CN114956499A - Ozonization conditioning coupled hydrothermal rapid stabilization treatment process for organic sludge - Google Patents

Abstract

The invention discloses an ozonization conditioning coupled hydrothermal rapid stabilization treatment process for organic sludge, which comprises the steps of stirring and homogenizing the sludge, sucking a sludge-water mixture into a pressurized ozone dissolved air flotation device, adding a cationic PAM medicament to complete the operations of ozone dissolved air release and slag scraping, feeding scum containing ozone microbubbles into a pyrohydrolysis reaction kettle, breaking the wall of the sludge through pyrohydrolysis, and then carrying out solid-liquid separation to reach the sludge stabilization standard. The invention transfers the pyrohydrolysis from the traditional front-end pretreatment process to the core treatment unit for realizing sludge stabilization, and the process realizes the direct deodorization of the noncondensable gas generated by the pyrohydrolysis, thereby avoiding the problem that the noncondensable gas of the traditional pyrohydrolysis reaction is difficult to treat. The invention combines the physicochemical property of the sludge, efficiently couples the sludge treatment process, fully exerts the catalytic oxidation efficiency of ozone, and truly realizes the purposes of reduction, harmlessness and recycling of the sludge treatment in a low-carbon and low-cost environment.

Description

A process for ozonation conditioning coupled with hydrothermal rapid stabilization of organic sludge

technical field

The invention belongs to the technical field of organic solid waste treatment and resource utilization, and particularly relates to an ozonation conditioning coupled hydrothermal rapid stabilization treatment process of organic sludge.

Background technique

Sludge undertakes the pollutants in the sewage, which is the continuation and inevitable requirement of the sewage treatment process. For sludge treatment with low organic matter content, high fine sand and metal content, and long mud age, it is not suitable for anaerobic digestion and other common foreign sludge treatment processes. For high sand content and low organic matter (organic matter content is less than 45%), it is necessary to adjust the traditional sludge treatment and disposal technology route. Thermal hydrolysis is generally used as the front end of the traditional sludge treatment technology route. The sludge after thermal hydrolysis is not stable, and subsequent processes such as anaerobic digestion and aerobic fermentation are required for further stabilization. Therefore, the investment cost, operation and maintenance cost and dosing cost are huge, and the technical route of sludge stabilization has been unable to break through the traditional technical barriers.

Compared with anaerobic digestion technology, the investment cost, operation and maintenance difficulty of aerobic fermentation technology are relatively low, and there are many engineering practice cases. In practical engineering applications, the constraints faced by sludge aerobic fermentation technology mainly include the following three points: (1) odor control during aerobic fermentation is difficult and costly, and there is a lack of cheap and reliable odor control technology; (2) Aerobic fermentation requires a stable source of conditioners, while the supply of traditional conditioners is restricted by seasons and regions; (3) The aerobic fermentation of sludge products is not smooth, and the land use of sludge products lacks planning and may exist Environmental risks, occupying a large area. Therefore, for the efficient coupling of low organic matter and high sand sludge treatment technology, it is necessary to develop an effective treatment process.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a kind of ozonation conditioning coupled hydrothermal rapid stabilization treatment process of organic sludge in order to solve the above problems, so as to solve the problems of large investment in traditional process, complicated process and high operation and maintenance cost, and the method has high feasibility, It is easy to operate, highly controllable and flexible, achieving a win-win situation of environmental protection and economic benefits.

The object of the present invention is achieved through the following technical solutions:

An ozonation conditioning coupling hydrothermal rapid stabilization treatment process of organic sludge, the sludge is stirred and homogenized, the mud-water mixture is sucked into a pressurized ozone dissolved air flotation device, and cationic PAM agent is added to complete the ozone dissolved air release and scraping Slag operation, the ozone-containing microbubble scum enters the thermal hydrolysis reaction kettle, and the thermal hydrolysis sludge breaks the wall, and then the solid-liquid separation reaches the sludge stabilization standard.

Further, the sludge is urban sewage treatment plant sludge with a high sand-containing organic matter of less than 45%, and the concentration of solid suspended solids ranges from 8,000 to 12,000 mg/L.

Further, the ozone dissolved gas release and slag scraping operations are completed in batches, and the batch completion time is less than or equal to 10min.

