Landfilling method for incinerator ash

Abstract

The invention discloses a landfill method for incinerator ash. The landfill method specifically comprises the following steps: (1) pretreatment; (2) sorting and purifying treatment; (3) curing treatment and stabilizing treatment; (4) a landfill site is selected, and the site is leveled; (5) transporting to a landfill site for landfill; and (6) the landfill is monitored and managed regularly, and if abnormal conditions are found, measures are taken in time for treatment and repair. By means of scientific landfill treatment and management measures, safe treatment of incinerator ash and environment protection can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of hazardous waste treatment, and more particularly to a landfill method for incinerator ash. Background Art

[0002] Incinerator ash is solid ash produced by the incineration system. It is mainly produced in the incinerator, flue gas dust collector and waste heat boiler, and is an inevitable by-product of the incineration process. Depending on the composition of the incineration raw materials and the incineration process, the mass of incinerator ash is generally 5%-30% of the total mass before incineration. Incinerator ash contains non-combustible inorganic matter and some unburned combustible organic matter, and its main components are metal or non-metal oxides.

[0003] The research on the treatment, disposal and reuse technology of incinerator ash is of great significance. Many countries have formulated technical policies for ash treatment and disposal based on their national conditions, mainly including tail gas neutralization carbonation method, cement solidification method, melt sintering method and landfill method. Among them, the landfill method refers to the method of sending the incinerator ash to a safe landfill for landfill after simple treatment on site. This is one of the safest and most reliable means of incinerator ash treatment.

[0004] However, my country's incinerator ash treatment technology is still in the stage of exploration and experience accumulation. The harmless disposal of incinerator ash has not received enough attention. There is a lack of incinerator ash harmless treatment processes and equipment with independent intellectual property rights that are in line with national conditions. In economically developed areas, the main method of disposal is to transport to safe landfills for landfill after simple treatment. In some economically underdeveloped areas where there are no conditions for building safe landfills, it is generally disposed of by stacking or transporting to landfills for landfill. In some areas, even in the case of immature technology, the incinerator ash is blindly reused, which is bound to cause a potential secondary pollution crisis.

[0005] Therefore, how to safely landfill incinerator ash is a problem that technical personnel in this field need to solve urgently. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a landfill method for incinerator ash to solve the deficiencies in the prior art. The present invention can achieve safe treatment of incinerator ash and environmental protection through scientific landfill treatment and management measures.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A landfill method for incinerator ash, specifically comprising the following steps:

[0009] (1) pre-treating the incinerator ash to obtain incinerator ash A;

[0010] (2) sorting and purifying the incinerator ash A to obtain the incinerator ash B;

[0011] (3) solidifying and stabilizing the incinerator ash B to obtain incinerator ash C;

[0012] (4) Select a landfill site and level the site;

[0013] (5) transporting the incinerator ash C to a landfill for landfill;

[0014] (6) Regularly monitor and manage landfills. If any abnormal situation is found, timely measures should be taken to deal with and repair it.

[0015] Furthermore, in the above step (1), the pretreatment includes crushing and screening.

[0016] A further beneficial effect of the above method is that the ash produced by the incinerator is subjected to necessary pretreatment, such as crushing and screening, to remove large impurities and materials not suitable for landfill.

[0017] Furthermore, in the above step (2), the separation is gravity separation or magnetic separation.

[0018] A further beneficial effect of the above method is that the physical properties of the various components of the ash are used for sorting, such as gravity sorting, magnetic separation, etc., to separate valuable metals and other recyclable materials. Then, the ash is further purified, such as removing harmful substances such as heavy metals, to ensure environmental safety after landfill.

[0019] Furthermore, in the above step (3), the solidification treatment is cement solidification, asphalt solidification, plastic solidification or lime solidification.

[0020] A further beneficial effect of the above method is that ash containing harmful substances such as heavy metals needs to be solidified and stabilized. Among them, the solidification treatment is to mix the ash with a curing agent to form a solid body, thereby reducing the possibility of harmful substances dissolving. Stabilization treatment is to use chemical agents to react with harmful substances in the ash to make it stable and harmless. The specific selection of curing agents and chemical agents depends on the nature of the ash and the treatment requirements.

[0021] Furthermore, in the above step (4), the landfill is provided with a bottom anti-seepage layer and a slope anti-seepage layer.

