CN115872792A - Method for controlling greenhouse gas emission in sludge composting process by utilizing heat drying sludge deep dehydration technology - Google Patents
Method for controlling greenhouse gas emission in sludge composting process by utilizing heat drying sludge deep dehydration technology Download PDFInfo
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- CN115872792A CN115872792A CN202211609368.9A CN202211609368A CN115872792A CN 115872792 A CN115872792 A CN 115872792A CN 202211609368 A CN202211609368 A CN 202211609368A CN 115872792 A CN115872792 A CN 115872792A
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- 239000010802 sludge Substances 0.000 title claims abstract description 119
- 238000009264 composting Methods 0.000 title claims abstract description 68
- 238000000034 method Methods 0.000 title claims abstract description 67
- 230000008569 process Effects 0.000 title claims abstract description 46
- 238000001035 drying Methods 0.000 title claims abstract description 37
- 239000005431 greenhouse gas Substances 0.000 title claims abstract description 30
- 230000018044 dehydration Effects 0.000 title claims abstract description 18
- 238000006297 dehydration reaction Methods 0.000 title claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000002361 compost Substances 0.000 abstract description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 12
- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical compound [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 abstract description 10
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 6
- 239000001272 nitrous oxide Substances 0.000 abstract description 5
- 230000000694 effects Effects 0.000 abstract description 4
- 239000003337 fertilizer Substances 0.000 abstract description 4
- 239000005416 organic matter Substances 0.000 abstract description 2
- 238000011899 heat drying method Methods 0.000 abstract 1
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 26
- 229910002092 carbon dioxide Inorganic materials 0.000 description 13
- 239000001569 carbon dioxide Substances 0.000 description 13
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 8
- YYRMJZQKEFZXMX-UHFFFAOYSA-L calcium bis(dihydrogenphosphate) Chemical compound [Ca+2].OP(O)([O-])=O.OP(O)([O-])=O YYRMJZQKEFZXMX-UHFFFAOYSA-L 0.000 description 5
- 229910000389 calcium phosphate Inorganic materials 0.000 description 5
- 235000019691 monocalcium phosphate Nutrition 0.000 description 5
- 239000000654 additive Substances 0.000 description 4
- 238000005273 aeration Methods 0.000 description 4
- 238000004062 sedimentation Methods 0.000 description 4
- 238000010792 warming Methods 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- QGBSISYHAICWAH-UHFFFAOYSA-N dicyandiamide Chemical compound NC(N)=NC#N QGBSISYHAICWAH-UHFFFAOYSA-N 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- 235000003140 Panax quinquefolius Nutrition 0.000 description 1
- 240000005373 Panax quinquefolius Species 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000003203 everyday effect Effects 0.000 description 1
- 210000003608 fece Anatomy 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000010871 livestock manure Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
- Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
- Y02A40/20—Fertilizers of biological origin, e.g. guano or fertilizers made from animal corpses
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/40—Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse
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- Fertilizers (AREA)
- Treatment Of Sludge (AREA)
Abstract
A method for controlling greenhouse gas emission in a sludge composting process by utilizing a heat drying sludge deep dehydration technology belongs to the technical field of sludge composting. It aims to solve the problems of high water content of the existing sludge and CO in the composting process 2 、CH 4 And N 2 The release of O causes greenhouse effect, and the release of nitrous oxide can reduce the fertilizer efficiency of the compost product. The method comprises the following steps: carrying out heat drying treatment on the sludge to obtain heat-dried sludge with the water content of below 70%, and then carrying out aerobic composting treatment. Compared with sludge compost which is not subjected to heat drying, the invention has the advantages that the sludge compost is subjected to heat drying, and CO is generated in the composting process 2 The discharge amount is remarkably reduced by 25.65%; CH in the composting process 4 The release amount is obviously reduced by 94.05 percent, and N is 2 The release amount of O is obviously reduced by 49.32 percent, the organic matter content of the sludge in unit volume is improved while the sludge volume is reduced, the loss of nitrogen is controlled, and the fertilizer efficiency is increased. Heat drying method in the inventionThe sludge deep dehydration technology is suitable for controlling the greenhouse gas emission in the sludge composting process.
Description
Technical Field
The invention belongs to the technical field of sludge composting; in particular to a method for controlling greenhouse gas emission in the sludge composting process by utilizing a heat drying sludge deep dehydration technology.
