CN102303988A - Method for preparing garden and park nutrient soil by adopting dewatered sludge through fermentation - Google Patents

Abstract

The invention provides a method for fermenting garden nutrient soil with dewatered sludge, which solves the problems of harmlessness, nutrition and humification of garden nutrient soil fermented with dewatered sludge. In the method, the prepared fermentation material adopts an aerobic-anaerobic alternate fermentation method, the aerobic period is ≥ 5 days, and a fermentation temperature above 50°C with the effect of killing coliform bacteria is generated (aerobic 5d-anaerobic 3d) The alternate method of ×3 can make the sludge fermented reach the harmless standard of garden nutrient soil. At the same time, the three alternate fermentations can promote the formation of available nitrogen, available phosphorus and humus in the fermented sludge, and improve the nutrient and putrefaction of the fermented sludge. Colonization, so as to achieve large-scale utilization of urban waste and realize the purpose of waste reuse.

Description

A method of fermenting garden nutrient soil with dewatered sludge

technical field

The invention relates to a treatment technology of municipal domestic garbage, in particular to a method for fermenting garden nutrient soil by using dewatered sludge to carry out an aerobic-anaerobic alternating method.

the

Background technique

Dewatered sludge mainly refers to sludge that has been treated by dehydration equipment in sewage plants and has a water content of about 80%. It contains a large amount of organic matter, microorganisms and pathogenic bacteria, and has an odor. In the prior art, there are mainly the following methods for treating dewatered sludge: landfill method, incineration method, aerobic fermentation method, anaerobic aerobic method, thermal drying method, etc., but the existing problem is that landfill method It occupies a large area, requires high site technology, and causes secondary pollution; the incineration method produces toxic and harmful gases that pollute the atmosphere, requires a large investment, and consumes high energy; the thermal drying method has a high cost; the fermentation method can be used for sludge composting, but the scale limited. In the existing sludge fermentation process, mushroom bags, crushed straw, crushed litter, sawdust, etc. are usually mixed with sludge, and then fermented. The use of dewatered sludge to ferment garden nutrient soil needs to meet the requirements of harmlessness, nutrition, and humification (referred to as three transformations); its harmlessness means that the coliform bacteria in the fermented sludge are less than 100 per g, trophication refers to the available nitrogen ≥ 0.12g·kg ^-1 and available phosphorus ≥ 0.03g·kg ^-1 in the fermented sludge, and humification refers to the content of humus in the fermented sludge ≥ 10g· kg ^-1 . Conventional sludge fermentation has two methods: aerobic and anaerobic. The aerobic method has a high and fast temperature rise in sludge and is effective in killing coliform bacteria. However, the degree of organic matter mineralization is high, and it is difficult to ensure the nutrient and Humification: The anaerobic method has low temperature rise and slow temperature rise, and the effect of killing coliform bacteria is poor, but the degree of mineralization of organic matter is low, and the degree of nutrition and humification of fermented sludge is higher than that of aerobic method. However, the simple aerobic method and anaerobic method are difficult to achieve the goal of "three modernizations" of the sludge fermentation garden nutrient soil.

At present, although there are researches on sludge alternate fermentation at home and abroad, the control of aeration and gas stop rather than the control of oxygen concentration is used to achieve good and anaerobic alternate fermentation, and there is no targeted solution to the sludge fermentation garden nutrition. Therefore, a better fermentation method is urgently needed to solve the problems in the prior art.

Contents of the invention

Aiming at the above-mentioned deficiencies in the prior art, the purpose of the present invention is to solve the problems of harmless, nutritious and humifying garden nutrient soil produced by fermenting dewatered sludge, and to provide a kind of simple operation and good fermenting effect. The invention discloses a method for fermenting dehydrated sludge into garden nutrient soil by using an aerobic-anaerobic alternating method.

The technical means used in the present invention is: a method for fermenting garden nutrient soil with dewatered sludge, characterized in that the method comprises the following steps:

1) Fermentation of dewatered sludge:

A. Sludge treatment: Take the sludge from the sewage treatment plant and reduce the moisture content to 75% by natural drying;

B. Mushroom package treatment: crush the remaining bag-shaped substrate waste after the mushrooms are planted to obtain crushed mushroom packages;

C. Preparation of seed soil: Mix the sludge treated in step A above with the crushed mushroom bag treated in step B above in a volume ratio of 1:1, spray the compound fermentation seed liquid, mix well and carry out aerobic Fermentation, the fermentation temperature is 50°C-70°C, and the time is maintained for 5-7 days to obtain the seed soil;

D. Preparation of fermentation materials: Mix the sludge treated in the above-mentioned step A with the pulverized mushroom bag processed in the above-mentioned step B and the strain soil obtained in the step C in a volume ratio of 1:1:1 to obtain a moisture content of 60 ~65% fermented material;

