Sludge pretreatment method for domestic sewage plant

Abstract

The invention relates to the technical field of sewage treatment, in particular to a sludge pretreatment method of a domestic sewage plant, the water content of sludge is reduced to 50-60%, and the sludge pretreatment method comprises the steps of auxiliary material selection, auxiliary material addition, uniform mixing and stirring and standing treatment. The water absorption performance of the auxiliary materials is utilized to reduce the water content of the sludge, meanwhile, the defects of traditional mechanical dehydration and chemical dehydration methods are avoided, and the method has the advantages of reducing the water content of the sludge, improving the treatment efficiency, reducing secondary pollution and being high in adaptability.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment, and in particular to a sludge pretreatment method for a domestic sewage treatment plant. Background Art

[0002] After domestic sewage treatment, the water content of the sludge produced is generally around 60-85%. Sludge with high water content has many problems, such as difficulty in subsequent treatment, high transportation cost, and large space occupation. At present, the water content of sludge needs to be reduced to below 65% for better subsequent treatment, such as using biotechnology and microbial aerobic fermentation process to further reduce the water content to 40%.

[0003] However, existing pretreatment methods are insufficient in reducing the water content of sludge. Traditional sludge dehydration methods, such as mechanical dehydration, can reduce the water content of sludge, but they are inefficient and energy consuming, and cause secondary pollution to the wastewater. Although chemical dehydration methods are more effective, they often require the addition of a large amount of chemical agents, which not only increases the treatment cost, but also causes secondary pollution to the environment. In addition, some emerging dehydration technologies, such as thermal drying or freeze drying, although effective, have high equipment investment and operating costs, making them difficult to be widely used in large-scale sewage treatment plants.

[0004] Existing equipment such as plate and frame filter presses are prone to secondary pollution during the treatment process, which not only increases the environmental burden, but also may affect the effectiveness of subsequent treatment processes. At the same time, these methods often require a long treatment time, reducing the efficiency of the entire sewage treatment system. In addition, existing technologies often lack flexibility and adaptability when treating sludge of different types and properties, making it difficult to meet the specific needs of different sewage treatment plants.

[0005] In view of the above problems, the existing technology needs to be improved urgently. Summary of the invention

[0006] The purpose of this application is to provide a sludge pretreatment method for a domestic sewage treatment plant, which has the advantages of reducing the water content of the sludge, improving the treatment efficiency, reducing secondary pollution, and having strong adaptability.

[0007] The present application provides a sludge pretreatment method for a domestic sewage plant, and the technical scheme is as follows: comprising the following steps:

[0008] a) Selection of auxiliary materials: Select dry carbon source auxiliary materials and / or nitrogen source auxiliary materials.

[0009] b) Adding auxiliary materials: adding the carbon source auxiliary material and / or nitrogen source auxiliary material selected in step a) to the sludge according to a set ratio.

[0010] c) Mixing and tossing: Use appropriate tossing equipment to fully stir the sludge after adding the auxiliary materials in step b) so that the auxiliary materials and the sludge are evenly mixed to obtain a mixture.

[0011] d) Standing or dehydration treatment: According to the actual situation, the mixture obtained in step c) is allowed to stand for a period of time to allow the water to further seep out and be absorbed by the auxiliary materials.

[0012] Furthermore, the present application also proposes that the carbon source auxiliary material is selected from straw, tree branches and leaves or sawdust.

[0013] Furthermore, the present application also proposes that the nitrogen source auxiliary material is animal manure.

[0014] Furthermore, the present application also proposes that in step b), the addition ratio of the carbon source auxiliary material and / or the nitrogen source auxiliary material is determined according to the initial water content of the sludge, the water content and adsorption performance of the carbon source and nitrogen source auxiliary materials.

[0015] Furthermore, the present application also proposes that the ratio of the sludge weight to the total weight of auxiliary materials is (7:3):1.

[0016] Furthermore, the present application also proposes that in step b), the turning and tossing time is 2-3 hours.

[0017] Furthermore, the present application also proposes that in step b), the standing time is controlled at 5-6 hours so that the sludge water content can be stably reduced to below 65%.