Background
Carbon dioxide (CO) is generated in the aerobic composting process of sludge 2 ) Methane (CH) 4 ) And nitrous oxide (N) 2 O) greenhouse gases. CH (CH) 4 As an important source of greenhouse gases, the potential for warming is about CO 2 28 times higher than that of the conventional diesel engine, and the emission of the diesel engine is not controlled, so that the global warming is increased. N is a radical of 2 The monomolecular warming potential of O is CO 2 296 times of the total nitrogen loss in the composting process, the greenhouse effect is more obvious, the influence on global warming is great, the total nitrogen loss accounts for 0 to 10 percent in the composting process, and the nitrogen loss is one of main forms in the composting process, so that N must be concerned in the composting process 2 O emission and corresponding measures are taken to reduce N 2 And (4) generation of O.
Compared with domestic research on the technical research of controlling and reducing greenhouse gas emission in the sludge composting processMostly by adjusting the composting process parameters and adding exogenous additives and the like. Studies have shown that the reduction of greenhouse gas emissions during composting is effective when the pile humidity is 65%, the aeration rate is 0.48L/(kg dm min) and the initial C/N is 2 (Frank Schuchardt. Effect of C/N ratio, aeration ratio and mobility content on ammonia and greenhouse gas emission reduction. J. Sub.]Journal of Environmental Sciences,2011,23 (10): 1754-1760). Rogover et al added a nitrogen-retaining agent, calcium superphosphate, in a composting experiment to make CH available during composting 4 The emission is reduced by 27.7 percent, and N is simultaneously added 2 The O emission is reduced by 62.9 percent, the total GHG emission equivalent is reduced by 30 percent (Royi, lizhou, frank Schuchardt, wangkun, jiangtao, ronwai. Calcium superphosphate additive has the function of reducing the emission of greenhouse gases and ammonia gas in pig manure compost [ J]Journal of agricultural engineering, 2012,28 (22): 235-242). Research shows that when the adding amount of the calcium superphosphate is 7 percent of the wet weight of a pile body, CH is generated in the sludge composting process 4 The cumulative yield is reduced by 89.2 percent, and CH 4 The cumulant is reduced by 68.2 percent (Chengui Hua, zenghuan, linzhijun, greenhouse gas release and detection and reduction control measures in the process of sludge composting by dehydration [ J]Science, technology and engineering, 2020,20 (06): 2500-2506.). On the basis of adding 5 percent of calcium superphosphate, the addition of 5 percent of dicyandiamide serving as a nitrification inhibitor can also effectively reduce the emission of greenhouse gases in the sludge composting process (chih, yuanjing, lizhou, he Sheng, zhangxi, the combination of calcium superphosphate and dicyandiamide reduces the greenhouse gases and NH in the sludge composting process 3 Discharge [ J]Agricultural engineering journal, 2017,33 (06): 199-206).
However, the existing methods or experiments for reducing the release of greenhouse gases in the composting process basically increase the composting cost to a certain extent by adding exogenous additives, and the inorganic salt ion additives can increase the salinity of the compost products and further influence the quality of the compost products.
Disclosure of Invention
The invention aims to solve the problems that the existing sludge has high water content and CO is generated in the composting process 2 Methane (CH) 4 ) And nitrous oxide (N) 2 O) greenhouse gas release leads to the greenhouse effect with simultaneous oxidation of nitrousThe release of nitrogen can reduce the fertilizer efficiency of compost products, and provides a method for controlling greenhouse gas emission in the sludge composting process by utilizing a heat drying sludge deep dehydration technology.
A method for controlling greenhouse gas emission in a sludge composting process by utilizing a heat drying sludge deep dehydration technology is realized by the following steps:
1. carrying out heat drying treatment on the sludge to obtain heat-dried sludge with the water content of below 70%;
2. and (3) carrying out aerobic composting treatment on the heat-dried sludge to finish the method.
The invention provides a method for controlling greenhouse gas emission in a sludge composting process by utilizing a heat drying sludge deep dehydration technology, compared with sludge composting which is not subjected to heat drying, the heat drying sludge composting has the advantages that the carbon dioxide emission in the composting process is obviously reduced by 25.65 percent; the release amount of methane in the composting process is obviously reduced by 94.05 percent, the release amount of nitrous oxide is obviously reduced by 49.32 percent, and greenhouse gases released in the composting process are effectively reduced, so that the pollution to the atmospheric environment caused by the gases released in the composting process is controlled.
