CN106316584A - Method and device for treating residual sludges - Google Patents

Abstract

The invention provides a method for treating excess sludge and an excess sludge treatment device. The method for treating excess sludge includes: uniformly mixing the excess sludge with a conditioner, placing it in ventilation for 7-16 days, and manually turning it every 12-36 hours One time; after 7-16 days of mixing the remaining sludge and conditioner, add earthworms to form compost, and wait for 56-63 days to obtain vermicompost sludge products. This product is used in high-efficiency agricultural fertilizer or soil conditioner. The present invention adds conditioner cow dung, alleviates the adverse effects of excess sludge on earthworms, further improves the growth and reproduction of earthworms in earthworm composting, ensures the balance of earthworm biomass, and enhances the degradation ability of organic matter in earthworm composting, thereby The composting efficiency is improved, and an effective way is provided for resource utilization of surplus sludge in villages and towns.

Description

Method for treating excess sludge and excess sludge treatment device

technical field

The invention belongs to the technical field of biological treatment, and in particular relates to a method for treating excess sludge and an excess sludge treatment device.

Background technique

During the "Thirteenth Five-Year Plan" period, my country will continue to strengthen the construction of domestic sewage treatment facilities in villages and towns, and the production of biological sludge will also continue to increase. Activated sludge method is currently the most widely used sewage biological treatment technology. The biggest disadvantage of this technology is that it produces a large amount of excess sludge. The excess sludge has high water content, high organic content, high microbial activity, and is easy to rot and smell Potential heavy metal and pathogenic microorganism hazards. If the excess sludge is not properly disposed of, it will pose a serious threat to land resources, water environment and sanitation environment in villages and towns, which is not conducive to the construction of a new socialist countryside.

At present, domestic biological treatment technologies for excess sludge stabilization mainly include anaerobic digestion, aerobic digestion, aerobic composting and vermicomposting, etc. These residual sludge biological treatment technologies mainly have the following limitations and deficiencies in practical application :

1. The investment and operation costs of anaerobic digestion technology are high, and a large amount of sludge residue and digestive juice remain, which cannot achieve the final treatment purpose.

2. The aerobic digestion technology has a great influence on the temperature and cannot effectively kill the pathogenic bacteria in the sludge. The dehydration performance of the digested sludge is poor, and the long-term aeration leads to high energy consumption.

3. The investment cost of aerobic composting technology is relatively high, and fixed fermentation tanks, stirring and ventilation equipment are required; a large amount of malodorous gas is produced during the process of microbial decomposition of organic matter; nitrogen loss is large, and the agricultural value of compost products is reduced.

4. In the sludge treatment system of earthworm composting, the residual sludge has high moisture content and low porosity, which can easily create an anaerobic environment and hinder the respiration of earthworms; the C/N ratio in the residual sludge is low, which may cause protein poisoning symptoms in earthworms ; Inorganic salts, heavy metals, pathogenic microorganisms, etc. contained in the remaining sludge do not use the growth and reproduction of earthworms; in terms of organic matter degradation and stability, the degradation rate of organic matter in traditional earthworm composting is low, and the stability of sludge needs to be improved; In the process of composting sludge, organic acids and ammonia gas that are toxic to earthworms will be produced. These organic substances can cause earthworms to die in trace amounts.

None of the above methods is an ideal biological treatment technology for excess sludge. However, compared with anaerobic digestion, aerobic digestion and aerobic composting, the above-mentioned shortcomings in the process of earthworm composting lead to limited function of earthworms and unsatisfactory compost stabilization effect. As a result, vermicomposting cannot be carried out efficiently for a long time.

Contents of the invention

The present invention aims at the deficiencies of the prior art, and its primary purpose is to provide a method for treating excess sludge.

The second object of the present invention is to provide an excess sludge treatment device for realizing the above method.

To achieve the above object, the solution of the present invention is:

A method for treating excess sludge, comprising the steps of:

(1) Mix the remaining sludge and conditioner evenly, place it in ventilation for 7‐16 days, and manually turn it every 12‐36 hours;

(2) After the remaining sludge and conditioner are mixed for 7-16 days, add earthworms to form compost, and wait for 56-63 days to obtain vermicompost sludge products.

Preferably, the dry weight ratio of excess sludge to conditioner is 1:3.

Preferably, the conditioner is cow dung.

Preferably, the cow manure has a pH value of 8.40±0.05 and a C/N ratio of 25.94±0.91.

Preferably, the earthworm is Eisenia chinensis.

Preferably, the temperature of the compost is 23±2° C., and the moisture content is 75±5%.

An excess sludge treatment device for implementing the above method for treating excess sludge, comprising: a cover and an open container arranged in sequence from top to bottom, the cover and the open container are detachably connected, and the cover is evenly distributed with through holes.

