CN110698025A - A kind of domestic sludge slurrying method and application of sludge after slurrying - Google Patents

Abstract

The invention provides a domestic sludge slurrying method and application of slurried sludge, wherein the domestic sludge slurrying method comprises the following steps: step S1, settling the domestic sludge to obtain pretreated sludge; step S2, adding the homogenizing agent into the pretreated sludge, uniformly mixing, and standing to obtain stable sludge; and step S3, performing high-pressure injection on the stabilized sludge. The invention has the beneficial effects that: (1) sodium chloride and calcium chloride are added as a homogenizing agent, so that the water content in the domestic sludge can be reduced by less than 75%; (2) a new balance can be established, so that the sludge is in a stable homogenate state, and the settling rate of sludge particles within 4 hours cannot exceed the requirement of 1 percent; (3) the viscosity of the sludge is reduced, and the subsequent treatment is facilitated; (4) the sludge state is more uniform through Venturi injection, the occupied area is small, and the homogenization time is shortened; (5) the sludge treated by the pulping method is more quickly fattened.

Description

A kind of domestic sludge slurrying method and application of sludge after slurrying

technical field

The invention belongs to the field of sludge slurrying, and particularly relates to a domestic sludge slurrying method and application of the slurry after slurrying.

Background technique

With the development of the city, the increase in the amount of urban sewage treatment and the deepening of the treatment degree, the amount of sludge generated has been increasing greatly. By 2018, the amount of sludge produced in my country was as high as 74.36 million tons, of which the amount of domestic sludge was 36.58 million tons, showing an upward trend year by year. Domestic sludge has a high water content, is perishable, has a strong odor, and contains parasite eggs, pathogenic microorganisms, etc. If it is not properly treated and discharged arbitrarily, it will cause secondary pollution. The existing sludge treatment methods in my country are mainly dehydration and then stacking or landfilling, and the treatment cost is expensive. Generally, the sludge treatment cost of a sewage treatment plant accounts for about 15-30% of the total operating cost and 10-25% of the total investment. Due to the huge cost of sludge treatment, some sewage treatment plants directly discharge sludge, causing serious damage to the environment. Sludge has become a major problem that plagues sewage treatment plants and the whole society.

In recent years, my country's environmental protection work has made great progress, and the state has invested a lot of money in sewage treatment. However, if the sludge, the accompanying organism of sewage treatment, is not properly treated, it will form a huge source of pollution and endanger the ecological environment. , In the sludge treatment, stacking and landfill is not a good way, not only waste of money, but also waste of land, which requires a technology for the harmless treatment and utilization of sludge.

In order to solve this problem, sludge composting technology is used to make sludge into fertilizer, which solves the problem of sludge pollution to the environment. The reasons are as follows: First, compared with other treatment methods, such as landfill and incineration, sludge composting has the advantages of less construction investment and lower operating costs, which is suitable for my country's national conditions. Second, the sludge is rich in nutrients. It contains high organic matter and abundant mineral nutrients such as nitrogen and phosphorus, which is an effective way to realize the resource utilization and recycling of sludge.

In order to realize that the domestic sludge can be better used in greening or agriculture, the sludge needs to be pulped first. The existing pulping technology for sludge processing is to use the form of pulping tank to receive, mix, and pulp. For chemical purposes, the moisture content of the adjusted sludge is 90-92%, and it is pumped into the subsequent treatment unit through the sludge pump. The top of the slurry tank is equipped with a vertical shaft mixer for stirring, and one side is designed to be open, which is used for dewatering sludge trucks to dump sludge, and the water supply pipe is connected through the top. During normal operation, the vertical shaft mixer continuously stirs, and when the sludge is dumped like a slurry tank, the water addition switch is turned on for adjustment.

Although the mixing, conditioning and pulping of sludge in the form of a slurry tank can achieve the effect, there are certain problems: the design of the open side of the sludge inlet, when the sludge truck dumps the sludge, it will cause a lot of spray splash, affecting the site hygiene. Due to the measurement problem, it is not easy to precisely match the amount of sludge and the amount of water added, it is difficult to adjust to the appropriate moisture content, and it is difficult to meet the process requirements.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, a method for slurrying domestic sludge and application of sludge after slurrying are provided.

The specific technical solutions are as follows:

A method for slurrying domestic sludge, which is different in that the method for slurrying domestic sludge comprises the following steps:

Step S1: carry out sedimentation treatment with domestic sludge to obtain pretreated sludge;

Step S2: adding the homogenizer to the pretreated sludge to mix evenly, and standing to obtain stable sludge;

Step S3: spraying the stabilized sludge with high pressure.

Further, in the step S1, the moisture content of the pretreated sludge is 90% to 95%.

Further, in the step S2, the homogenizing agent includes bentonite and β-naphthalenesulfonic acid formaldehyde condensate, and the mixture is uniformly mixed after stirring for 2 to 4 minutes.

Further, in the step S2, the standing time is 3 days.

Further, in the step S3, the stabilized sludge is ejected in a venturi injector through micro-holes with a diameter of 0.6-0.8 mm.

Further, the weight ratio of the homogenizer to the pretreated sludge is: (0.1-0.15):1.

An application of the domestic sludge treated by the above method, the difference lies in the application of the sludge treated by the pulping method in the sludge fattening.

Further, after the stabilized sludge is formed into a spherical shape, the sludge is fattened.