2) Pack fermentation materials:

Put the fermented material prepared in step 1) into the fermenter, the tightness is natural, when the volume of fermented material is 4/5-5/6 of the volume of the fermenter, stop loading, and cover the lid of the fermenter ;

3) Fermented garden nutrient soil:

Using the aerobic-anaerobic alternating method to ferment the fermented material in step 2) into garden nutrient soil, the number of aerobic-anaerobic alternating in the aerobic-anaerobic alternating method is three times, each time The alternate steps are:

①Aerobic, that is, ventilate first for 5 minutes, and the ventilation volume is 1.4~2.8m ³ ·(h·t) ^-1 ; then stop the gas for 30 minutes; repeat the above operation for 5 days;

再厌氧：停止通气3天。

Re-anaerobic: Stop ventilation for 3 days.

Further, in Step 1) C, the composite fermentation seed liquid is two or more compound fermentation seed liquids of actinomycetes, bacteria, and fungi.

Further, in step 1) step C, the aerobic fermentation is carried out in the air by machine turning in the fermentation tank. According to the difference of fermentation temperature, turn the pile 1 to 4 times a day, and the fermentation temperature is 50-70 ℃ for 5 to 7 days.

Further, the volume percent concentration of gaseous oxygen in the aerobic period in the step 3) is 5%-21%; the volume percent concentration of gaseous oxygen in the anaerobic period is <5%.

Compared with the prior art, the present invention has the following advantages:

1, the present invention adopts the alternate use of aerobic-anaerobic three times, makes the fermented nutrient soil reach the garden soil requirement of harmless, nutrientization, humification, and it not only satisfies the huge market demand of my country's garden soil, Moreover, it is helpful for the large-scale treatment of urban sludge resources and realizes the reuse of waste, thereby playing a positive role in the protection of the water environment in the Three Gorges Reservoir area.

2. The present invention adopts three aerobic-anaerobic alternation methods to ferment dewatered sludge into nutrient soil, wherein the three aerobic-anaerobic alternation methods are: the first aerobic-anaerobic alternation process is strong sterilization, so that The survival rate of coliforms in the fermented sludge has dropped significantly; the second good-anaerobic alternating process is the standard sterilization period, so that the coliforms in the fermented sludge are less than 100/g, so that the fermented sludge can reach the landscaping soil standard ; At the same time, its available nitrogen and phosphorus content reaches the level of high-quality garden soil, effective nitrogen and phosphorus content, effective nitrogen ≥ 0.12g·kg ^-1 , and available phosphorus ≥ 0.03g·kg ^-1 ; the third good-anaerobic alternation process is a stable sterilization period , to control the coliform bacteria in the fermented sludge, and to make the humus content of the fermented material ≥10g·kg ^-1 .

3. The present invention adopts the aerobic-anaerobic alternating method to ferment the dewatered sludge into nutrient soil, wherein controlling the oxygen concentration in the aerobic period is to ensure the respiration of aerobic microorganisms to maintain their life activities, and the microorganisms decompose the sludge The organic matter releases heat at the same time, so that the temperature of the sludge rises to reach the harmless temperature; and in the aerobic period, the aeration and stoppage are regularly repeated, on the one hand, to ensure the oxygen concentration required by the microorganisms, on the other hand, it is consistent with continuous aeration. Compared with gas, it saves energy consumption, and it is also beneficial to maintain the fermentation temperature in the barrel in winter; the anaerobic period is not ventilated, and the oxygen concentration in the fermentation material is lower than 5%, which is conducive to the decomposition of refractory lignin and cellulose by anaerobic microorganisms. Conducive to the formation of humus. Therefore, it is ensured that the method of the present invention can make the dewatered sludge fermented to meet the requirements of harmless, nutritious and humic garden soil.

4. The method of the present invention ferments garden nutrient soil, which saves energy, can reduce emissions of CO ₂ , CH ₄ , etc. during fermentation, and saves 35% of power consumption.

5. The method of the present invention ferments garden nutrient soil, the method is simple, the investment is small, and it is easy to popularize.

This invention has been supported by the National Water Pollution Control and Treatment Science and Technology Major Project (2009ZX07315-002), and the Key Technology Research and Demonstration of Sludge Reduction and Recycling of Urban Sewage Treatment Plants in the Three Gorges Reservoir Area (2009ZX07315-002-02).

the

Description of drawings

Fig. 1 is the alternate fermentation device of sludge; Wherein

1-Test barrel, 2-Insulation layer, 3-Air distribution board, 4-Pier, 5-Fermentation material, 6-Air outlet, 7-Intake pipe, 8-Power supply, 9-Time relay, 10-Electric box, 11-solenoid valve, 12-gas flow meter, 13, air pump;

Figure 2 is the change of average oxygen concentration before and after gas stop;

Fig. 3 is the temperature variation of different alternating ways.

