Sludge odorless treatment process based on biological flocculant

Abstract

The invention relates to the technical field of sludge treatment, in particular to a sludge odorless treatment process based on a biological flocculant. According to the method, the biological flocculant is adopted to treat the sludge, the treated sludge is subjected to filter pressing and then is used for aerobic composting, no odor is generated in the composting process, the method is more environmentally friendly, meanwhile, the composting efficiency can be greatly improved, and treatment and resource utilization of the sludge are more convenient; wherein the biological flocculant is prepared from 10 to 20 parts of glycoprotein, 40 to 60 parts of mucopolysaccharide, 30 to 50 parts of cellulose, 1 to 10 parts of calcium chloride and 10 to 20 parts of sulfur autotrophic denitrification freeze-dried thalli; the flocculant is safe and pollution-free, has good flocculation and deodorization effects, is convenient to dehydrate after flocculation, can effectively reduce the dehydration cost, and has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of sludge treatment, and in particular to a sludge deodorization treatment process based on a biological flocculant. Background Art

[0002] Sludge contains a large amount of nutrients that can be used by plants, such as nitrogen, carbon, potassium, humus, and trace elements such as zinc, copper, and iron, which can be used as resources. However, sludge also contains a large number of pathogens, parasites (eggs), and heavy metals such as copper, aluminum, zinc, chromium, and mercury, as well as polychlorinated biphenyls, dioxins, radioactive elements and other toxic and harmful substances that are difficult to degrade. If not effectively treated, the toxic and harmful substances in the sludge will contaminate the soil and water, causing serious pollution and damage to the environment.

[0003] High-temperature aerobic fermentation is one of the existing ways to treat and utilize sludge as a resource. High-temperature aerobic fermentation relies on widely distributed bacteria, actinomycetes, fungi and other microorganisms in nature to controllably promote the transformation of organic matter that can be degraded by microorganisms into stable humus under certain artificial conditions. After aerobic fermentation, urban sludge is used for farmland, landscaping, and reclamation of wasteland and barren land. It can not only solve the problem of the disposal of urban sludge, but also improve soil structure, which is of great significance to environmental protection and the comprehensive recycling of resources.

[0004] The odor problem during the aerobic biological fermentation of municipal sludge is a difficult problem that plagues the normal operation of sludge treatment plants. A variety of odorous substances such as ammonia, hydrogen sulfide, methyl mercaptan, and methyl sulfide are produced during the aerobic biological fermentation of sludge. If they are not properly handled and controlled, they will cause serious environmental problems. It is generally believed that ventilation conditions are the main reason affecting the generation of odor during aerobic fermentation of sludge. Although aerobic fermentation of sludge is carried out under ventilation conditions and the compost is turned during the fermentation process, in the early stage of aerobic composting, the microorganisms in the compost multiply and oxygen is consumed. There will still be an oxygen-deficient and anaerobic environment inside the compost. In this oxygen-deficient / anaerobic environment, a large amount of odor will be produced, causing serious pollution to the surrounding environment and posing a threat to the health of the operators.

[0005] Although improving ventilation conditions can reduce the generation of odor and treat the odor brought out, it can avoid secondary pollution of odor, but it cannot fundamentally solve the odor problem in the aerobic biological fermentation process of sludge. Therefore, the present invention proposes a biological flocculant and a sludge odor-free treatment process, which provides a solution to the odor problem in the aerobic biological fermentation process of sludge. Summary of the invention

[0006] The purpose of the present invention is to provide a sludge deodorization treatment process based on a biological flocculant to solve the problem of odor in the existing sludge aerobic fermentation process.

[0007] To achieve the above object, the present invention adopts the following technical scheme: a sludge odor-free treatment process based on biological flocculants, comprising the following steps:

[0008] S1. Mix the bioflocculant and the sludge evenly, control the pH of the sludge to be weakly alkaline during the mixing process, and then let it stand and concentrate to obtain flocculated concentrated sludge;

[0009] S2, transporting the concentrated sludge obtained in S1 to a dehydration device for dehydration to obtain dehydrated sludge;

[0010] S3, aerobic composting of the sludge after dehydration in S2 can complete the sludge deodorization process of the present invention.

[0011] Furthermore, in the S1, the pH of the sludge is controlled to be 8-9.

[0012] Furthermore, in the S1, the added amount of the biological flocculant is 100-200 kg / t of absolute dry sludge.

[0013] Furthermore, the composition of the biological flocculant includes 10-20 parts of glycoprotein, 40-60 parts of mucopolysaccharide, 30-50 parts of cellulose, 1-10 parts of calcium chloride and 10-20 parts of sulfur autotrophic denitrification freeze-dried bacteria.

[0014] Furthermore, the sources of the glycoprotein, mucopolysaccharide and protein include yam, cactus, cassava, potato, bovine submandibular gland and gastropod mucus.

[0015] Furthermore, the cellulose is carboxymethyl cellulose.

[0016] Furthermore, in S2, the dehydration equipment includes a belt filter press and a plate and frame filter press, the number of filtration is one or more times, and the moisture content of the dehydrated sludge obtained is not more than 65%.

[0017] Furthermore, in S3, the ventilation volume during aerobic composting is 2 to 5 m 3 Air / m 3 Mud·h.

[0018] Furthermore, in the S3, the aerobic composting is completed in 10 days, and the compost turning operation is performed every 1 to 3 days.

[0019] Furthermore, no odor is generated during the aerobic composting process.