[0022] A further beneficial effect of adopting the above method is that a suitable landfill is selected for ash landfilling. The landfill should be equipped with complete environmental protection facilities such as an impermeable layer and a leachate recovery system to prevent the ash from polluting the soil and groundwater.

[0023] Furthermore, the structure of the bottom anti-seepage layer from the waste pile to the base layer is: compacted base layer, 6000g / m 2 Sodium bentonite blanket, 1.0mm HDPE smooth anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth anti-seepage membrane, 600g / m 2 Polypropylene geotextile and 300mm pebble layer.

[0024] Furthermore, the structure of the slope anti-seepage layer from the waste pile to the foundation layer is: compacted foundation layer, cement mortar wall, 1.0mm HDPE double rough surface anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth surface anti-seepage membrane, 600g / m 2 Polypropylene geotextile, 300mm pebble layer and tyres.

[0025] Furthermore, in the above step (5), the landfill speed and height are controlled during the landfill process.

[0026] A further beneficial effect of adopting the above method is to ensure the stability and safety of the landfill.

[0027] Furthermore, in the above step (5), the landfill is covered and compacted.

[0028] A further beneficial effect of adopting the above method is that the exposure and flying of ash are reduced.

[0029] Furthermore, in the above step (6), the monitored indicators include leachate, groundwater and soil.

[0030] A further beneficial effect of adopting the above method is that the landfill is regularly monitored and managed, including monitoring environmental quality indicators such as leachate, groundwater and soil of ash. If any abnormality is found, timely measures should be taken to handle and repair it.

[0031] In the present invention, the saturated permeability coefficient of the natural base layer of the landfill cannot reach 1.0×10 -7cm / s and 5m thickness cannot meet the requirements of anti-seepage, so double artificial lining is selected for anti-seepage. The upper artificial synthetic lining can be made of HDPE film with a thickness of 2.0mm. The lower artificial synthetic lining can be made of HDPE film with a thickness of 1.0mm. The performance indicators of HDPE membrane should meet the design and relevant specifications, and meet the requirements of "High-density polyethylene geomembrane for landfill" (CJ / T234-2006). The technical indicators of sodium-based bentonite pads should meet the requirements of "Sodium-based bentonite waterproof blanket" (JG / T193-2006); the technical indicators of geotextiles meet the requirements of "Geosynthetics Filament Spunbond Needle Punched Nonwoven Geotextiles" (GB / T17639-2008); the technical indicators of geocomposite drainage nets meet the requirements of "Geodetic Drainage Nets for Landfills" (CJT452-2014). In order to protect the artificial synthetic lining on the excavated slope, a layer of sodium bentonite blanket (GCL) is arranged below the layer as an auxiliary anti-seepage facility and as the lower protective layer of the artificial synthetic lining. According to the specifications, a sewage secondary drainage layer must be set between the two layers of artificial synthetic lining. Since the drainage volume of this layer is not large, a composite geotextile drainage net is selected to separate it for the convenience of construction. The composite geotextile drainage net itself has two layers of non-woven geotextiles on the upper and lower surfaces, which can also serve as a protective layer. At the same time, a 663×4.7HDPE perforated pipe is set as a leakage monitoring pipe; the protective layer of the upper HDPE membrane is a composite geotextile drainage grid: the sewage drainage layer is laid on the HDPE membrane protective layer.

[0032] The 0.30m thick bagged gravel and composite drainage geogrid are laid on the anti-seepage layer at the bottom of the field, which can not only guide the leachate, but also prevent the damage to the geomembrane during construction and operation. The drainage pipe at the bottom of the field: buried at the bottom of the pebble diversion layer, collects and drains the leachate into the regulating tank. The drainage pipe is arranged at the bottom of the field, using DN200HDPE (high-density polyethylene) porous pipes, and the main slope of the excavation bottom is reduced by 1% to ensure the rapid discharge of sewage. The sewage collected by the drainage pipe at the bottom of the field is discharged into the leachate regulating tank and then reused in the stabilization and curing workshop. In order to timely monitor, collect and export sewage caused by the damage of the main anti-seepage membrane at the bottom of the landfill, a sewage monitoring and collection system is set up between the main anti-seepage membrane and the secondary anti-seepage membrane at the bottom of the landfill, that is, a secondary sewage collection system is set up between the main and secondary anti-seepage membranes at the bottom of the landfill; a composite geotextile drainage net is used for collection, and 663×4.7 HDPE pipes are used to export it downstream, and a leakage detection well is set up outside the landfill, and the leakage detection pipe is connected to the detection well. The secondary sewage collection system is inspected regularly. If there is leakage, the main anti-seepage membrane is damaged, and measures need to be taken according to the situation. The air guide shaft is used, and the air guide shaft spacing is 50m with reference to the experience of similar landfills that have been in operation. According to the geological survey data collected in the surrounding areas, the surrounding groundwater level is buried more than 9m deep. Groundwater will not damage the anti-seepage layer of this landfill, so this project does not have groundwater drainage and treatment facilities, but sets up groundwater monitoring wells to monitor groundwater regularly.