Further, the ozone-containing microbubble scum enters the thermal hydrolysis reactor through the pipeline booster pump.

Further, the ozone dissolved air flotation device and the thermal hydrolysis reactor are both airtight micro-negative pressure devices,

The top of the ozone-dissolved air flotation device is connected to an arched row-shaped row pipe, and the top of the thermal hydrolysis reaction kettle is connected to an exhaust pipe, both of which are used to extract mixed waste gas containing high-concentration ozone. The exhaust pipe is uniformly extracted, and the arched round pipe is used to promote the condensation of water vapor. The scraper directly scrapes the high moisture content scum to the collection tank, and the collection tank enters the thermal hydrolysis reactor according to the set logic;

The arched row pipeline and the gas pipeline are connected to the ozone decomposing chamber, and the ozone decomposing chamber is connected to the ozone advanced treatment chamber, and the ozone advanced treatment chamber is an acid pool with pH=5.

Further, the effective water depth in the ozone dissolved air flotation device is 1.8m～2m, the hydraulic retention time of the contact chamber is 1.2min～1.5min, the hydraulic retention time of the separation chamber is not more than 8min, and the surface load of the separation chamber is ⁶ ～8m3 /(m ² /h), the working pressure of the ozone dissolved gas tank is 0.6Mpa, and the dissolved gas water is tap water or the effluent of urban sewage treatment plant.

Further, the mass ratio of the cationic PAM configuration is 4‰˜5‰.

Further, the pressurized ozone dissolved air flotation device injects ozone under the condition of 100°C, and the addition amount of ozone in the wastewater is 8-10 mg/L.

Further, the ozone content of the mixed waste gas with high concentration ozone produced by the pressurized ozone dissolved air flotation device is 15-27 mg/L, and the treatment efficiency of odor and methyl mercaptan generated by thermal hydrolysis is over 90%.

Further, the thermal hydrolysis reaction temperature in the thermal hydrolysis reactor is 180-200°C.

Compared with the prior art, the present invention has the following beneficial effects:

1. Thermal hydrolysis is generally used as the front end of the traditional sludge treatment technology route. The sludge after thermal hydrolysis is not stable, and subsequent processes such as anaerobic digestion and aerobic fermentation are required for further stabilization. Therefore, the investment cost, operation and maintenance cost and dosing cost are huge, and the technical route of sludge stabilization has been unable to break through the traditional technical barriers. The invention takes the characteristics of the sludge as a breakthrough point, simplifies the technical route of sludge stabilization through parameter control, and proposes a new solution route for low organic matter sludge.

2. Thermal hydrolysis will produce odor, odor such as methyl mercaptan, and the odor problem caused by thermal hydrolysis has a great impact on human health, the factory boundary and the surrounding environment. Thermal hydrolysis projects must be combined with odor. Processing facilities. The invention saves the investment and maintenance cost of odor treatment facilities, and combines the high-content ozone mixed waste gas with large-capacity pressurized ozone-dissolved air flotation at the front end and the thermally hydrolyzed odor, which can solve the problem that the thermally hydrolyzed non-condensable odor is difficult to treat. , while reducing the emission of the greenhouse gas _O3 in the air flotation, killing two birds with one stone.

3. Generally, the addition amount of ozone in wastewater is 3-5mg/L, and the addition amount of the present invention is 8-10mg/L. Excessive ozone is injected into the sludge, which is concentrated by ozone flotation, and the scum entrains ozone into thermal hydrolysis. Thermal hydrolysis is releasing organic matter. Ozone has a strong catalytic effect, and one step thermal hydrolysis can stabilize it. Carry out land use, in which the seed germination rate can reach 100%, and the oxygen consumption rate can be reduced by 30%. The invention gives full play to the effect of ozone catalytic oxidation. In the air flotation and thermal hydrolysis devices, ozone entrains the sludge to play a catalytic oxidation role and assists the sludge to break the wall; in the waste gas treatment, the excess ozone generated by the air flotation can fully digest the heat. Odor produced by hydrolysis, make full use of ozone means.