Detailed ways:

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

In order to determine the control parameters for fermenting garden nutrient soil with good-anaerobic alternating method to meet the requirements of harmlessness, nutrition and humification, in the process of fermenting garden nutrient soil with dewatered sludge, a feasibility test was first carried out, and then Carry out a confirmatory test to test indicators such as the temperature of sludge alternate fermentation, coliform bacteria, roundworm eggs, available nitrogen, available phosphorus, humus, gaseous oxygen concentration, etc., so as to obtain the optimal control parameters of the aerobic-anaerobic alternate method, analyze The comprehensive effect of the obtained optimal control parameters on the fermented sludge.

1. Feasibility test

1 Materials and methods

1.1 Fermentation device

The specifications and configuration of the fermentation device are shown in Figure 1. The main part of the fermentation device includes a test tank 1, an air distribution plate 3, a buttress 4 and an insulation layer 2; three support piers 4 are placed inside the test tank 1, and the support piers 4 are located The bottom of the air distribution board 3 is used to support the air distribution board 3; a layer of palm mat is placed on the air distribution board 3, and fermentation materials 5 are stacked on the mat; the bottom of the air distribution board 3 is connected with the air intake pipe 7, and the air intake pipe 7 passes The bottom of the air distribution plate 3 ventilates the fermentation material 5 from bottom to top; the outside of the test barrel 1 is also wrapped with an insulation layer 2, and the insulation layer 2 is used to maintain the fermentation temperature in the test barrel. The automatic control part of fermentation device comprises electric box 10, solenoid valve 11 and air pump 13; Time relay 9 is arranged in electric box 10, and time relay 9 is connected with solenoid valve 11, and solenoid valve 11 is connected with air pump 13; During the power supply, the opening or closing of the electromagnetic valve 11 is controlled by setting the time on the time relay 9, and the opening or closing of the electromagnetic valve 11 controls the opening or closing of the air pump 13, thereby controlling the ventilation or stopping the air in the test barrel; The air pump 13 is connected with the gas flow meter 12 , and the gas flow meter 12 is used to adjust the ventilation rate of the air pump 13 . Described insulation layer 2 is rubber-plastic insulation cotton, thick 5cm.

1.2 Test equipment

ACO-012 air pump (150L min ^-1 , 0.042Mpa), CY-12CB oxygen meter, EST thermometer, TU-1900 ultraviolet spectrophotometer, PHS-3C digital display acidity meter, DDS-11A digital display conductivity Rate meter, portable soil heavy metal tester, muffle furnace, LDZX-40B1 sterilizer, LRH-250A constant temperature incubator, digital microscope.

1.3 Test material

Dewatered sludge: provided by Chongqing Lijiatuo Sewage Treatment Plant.

Sludge treatment: The dewatered sludge is used for batching when the moisture content drops from 80% to 75% after spreading.

Mushroom bag: the bag-shaped substrate waste left after mushroom planting (moisture content 30%), provided by Chongqing Institute of Landscape Science.

Strain soil: 1 part of sludge (moisture content 75%) + 1 part of crushed mushroom bag according to the volume ratio, spray the compound fermentation seed liquid and mix well, and then aerobically ferment in the fermentation device. The aerobic fermentation is used in the fermentation tank Fermentation is carried out in the air by machine turning. According to the different fermentation temperatures, turn the pile 1 to 4 times a day, and keep the fermentation temperature at 50-70°C for 5-7 days (days) to obtain the seed soil (moisture content 45%) . The compound fermentation strain liquid is two or more compound fermentation strain liquids of actinomycetes, bacteria and fungi (provided by Chongqing Institute of Garden Science).

Proportion of fermentation materials: According to the volume ratio, it is 1 part of sludge with a moisture content of 75% + 1 part of crushed mushroom bag + 1 part of bacterial seed soil, and the moisture content after mixing the ingredients is 60-65%.

Fermentation test tank: the specification is 420L, and the amount of fermentation material loaded is 0.35m ³ .

1.4 Oxygen concentration control of fermentation materials: the gaseous oxygen concentration in the aerobic period is 5% to 21%, and the gaseous oxygen concentration in the anaerobic period is <5%.

1.5 Test indicators and methods

Fermentation temperature test: 8:00, 14:00, 20:00 daily fermentation temperature test for the middle and upper part of the material in the fermentation device, oxygen concentration test before and after ventilation and gas stop, to determine the oxygen consumption at different fermentation temperatures, take The average value of oxygen concentration at the same time at each temperature.

Sampling method: at the end of aerobic and anaerobic, take 200g samples from the middle of the upper, middle and lower layers of the fermentation material, mix well, air dry, grind, divide into 2~3 groups and test at the same time.