[0033] The landfill area adopts the operation process of layered paving, round-trip rolling, and daily covering. The waste residue from the workshop is unloaded to the designated operation unit via the access road, and then paved and rolled by crawler bulldozers, and finally covered. Operation area: The waste operation unit is the basic structural unit of the entire landfill area. In order to facilitate centralized operations and reduce the coverage area, combined with the landfill terrain, its width should be set as narrow as possible, but it should also be convenient for transport vehicles to unload, and a certain passage should be left. When the amount of hazardous waste changes due to solidification production or other arrangements are required, the operation area can be appropriately increased; Operation method: For waste from the solidification station, after identification to meet the entry conditions, it is transported to the designated unit for paving. If the moisture content is relatively high (non-rainy season), it is difficult to directly use the compaction machine, and the compaction effect is not ideal. Therefore, it can be stacked in the operation unit for 2 to 3 days, making full use of the large evaporation in the area to reduce its moisture content. When appropriate, it can be turned over mechanically or manually under protective conditions for several times, and rolling can be started after the moisture content is reduced. During the whole process, attention should be paid to weather changes at any time, so as to allow the water in the waste pile to evaporate as much as possible, and to prevent rainfall outside the landfill from directly entering the landfill waste residue. The waste residue that enters the landfill later is unloaded on the surface of the pile that has been piled and compacted, and the steps are the same as before.

[0034] It can be seen from the above technical solution that compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1. Reduce environmental pollution: The present invention can isolate and fix harmful substances in the incinerator ash through landfill treatment, thereby reducing its pollution to the soil, groundwater and air.

[0036] 2. Resource recovery and utilization: The present invention sorts and purifies the incinerator ash before landfilling, and can recover valuable substances such as metals, thereby realizing resource reuse.

[0037] 3. Saving land resources: The present invention selects a suitable landfill site for the landfill of incinerator ash, which can make full use of land resources and avoid the incinerator ash occupying a large amount of precious land resources.

[0038] 4. Ensure public safety: The present invention can ensure that the incinerator ash will not cause harm to the surrounding environment and residents through strict landfill treatment and management measures, thereby ensuring public safety. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] The landfill method of incinerator ash specifically comprises the following steps:

[0042] (1) crushing and screening the incinerator ash to remove large impurities and materials not suitable for landfill, thereby obtaining incinerator ash A;

[0043] (2) gravity sorting the incinerator ash A to separate valuable metals and other recyclable materials, and then purifying the incinerator ash to remove heavy metals to obtain incinerator ash B;

[0044] (3) subjecting the incinerator ash B to cement solidification and stabilization treatment to obtain the incinerator ash C;

[0045] (4) Select a landfill site and level the site;

[0046] Among them, the landfill is equipped with a bottom anti-seepage layer and a slope anti-seepage layer;

[0047] The structure of the bottom anti-seepage layer from the waste pile to the base layer is: compacted base layer, 6000g / m 2Sodium bentonite blanket, 1.0mm HDPE smooth anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth anti-seepage membrane, 600g / m 2 Polypropylene geotextile and 300mm pebble layer;

[0048] The structure of the slope anti-seepage layer from the waste pile to the foundation layer is: compacted foundation layer, cement mortar wall, 1.0mm HDPE double rough surface anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth surface anti-seepage membrane, 600g / m 2 Polypropylene geotextile, 300mm pebble layer and tires;

[0049] (5) The incinerator ash C is transported to a landfill for landfilling. During the landfilling process, the landfilling speed and height are controlled to ensure the stability and safety of the landfill. After landfilling, the ash is covered and compacted to reduce the exposure and flying of the ash;

[0050] (6) Regularly monitor and manage the landfill, including monitoring the leachate, groundwater and soil of the ash. If any abnormality is found, timely measures should be taken to treat and repair it.