Preferably, the density of the through holes is 1.67 holes/cm ² , and the hole diameter is 6-10 mesh.

Preferably, the shape of the open-top container is cylindrical.

Preferably, the open container has a diameter of 10-20cm and a height of 15-24cm.

A vermicompost sludge product is produced by treating excess sludge as described above.

The above-mentioned vermicompost sludge products are used in high-efficiency agricultural fertilizers or soil conditioners.

Owing to adopting said scheme, the beneficial effect of the present invention is:

1. The present invention adds cow dung as a conditioning agent for excess sludge. After 60 days of reaction, the pH value and the C/N ratio in the vermicompost all increase, thereby improving the growth and reproduction of earthworms and reducing the mortality of earthworms , to provide favorable conditions for improving the composting effect.

2. The present invention adds cow dung as a conditioning agent for excess sludge, and the activity of antioxidant enzymes shows that cow dung can reduce the activity of catalase (CAT) and peroxidase (POD) in earthworms, thereby alleviating excess sludge The stress effect on earthworms; in addition, the conditioner cow dung can accelerate the degradation of organic matter in earthworm compost, reduce the content of available heavy metals (DTPA state heavy metals), and significantly improve the agricultural resource value of earthworm compost.

3. The present invention adds cow dung as a conditioning agent for excess sludge, which can significantly improve the humification degree of vermicomposting and the stabilization degree of humic acid.

4. The method for treating excess sludge of the present invention has low infrastructure cost, low operating cost, convenient management, and high agricultural fertilizer efficiency of vermicompost sludge products, which is especially suitable for processing the vast villages and towns where my country's economic technology is relatively weak, and those who do not have In the area of a small sewage plant where excess sludge treatment structures are established; the invention can realize on-site treatment of excess sludge, prevent secondary pollution of excess sludge, and realize resource utilization of excess sludge.

5. The present invention treats excess sludge, and the obtained vermicompost sludge product contains earthworm excrement, has good particle aggregation performance, has certain antibacterial effect, and is rich in nitrogen, phosphorus, and potassium that are easy to be absorbed and utilized by plants It can be used as high-efficiency agricultural fertilizer or soil conditioner.

detailed description

The invention provides a method for treating excess sludge and an excess sludge treatment device for realizing the method.

<How to deal with excess sludge>

A method for treating excess sludge comprises the steps of:

(1) Mix the remaining sludge and conditioner evenly, place it in ventilation for 7‐16 days, and manually turn it every 12‐36 hours;

(2) After the remaining sludge and conditioner are mixed for 7-16 days, add earthworms to form compost, and wait for 56-63 days to obtain vermicompost sludge products.

Wherein, in step (1), the time for mixing and ventilating the excess sludge and conditioner can be 7-16 days, preferably 10-14 days.

The excess sludge can be excess sludge from a domestic sewage treatment plant in Shanghai.

In step (1), manual flipping is performed every 12-36h, preferably 24-36h.

In step (1), the dry weight ratio of excess sludge to conditioner is 1:3.

In step (1), the conditioning agent is cow dung, which can be cow dung from a breeding factory in Pudong New Area, Shanghai. The pH of cow manure was 8.40±0.05, and the C/N ratio was 25.94±0.91.

In step (2), the time for mixing the remaining sludge and the conditioner may be 7-16 days, preferably 10-14 days.

In step (2), earthworms are added to form compost, and the waiting time may be 56-63 days, preferably 60 days.

The earthworms can be Eisenia fetida, which mainly comes from an earthworm farm in the Donghai Farm in the suburbs of Shanghai.

The weight of a single earthworm is about 0.3g, and the body length is about 5cm. The number of earthworms added to each open container is 25.

In step (2), the temperature of the compost is 23±2° C., and the moisture content is 75±5%.

<Vermicompost Sludge Products>

A vermicompost sludge product is produced by treating excess sludge as described above.

<Application of Vermicompost Sludge Products>

The vermicompost sludge produced by the above method for treating excess sludge can be used as high-efficiency agricultural fertilizer or soil conditioner.

<Excess sludge treatment device>

An excess sludge treatment device for implementing the above method for treating excess sludge includes: a cover and an open container arranged in sequence from top to bottom, the cover and the open container are detachably connected, and the cover is evenly distributed with through holes.

Wherein, the open-top container may be a polyethylene plastic container, or a container made of other materials, and there is no special limitation here.

The purpose of evenly distributing the through holes in the cover is for the earthworms to breathe fresh air, which is beneficial to the growth and reproduction of the earthworms.

After adding earthworms to react, cover the lid to prevent earthworms from escaping.

The density of the through holes is 1.67 holes/cm ² , and the hole diameter is 6-10 mesh, preferably 8 mesh.

The shape of the open container is cylindrical, or other shapes, which are not particularly limited here.

