Sewage zero discharge system for waste incineration power plant

Abstract

The utility model discloses a waste incineration power plant sewage zero discharge system, which comprises a leachate treatment system, a production wastewater treatment system and a recycling system, the leachate treatment system is communicated with the recycling system, and the leachate treatment system, the production wastewater treatment system and the recycling system are communicated pairwise. The landfill leachate treatment system is used for treating landfill leachate, flushing water of a discharging hall and a leachate pipeline, domestic sewage and initial rainwater; the production wastewater treatment system is used for treating circulating water and sewage, and the recycling system is responsible for conveying water to each production water consumption point. The treatment is more targeted, the treatment effect is higher, the treatment cost of sewage and wastewater is reduced, the amount of concentrated liquid can be reduced by adopting the material membrane system and the DTRO system, and stable combustion of the incinerator is guaranteed. The co-processing capability of the whole waste incineration power plant is fully exerted, the reuse rate of water is improved, the water consumption is reduced, and the effect of zero discharge of sewage is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of circulating water treatment in garbage dumps, in particular to a wastewater zero-discharge system for garbage incineration power plants. Background Art

[0002] Typically, a large amount of wastewater is generated during the operation of a waste incineration power plant, including circulating wastewater from turbine and generator cooling water; domestic sewage from factory employees; initial rainwater from roads, transport trestles, and weighbridges within the plant area, which are prone to pollution from garbage truck transportation; concentrated water from desalination equipment; and leachate from waste storage. As shown below, the volume and quality of different wastewater streams from a domestic waste incineration power plant vary significantly:

[0003] Landfill leachate, water volume: 190m³ / d, COD Cr : 70000mg / L, BOD5: 30000mg / L, SS: 20000mg / L, NH3-N: 2000mg / L;

[0004] Initial rainwater, water volume: 150m³ / d, COD Cr :500mg / L,BOD5:300mg / L,SS:370mg / L,NH3-N:40mg / L;domestic sewage, water volume: 9m³ / d, COD Cr : 450mg / L, BOD5: 200mg / L, SS: 250mg / L, NH3-N: 35mg / L;

[0005] Concentrated water, water volume: 25m³ / d, TDS: 3500 mg / L, Cl - :600 mg / L;

[0006] Circulating cooling water wastewater, water volume: 230m³ / d, conductivity 3200 uS.cm - , turbidity: 15, alkalinity: 300mg / L, hardness 1200mg / L, pH≤8.5.

[0007] For these sewage and wastewaters with large differences in water volume and quality, many projects collect them and then uniformly treat the leachate. The water quality meets the heavy metal and water volume standards specified in the "Standard for Pollution Control of Municipal Waste Incineration" GB18485-2014, and other indicators meet the third-level emission standards of the "Integrated Sewage Discharge Standard" GB8978-1996 and are included in the municipal sewage treatment plant for subsequent treatment.

[0008] This treatment method not only fails to fully utilize wastewater, but also increases the water treatment costs of waste-to-energy plants. Wastewater should be carefully differentiated according to its water quality characteristics, and different treatment processes should be adopted. Treated wastewater should be reused according to its water quality. Advanced water treatment processes should also be used to reduce the amount of wastewater generated during the water treatment process, fully utilizing the wastewater generated, and achieving zero wastewater discharge from waste-to-energy plants, thereby achieving water conservation.

[0009] Therefore, a waste incineration power plant wastewater zero discharge system is provided to solve the above problems. Summary of the Invention

[0010] The technical problem to be solved by the present invention is that existing waste incineration power plants generally treat all wastewater in a unified manner and discharge it only after it meets the standards. This treatment method has low wastewater utilization efficiency and high treatment costs. Therefore, a waste incineration power plant wastewater zero discharge system is provided, which includes:

[0011] A leachate treatment system, a production wastewater treatment system and a reuse system, wherein the leachate treatment system and the reuse system are connected, and the leachate treatment system, the production wastewater treatment system and the reuse system are connected in pairs;

[0012] The leachate treatment system includes a first regulating tank, an anaerobic UASB, a secondary AO, a UF system, a sludge thickening tank, an RO system, a material membrane system, a reverse osmosis system and a DTRO system; the first regulating tank and the anaerobic UASB, the secondary AO, the UF system, the RO system and the reverse osmosis system are sequentially connected, the sludge in the first regulating tank and the secondary AO are transported to the sludge thickening tank, and the supernatant in the sludge thickening tank is returned to the secondary AO through a pipeline; the sludge thickening tank is also used to concentrate the sludge generated by the production wastewater treatment system, The secondary AO directly receives flushing water from the unloading hall, leachate pipeline, domestic sewage and initial rainwater. The concentrated water end of the RO system is connected to the material membrane system, the secondary concentrated water end of the material membrane system is connected to the secondary AO, the primary concentrated water end of the material membrane system is connected to the reuse system, and the clear liquid end of the material membrane system is connected to the reverse osmosis system; the concentrated water end of the reverse osmosis system is connected to the DTRO system, and the water outlet end of the reverse osmosis system is connected to the reuse system; the concentrated water end of the DTRO system is connected to the reuse system; and the clear liquid end of the DTRO system is connected to the reuse system.