[0051] Example 2

[0052] The landfill method of incinerator ash specifically comprises the following steps:

[0053] (1) crushing and screening the incinerator ash to remove large impurities and materials not suitable for landfill, thereby obtaining incinerator ash A;

[0054] (2) gravity sorting the incinerator ash A to separate valuable metals and other recyclable materials, and then purifying the incinerator ash to remove heavy metals to obtain incinerator ash B;

[0055] (3) subjecting the incinerator ash B to asphalt solidification and stabilization treatment to obtain incinerator ash C;

[0056] (4) Select a landfill site and level the site;

[0057] Among them, the landfill is equipped with a bottom anti-seepage layer and a slope anti-seepage layer;

[0058] The structure of the bottom anti-seepage layer from the waste pile to the base layer is: compacted base layer, 6000g / m 2 Sodium bentonite blanket, 1.0mm HDPE smooth anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth anti-seepage membrane, 600g / m 2 Polypropylene geotextile and 300mm pebble layer;

[0059] The structure of the slope anti-seepage layer from the waste pile to the foundation layer is: compacted foundation layer, cement mortar wall, 1.0mm HDPE double rough surface anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth surface anti-seepage membrane, 600g / m 2 Polypropylene geotextile, 300mm pebble layer and tires;

[0060] (5) The incinerator ash C is transported to a landfill for landfilling. During the landfilling process, the landfilling speed and height are controlled to ensure the stability and safety of the landfill. After landfilling, the ash is covered and compacted to reduce the exposure and flying of the ash;

[0061] (6) Regularly monitor and manage the landfill, including monitoring the leachate, groundwater and soil of the ash. If any abnormality is found, timely measures should be taken to treat and repair it.

[0062] Example 3

[0063] The landfill method of incinerator ash specifically comprises the following steps:

[0064] (1) crushing and screening the incinerator ash to remove large impurities and materials not suitable for landfill, thereby obtaining incinerator ash A;

[0065] (2) subjecting the incinerator ash A to magnetic separation to separate valuable metals and other recyclable materials, and then subjecting it to purification treatment to remove heavy metals to obtain incinerator ash B;

[0066] (3) subjecting the incinerator ash B to plastic solidification and stabilization treatment to obtain incinerator ash C;

[0067] (4) Select a landfill site and level the site;

[0068] Among them, the landfill is equipped with a bottom anti-seepage layer and a slope anti-seepage layer;

[0069] The structure of the bottom anti-seepage layer from the waste pile to the base layer is: compacted base layer, 6000g / m 2 Sodium bentonite blanket, 1.0mm HDPE smooth anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth anti-seepage membrane, 600g / m 2 Polypropylene geotextile and 300mm pebble layer;

[0070] The structure of the slope anti-seepage layer from the waste pile to the foundation layer is: compacted foundation layer, cement mortar wall, 1.0mm HDPE double rough surface anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth surface anti-seepage membrane, 600g / m 2 Polypropylene geotextile, 300mm pebble layer and tires;

[0071] (5) The incinerator ash C is transported to a landfill for landfilling. During the landfilling process, the landfilling speed and height are controlled to ensure the stability and safety of the landfill. After landfilling, the ash is covered and compacted to reduce the exposure and flying of the ash;

[0072] (6) Regularly monitor and manage the landfill, including monitoring the leachate, groundwater and soil of the ash. If any abnormality is found, timely measures should be taken to treat and repair it.

[0073] Performance Testing

[0074] The incinerator ash of a batch of domestic waste was randomly divided into 3 parts, which were treated according to the methods of Examples 1-3, and then entered the independent landfill area of ​​the landfill for landfill disposal. The leachate pollutants of the incinerator ash C before entering the landfill and the water pollutants directly discharged from the discharge port of the landfill leachate treatment facility after landfill were detected according to the detection standards and detection methods of the "Pollution Control Standards for Domestic Waste Landfills" (GB 16889-2024), and the average values ​​were taken.

[0075] The results are shown in Tables 1 and 2.