Harmless, nutritious, and humicizing test indicators: coliform bacteria, roundworm eggs, available nitrogen, available phosphorus, total potassium, moisture content, organic matter, pH, electrical conductivity EC, humus, etc. For the test method, see "Examination Methods for Sludge from Municipal Sewage Treatment Plants" (CJ/T 221-2005).

Feasibility test of aerobic-anaerobic alternating method

Experimental method: Three groups of aerobic, alternating and anaerobic were designed for the test (the aerobic and anaerobic test were the control test groups), with three fermentation devices in each group, and the test period was 28 days. Aerobic method test design: 1st~28d (aerobic); alternate fermentation test design: 1st~7d (aerobic), 8th~10d (anaerobic), 11th~15d (aerobic), 16th~ 19d (anaerobic), 20th~23d (aerobic), 25th~28d (anaerobic); anaerobic method test design: 1st~28d (anaerobic); test results are shown in Table 1 Alternate method feasibility test test result.

Table 1 Alternative method feasibility test test results

Table 2 Comprehensive evaluation of alternative method feasibility test

Result analysis: As can be seen from Table 1, the results of each group of experiments after fermentation are compared as follows:

The average available nitrogen content: anaerobic method 0.859 g·kg ^-1 > alternate method 0.856 g·kg ^-1 > aerobic method 0.798g·kg ^-1 , the alternate method is 7.4% higher than the aerobic method, indicating that the alternate method can improve the effective nitrogen content Nitrogen content;

Average available phosphorus content: alternate method 1.852g·kg ^-1 > aerobic method 1.692g·kg ^-1 > anaerobic method 1.636 g·kg ^-1 , the alternate method is 9.4% higher than the aerobic method and 13.2% higher than the anaerobic method %, indicating that the alternate method can increase the available phosphorus content;

Average humus content: Alternative method 10.510 g·kg ^-1 > Anaerobic method 9.398 g·kg ^-1 > Aerobic method 8.768 g·kg ^-1 , indicating that the alternation method can increase the humus content.

Test conclusion: According to the results of the comprehensive evaluation of the feasibility test of the alternate method in Table 2, it can be seen that the alternate method is 89 points > the aerobic method is 61 points > the anaerobic method is 47 points. law is feasible.

ventilation test

The ventilation test group is divided into 9 groups, and each group lasts for 25 days. Analyze the relationship between temperature, gaseous oxygen concentration, ventilation volume, ventilation time, and gas stop time, and determine the mortality rate of coliform bacteria at different temperatures. The ventilation methods and results of the test are shown in Table 3.

the

Table 3 Ventilation methods and results

It can be seen from Table 3 that when the aeration volume in the aerobic section is 1.4~2.8 m ³ (h·t) ^-1 , the highest fermentation temperature is ≥50°C; the aeration volume is >2.8 m ³ (h·t) ^-1 or <1.4 m ³ (h · t) ^-1 , the highest fermentation temperature <50 ℃. When the aeration volume is 1.4~2.8 m ³ (h·t) ^-1 , when the aeration is 5 minutes and the aeration is stopped for 30 minutes, the fermentation temperature is ≥50°C and the duration is 3 days (that is, the temperature on the 4th-6th day d is greater than 50°C) , which can kill most of the coliforms, etc., which is conducive to achieving harmless standards; when the aeration volume is 1.4~2.8 m ³ (h·t) ^-1 , when the aeration is 5 minutes and the aeration is stopped for 45 minutes, the fermentation temperature ≥ 50°C, the duration can only be maintained for 1 day (day), the mortality rate of coliform bacteria is low, and the harmless requirements cannot be met in the end, so the ventilation method is determined to be ventilation volume 1.4~2.8 m ³ ·(h·t) ^-1 , ventilation 5min, stop gas for 30min.

It can be seen from Figure 2 that the gaseous oxygen concentration increased from 5.3% to 20.6% (Figure 2a-b) in the aerobic stage for 3 minutes, and reached 20.7% in 5 minutes (Figure 2, b-c), and decreased from 20.7% to 5.4% in 30 minutes after stopping the gas (Figure 2, b-c). Figure 2c-d), it dropped to 3.8% after 45 minutes of gas stop, and 1.5% after 70 min of gas stop (Figure 2d-e). In Fig. 2, the oxygen concentration in section c-d drops quickly, and the oxygen concentration in section d-e drops slowly. Point d is the inflection point of oxygen concentration drop after gas stop. The oxygen concentration at the inflection point and the time of gas stop are used as the basis for the next ventilation. It is 5min, and the gas stop time is 30min, which is consistent with the above conclusion.