Compared with the prior art, the beneficial effects of the present invention are: (1) the homogenizer can reduce the water content in the domestic sludge to less than 75%; (2) a new balance can be established to keep the sludge in a stable homogenized state , the sedimentation rate of the sludge particles in 4 hours cannot exceed the requirement of 1%; (3) reduce the viscosity of the sludge to facilitate subsequent treatment; (4) Venturi jetting makes the sludge state more uniform, and the footprint is small and shortened evenly (5) The sludge after the slurry treatment of the present invention is evenly dispersed, and the sludge is cooked more quickly; (5) The sludge treated by the slurry method of the present invention can be directly used as the raw material of the compost ball, without the need for Dehydration, no need to add other raw materials.

Detailed ways

The principles and features of the present invention will be described below with reference to the embodiments. The examples are only used to explain the present invention, but not to limit the scope of the present invention.

The moisture content of sludge is generally high. In the traditional process, in order to facilitate the transportation, treatment and disposal of sludge, it is generally necessary to dewater the sludge. very large. The sludge specific resistance is usually used to measure the dewatering performance of the sludge, which reflects the resistance of water passing through the sludge particles. It can be seen that the sludge specific resistance is proportional to the filtration pressure and the square of the filtration area, and is proportional to the square of the filtration pressure and the filtration area. The kinematic viscosity of the filtrate is inversely proportional to the dry solids weight of the filter cake and depends on the nature of the sludge.

Due to the large specific resistance, specific surface area, capillary water absorption and cohesion of the sludge, the dispersibility of the sludge during the slurrying process is poor, and it is easy to be separated into layers. The nuclear power performance of ions is large, the dispersibility coefficient of sludge particles and solvent is large, and it is difficult for sludge particles to mix with aqueous solution. The homogeneous slurry achieved is to fully mix the sludge particles with the sewage, that is, to increase the specific resistance of the sludge to achieve. If only pulping equipment is used to treat sludge by physical action, although the filtration pressure and filtration area can be increased to achieve a certain solid-liquid mixing effect, it is difficult to adjust the appropriate moisture content and the action time is long. For the low utilization efficiency of the equipment, it is difficult to meet the process requirements, and after the late treatment, the sludge particles will also sink due to gravity, the storage time is not long and the state is unstable.

Rapid composting process: The current composting process for sludge is mainly based on the decomposition process of organic matter by microorganisms. Among them, the sludge composting process can be divided into strip composting system, forced ventilation static stacking composting system and silo-type composting in the factory. These composting technologies have large area, high requirements on climatic conditions, and long composting cycle. In addition, it requires a lot of manpower to turn the heap and other shortcomings, not only can not deal with sludge on a large scale, but also difficult to meet the needs of the current society. And through the slurry technology of liquefaction and mixing, the sludge treatment steps can be simplified, the treatment cost can be reduced, and the effect of fast fattening can be achieved.

Example 1

A method for slurrying domestic sludge, the method for slurrying domestic sludge comprises the following steps:

Step S1 : performing sedimentation treatment on the domestic sludge to obtain pretreated sludge, wherein the moisture content of the pretreated sludge is 90% to 95%.

Step S2: adding a homogenizer to the pretreated sludge and mixing evenly, and standing for 3 days to obtain a stable sludge; the homogenizer includes bentonite and β-naphthalenesulfonic acid formaldehyde condensate (FDN), and stirs for 2 to 4 minutes After mixing evenly, the weight ratio of the homogenizer to the pretreated sludge is: (0.1-0.15):1.

Step S3: The stabilized sludge is ejected at high pressure in a venturi injector through micropores with a diameter of 0.6-0.8 mm.

Embodiment 2

In step S3, the stabilized sludge is ejected to the granulation equipment at high pressure in a venturi ejector through micro-holes with a diameter of 0.6-0.8 mm, and the stabilized sludge is formed into a ball, and then the sludge is fattened and cooked. Anaerobic fermentation is carried out in units of spheres to become slow-release fertilizer for crops.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (8)

1. A method for slurrying domestic sludge, wherein the method for slurrying domestic sludge comprises the following steps: Step S1: carry out sedimentation treatment with domestic sludge to obtain pretreated sludge; Step S2: adding the homogenizer to the pretreated sludge to mix evenly, and standing to obtain stable sludge; Step S3: spraying the stabilized sludge with high pressure. 2 . The method for slurrying domestic sludge according to claim 1 , wherein, in the step S1 , the moisture content of the pretreated sludge is 90% to 95%. 3 . 3. A method for slurrying domestic sludge according to claim 1, characterized in that, in the step S2, the homogenizing agent comprises bentonite and β-naphthalenesulfonic acid formaldehyde condensate, and is mixed after stirring for 2min-4min evenly. 4 . The method for slurrying domestic sludge according to claim 1 , wherein, in the step S2 , the standing time is 3 days. 5 . 5 . The method for slurrying domestic sludge according to claim 1 , wherein in the step S3 , the stabilized sludge is sprayed in a venturi injector through micropores with a diameter of 0.6-0.8 mm. 6 . out. 6 . The method for slurrying domestic sludge according to claim 1 , wherein the weight ratio of the homogenizer to the pretreated sludge is: (0.1-0.15):1. 7 . 7 . An application of the domestic sludge treated by the slurrying method according to any one of the claims 1 to 6 , wherein the sludge treated by the slurrying method is in the sludge fattening process. Applications. 8 . The application according to claim 1 , wherein the stabilized sludge is formed into a spherical shape and then the sludge is fattened. 9 .