[0076] Table 1 Average detection values ​​of pollutants in leachate of Examples 1-3

[0077] Serial number Pollutant Project Control limit (mg / L) Average detection value (mg / L) 1 Total Mercury 0.05 0.01 2 Total Copper 40 2 3 Total Zinc 100 5 4 Total Lead 0.25 0.02 5 Total Cadmium 0.15 0.01 6 Total Beryllium 0.02 Not detected 7 Total Barium 25 1 8 Total Nickel 0.5 0.1 9 Total Arsenic 0.3 0.08 10 Total Chromium 4.5 0.2 11 Hexavalent Chromium 1.5 0.1 12 Total Selenium 0.1 0.03

[0078] Table 2 Average detection values ​​of water pollutants directly discharged from Examples 1-3

[0079] Serial number Pollutant Project Emission limit (mg / L) Average detection value (mg / L) 1 Chroma 40 3 2 <![CDATA[Chemical Oxygen Demand (COD Cr )]]> 100 12 3 <![CDATA[Biochemical Oxygen Demand (BOD 5 )]]> 30 2 4 Suspended matter 30 1 5 Total Nitrogen 40 0.9 6 Ammonia nitrogen 25 0.7 7 Total Phosphorus 3 0.1 8 Fecal coliform count / (pieces / L) 10000 152 9 Total Copper 0.5 0.06 10 Total Zinc 1 0.04 11 Total Mercury 0.001 0.0003 12 Total Cadmium 0.01 0.005 13 Total Chromium 0.1 0.07 14 Hexavalent Chromium 0.05 0.01 15 Total Arsenic 0.1 0.02 16 Total Lead 0.1 0.01 17 Total Beryllium 0.002 Not detected 18 Total Nickel 0.05 0.01

[0080] It can be seen from Table 1-2 that the average detection values ​​of the municipal solid waste incinerator ash treated and landfilled by the methods of Examples 1-3, the leachate pollutants of the incinerator ash C before entering the site, and the water pollutants directly discharged from the discharge port of the landfill leachate treatment facility after landfilling are significantly lower than the control limits and emission limits, and all comply with the "Pollution Control Standards for Municipal Solid Waste Landfills" (GB 16889-2024).

[0081] The above experiments show that the present invention can achieve safe treatment of incinerator ash and environmental protection through scientific landfill treatment and management measures.

[0082] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A landfill method for incinerator ash, characterized in that: The specific steps include: (1) pre-treating the incinerator ash to obtain incinerator ash A; (2) sorting and purifying the incinerator ash A to obtain the incinerator ash B; (3) solidifying and stabilizing the incinerator ash B to obtain incinerator ash C; (4) Select a landfill site and level the site; (5) transporting the incinerator ash C to a landfill for landfill; (6) Regularly monitor and manage landfills. If any abnormal situation is found, timely measures should be taken to deal with and repair it.

2. The landfill method of incinerator ash according to claim 1, characterized in that: In step (1), the pretreatment includes crushing and screening.

3. The landfill method of incinerator ash according to claim 1, characterized in that: In step (2), the separation is gravity separation or magnetic separation.

4. The landfill method of incinerator ash according to claim 1, characterized in that: In step (3), the solidification treatment is cement solidification, asphalt solidification, plastic solidification or lime solidification.

5. The landfill method of incinerator ash according to claim 1, characterized in that: In step (4), the landfill is provided with a bottom anti-seepage layer and a slope anti-seepage layer.

6. The landfill method of incinerator ash according to claim 5, characterized in that: The structure of the bottom anti-seepage layer from the waste pile to the base layer is: compacted base layer, 6000g / m 2 Sodium bentonite blanket, 1.0mm HDPE smooth anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth anti-seepage membrane, 600g / m 2 Polypropylene geotextile and 300mm pebble layer.

7. The landfill method of incinerator ash according to claim 5, characterized in that: The structure of the slope anti-seepage layer from the waste pile to the foundation layer is: compacted foundation layer, cement mortar wall, 1.0mm HDPE double rough surface anti-seepage membrane, geocomposite drainage net, 2mm HDPE smooth surface anti-seepage membrane, 600g / m 2 Polypropylene geotextile, 300mm pebble layer and tyres.

8. The landfill method of incinerator ash according to claim 1, characterized in that: In step (5), the landfill speed and height are controlled during the landfill process.

9. The landfill method of incinerator ash according to claim 1, characterized in that: In step (5), the landfill is covered and compacted.

10. The landfill method of incinerator ash according to claim 1, characterized in that: In step (6), the monitored indicators include leachate, groundwater and soil.