The diameter of the open container is 10-20cm, preferably 15cm; the height is 15-24cm, preferably 20cm.

The present invention will be further described below in conjunction with the shown embodiments.

Embodiment 1: a kind of method for processing excess sludge

The method for processing surplus sludge in the present embodiment, it may further comprise the steps:

(1), the conditioner cow dung (dry weight in this embodiment is 150g) and the remaining sludge with a moisture content of 80% (dry weight in this embodiment is 50g) are evenly mixed according to the dry weight ratio of 3:1, and cool Ventilate and place for 14 days, and turn it manually every 24 hours;

(2) After the remaining sludge and conditioner are mixed for 14 days, add 25 earthworms to each open container to form compost. The temperature of the compost is 23±2°C and the moisture content is 75±5%. After waiting for 60 days with the cover, the vermicompost sludge product is obtained.

Among them, the ventilated storage time is acceptable within 7-16 days, the frequency of manual turning is also acceptable within 12-36 hours, and the waiting time after adding earthworms is acceptable within 56-63 days.

The added earthworm is Eisenia fetida, which belongs to the family Orthophidae and belongs to the genus Eisenia, commonly known as red earthworm. The earthworm selected in this embodiment is plump and active, with a monomer weight of about 0.3 g and a body length of about 5 cm.

Embodiment 2: A kind of excess sludge treatment device

An excess sludge treatment device for implementing the above method for treating excess sludge includes: a cover and an open container arranged in sequence from top to bottom, the cover and the open container are detachably connected, and the cover is evenly distributed with through holes.

Wherein, open type container is the cylindrical container of polyethylene plastics, and its diameter is 10-20cm (can be preferably 15cm in the present embodiment), and height is 15-24cm (can be preferably 20cm in the present embodiment), lid through The density of the holes is 1.67/cm ² , and the hole diameter is 6-10 mesh (8 mesh may be preferred in this embodiment).

The size or shape of the excess sludge treatment device in this embodiment is for illustration purposes only, and is not considered as a limitation to the actual size or actual shape of the product of the present invention. Those skilled in the art can, after knowing the specific content of the present invention Change the specific size or shape of each component according to the actual situation, so as to realize the enlargement or reduction of the product of the present invention.

<experiment>

The following experiment was carried out with the vermicompost sludge product obtained in Example 1.

<Experiment 1>

The purpose of this experiment is to study the effect of cow dung on vermicomposting.

The experiment was carried out by adding conditioner cow dung. After 60 days, the number of earthworms, body weight gain, average weight, number of cocoons, changes in the activity of antioxidant enzymes in earthworms, and the changes in organic matter and heavy metal indicators were measured after 60 days. Changes. Table 1 shows the changes of earthworms and various substances before adding cow dung to the reaction and after adding cow dung to the reaction for 60 days:

Table 1: Changes in earthworms and various substances before and after 60 days of reaction with cow dung

It can be seen from the above table that after adding cow dung for 60 days, the pH value and C/N ratio in the vermicompost both increased. Based on the positive correlation between pH value and C/N ratio and earthworm reproductive ability, because the pH value and C/N ratio of earthworm compost are low before adding cow manure, which is not conducive to the production of earthworms, and the addition of high content After cow dung with a higher pH value and higher C/N ratio, the pH value of earthworm composting increased by 3.0%, and the C/N ratio increased by 4.92%, thus improving the growth and reproduction of earthworms and providing favorable conditions for improving the composting effect .

Before the reaction without adding cow dung in this experiment, the organic matter content of the remaining sludge was 355.47g/kg, and after adding cow manure for 60 days, the organic matter content of the vermicompost sludge product was 247.33g/kg; Before, the pH value of the remaining sludge was 6.34±0.06, and after adding cow manure for 60 days, the pH value of the vermicompost sludge product was 6.53±0.09, all of which met the "People's Republic of China Urban Construction Industry Standards (CJ/T 309‐ 2009) "The agricultural value of sludge stipulated in urban sewage treatment plants, its organic matter content is not less than 200g/kg, and the nutritional index requirements of pH value is 5.5-9; in addition, the conditioner cow dung also accelerates the degradation of organic matter, The effective heavy metal content of vermicomposting is reduced, so vermicomposting sludge products have good economic benefits.

In conclusion, the results of this experiment confirmed that the addition of cow dung as a conditioner for excess sludge improved the growth and reproduction of earthworms, enhanced the degradation capacity of organic matter in earthworm composting, and improved the composting efficiency.

<Experiment 2>

The purpose of this experiment is to study the effect of cow dung on the growth and reproduction of earthworms.