It can be seen from Table 3 that when the material fermentation temperature is above 50°C, the mortality rate of coliform bacteria is 82.7% when it lasts for 1 day (day), and it is more than 91.6% when it lasts for 3 days. The fermentation temperature should be ≥50°C and maintained for more than 1 day.

Alternate fermentation test

There were 6 groups of alternating test components, each group had two fermentation devices, and the design of each test group was shown in Table 4.

The aerobic stage ventilation method obtained from the ventilation test is that the ventilation time is 5 minutes (the gaseous oxygen concentration rises from 5% to 21%), the stop time is 30 minutes (the gaseous oxygen concentration drops from 21% to 5%), and the ventilation volume is 1.4-2.8m ³ • (h·t) ^-1 Alternate trials were performed.

Oxygen concentration control of fermentation materials: the gaseous oxygen concentration in the aerobic period is 5% to 21%, and the gaseous oxygen concentration in the anaerobic period is <5%.

Through experiments with different configurations of aerobic-anaerobic days and different alternating times, the best alternate way of making garden nutrient soil by alternate fermentation of dewatered sludge was determined. The tests and results of different alternation methods are shown in Table 4.

Table 4 Experiments and results of different alternate modes

Analysis of test results:

(1) First alternate

Alternation mode in the aerobic section over 5 days (days): the highest temperature in the first alternation is 52.8°C, the mortality rate of coliform bacteria is 83.3-91.7%, and the coliform bacteria is reduced from 2400 g ^-1 to an average of 270 g ^-1 , but still higher than the harmless index of 100 g ^-1 ; after the first alternation, judging from the mortality rate of coliform bacteria, the highest temperature must rise above 50 degrees to achieve harmless Requirements, indicating that the aerobic period should be greater than or equal to 5 days, (however, whether the anaerobic period is 3 days or 5 days is not known until the final comprehensive evaluation). According to the requirements of sludge fermentation first to achieve harmlessness, followed by nutrition and humification, coliform bacteria are harmless indicators. When the fermentation temperature is higher than 50 degrees, the mortality rate of coliform bacteria is high, so when the aerobic period It takes 5 days or more for the mortality rate of coliform bacteria to be high. Nutritization and humification indicators mainly refer to the content of available nitrogen, phosphorus and humus. After the first alternation, the available nitrogen and phosphorus contents of aerobic 5 days were higher than those of aerobic 3 days and aerobic 7 days, and the content of humus content is not much different.

(2) Second alternation

From the data parameters of the second alternation, among the six alternation methods for the second alternation, when the fermentation temperature is 41.2-46.5°C, the mortality rate of coliform bacteria is between 60.0-77.5%, and the mortality rate of coliform bacteria is 60.0-77.5%. decreased to 70-90 units·g ^-1 , lower than 100 units·g ^-1 ; after the second alternation, the content of available nitrogen in each group decreased, the content of available phosphorus increased slightly, and the content of humus However, the growth rate of humic substances in aerobic 5 days was higher than that of other groups.

(3) The third alternation

From the data parameters of the third alternation, when the fermentation temperature is 29.8～33.1℃, the mortality rate of coliform bacteria is between 28.6～37.5%, and the coliform group is 50～60·g ^-1 , less than 100 g index; when the third alternation ended, the aerobic 3-day did not reach the harmless standard, the aerobic 5-day and aerobic 7-day reached the harmless standard, but the aerobic 5-day humus was higher than In the other groups, in the two groups of aerobic 5 days, the humus of anaerobic 3 days was higher than that of anaerobic 5 days.

It can be seen from Table 4 that after three alternations, the highest fermentation temperature in the aerobic section of 5d (days) is higher than that of the aerobic 3d (days) alternation mode, and the aerobic 3d (days) cannot make the sludge meet the harmless requirements. The available nitrogen content of the fermented sludge increased, the available phosphorus decreased slightly on the whole, and the humus increased significantly. However, considering the various indicators in the fermented soil comprehensively, the alternating mode of 5d → 3d is the best. Although the alternating method of 7d → 3d can also make the soil meet the requirements of harmlessness, nutrition and humification, but in terms of time efficiency, 5 days of aerobic treatment is shorter, more economical and economical. And the aerobic 3-day alternating method, the soil obtained at the end cannot meet the requirements for garden use, so it is not considered here. Therefore, the alternation of 5d (days) → 3d (days) has the shortest time and can be used as an alternation of sludge fermentation in the future. From the perspective of the number of alternations, although one alternation can kill most coliform bacteria, the content of available nitrogen, phosphorus and humus is low, so three times of alternate fermentation are needed to promote the effective nitrogen, available phosphorus, and humus of fermented sludge. Formation, so that the number of coliform bacteria meets the requirements of garden soil.