The sludge heat drying technology can reduce the water content of the sludge to be below 70 percent, improve the organic matter content of the sludge in unit volume while reducing the volume of the sludge, carry out composting after the sludge is heat dried, and realize the harmless and resource treatment of the sludge to a great extent. Meanwhile, the invention effectively reduces N 2 The generation of O controls the loss of nitrogen in the composting process and increases the fertilizer efficiency of the composting product.
The deep dehydration technology of the heat drying sludge is suitable for controlling the emission of greenhouse gases in the sludge composting process.
Drawings
FIG. 1 shows CO generated in the process of concentrating dewatered sludge and thermally drying sludge compost in the example 2 The release variation graph is shown in which the value of 9632represents concentrated dewatered sludge, the value of 9679represents heat-dried sludge;
FIG. 2 is a diagram illustrating the process of concentrating dewatered sludge and thermally drying sludge in the composting process according to the embodiment 4 Release Change Curve, wherein, 9632denotes condensed dewatered sludge, 9679denotes hot dryingSludge is dissolved;
FIG. 3 shows the example of the concentration of N in the process of sludge dewatering and sludge composting by heat drying 2 O-release change curve diagram, wherein, 9632represents condensed and dehydrated sludge, 9679represents heat drying sludge.
Detailed Description
The technical solution of the present invention is not limited to the following specific embodiments, but includes any combination of the specific embodiments.
The first embodiment is as follows: the embodiment of the method for controlling greenhouse gas emission in the sludge composting process by utilizing the deep dehydration technology of the heat-dried sludge is realized by the following steps:
1. carrying out heat drying treatment on the sludge to obtain heat-dried sludge with the water content of below 70%;
2. and (3) carrying out aerobic composting treatment on the heat-dried sludge to finish the method.
In this embodiment, the moisture content is a percentage of the mass of moisture in the heat-dried sludge to the oven-dried mass of the heat-dried sludge.
In the embodiment, the heat drying treatment adopts a heat drying device; when the steam pressure in the boiler reaches 18bar, the heat drying equipment starts the steam to preheat a steam pipeline; when the temperature of the preheated steam pipeline reaches 65 ℃, an isolation valve is opened to heat the internal heat exchanger; when the temperature of the built-in heat exchanger reaches above 70 ℃, sludge is fed to prepare the heat drying sludge with the water content below 70 percent.
The second embodiment is as follows: the present embodiment is different from the first embodiment in that the water content of the sludge in the first step is 65% to 99.99%. Other steps and parameters are the same as those in the first embodiment.
The third concrete implementation mode: the difference between the embodiment and the first embodiment is that the heat-dried sludge in the second step can be mixed with an organic conditioner for aerobic composting. Other steps and parameters are the same as those in the first embodiment.
The fourth concrete implementation mode: the third difference between the embodiment and the specific embodiment is that the mass ratio of the heat drying sludge to the organic conditioner is (2-10): 1. Other steps and parameters are the same as those in the third embodiment.
The fifth concrete implementation mode: the fourth difference between the present embodiment and the specific embodiment is that the mass ratio of the heat-dried sludge to the organic conditioner is 5. Other steps and parameters are the same as those in the fourth embodiment.
The beneficial effects of the present invention are demonstrated by the following examples:
example (b):
a method for controlling greenhouse gas emission in a sludge composting process by utilizing a heat drying sludge deep dehydration technology is realized by the following steps:
1. carrying out heat drying treatment on the sludge to obtain heat-dried sludge with the water content of below 70%;
2. and (3) carrying out aerobic composting treatment on the heat-dried sludge to finish the method.
In the embodiment, the sludge is municipal dewatered sludge with the water content of 80%, and is mixed sludge of a primary sedimentation tank and a secondary sedimentation tank after being treated by a concentration dewatering process, and is taken from a littoral sewage treatment plant in Harbin city.
The municipal dewatered sludge is further dewatered by adopting fluidized bed heat drying equipment, and the method comprises the following steps: starting a boiler, when the steam pressure in the boiler reaches 18bar, starting the steam, and preheating a steam pipeline for 15min; when the temperature of the preheated steam pipeline reaches 65 ℃, an isolation valve is opened to heat a heat exchanger in the fluidized bed heat drying machine; when the temperature of the internal heat exchanger reaches 80 ℃, the sludge is sent into municipal dewatered sludge to prepare heat-dried sludge with the water content of 61.53 +/-3.33 percent.