[0018] Furthermore, the present application also proposes that in step d), the mixture is turned over by a turning device and then spread out and left to stand for 5-6 hours.

[0019] From the above, it can be seen that the sludge pretreatment method for a domestic sewage treatment plant provided in the present application includes auxiliary material selection, auxiliary material addition, mixing and turning, and standing or dehydration treatment steps. By selecting appropriate carbon source and nitrogen source auxiliary materials and fully mixing them with the sludge, the water content of the sludge is reduced by utilizing the water absorption properties of the auxiliary materials. At the same time, the shortcomings of traditional mechanical dehydration and chemical dehydration methods are avoided. It has the advantages of reducing sludge water content, improving treatment efficiency, reducing secondary pollution, and strong adaptability. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below through embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the scope of the present application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present application.

[0021] After the treatment process in the domestic sewage plant, the water content of the sludge produced is generally around 65-85%. There are many problems with sludge with high water content, such as difficulty in subsequent treatment, high transportation cost, and taking up a lot of space. At present, the water content of sludge needs to be reduced to below 65% for better subsequent treatment, such as using biotechnology and microbial aerobic fermentation technology to further reduce the water content to 40%, achieve sludge reduction, harmless and resource-based production of nutrient soil. However, existing pretreatment methods are insufficient in reducing the water content of sludge, have low efficiency or high cost, and are prone to secondary pollution. Therefore, an efficient and economical sludge pretreatment method is needed.

[0022] In order to overcome these problems, the present application proposes a sludge pretreatment method for a domestic sewage treatment plant. Biotechnology and microbial aerobic fermentation process are used to achieve sludge reduction, harmlessness, and resource-based production of nutrient soil. By selecting dry carbon source auxiliary materials and / or nitrogen source auxiliary materials, and adding them to the sludge according to a set ratio, the auxiliary materials and the sludge are evenly mixed by sufficient turning, and finally, the water is allowed to further seep out and be absorbed by the auxiliary materials by standing. These technical features cooperate with each other to effectively reduce the water content of the sludge, and solve the problems of high subsequent treatment difficulty, high transportation cost, and large space occupation caused by high water content of sludge in the process of domestic sewage treatment.

[0023] In the specific implementation process, it is first necessary to select dry carbon source auxiliary materials and / or nitrogen source auxiliary materials. Carbon source auxiliary materials can be straw, branches and leaves or sawdust, while nitrogen source auxiliary materials can be animal manure. When selecting auxiliary materials, it is necessary to consider the initial water content of the sludge, the water content and adsorption properties of the carbon source and nitrogen source auxiliary materials to determine the appropriate addition ratio. Usually the ratio of sludge weight to total auxiliary material weight is 7:3.

[0024] After adding the auxiliary materials, it is necessary to use appropriate turning equipment to fully turn the sludge so that the auxiliary materials and sludge are evenly mixed. The turning time is generally controlled at 2-3 hours. After turning, according to the actual situation, you can choose to let the mixture stand for a period of time to allow the water to further seep out and be absorbed by the auxiliary materials. The standing time is generally controlled at about 6 hours, so that the water content of the sludge can be steadily reduced to below 65%. After turning the mixture with the turning equipment, continue to spread it out and let it stand for 5-6 hours.

[0025] Compared with the prior art, the method of the present application effectively improves the sludge precipitation efficiency, reduces the treatment cost, and avoids secondary pollution by selecting suitable auxiliary materials and turning methods. Specifically, by selecting dry carbon source auxiliary materials and / or nitrogen source auxiliary materials, and adding them to the sludge according to the set ratio, the auxiliary materials and the sludge are evenly mixed by sufficient turning, and finally the water is allowed to further seep out and be absorbed by the auxiliary materials by standing. These technical features cooperate with each other to effectively reduce the water content of the sludge, and solve the problems of high subsequent treatment difficulty, high transportation cost, and large space occupation caused by high water content of sludge in the process of domestic sewage treatment.