4. The dosing of the present invention only adds 4‰ to 5‰ of PAM, and does not require additional flocculants such as PAC. The present invention has no requirement for reducing the moisture content of the ozone flotation scum, and the main function of the air flotation device is to entrain the ozone to rapidly concentrate, and to give full play to the catalytic effect of ozone. Therefore, the function of the present invention is substantially different from that of the traditional air flotation. The PAM aqueous solution is dissolved under the catalysis of high temperature ozone, so the entire technical route reduces the input and pollution of iron and aluminum salts.

Description of drawings

Figure 1 is a schematic diagram of the ozonation conditioning coupled with hydrothermal rapid stabilization treatment process of organic sludge.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

An ozonation conditioning coupled hydrothermal rapid stabilization treatment process for organic sludge, which is mainly suitable for urban sewage treatment plant sludge with a high sand-containing organic matter content of less than 45% (such as the Yangtze River Economic Belt in China). Figure 1 shows the organic sludge. Schematic diagram of mud ozonation conditioning coupled with hydrothermal rapid stabilization treatment process. The main equipment includes ozone dissolved air flotation device 1 and thermal hydrolysis reactor 2, both of which are closed micro-negative pressure devices, ozone dissolved air flotation device 1 and thermal The hydrolysis reaction kettles 2 are connected by a pipeline provided with a booster pump 7, the top of the ozone dissolved air flotation device 1 is connected to an arched row pipeline 3, and the ozone dissolved air flotation device 1 is connected to the ozone dissolved air tank 6. The top of the hydrolysis reactor 2 is connected to an exhaust pipe, which is used to extract the mixed waste gas containing high concentration ozone. The structure of the air flotation device adopts the upper arched row pipe 3 for uniform extraction, and the arched circular pipe is used to promote the condensation of water vapor. The high moisture content scum is scraped to the collection tank, and the collection tank enters the thermal hydrolysis reaction kettle according to the set logic; the arched row pipeline and the gas pipeline are connected to the ozone digestion chamber 4, and the ozone digestion chamber 4 is connected to the ozone advanced treatment chamber 5, The ozone advanced treatment chamber 5 is an acid pool with pH=5.

During the specific treatment, the following steps are specifically included: stirring and homogenizing the sludge (without drug addition), and the SS concentration of the sludge ranges from 8000 to 12000 mg/L. The mud-water mixture is sucked into the pressurized ozone dissolved air flotation device, the traditional iron-aluminum salt coagulant is abandoned, and an appropriate dose of ozone is introduced, and only cationic PAM is added to quickly complete the ozone dissolved gas release and slag scraping operations. The ozone-containing microbubble scum (with a moisture content of about 92%) enters the thermal hydrolysis reactor through a pipeline booster pump, and after the thermal hydrolysis sludge is broken and concentrated, the sludge stabilization standard can be achieved. The high-concentration ozone mixed waste gas generated by the air flotation device is fully reacted with the odor generated by thermal hydrolysis and then discharged up to the standard.

The invention transfers thermal hydrolysis from the traditional front-end pretreatment process to the core treatment unit for realizing sludge stabilization, and the process realizes that the non-condensable gas generated by thermal hydrolysis directly realizes deodorization and avoids the non-condensable gas of traditional thermal hydrolysis reaction gas. The problem of odor is difficult to deal with. Combined with the physical and chemical properties of sludge, the sludge treatment process is efficiently coupled, and the effect of ozone catalytic oxidation is fully utilized.

The following is an example of a specific application:

An ozonation conditioning coupled hydrothermal rapid stabilization treatment process for organic sludge: the sludge (without dosing) of the urban sewage treatment plant is stirred and homogenized, the SS concentration range is 12000mg/L, and the sludge-water mixture is sucked into the pressurized ozone dissolved gas Floating device, the effective water depth of a single facility is 1.8m, the temperature is injected at 100°C, the ozone addition amount is 10mg/L, and 5‰ cationic PAM agent is added at the same time, and the ozone dissolved gas release and slag scraping operations are quickly completed, and the hydraulic retention time of the contact chamber is At 1.5min, the hydraulic retention time of the separation chamber is 8min, the batch completion time is 9.5min, the working pressure of the ozone dissolved gas tank is 0.6Mpa, and the dissolved gas water is the effluent of the urban sewage treatment plant. The ozone-containing microbubble scum (with a moisture content of more than 95%) enters the thermal hydrolysis reactor through the pipeline booster pump, and the sludge is broken through the 200 ℃ thermal hydrolysis reactor, and then the sludge is stabilized after solid-liquid separation. standard. Among them, the air flotation device and the thermal hydrolysis reaction kettle are sealed with a slight negative pressure, and the upper arched row pipeline evenly extracts the mixed waste gas containing high concentration ozone, the ozone content is 27mg/L, and the odor generated by thermal hydrolysis is in the ozone It is mixed in the digestion chamber, and then discharged to the standard after being treated in the ozone advanced treatment chamber.