In the embodiment, the heat-dried sludge is mixed with an organic conditioner and then aerobic composting treatment is carried out; the mass ratio of the heat-dried sludge to the organic conditioner is 5.
The organic conditioning agent described in this example was wood chips with a diameter of 1 cm.
The aerobic composting treatment in this example: continuous positive blast aeration is adopted in the composting process, and the aeration quantity is 0.2-1.0L/min/kg of composting raw materials.
The aerobic composting treatment in this example: in the composting process, the pile is turned once every day in the high-temperature period, and the pile is turned once every week in the cooling period and the decomposing period.
Control group: concentrated dewatered sludge with water content of 85.01 +/-0.04% is mixed sludge of a primary sedimentation tank and a secondary sedimentation tank after treatment of the concentrated dewatering process and is taken from a littoral sewage treatment plant in Harbin city; aerobic composting conditions were the same as in this example.
As a result: in the present example and the control group, the physicochemical properties of the starting materials are shown in Table 1, and after aerobic composting, carbon dioxide (CO) was added 2 ) Methane (CH) 4 ) Nitrous oxide (N) 2 O) the dynamic change of the emission is respectively shown in figures 1-3, and the heat drying treatment of the sludge can effectively reduce the release of greenhouse gases in the composting process. CO of concentrated and dehydrated sludge and heat-dried sludge on the fifth day 2 The concentrations are 46290ppm and 25219ppm respectively, and CO in the compost body starts from the 6 th day of composting 2 The concentration is also gradually reduced, and CO is generated after 30 days of composting 2 The concentration was maintained at a steady level. Compared with concentrated sludge compost, the sludge compost total CO after heat drying treatment 2 The release amount is reduced by 25.65%. CH released from condensed and dewatered sludge 4 The highest concentration value is 826.73ppm, and CH generated by the sludge is thermally dried 4 The highest concentration is only 5ppm, compared with the concentrated sludge compost, the total CH of the sludge compost after heat drying treatment 4 The release amount is reduced by 94.05%. N for thickening dewatered sludge and heat-dried sludge 2 The peak values of O emission appear on the 4 th day of the compost heating period and are respectively 4.00ppm and 0.46ppm, and the total N of the sludge compost after the heat drying treatment 2 The O release amount is reduced by 49.32 percent compared with the concentrated sludge compost. In summary, the deep dehydration technology of the sludge by heat drying can effectively control the emission of greenhouse gases in the sludge composting process.
TABLE 1 physicochemical Properties of concentrated dewatered sludge and Heat-dried sludge
Claims (5)
1. A method for controlling greenhouse gas emission in a sludge composting process by utilizing a heat drying sludge deep dehydration technology is characterized by comprising the following steps:
1. carrying out heat drying treatment on the sludge to obtain heat-dried sludge with the water content of below 70%;
2. and (3) carrying out aerobic composting treatment on the heat-dried sludge to finish the method.
2. The method for controlling the emission of greenhouse gases in the sludge composting process by utilizing the deep dehydration technology of the heat drying sludge as claimed in claim 1, wherein the water content of the sludge in the first step is 65-99.99%.
3. The method for controlling greenhouse gas emission in the sludge composting process by using the deep dehydration technology of the heat-dried sludge as claimed in claim 1, wherein the heat-dried sludge in the second step can be mixed with an organic conditioner for aerobic composting.
4. The method for controlling greenhouse gas emission in the sludge composting process by utilizing the deep dehydration technology of the heat-dried sludge as claimed in claim 3, wherein the mass ratio of the heat-dried sludge to the organic conditioner is (2-10): 1.
5. The method for controlling greenhouse gas emission in the sludge composting process by utilizing the deep dehydration technology of the heat-dried sludge as claimed in claim 4, wherein the mass ratio of the heat-dried sludge to the organic conditioner is 5.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211609368.9A CN115872792A (en) | 2022-12-14 | 2022-12-14 | Method for controlling greenhouse gas emission in sludge composting process by utilizing heat drying sludge deep dehydration technology |
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| CN202211609368.9A CN115872792A (en) | 2022-12-14 | 2022-12-14 | Method for controlling greenhouse gas emission in sludge composting process by utilizing heat drying sludge deep dehydration technology |
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| CN202211609368.9A Pending CN115872792A (en) | 2022-12-14 | 2022-12-14 | Method for controlling greenhouse gas emission in sludge composting process by utilizing heat drying sludge deep dehydration technology |
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- 2022-12-14 CN CN202211609368.9A patent/CN115872792A/en active Pending
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