[0026] In the specific implementation process, it is first necessary to select dry carbon source auxiliary materials and / or nitrogen source auxiliary materials. Carbon source auxiliary materials can be straw, branches and leaves or sawdust, while nitrogen source auxiliary materials can be animal manure. When selecting auxiliary materials, it is necessary to consider the initial water content of the sludge, the water content and adsorption properties of the carbon source and nitrogen source auxiliary materials to determine the appropriate addition ratio. Usually, the ratio of sludge weight to total auxiliary material weight is 7:3.

[0027] Compared with the prior art, the method of the present application effectively improves the sludge dehydration efficiency, reduces the treatment cost, and avoids secondary pollution by selecting suitable auxiliary materials and turning methods. Specifically, by selecting dry carbon source auxiliary materials and / or nitrogen source auxiliary materials, and adding them to the sludge according to the set ratio, the auxiliary materials and the sludge are evenly mixed by sufficient turning, and finally the water is allowed to further seep out and be absorbed by the auxiliary materials by standing. These technical features cooperate with each other to effectively reduce the water content of the sludge, and solve the problems of high subsequent treatment difficulty, high transportation cost, and large space occupation caused by high water content of sludge in the process of domestic sewage treatment.

[0028] In the specific implementation process, it is first necessary to select dry carbon source auxiliary materials and / or nitrogen source auxiliary materials. Carbon source auxiliary materials can be straw, branches and leaves or sawdust, while nitrogen source auxiliary materials can be animal manure. When selecting auxiliary materials, it is necessary to consider the initial water content of the sludge, the water content and adsorption properties of the carbon source and nitrogen source auxiliary materials to determine the appropriate addition ratio. Usually, the ratio of sludge weight to total auxiliary material weight is 7:3.

[0029] Compared with the prior art, the method of the present application effectively improves the sludge dewatering efficiency, reduces the treatment cost and avoids secondary pollution by selecting suitable auxiliary materials and turning methods.

[0030] Furthermore, the present application also proposes that the carbon source auxiliary material is selected from straw, tree branches and leaves or sawdust.

[0031] The technical feature of the present application is to select straw, branches and leaves or sawdust as carbon source auxiliary materials. The purpose of selecting these materials is to utilize their adsorption properties and organic matter content to improve the effect of sludge pretreatment, which is specifically manifested in more effectively reducing the water content of the sludge, thereby solving the problem of high water content in the sludge treatment process. Through the use of these carbon source auxiliary materials, the sludge can be made easier to handle, the transportation cost can be reduced, and the space occupied can be reduced, thereby improving the efficiency and economy of sludge pretreatment.

[0032] Specifically, straw, branches, leaves and sawdust as carbon source auxiliary materials have good adsorption properties and high organic matter content. The fiber structure of straw is relatively loose and can absorb a large amount of water. At the same time, its decomposition rate is moderate, which helps to gradually release organic matter during the pretreatment process. Branches and leaves have a higher carbon-nitrogen ratio, which helps to adjust the carbon-nitrogen balance of sludge and further improve the treatment performance of sludge. Sawdust, due to its fine particles and high specific surface area, can provide a larger adsorption surface and effectively reduce the water content of sludge.

[0033] By selecting the above-mentioned carbon source auxiliary materials, the dehydration effect of the sludge can be significantly improved, and the sludge water content can be reduced to below 65%, which is convenient for subsequent treatment. Therefore, the present application overcomes the problems of low pretreatment efficiency and high cost of mechanical dehydration in the prior art, and secondary pollution of wastewater discharge, etc. by selecting suitable carbon source auxiliary materials, thereby providing an efficient and economical sludge pretreatment method. Compared with the prior art, the technical solution of the present application has significant advantages, which can more effectively reduce the water content of sludge, reduce treatment costs, avoid secondary pollution, and improve the overall efficiency and economy of sludge treatment.

[0034] Furthermore, the present application also proposes that the nitrogen source auxiliary material is animal manure.