The foregoing description of the embodiments is provided to facilitate understanding and use of the invention by those of ordinary skill in the art. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should all fall within the protection scope of the present invention.

Claims (10)

1. an ozonation conditioning coupled hydrothermal rapid stabilization treatment process of organic sludge, is characterized in that, the sludge is stirred and homogenized, the mud-water mixture is sucked into the pressurized ozone dissolved air flotation device, and cationic PAM medicament is added to complete the process. Ozone dissolved gas release and slag scraping operation, ozone-containing microbubble scum enters the thermal hydrolysis reactor, and the thermal hydrolysis sludge breaks the wall, and then reaches the sludge stabilization standard after solid-liquid separation. 2 . The ozonation conditioning coupled hydrothermal rapid stabilization treatment process of organic sludge according to claim 1 , wherein the sludge is an urban sewage treatment plant with high sand-containing organic matter less than 45%. 3 . Mud, the concentration of suspended solids ranges from 8000 to 12000 mg/L. 3 . The ozonation conditioning coupled hydrothermal rapid stabilization treatment process of organic sludge according to claim 1 , wherein the ozone dissolved gas release and slag scraping operations are completed in batches, and the batch completion time is less than or equal to 10 min. 4 . 4 . The ozonation conditioning coupled hydrothermal rapid stabilization treatment process of organic sludge according to claim 1 , wherein the ozone-containing microbubble scum enters the thermal hydrolysis reactor through a pipeline booster pump. 5 . 5. The ozonation conditioning coupling hydrothermal fast stabilization treatment process of a kind of organic sludge according to claim 1, is characterized in that, described ozone dissolved air flotation device and thermal hydrolysis reaction kettle are all airtight micro-negative pressure device, The top of the ozone-dissolved air flotation device is connected with an arched row row pipe, and the top of the thermal hydrolysis reactor is connected with an exhaust pipe, both of which are used to extract mixed waste gas containing high-concentration ozone; The arched row pipeline and the gas pipeline are connected to the ozone decomposing chamber, and the ozone decomposing chamber is connected to the ozone advanced treatment chamber, and the ozone advanced treatment chamber is an acid pool with pH=5. 6 . The ozonation conditioning coupled hydrothermal rapid stabilization treatment process for organic sludge according to claim 1 , wherein the effective water depth in the ozone dissolved air flotation device is 1.8m to 2m, and the contact chamber The hydraulic retention time is 1.2min-1.5min, the hydraulic retention time of the separation chamber is not more than 8min, the surface load of the separation chamber is 6-8m ³ /(m ² /h), the working pressure of the ozone dissolved gas tank is 0.6Mpa, and the dissolved gas water is Tap water or effluent from urban sewage treatment plants. 7 . The ozonation conditioning coupled hydrothermal rapid stabilization treatment process for organic sludge according to claim 1 , wherein the cationic PAM configuration mass ratio is 4‰～5‰. 8 . 8 . The ozonation conditioning coupled hydrothermal rapid stabilization treatment process of organic sludge according to claim 1 , wherein the pressurized ozone dissolved air flotation device injects ozone under the condition of 100° C., and the ozone is in the waste water. The addition amount of 8-10mg/L. 9 . The ozonation conditioning coupled hydrothermal rapid stabilization treatment process of organic sludge according to claim 1 , wherein the ozone content of the mixed waste gas of high concentration ozone generated by the pressurized ozone dissolved air flotation device At 15-27mg/L. 10 . The ozonation conditioning coupled hydrothermal rapid stabilization treatment process for organic sludge according to claim 1 , wherein the thermal hydrolysis reaction temperature in the thermal hydrolysis reactor is 180-200° C. 11 .

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