore, a set of sludge dewatering process system combining conditioning and sludge-water separation needs to be developed, sludge conditioning and sludge dewatering can be continuously completed, the purpose of reducing the sludge production to the maximum extent is achieved, and the method is a sustainable and environment-friendly development direction.

Disclosure of Invention

In order to solve the problems, the invention provides a method for circularly conditioning and dehydrating sludge, which adopts the following technical scheme:

a sludge circulating, conditioning and dehydrating system comprises a gravity concentration tank, a regulating tank and an electrochemical oxidation device, wherein the gravity concentration tank is provided with at least 2 sludge inlet pipes, at least one of the 2 sludge inlet pipes is a circulating sludge inlet pipe, at least one of the 2 sludge inlet pipes is a fresh residual sludge inlet pipe, and the pipe orifice of the circulating sludge inlet pipe is deeper than the pipe orifice of the fresh residual sludge inlet pipe; the middle part of the gravity concentration tank is provided with a circulating sludge discharge pipe which is positioned at 1/2-2/3 parts of the gravity concentration tank and is lower than the pipe orifice of the circulating sludge inlet pipe, and the bottom of the gravity concentration tank is provided with a sludge discharge pipe.

The pipe orifice of the circulating sludge inlet pipe is 30-80cm deeper than the pipe orifice of the fresh residual sludge inlet pipe.

The adjusting tank is provided with a stirrer.

The electrochemical oxidation device is a movable integrated electrochemical device, the input voltage range is 10-32V, the electrode module is of a detachable structure, and circulating sludge enters from the bottom and flows out from the upper part.

The method for sludge circulation conditioning and dewatering by using the system of claim 1, wherein the excess sludge is firstly subjected to gravity concentration, then is conditioned by full aeration, and finally is subjected to oxidation treatment by using an electrochemical reaction; the gravity concentration is to feed the residual sludge into a gravity concentration tank from a fresh residual sludge feeding pipe; the full aeration is to send the sludge in the layered sedimentation zone into a regulating tank, add electrolyte and carry out aeration treatment; the electrochemical oxidation treatment is to carry out electrochemical oxidation treatment on the sludge after the aeration treatment by using an electrochemical oxidation device.

The time of aeration treatment is 10-60 min.

The electrolyte is sodium sulfate.

The treatment time of the electrochemical oxidation treatment is 10-40 min.

The beneficial effects obtained by the invention are as follows:

the electrochemical sludge conditioning technology and the gravity concentration technology are organically combined together, so that the sludge dewatering performance is improved, and the sludge can be efficiently reduced. After the residual sludge enters a gravity concentration tank, primarily concentrating to separate easily separated mud and water, and conveying sludge difficult to dewater to a layering sedimentation zone stage to a regulating tank and an electrochemical oxidation device. After full aeration is carried out in the regulating tank, the sludge in the stratified precipitation zone is conditioned through electrochemical cathode-anode coupling oxidation, strong oxidant generated by electrochemical reaction is utilized to destroy the structure of flocculating constituents in the sludge and cell walls of microorganisms to cause cell lysis, capillary water and bound water are released, and the improvement of sludge dewatering performance is realized. The conditioned circulating sludge returns to the gravity concentration tank again for further concentration. The invention has the advantages of simple equipment operation, fast treatment reaction, strong stability, good dehydration effect, low operation cost and the like, and simultaneously, no additional chemical reagent is needed, and no secondary pollution is caused. In addition, the method combines a gravity concentration method and an electrochemical oxidation method, and is an environment-friendly technical method.

Description of the drawings:

FIG. 1 is a schematic view of the process and apparatus of the present invention.

In the figure, 1 circulating sludge inlet pipe, 2 fresh residual sludge inlet pipe, 3 gravity concentration tank, 4 sludge discharge pipe, 5 adjusting tank, 6 aeration device, 7 electrochemical oxidation device, 8 electrode module, 9 circulating sludge discharge pipe, 10 circulating sludge discharge pipe valve and 11 sludge discharge pipe valve.

Detailed Description

The invention will be further described with reference to the accompanying drawings, to which, however, the invention is not restricted.

Example 1

The circulating sludge discharge pipe is positioned at 1/2 of the gravity concentration tank 3, and the pipe orifice of the circulating sludge inlet pipe 1 is 30cm deeper than the pipe orifice of the fresh residual sludge inlet pipe 2.

Residual sludge with the water content of 98.2-99.5 percent is taken as a treatment object, and the residual sludge is injected into the gravity concentration tank 3 from a fresh residual sludge inlet pipe 2. After the fresh excess sludge is concentrated for 5 hours in the gravity concentration tank 3, a valve 10 on a circulating sludge discharge pipe is opened, so that the sludge in the stratified sedimentation zone flows into the regulating tank 5 under the action of gravity, and the settled sludge is discharged through a sludge discharge pipe 4.

After the sludge in the layered sedimentation zone flowed into the adjusting tank 5, sodium sulfate was added as an electrolyte, and the ratio of the added sodium sulfate to the sludge was 6 mg/L. Adding electrolyte while aerating, and stirring with a stirrer with blowing rate of 1.2m³H is used as the reference value. And (3) blowing and aerating the circulating sludge in the regulating tank 5 for 30min to fully aerate the sludge in the regulating tank 5.

The liquid level in the regulating tank 5 is higher than that of the electrochemical oxidation device 7, the circulating sludge can automatically flow into the electrochemical oxidation device 7, and the circulating sludge is electrolyzed in the electrochemical oxidation device 7 for 30 min.

The electrochemical oxidation device 7 is a movable integrated electrochemical device, the input voltage range is 30V, and the anode in the electrode module 8 is Ti/PbO₂The electrode plate, the negative pole is graphite electrode plate, adopts unipolar type connected mode, and the liquid circuit connected mode is the tandem type, and the electrode interval is 2 cm.