[0013] Furthermore, it also includes a sludge dewatering mechanism, the filtrate of the sludge dewatering mechanism is returned to the secondary AO through a pipeline, and the dehydrated sludge in the sludge dewatering mechanism is sent to an external incinerator for incineration.

[0014] Furthermore, the production wastewater treatment system includes a second regulating tank, a coagulation flotation tank, and a sand filter. The water inlet of the second regulating tank is connected to the circulating water sewage, and the outlet of the second regulating tank is connected to the coagulation flotation tank. The sludge generated by the coagulation flotation tank is sent to the sludge thickening tank. The coagulation flotation tank is also connected to the sand filter.

[0015] Furthermore, the reuse system includes a concentrated water back-spray system and a cooling tower circulating water reuse system; the cooling tower circulating water reuse system is connected to the reverse osmosis system and the clear liquid end of the DTRO system, and the concentrated water back-spray system is also connected to the primary concentrated water end of the material membrane system and the concentrated water end of the DTRO system.

[0016] Furthermore, the reuse system also includes a water system for flue gas purification mechanism, feeding hopper and chute, boiler room, flue gas purification room flushing, slag discharger, and grate slag conveyor; the water output from the sand filter is pumped to the water points in the flue gas purification, feeding hopper and chute, boiler room, flue gas purification room flushing, slag discharger and grate slag conveyor, and also includes chemical water concentrate, which is directly used for water use in the slag discharger and grate slag conveyor.

[0017] The implementation of this utility model has the following beneficial effects:

[0018] 1. This new waste incineration power plant zero-discharge system distinguishes wastewater based on its different water quality characteristics, primarily categorizing it into four types: landfill leachate; unloading hall, leachate pipe flushing, domestic sewage, and initial rainwater; circulating water drainage; and chemical wastewater concentrate. Separate treatment systems are then deployed for each of these water quality types: a leachate treatment system and a production wastewater treatment system. This results in more targeted treatment, improved effectiveness, and reduced wastewater treatment costs.

[0019] 2. The use of a material membrane system and DTRO system can significantly reduce the amount of concentrated liquid, and the remaining small amount of concentrated water can be sprayed back. Since most of the wastewater has been fully utilized, the remaining small amount of concentrated water sprayed back will not cause the incinerator furnace temperature to drop too low, ensuring stable combustion in the incinerator.

[0020] 3. Depending on the water quality requirements of the plant's water-using equipment, some wastewater can be reused without treatment. For example, wastewater from chemical treatment can be directly used in the slag discharger and grate slag conveyor. Circulating water wastewater, after simple treatment, can be used for plant-wide water-using equipment. Treated wastewater that meets standards is reused as circulating water in the cooling tower, achieving zero wastewater discharge for the entire waste-to-energy plant. Sludge generated during the water treatment process is incinerated in the boiler, achieving zero sludge discharge. This fully utilizes the co-processing capabilities of the entire waste-to-energy plant, increases water reuse, and reduces water consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural diagram of the utility model. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention. Example

[0023] Please refer to the instruction manual Figure 1 This embodiment provides a waste incineration power plant wastewater zero discharge system, the waste incineration power plant wastewater zero discharge system comprising:

[0024] The leachate treatment system 1, the production wastewater treatment system 2 and the reuse system 3 are connected, and the leachate treatment system 1, the production wastewater treatment system 2 and the reuse system 3 are connected in pairs;

[0025] The leachate treatment system 1 includes a first regulating tank 10, an anaerobic UASB 11, a secondary AO 12, a UF system 13, a sludge thickening tank 18, an RO system 14, a material membrane system 16, a reverse osmosis system 15 and a DTRO system 17; the first regulating tank 10 and the anaerobic UASB 11, the secondary AO 12, the UF system 13, the RO system 14 and the reverse osmosis system 15 are sequentially connected, and the sludge in the first regulating tank 10 and the secondary AO 12 are transported to the sludge thickening tank 18, and the supernatant in the sludge thickening tank 18 is returned to the secondary AO 12 through a pipeline; the sludge thickening tank 18 is also used to concentrate The sludge generated by the production wastewater treatment system 2 is reduced, and the secondary AO12 directly receives the unloading hall, leachate pipe flushing water, domestic sewage and initial rainwater. The concentrated water end of the RO system 14 is connected to the material membrane system 16, the secondary concentrated water end of the material membrane system 16 is connected to the secondary AO12, the primary concentrated water end of the material membrane system 16 is connected to the reuse system 3, the clear liquid end of the material membrane system 16 is connected to the reverse osmosis system 15, the concentrated water end of the reverse osmosis system 15 is connected to the DTRO system 17, and the effluent end of the reverse osmosis system 15 is connected to the reuse system 3; the concentrated water end of the DTRO system 17 is connected to the reuse system 3, and the clear liquid end of the DTRO system 17 is connected to the reuse system 3

[0026] It also includes a sludge dewatering mechanism 19, the filtrate of the sludge dewatering mechanism is returned to the secondary AO12 through a pipeline, and the dewatered sludge in the sludge dewatering mechanism is sent to an external incinerator for incineration 43.