25% excess sludge and 75% cow dung are uniformly mixed, compared with 100% excess sludge (without adding cow dung) to treat earthworm composting, the mortality rate of earthworms is only 8.0%, and the average weight of earthworms is 573.78±2.31mg/barrel, The body weight increased by 372.35±1.67mg/piece, the amount of worm cocoons was 243, the average weight of earthworms increased by 154.5%, and the amount of worm cocoons increased by 872% after composting for 60 days. After adding conditioner cow manure, the adaptability of earthworms to the compost environment was significantly improved, and the growth and reproduction of earthworms were significantly improved.

Therefore, the present invention adds cow dung as a conditioning agent for excess sludge, which reduces the mortality of earthworms and obviously improves the growth and reproduction of earthworms.

This experiment confirmed that the addition of cow dung as a conditioner for excess sludge, especially the mixing of excess sludge and conditioner at a dry weight ratio of 1:3, compared with 100% excess sludge (without adding cow dung) to treat vermicomposting, Significantly improved the growth and reproduction of earthworms.

<Experiment 3>

The purpose of this experiment is to detect the change of antioxidant enzyme activity in earthworms after adding cow dung as a conditioner for excess sludge, and the change of organic matter content in earthworm compost after adding cow dung for 60 days.

The determination of peroxidase (POD) activity and catalase (CAT) activity in earthworms were carried out in kits developed by Nanjing Jiancheng Bioengineering Institute.

When treating the vermicomposting of excess sludge, cow dung is added as a conditioner, and the excess sludge and cow dung are uniformly mixed at a dry weight ratio of 1:3. In the control group, after 60 days of the experiment, the POD enzyme and CAT enzyme activities in the earthworms in the control group were 130.3U/gprot and 568.7U/gprot respectively, and the POD enzyme and CAT enzyme activities in the earthworms in the test group added with cow dung as the conditioner were respectively It was 66.4U/gprot and 268.1U/gprot. Therefore, the decrease of antioxidant enzyme activity indicated that the conditioner cow dung can alleviate the stress effect of residual sludge on earthworms. After adding cow manure for 60 days, the TOC content of organic matter in vermicompost decreased by 30.42%, and the value of total nitrogen (TN) and available phosphorus (AP) increased by 34.90% and 30.00%, respectively, indicating that its agricultural resource value has increased significantly; The humification index increased by 17.78%, which promoted the degradation of organic matter into more stable humic substances.

Therefore, cow dung as a conditioner alleviates the stress effect of excess sludge on earthworms, improves the growth and reproduction of earthworms; accelerates the degradation of organic matter, reduces the content of effective heavy metals in earthworm composting, and improves the humus of earthworm composting. The degree of stabilization and the degree of stabilization of humic acid, thus improving the value of agricultural resources of vermicomposting.

In conclusion, the addition of organic conditioner cow manure can improve the growth conditions of earthworms in vermicomposting, alleviate the adverse effects of excess sludge on earthworms, further improve the growth and reproduction of earthworms in vermicomposting, ensure the balance of earthworm biomass, and enhance the The degradability of organic matter improves the composting efficiency and provides an effective way for the resource utilization of surplus sludge in villages and towns.

The above description of the embodiments is for those of ordinary skill in the art to understand and use the present invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. 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 fall within the protection scope of the present invention.

Claims (10)

1. the method processing excess sludge, it is characterised in that: comprise the steps:

(1), excess sludge is uniformly mixed with conditioner, ventilate and place 7 16d, manually stir once every 12 36h；

(2), after described excess sludge and described conditioner mix 7 16d, add Lumbricus to form compost, wait 56 63d After, obtain earthworm fecal sludge product.

Method the most according to claim 1, it is characterised in that: described excess sludge is 1 with the dry weight ratio of described conditioner: 3。

Method the most according to claim 1, it is characterised in that: described conditioner is cattle manure；

Or the pH value of described cattle manure is 8.40 ± 0.05, C/N ratio is 25.94 ± 0.91.

Method the most according to claim 1, it is characterised in that: described Lumbricus is Eisenia foetida.

Method the most according to claim 1, it is characterised in that: the temperature of described compost is 23 ± 2 DEG C, moisture content is 75 ± 5%.

6. the excess sludge processing means realizing the method for claim 1, it is characterised in that: including: on to Under the lid that sets gradually and open type container, described lid and described open type container removably connect, described lid is uniform It is dispersed with through hole.

Excess sludge processing means the most according to claim 6, it is characterised in that: the density of described through hole is 1.67/ cm², aperture is 6 10 mesh.

Excess sludge processing means the most according to claim 6, it is characterised in that: being shaped as of described open type container is round Cylindricality；And/or,

A diameter of 10 20cm of described open type container, a height of 15 24cm.

9. an earthworm fecal sludge product, it is characterised in that: it is prepared from by the method as described in claim 1 to 5 is arbitrary.

10. an earthworm fecal sludge product as claimed in claim 9 is applied in efficient agriculture fertilizer or soil conditioner.