5 comprehensive evaluation

Table 5 Comprehensive evaluation table of different alternative methods

The evaluation principle of the effect of sludge fermented garden nutrient soil: first consider the harmlessness, then the nutrient, then the humification, and finally the time. According to Chongqing City's "Garden Planting Soil Quality Standard" (DBJ/T50-044-2005), the soil quality of the nutrient soil fermented by the above six alternate methods is evaluated. The evaluation results are shown in Table 5. According to Chongqing City's "Garden Planting Soil Quality Standard" ( DBJ/T50-044-2005) stipulates the first-class soil standard: the soil quality evaluation score is 85~100 as the first-class soil, and the fermentation method of (good 5d-hateful 3d)×3 has the highest score and the shortest time, and its fermentation method The nutrient soil can reach the standard of first-class soil, so as to meet the needs of garden soil. Therefore, the fermentation method of (good 5d-hate 3d)×3 is selected as the best alternate fermentation method.

6 Conclusion

The best reference control parameters for the production of "three modernizations" garden nutrient soil by using the good-anaerobic alternating method to ferment dewatered sludge are as follows:

Alternation method: each alternation is aerobic 5d-anaerobic 3d, alternating three times, namely (good 5d-anaerobic 3d)×3.

Ventilation mode in the aerobic period: ventilation for 5 minutes, stop gas for 30 minutes, ventilation volume 1.4~2.8m ³ ·(h·t) ^-1 .

Proportion of fermentation materials: volume ratio is 1 part of sludge with a moisture content of 75% + 1 part of crushed mushroom bag + 1 part of bacterial seed soil.

the

2. Confirmatory experiment

According to the results obtained from the aforementioned feasibility test, specific implementation will be carried out.

1 Materials and methods

1.1 Fermentation device

Same as the feasibility test part.

1.2 Experimental Instruments

Same as the feasibility test part.

1.3 Experimental materials

Same as the feasibility test part.

1.4 Test indicators and methods

Same as the feasibility test part.

1.5 Implementation method:

Test group design: The experiment is divided into 3 groups, each group has 2 test barrels with a volume of 0.42m ³ .

Alternate method: Alternate method 1 is (good 3d-hate 3d)×3, alternate method 2 is (good 5d-hate 3d)×3, and alternate method 3 is (good 7d-hate 3d)×3, of which alternate method 1 and Alternate method 3 is a comparative test, and the results of the three alternate methods are shown in Table 6.

Material loading into barrels: put the ingredients into the fermentation device, the tightness is naturally not required to be pressed tightly, when the top of the ingredients is flattened and the distance from the edge of the fermentation device is 10cm, the filling can be stopped (about 0.35m ³ ), and the lid of the barrel will be closed.

Good-anaerobic alternation method: aerobic for 5 days first, and then anaerobic for 3 days, that is, good for 5 days-anaerobic for 3 days; good-anaerobic alternating method for a total of three times, that is, (good for 5 days-anaerobic for 3 days)×3.

Oxygen concentration control of fermentation materials: the gaseous oxygen concentration in the aerobic period is 5% to 21%, and the gaseous oxygen concentration in the anaerobic period is <5%.

Ventilation method in aerobic period: ventilation time 5 minutes (gaseous oxygen concentration rises from 5% to 21%), gas stop time 30 minutes (gaseous oxygen concentration drops from 21% to 5%), ventilation volume 1.4～2.8m3·(h·t ) ^-1 .

Table 6 Implementation Results of Alternate Method

2 specific implementation steps

First spread the dewatered sludge to reduce the moisture content to 75%, and mix it with the crushed mushroom bag and seed soil in a volume ratio of 1:1:1 to form a fermentation material. After batching, the moisture content is 60-65%. Then, put the ingredients into the fermentation device. Naturally, there is no need to apply force to tighten the tightness. When the top of the ingredients is flattened and the distance from the edge of the fermentation device is 10cm, the filling can be stopped (about 0.35m ³ ), and the lid is closed, and the fermentation process is carried out separately. Alternate fermentation of (good 3d-hate 3d)×3, (good 5d-hate 3d)×3, (good 7d-hate 3d)×3. Aerobic period: ventilation time is 5 minutes, gas stop time is 30 minutes, ventilation volume is 1.4~2.8m ³ ·(h·t) ^-1 , anaerobic period: ventilation is stopped so that the gaseous oxygen concentration is less than 5%. Finally, test the data of detoxification, trophicization and humification. Fermentation temperature test: 8:00, 14:00, 20:00 every day to test the temperature of the middle and upper middle of the material in the fermentation device; oxygen concentration test: test before and after ventilation and before and after gas stop; sampling method: aerobic end 1. At the end of anaerobic fermentation, 200g samples were taken from the middle of the upper, middle and lower layers of the fermentation material, mixed, air-dried, ground, and divided into 2~3 groups for simultaneous testing. For test methods of coliform, roundworm eggs, available nitrogen, available phosphorus, total potassium, moisture content, organic matter, pH, electrical conductivity EC, humus, etc., see "Urban Sewage Treatment Plant Sludge Inspection Methods" (CJ/T 221-2005) .