[0035] The technical solution of the present application includes selecting animal manure as a nitrogen source auxiliary material. Animal manure as a nitrogen source auxiliary material can provide abundant nitrogen elements, which is helpful for the degradation of sludge and the improvement of nutrients. By selecting animal manure, the efficiency of sludge pretreatment can be improved, nutrients can be increased, and secondary pollution can be reduced.

[0036] The selection of animal manure as a nitrogen source auxiliary material can be achieved in a variety of ways. For example, different types of animal manure such as chicken manure, cow manure, and pig manure can be selected, and the specific selection depends on the actual local conditions and the availability of resources. Animal manure can be properly pretreated before use, such as drying, to reduce its water content and improve its adsorption performance. In addition, the addition ratio of animal manure can be determined based on the initial water content of the sludge, the water content of the animal manure, and the adsorption performance to achieve the best pretreatment effect.

[0037] By selecting animal manure as a nitrogen source auxiliary material, the present application solves the problem of selecting a nitrogen source auxiliary material in the sludge pretreatment process. Compared with the mechanical dehydration and chemical dehydration of the prior art, the method of the present application improves the efficiency of sludge pretreatment, reduces costs, and reduces secondary pollution. Therefore, the technical solution of the present application has significant advantages in the field of sludge pretreatment.

[0038] Furthermore, the present application also proposes that in step b), the addition ratio of the carbon source auxiliary material and / or the nitrogen source auxiliary material is determined according to the initial water content of the sludge, the water content and adsorption performance of the carbon source and nitrogen source auxiliary materials.

[0039] The technical feature of step b) is to determine the addition ratio of the carbon source auxiliary material and / or the nitrogen source auxiliary material according to the initial water content of the sludge, the water content and adsorption performance of the carbon source and nitrogen source auxiliary materials. This technical feature plays a key role in solving the problem of how to determine the appropriate auxiliary material addition ratio.

[0040] By considering the initial moisture content of the sludge, the initial state of moisture in the sludge can be accurately assessed, thereby determining how much auxiliary material needs to be added for adsorption. The moisture content of carbon and nitrogen auxiliary materials directly affects their adsorption capacity, so it must be considered when determining the addition ratio. The adsorption properties of auxiliary materials determine their efficiency in adsorbing moisture from sludge, so it is also an important factor in determining the addition ratio.

[0041] Through the above scheme, the addition ratio of auxiliary materials can be effectively adjusted, making the sludge treatment process more efficient, and ultimately achieving the purpose of reducing the water content of the sludge.

[0042] Specifically, the initial moisture content of the sludge can be determined by conventional moisture determination methods. The moisture content of carbon source auxiliary materials and nitrogen source auxiliary materials can be determined by drying method or other appropriate moisture determination methods. Adsorption performance can be evaluated by laboratory experiments, for example, by determining the amount of water adsorbed by the auxiliary material over a certain period of time to determine its adsorption performance. Based on these parameters, the optimal auxiliary material addition ratio can be determined by calculation or experiment.

[0043] For example, assuming that the initial water content of the sludge is 80%, the water content of the carbon source auxiliary material is 10%, and the water content of the nitrogen source auxiliary material is 15%. Through experiments, it is known that the carbon source auxiliary material has better adsorption performance and can adsorb 50% of its own weight of water, while the nitrogen source auxiliary material has a slightly worse adsorption performance and can adsorb 30% of its own weight of water. In this case, the optimal auxiliary material addition ratio can be calculated based on these parameters to achieve the best sludge dehydration effect.

[0044] Therefore, by comprehensively considering the initial moisture content of the sludge, the moisture content and adsorption performance of the carbon source and nitrogen source auxiliary materials, the addition ratio of the auxiliary materials can be accurately determined, making the sludge pretreatment process more efficient and reducing the moisture content of the sludge, thereby solving the problems of low efficiency and high cost in the existing technology.

[0045] Furthermore, the present application also proposes that the ratio of sludge weight to total auxiliary material weight is 7:3.