After electrochemical conditioning, the sludge is sent to a gravity concentration tank 3 through a circulating sludge inlet pipe 1, and the sludge inlet flow of the circulating sludge is controlled to be 1/2 of the sludge inlet amount of fresh residual sludge. Fresh excess sludge and circulating sludge are subjected to gravity concentration in a gravity concentration tank 3, a valve 10 on a circulating sludge discharge pipe is opened, so that the sludge in a layering sedimentation zone flows into an adjusting tank 5 under the action of gravity, and the settled sludge is discharged from a sludge discharge pipe 4 at the bottom of the gravity concentration tank.

The above process is repeated.

Example 2

The circulating sludge discharge pipe is positioned at 1/2 of the gravity concentration tank 3, and the pipe orifice of the circulating sludge inlet pipe 1 is 50cm deeper than the pipe orifice of the fresh residual sludge inlet pipe 2.

Residual sludge with the water content of 98.2-99.5 percent is taken as a treatment object, and the residual sludge is injected into the gravity concentration tank 3 from a fresh residual sludge inlet pipe 2. After the fresh excess sludge is concentrated for 5 hours in the gravity concentration tank 3, a valve 10 on a circulating sludge discharge pipe is opened, so that the sludge in the stratified sedimentation zone flows into the regulating tank 5 under the action of gravity, and the settled sludge is discharged through a sludge discharge pipe 4.

After the sludge in the layered sedimentation zone flowed into the adjusting tank 5, sodium sulfate was added as an electrolyte, and the ratio of the added sodium sulfate to the sludge was 6 mg/L. Adding electrolyte while aerating, and stirring with a stirrer with blowing rate of 1.2m³H is used as the reference value. And (3) blowing and aerating the circulating sludge in the regulating tank 5 for 10min to fully aerate the sludge in the regulating tank 5.

The liquid level in the regulating tank 5 is higher than that of the electrochemical oxidation device 7, the circulating sludge can automatically flow into the electrochemical oxidation device 7, and the circulating sludge is electrolyzed in the electrochemical oxidation device 7 for 10 min.

The electrochemical oxidation device 7 is a movable integrated electrochemical device, the input voltage range is 10V, and the anode in the electrode module 8 is Ti/PbO₂The electrode plate, the negative pole is graphite electrode plate, adopts unipolar type connected mode, and the liquid circuit connected mode is the tandem type, and the electrode interval is 2 cm.

After electrochemical conditioning, the sludge is sent to a gravity concentration tank 3 through a circulating sludge inlet pipe 1, and the sludge inlet flow of the circulating sludge is controlled to be 1/2 of the sludge inlet amount of fresh residual sludge. Fresh excess sludge and circulating sludge are subjected to gravity concentration in a gravity concentration tank 3, a valve 10 on a circulating sludge discharge pipe is opened, so that the sludge in a layering sedimentation zone flows into an adjusting tank 5 under the action of gravity, and the settled sludge is discharged from a sludge discharge pipe 4 at the bottom of the gravity concentration tank.

The above process is repeated.

Example 3

The circulating sludge discharge pipe is positioned at 2/3 of the gravity concentration tank 3, and the pipe orifice of the circulating sludge inlet pipe 1 is 80cm deeper than the pipe orifice of the fresh residual sludge inlet pipe 2.

Residual sludge with the water content of 98.2-99.5 percent is taken as a treatment object, and the residual sludge is injected into the gravity concentration tank 3 from a fresh residual sludge inlet pipe 2. After the fresh excess sludge is concentrated for 5 hours in the gravity concentration tank 3, a valve 10 on a circulating sludge discharge pipe is opened, so that the sludge in the stratified sedimentation zone flows into the regulating tank 5 under the action of gravity, and the settled sludge is discharged through a sludge discharge pipe 4.

After the sludge in the layered sedimentation zone flowed into the adjusting tank 5, sodium sulfate was added as an electrolyte, and the ratio of the added sodium sulfate to the sludge was 6 mg/L. Adding electrolyte while aerating, and stirring with a stirrer with blowing rate of 1.2m³H is used as the reference value. And blowing and aerating the circulating sludge in the regulating tank 5 for 60min to fully aerate the sludge in the regulating tank 5.

The liquid level in the regulating tank 5 is higher than that of the electrochemical oxidation device 7, the circulating sludge can automatically flow into the electrochemical oxidation device 7, and the circulating sludge is electrolyzed in the electrochemical oxidation device 7 for 40 min.

The electrochemical oxidation device 7 is a movable integrated electrochemical device, the input voltage range is 32V, and the anode in the electrode module 8 is Ti/PbO₂The electrode plate, the negative pole is graphite electrode plate, adopts unipolar type connected mode, and the liquid circuit connected mode is the tandem type, and the electrode interval is 2 cm.

After electrochemical conditioning, the sludge is sent to a gravity concentration tank 3 through a circulating sludge inlet pipe 1, and the sludge inlet flow of the circulating sludge is controlled to be 1/2 of the sludge inlet amount of fresh residual sludge. Fresh excess sludge and circulating sludge are subjected to gravity concentration in a gravity concentration tank 3, a valve 10 on a circulating sludge discharge pipe is opened, so that the sludge in a layering sedimentation zone flows into an adjusting tank 5 under the action of gravity, and the settled sludge is discharged from a sludge discharge pipe 4 at the bottom of the gravity concentration tank.

The above process is repeated.

Through determination, after the method disclosed by the invention is used, the water content of the sludge discharged from the sludge discharge pipe is 88% -91%, and the water content before a comparison experiment is 98.2-99.5%, and the experiment result proves that the method can effectively reduce the water content.