Analysis of Implementation Result of Three Alternative Ways

(1) First alternate

Table 6 shows that in the first alternation, the highest fermentation temperature: 3d, 5d, and 7d in the aerobic period were 47.6°C, 54.6°C, and 55.1°C; the mortality rate of coliform bacteria: 30.8% in the 3d, 5d, and 7d in the aerobic stage , 93.1%, 95.4%; available nitrogen, available phosphorus content: available nitrogen 1.50 g·kg ^-1 , 1.52 g·kg ^-1 , 1.43 g·kg ^-1 , available phosphorus 1.07 in 3d, 5d, 7d of aerobic period respectively g·kg ^-1 , 1.33 g·kg ^-1 , 1.14g·kg ^-1 ; humus content: 8.15 g·kg ^-1 , 8.52 g·kg ^-1 , 8.30g· kg ^-1 . It can be seen from the analysis that after the first alternation, the mortality rate of coliform bacteria in aerobic 7 days > aerobic in 5 days > aerobic in 3 days, although the first alternation killed most of the coliforms (that is, the strong sterilization stage ), but the coliforms have not yet reached the greening soil standard ≤ 100 g ^-1 , that is, they have not met the requirement of harmlessness; the available nitrogen and phosphorus content are higher than the first-level standard of greening soil, that is, available nitrogen ≥ 0.12g· kg ^-1 , available phosphorus ≥ 0.03g·kg ^-1 , and aerobic for 5 days was higher than the other two groups; the humus content was lower than 10g·kg ^-1 , which did not meet the requirements of humification. Therefore, although the three alternate methods of the first alternate sludge fermentation have met the nutritional requirements, they have not yet met the harmless and humic requirements, and alternate fermentation is required again.

(2) Second alternation

Table 6 shows that in the second alternation, the highest fermentation temperature: 35.6°C, 33.1°C, and 32.6°C in the 3d, 5d, and 7d of the aerobic period; the mortality rate of coliform bacteria: 75.0% in the 3d, 5d, and 7d of the aerobic period , 55.6%, 58.3%; available nitrogen, available phosphorus content: available nitrogen 1.41 g·kg ^-1 , 1.45 g·kg ^-1 , 1.27g·kg ^-1 , available phosphorus 1.13 g·kg ^-1 , 1.39 g·kg ^-1 , 1.41g·kg ^-1 ; humus content: 8.56 g·kg ^-1 , 9.67 g·kg ^-1 , 9.39g· kg ^-1 . The analysis shows that after the second alternation, after 5 days and 7 days of aerobic conditions, the number of coliform bacteria decreased (standard sterilization stage), reaching the greening soil standard ≤ 100 g ^-1 , meeting the harmless requirements, but good Oxygen was not reached for 3 days; the second alternate available nitrogen and available phosphorus were all higher than the first-level standard for greening soil, that is, available nitrogen ≥ 0.12g·kg ^-1 , available phosphorus ≥ 0.03g·kg ^-1 , available nitrogen content It is aerobic for 5 days and aerobic for 3 days > aerobic for 7 days, and the available phosphorus is the highest for aerobic 7 days; the humus content is the highest for aerobic 5 days, but the humus content is lower than that of the garden nutrient soil. Chemical index, that is, humus content ≥ 10g·kg ^-1 . Therefore, after the second alternate sludge fermentation, although the aerobic 5-day and 7-day methods have met the requirements of harmlessness and nutrition, they have not yet met the requirements of humification, and a third alternate fermentation is required.