[0046] Through a reasonable weight ratio, it can be ensured that the auxiliary materials can achieve the best effect when absorbing moisture in the sludge, thereby effectively reducing the water content of the sludge. The weight ratio of sludge to auxiliary materials is set between 7:3, which can play an important role in optimizing the sludge pretreatment effect. Specifically, this ratio can enable the auxiliary materials to achieve the best effect when absorbing moisture in the sludge, thereby effectively reducing the water content of the sludge. By setting this ratio, it can be ensured that during the sludge pretreatment process, the auxiliary materials can fully absorb the moisture in the sludge to achieve the best pretreatment effect.

[0047] Specifically, the ratio of sludge weight to total weight of auxiliary materials is set to 7:3, which can be achieved in the following ways: First, according to the initial water content of the sludge, the water content and adsorption performance of the carbon source and nitrogen source auxiliary materials, the specific amount of auxiliary materials added is determined. Then, the determined auxiliary materials are added to the sludge according to the set ratio, and fully stirred so that the auxiliary materials and the sludge are evenly mixed to obtain a mixture. Next, according to the actual situation, the mixture is allowed to stand for a period of time so that the water further seeps out and is absorbed by the auxiliary materials, thereby achieving the purpose of reducing the water content of the sludge. As a preferred embodiment, dry carbon source auxiliary materials and / or nitrogen source auxiliary materials, such as straw, branches and leaves, sawdust, animal feces, etc., can be selected to be mixed as auxiliary materials.

[0048] Therefore, by setting the ratio of sludge weight to the total weight of auxiliary materials to 7:3, the present application provides an efficient and economical sludge pretreatment method. Compared with the prior art, the method of the present application is more efficient in reducing the water content of sludge, can effectively solve the problems of low efficiency and high cost of the existing pretreatment methods, and avoid the generation of secondary pollution. By setting a reasonable weight ratio, it can be ensured that the auxiliary materials achieve the best effect when absorbing the water in the sludge, thereby significantly improving the effect of sludge pretreatment.

[0049] Furthermore, the present application also proposes that in step b, the turning time is 2-3 hours.

[0050] In the sludge pretreatment process, the turning time is set to 2-3 hours. This technical feature plays an important role in solving the problem of low treatment efficiency and poor effect caused by improper turning time. By setting a reasonable turning time, it can ensure that the auxiliary materials are fully mixed with the sludge, thereby improving the efficiency and effect of sludge pretreatment.

[0051] The setting of the tossing time can be adjusted according to the specific properties of the sludge and the type of auxiliary materials. For example, for sludge with a high water content, a longer tossing time can be selected to ensure that the auxiliary materials can fully absorb the water; while for drier sludge, a shorter stirring time can be selected to avoid excessive tossing and increase energy consumption. The tossing equipment can be a conventional tossing device, or a more efficient mechanical tossing device can be used to improve the mixing effect.

[0052] The present application further optimizes the sludge pretreatment process by reasonably setting the turning time, ensures the full mixing of auxiliary materials and sludge, and improves the efficiency and effect of pretreatment. Compared with the prior art, the present application can more effectively reduce the water content of sludge and reduce the difficulty and cost of subsequent treatment.

[0053] Furthermore, the present application also proposes that in step b), the standing time is controlled at 5-6 hours so that the sludge water content can be stably reduced to below 65%.

[0054] The technical solution of the present application reduces the water content of the sludge by controlling the standing time. Specifically, by controlling the standing time to 5-6 hours in step b), the water content of the sludge can be stably reduced to below 65%. This technical feature plays a key role in solving the problem of excessive water content in the sludge. By extending the standing time, the water in the sludge can further seep out and be absorbed by the auxiliary materials, thereby effectively reducing the water content of the sludge and meeting the requirements of subsequent treatment.

[0055] The standing time in step b) is controlled to be 5-6 hours, which can be achieved in a variety of ways. For example, the standing time can be adjusted according to the initial water content of the sludge and the adsorption performance of the auxiliary material. Further, different types of auxiliary materials, such as dry carbon source auxiliary materials and / or nitrogen source auxiliary materials, can be used to improve the absorption efficiency of water. In addition, the mixture can be regularly turned over during the standing process to promote uniform seepage and absorption of water.