[0027] The production wastewater treatment system 2 includes a second regulating tank 21, a coagulation flotation tank 22, and a sand filter 23. The water inlet of the second regulating tank 21 is connected to the circulating water sewage 33, and the outlet of the second regulating tank 21 is connected to the coagulation flotation tank 22. The sludge produced by the coagulation flotation tank 22 is sent to the sludge thickening tank 18. The coagulation flotation tank 22 is also connected to the sand filter 23.

[0028] The reuse system 3 includes a concentrated water return spray system 41 and a cooling tower circulating water reuse system 42; the cooling tower circulating water reuse system 42 is connected to the reverse osmosis system 15 and the clear liquid end of the DTRO system 17, and the concentrated water return spray system 41 is also connected to the primary concentrated water end of the material membrane system 16 and the concentrated water end of the DTRO system 17.

[0029] The recycling system 3 also includes a flue gas purification mechanism 44, a feed hopper and chute 45, a boiler room and flue gas purification room flushing 46, and a slag discharger and grate slag conveyor 47. The water from the sand filter 23 is pumped to various water points, including the flue gas purification mechanism 44, the feed hopper and chute 45, the boiler room and flue gas purification room flushing 46, the slag discharger and grate slag conveyor 47. The concentrated water 34 is directly used for the slag discharger and grate slag conveyor 47.

[0030] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "two ends", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] In the present invention, unless otherwise clearly stipulated and limited, the terms "install", "set", "connect", "fix", "screw" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0032] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A waste incineration power plant wastewater zero discharge system, characterized in that: It includes a leachate treatment system, a production wastewater treatment system and a reuse system, wherein the leachate treatment system and the reuse system are connected, and the leachate treatment system, the production wastewater treatment system and the reuse system are connected in pairs; The leachate treatment system includes a first regulating tank, an anaerobic UASB, a secondary AO, a UF system, a sludge thickening tank, an RO system, a material membrane system, a reverse osmosis system and a DTRO system; the first regulating tank and the anaerobic UASB, the secondary AO, the UF system, the RO system and the reverse osmosis system are sequentially connected, the sludge in the first regulating tank and the secondary AO are transported to the sludge thickening tank, and the supernatant in the sludge thickening tank is returned to the secondary AO through a pipeline; the sludge thickening tank is also used to concentrate the sludge generated by the production wastewater treatment system, The secondary AO directly receives flushing water from the unloading hall, leachate pipeline, domestic sewage and initial rainwater. The concentrated water end of the RO system is connected to the material membrane system, the secondary concentrated water end of the material membrane system is connected to the secondary AO, the primary concentrated water end of the material membrane system is connected to the reuse system, and the clear liquid end of the material membrane system is connected to the reverse osmosis system; the concentrated water end of the reverse osmosis system is connected to the DTRO system, and the water outlet end of the reverse osmosis system is connected to the reuse system; the concentrated water end of the DTRO system is connected to the reuse system; and the clear liquid end of the DTRO system is connected to the reuse system.

2. The zero-discharge wastewater system for waste incineration power plants according to claim 1 is characterized in that: It also includes a sludge dewatering mechanism, the filtrate of which is returned to the secondary AO through a pipeline, and the dehydrated sludge in the sludge dewatering mechanism is sent to an external incinerator for incineration.

3. The zero-discharge wastewater system for waste incineration power plants according to claim 2 is characterized in that: The production wastewater treatment system includes a second regulating tank, a coagulation flotation tank, and a sand filter. The water inlet of the second regulating tank is connected to the circulating water sewage, and the outlet of the second regulating tank is connected to the coagulation flotation tank. The sludge generated in the coagulation flotation tank is sent to the sludge thickening tank. The coagulation flotation tank is also connected to the sand filter.

4. The zero-discharge wastewater system for waste incineration power plants according to claim 3 is characterized in that: The recycling system includes a concentrated water back-spray system and a cooling tower circulating water recycling system; the cooling tower circulating water recycling system is connected to the reverse osmosis system and the clear liquid end of the DTRO system, and the concentrated water back-spray system is also connected to the primary concentrated water end of the material membrane system and the concentrated water end of the DTRO system.

5. The zero-discharge wastewater system for waste incineration power plants according to claim 4 is characterized in that: The reuse system also includes a water system for flue gas purification mechanism, feeding hopper and chute, boiler room, flue gas purification room flushing, slag discharger, and grate slag conveyor; the water output from the sand filter is pumped to the water points in the flue gas purification, feeding hopper and chute, boiler room, flue gas purification room flushing, slag discharger and grate slag conveyor, and also includes chemical water concentrate, which is directly used for water use in the slag discharger and grate slag conveyor.

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