[0020] Beneficial effects of the present invention:

[0021] The method of the present invention has a simple process flow and adopts a biological flocculant. On the one hand, it has a good flocculation effect, and on the other hand, it is safe, pollution-free and easy to use. In addition, in the subsequent aerobic composting process, it can also solve the problem of odor release, and provide a solution to the odor problem in the aerobic biological fermentation process of sludge. At the same time, the flocculation effect is good, and it is easy to dehydrate after flocculation, which can effectively reduce the dehydration cost. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0023] Example 1

[0024] The bioflocculant of the present invention can be obtained by taking 15 parts of yam glycoprotein, 50 parts of bovine submandibular gland mucopolysaccharide, 40 parts of carboxymethyl cellulose, 5 parts of calcium chloride and 15 parts of sulfur autotrophic denitrification freeze-dried bacteria and mixing them evenly.

[0025] Example 2

[0026] The residual sludge from a municipal sewage treatment plant was measured and found to have a water content of 98.3%.

[0027] Take 1000 kg of the above municipal sludge and place it in a stirring tank. Under the stirring condition of 80 r / min, add 2.5 kg of the biological flocculant of Example 1 into the stirring tank and stir to mix. During the stirring process, the pH is controlled to be 8.5-9, and the stirring time is 20 min. After completion, let it stand and settle. After the sedimentation is completed, the concentrated sludge at the bottom of the stirring tank is pumped to the sludge dewatering machine for dehydration.

[0028] In this embodiment, the concentrated sludge is dehydrated by a two-stage dehydration device, and the dehydration equipment adopts an ordinary belt filter press. After one filtration, it is measured that the water content in the filter sludge is 82.7%. The filter sludge is filtered for the second time. After dehydration, the water content of the sludge is 61.4%.

[0029] The dewatered sludge was aerobically composted, and the ventilation volume was maintained at 3.5m 3 Air / m 3 Mud·h, and the compost is turned every 2 days during the composting process. After 10 days, the entire aerobic composting process is completed. During the whole process, there is no odor in the workshop, which completely solves the problem of odor generated in the traditional aerobic composting process.

[0030] Comparative Example 1

[0031] In this comparative example, PAM was used to flocculate the sludge, and the conditions of flocculation and dehydration after flocculation were the same as those in Example 2.

[0032] In this comparative example, the moisture content of the sludge after the first filtration and dehydration by an ordinary belt filter press was 85.8%, and the moisture content of the sludge after the second filtration and dehydration by an ordinary belt filter press was 73.1%. The moisture content of the obtained sludge was relatively high and was not suitable for aerobic composting.

[0033] In this comparative example, the secondary filter-pressed sludge was filtered again using a high-pressure belt filter press, and the moisture content of the sludge finally obtained was 58.8%.

[0034] The obtained sludge was used for aerobic composting, and the conditions of aerobic composting were the same as those in Example 2.

[0035] Finally, the aerobic composting time is 27 days, and a lot of odor is generated in the early stage of composting, which is not conducive to environmental protection.

[0036] The total nitrogen content in the sludge after aerobic composting was measured, and the total nitrogen content was 31.2 g / kg. The total nitrogen content in the sludge after aerobic composting in Example 2 was measured, and the total nitrogen content was 74.8 g / kg. The nitrogen content in the fertilizer obtained in Example 2 was significantly higher than that in this comparative example, indicating that the fertilizer obtained in Example 2 has better soil fertility.

[0037] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A sludge deodorization treatment process based on biological flocculants, characterized in that: The following steps are involved: S1. Mix the bioflocculant and the sludge evenly, control the pH of the sludge to be weakly alkaline during the mixing process, and then let it stand and concentrate to obtain flocculated concentrated sludge; S2, transporting the concentrated sludge obtained in S1 to a dehydration device for dehydration to obtain dehydrated sludge; S3, aerobic composting of the sludge after dehydration in S2 can complete the sludge deodorization process of the present invention.

2. The sludge deodorization treatment process based on biological flocculants according to claim 1 is characterized by: In the S1, the pH of the sludge is controlled to be 8-9.

3. The sludge deodorization treatment process based on bioflocculant according to claim 1, characterized in that: In the S1, the added amount of the biological flocculant is 100-200 kg / t of absolutely dry sludge.

4. The sludge deodorization treatment process based on biological flocculants according to claim 3 is characterized by: The biological flocculant comprises 10-20 parts of glycoprotein, 40-60 parts of mucopolysaccharide, 30-50 parts of cellulose, 1-10 parts of calcium chloride and 10-20 parts of sulfur autotrophic denitrification freeze-dried bacteria.

5. The sludge deodorization treatment process based on biological flocculants according to claim 4 is characterized in that: The sources of the glycoprotein, mucopolysaccharide and protein include yam, cactus, cassava, potato, bovine submandibular gland and gastropod mucus.

6. The sludge deodorization treatment process based on biological flocculants according to claim 4 is characterized by: The cellulose is carboxymethyl cellulose.

7. The sludge deodorization treatment process based on biological flocculants according to claim 1 is characterized by: In the above-mentioned S2, the dehydration equipment includes a belt filter press and a plate and frame filter press, the number of filtration is one or more times, and the moisture content of the dehydrated sludge is not more than 65%.

8. The sludge deodorization treatment process based on biological flocculants according to claim 1 is characterized by: In S3, the ventilation volume during aerobic composting is 2 to 5 m 3 Air / m 3 Mud·h.

9. The sludge deodorization treatment process based on bioflocculant according to claim 1, characterized in that: In the above-mentioned S3, the aerobic composting is completed in 10 days, and the compost turning operation is performed every 1 to 3 days.

10. A sludge deodorization treatment process based on a bioflocculant according to any one of claims 1 to 9, characterized in that: During the aerobic composting process, no odor is generated.