[0056] The present application can effectively reduce the water content of sludge by controlling the standing time, and has significant advantages over the prior art. First, the method of the present application is simple and easy to implement, and does not require complex equipment and high costs. Secondly, by extending the standing time, a significant decrease in the water content of sludge can be achieved without increasing energy consumption, avoiding the problem of secondary pollution. Finally, the method of the present application is applicable to various types of sludge pretreatment and has broad application prospects.

[0057] Furthermore, the steps of pouring and spreading the mixture can be achieved manually or mechanically.

[0058] Furthermore, the present application also proposes that in step d), the mixture is flipped by a material flipping device and then spread out and left to stand for 5-6 hours.

[0059] By turning the mixture with a turning device and letting it stand for 5-6 hours, the contact area of ​​the mixture can be significantly increased and the evaporation of water can be promoted. Turning the mixture helps to bring the internal water to the surface, accelerate the evaporation process of water, and also helps the auxiliary materials to better absorb water, thereby further reducing the water content of the sludge during the standing process.

[0060] The technical features of the present application promote water evaporation and water absorption of auxiliary materials by increasing the contact area of ​​the mixture and turning the mixture, thereby further reducing the water content of the sludge during the standing process. The implementation method of this technical feature may include using mechanical turning equipment, such as a turning machine, to ensure uniform and thorough turning. The standing time and turning time can be adjusted according to specific environmental conditions, such as air temperature, humidity, and sunlight intensity. As a preferred embodiment, it is possible to choose to stand and turn during the period of strongest sunlight to maximize the use of natural conditions to accelerate water evaporation.

[0061] Through the above technical solution, the present application effectively solves the problem of further reduction of water content of the sludge mixture during the static process. Compared with the prior art, the present application reduces the water content of the sludge more efficiently by extending the static time and turning the mixture, achieving the effect of pretreatment and facilitating subsequent treatment. This method not only improves the treatment efficiency, but also reduces the treatment cost and avoids the problem of secondary pollution.

[0062] The above are only specific embodiments of the present application, but the technical features of the present application are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present application to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present application.

Claims

1. A method for pre-treating sludge from a domestic sewage plant, characterized in that The following steps are involved: a) Selection of auxiliary materials: Select dry carbon source auxiliary materials and / or nitrogen source auxiliary materials; b) adding auxiliary materials: adding the carbon source auxiliary material and / or nitrogen source auxiliary material selected in step a) to the sludge according to a set ratio; c) Mixing and tossing: using appropriate tossing equipment to fully stir the sludge after adding the auxiliary materials in step b) so that the auxiliary materials and the sludge are evenly mixed to obtain a mixture; d) Standing: According to actual conditions, the mixture obtained in step c) is allowed to stand for a period of time to allow the water to further seep out and be absorbed by the auxiliary materials.

2. The method for pretreatment of sludge from a domestic sewage plant according to claim 1, characterized in that: The carbon source auxiliary material is selected from straw, branches and leaves or sawdust.

3. The method for pretreatment of sludge from a domestic sewage plant according to claim 1, characterized in that: The nitrogen source auxiliary material is animal feces.

4. The method for pretreatment of sludge from a domestic sewage plant according to claim 1, characterized in that: In step b), the addition ratio of the carbon source auxiliary material and / or the nitrogen source auxiliary material is determined according to the initial water content of the sludge, the water content and adsorption performance of the carbon source and nitrogen source auxiliary materials.

5. The method for pretreatment of sludge from a domestic sewage plant according to claim 4, characterized in that: in, The ratio of the sludge weight to the total weight of auxiliary materials is 7:

3.

6. The method for pretreatment of sludge from a domestic sewage plant according to claim 1, characterized in that: In step b), the stirring time is 2-3 hours.

7. The method for pretreatment of sludge from a domestic sewage plant according to claim 1, characterized in that: In step b), the standing time is controlled at 5-6 hours, so that the water content of the sludge can be stably reduced to below 65%.

8. The method for pretreatment of sludge from a domestic sewage plant according to claim 1, characterized in that: In step d), the mixture is turned over by a turning device and then left to stand for 5-6 hours.