(3) The third alternation

Table 6 shows that in the third alternation, the highest fermentation temperature: 3d, 5d, and 7d in the aerobic period were 37.8°C, 47.2°C, and 45.1°C; the mortality rate of coliform bacteria: 20.0 %, 37.5%, 60.0%; available nitrogen and available phosphorus content: 1.33 g·kg ^-1 , 1.42 g·kg ^-1 , 1.47g·kg ^-1 1.31 g·kg ^-1 , 1.42 g·kg ^-1 , 1.37g·kg ^-1 ; humus content: 9.65 g·kg ^-1 , 12.53 g·kg ^-1 , 11.14g on the 3d, 5d, and 7d of the aerobic period, respectively • kg ⁻¹ . According to the analysis, after the third alternation, the number of coliform bacteria continued to decrease in the 5-day and 7-day aerobic methods (stable sterilization stage), which was lower than the greening soil standard ≤ 100 g ^-1 ; aerobic 3 days The coliform bacteria in the three methods are still not up to the standard; the available nitrogen and available phosphorus of the three methods are all higher than the first-level standard of greening soil, that is, available nitrogen ≥ 0.12g·kg ^-1 , available phosphorus ≥ 0.03g·kg ^-1 ; humus content: The humification index of garden nutrient soil was lower than 10g·kg ^-1 in aerobic period 3d, while the humification index of 5d and 7d in aerobic period was higher than 10g·kg ^-1 of garden nutrient soil. After the completion of the three alternations, the aerobic 3-day humus did not meet the harmless requirements and cannot be considered as a control parameter for the production of garden nutrient soil, while the aerobic 5-day humus was higher than the aerobic 7-day humus, although the effective nitrogen and phosphorus content of the two Both are higher, but the production cycle of aerobic 5 days is shorter than that of aerobic 7 days. Therefore, the optimal alternation is the alternation of aerobic 5 days-anaerobic 3 days.

Overview

Table 7 Comprehensive evaluation and analysis of the implementation results of the alternate method

According to the comprehensive evaluation analysis (see Table 7), the total scores of aerobic period 3d, 5d, and 7d are 45 points, 82 points, and 64 points respectively, and the soil quality evaluation scores of the three alternate methods are 78.7 points, 91.3 points, and 79.3 points, respectively. , which shows that after the third alternation, the effects of fermenting harmless, nutritious, and humic garden nutrient soils with three alternate methods are: (good 3d-disgusting 3d)×3 alternate method is the worst, The second is the alternating method of (good 7d-hate 3d)×3, and the best is the alternating method of (good 5d-hate 3d)×3. This method is not only economical and time-saving, but also has the best fermentation effect, making the fermented The sludge can meet the soil requirements of garden nutrient soil, and find a reasonable place for waste reuse of sludge and mushroom bag waste, effectively saving resources.

Claims (4)

1. the method with dewatered sludge ferment system gardens nutrition soil is characterized in that said method comprises the steps:

1) fermentation of dewatered sludge:

A, sludge treatment: get the mode of sludge of sewage treatment plants through natural airing and make water ratio drop to 75%;

B, mushroom bag are handled: the remaining bag shape matrix waste material in the plantation back of will pestering is pulverized, and obtains pulverizing the mushroom bag;

C, preparation bacterial classification soil: the mud that the above-mentioned A step is handled and above-mentioned B step processing the pulverizing mushroom wrap after the mode of 1:1 is mixed by volume; Spray complex ferment bacterial classification liquid, the laggard aerobe fermentation of acting charitably of mixing, 50 ℃～70 ℃ of leavening temperatures; Time kept 5～7 days, obtained bacterial classification soil;

D, preparation fermentation materials: pulverizing mushroom bag that the mud that the above-mentioned A step is handled and above-mentioned B step handle and C go on foot the bacterial classification soil that obtains and are the mode mixing of 1:1:1 by volume, and obtaining water ratio is 60～65% fermentation materials;

2) dress fermentation materials:

The fermentation materials of preparing in the step 1) is packed in the fermentation unit, the degree of tightness nature, when the dress fermentation materials volume when being fermentation unit volumetrical 4/5～5/6, stop to feed, cover the bung of fermentation unit;

3) ferment system gardens nutrition soil:

Adopt aerobic-anaerobism alternative method with step 2) the fermentation materials ferment process gardens nutrition soil, said aerobic-the anaerobism alternative method in aerobic-anaerobism alternative number of times be three times, aerobic at every turn-anaerobism alternative step is:

1. aerobic, i.e. ventilation earlier, the time is 5min, air flow is 1.4 ~ 2.8m ³(ht) ^-1Stop the supple of gas or steam, the time is 30min again; Repeat aforesaid operations 5 days;

re anaerobic: Stop ventilation 3 days.

2. according to the said method with dewatered sludge ferment system gardens nutrition soil of claim 1, it is characterized in that step 1) C is in the step, said complex ferment bacterial classification liquid is two or more the complex ferment bacterial classification liquid in actinomycetes, bacterium, the fungi.

3. according to the said method of claim 1 with dewatered sludge ferment system gardens nutrition soil; It is characterized in that; Step 1) C is in the step; Said aerobic fermentation is employed in the fermenter and ferments in air with the mode of machine turning; Difference according to leavening temperature; Turning every day 1～4 time, leavening temperature was kept 5～7 days for 50～70 ℃.

4. the method with dewatered sludge ferment system gardens nutrition soil according to claim 1 is characterized in that the concentration expressed in percentage by volume of the gaseous oxygen of the aerobic phase in the said step 3) is 5%～21%; The concentration expressed in percentage by volume of the gaseous oxygen of anaerobic phase is＜5%.

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