An iron bucket plastic bucket hazardous waste resourceization wastewater treatment system based on segmented oxidation and dynamic regulation

Abstract

An iron bucket plastic bucket hazardous waste resourceization sewage treatment system based on segmented oxidation and dynamic regulation, strong alkali wastewater enters the first artificial grid, the first oil separation tank, the strong alkali water adjusting tank, the PH adjusting tank, the demulsification tank, the first coagulation sedimentation tank, the sand filter and the reuse water tank in sequence through the water inlet; the comprehensive wastewater enters the physical and chemical pretreatment unit, the hydrolysis acidification tank, the nutrition tank dosing tank, the anaerobic UASB tank, the AO biochemical tank, the secondary sedimentation tank, the Fenton advanced oxidation unit and the biological aerated filter in sequence through the water inlet, the sludge inlets of the first coagulation sedimentation tank, the anaerobic UASB tank, the secondary sedimentation tank and the Fenton advanced oxidation unit are connected with the sludge tank inlet in sequence, the utility model discloses scientific and reasonable design, multi-mode switchable process flow, 18% lower than traditional process, energy consumption reduces 25% at low load; effectively reduce the water treatment cost of 0.8-1.2 yuan per ton, and the social and economic benefits are remarkable.

Description

Technical Field

[0001] This utility model relates to the field of industrial wastewater treatment technology, and in particular to a wastewater treatment system for the resource recovery of hazardous waste such as iron drums and plastic drums based on segmented oxidation and dynamic control. Background Technology

[0002] For the complex wastewater treatment scenarios generated during the resource recovery process of hazardous waste iron drums (after cleaning, shaping, and crushing) and plastic drums (after cleaning and crushing) containing various high concentrations of recalcitrant organic matter, existing technologies have the following drawbacks: 1. Pre-treatment of Fenton oxidation leads to resource waste: Existing technologies generally place Fenton oxidation in the pretreatment stage, indiscriminately oxidizing biodegradable COD, resulting in the depletion of H2O2 and Fe. 2+ 1. Excessive consumption of reagents (approximately 30% increase in dosage), and secondary pollutants generated by the oxidation reaction require additional treatment; 2. Fixed process flow: Conventional processes use fixed treatment routes and cannot flexibly switch operating modes according to water quality fluctuations, resulting in wasted energy consumption (electricity consumption increases by 15%-20%) during low load or intermittent water intake; 3. Low pre-treated wastewater reuse rate: Special wastewater such as wastewater from broken iron drums and plastic drums is mostly directly discharged or enters the biological unit after physical and chemical treatment, without realizing the recycling of the cleaning process, and the water resource utilization rate is less than 40%.

[0003] Therefore, for the complex wastewater generated during the recycling of hazardous waste iron drums and plastic drums, the following technical problems urgently need to be solved: how to avoid the ineffective consumption of biodegradable COD by Fenton oxidation and accurately treat the recalcitrant components; how to construct a dynamically adjustable treatment process to adapt to different water quality / quantity conditions; and how to achieve the resource-based reuse of pretreated wastewater to reduce the raw water load and water resource consumption to meet current needs. Utility Model Content

[0004] In view of the above situation and to overcome the defects of the existing technology, the purpose of this utility model is to provide a wastewater treatment system for the resource recovery of hazardous waste such as iron drums and plastic drums based on segmented oxidation and dynamic control, which can effectively solve the problem of treating complex water quality wastewater generated during the resource recovery process of hazardous waste iron drums and plastic drums.

[0005] To achieve the above objectives, the technical solution provided by this utility model is a wastewater treatment system for hazardous waste from iron and plastic drums, based on segmented oxidation and dynamic control. The wastewater is divided into highly alkaline wastewater and mixed wastewater, which are treated in two separate streams. The highly alkaline wastewater enters sequentially through an inlet into a first artificial screen, a first oil separator, a highly alkaline water conditioning tank, a pH conditioning tank, a demulsification tank, a first coagulation sedimentation tank, a sand filter, and a recycled water tank. The mixed wastewater enters sequentially through an inlet into a connected physicochemical pretreatment unit, a hydrolysis acidification tank, a nutrient addition tank, an anaerobic UASB tank, an AO biological treatment tank, a secondary sedimentation tank, and a Fenton advanced oxidation unit. The sludge discharge outlets of the aerated biological filter, the first coagulation sedimentation tank, the anaerobic UASB tank, the secondary sedimentation tank, and the Fenton advanced oxidation unit are connected to the sludge tank inlet, the sludge tank outlet is connected to the sludge thickening tank inlet, and the sludge thickening tank outlet is connected to the plate and frame dewatering machine inlet. An online TOC monitor is installed on the pipeline between the physicochemical pretreatment unit and the hydrolysis acidification tank. A four-way solenoid valve is installed at the outlet of the hydrolysis acidification tank. The other three valve ports of the four-way solenoid valve are connected to the nutrient tank addition tank, the AO biological tank, and the inlet of the Fenton advanced oxidation unit, respectively. The online TOC monitor and the four-way solenoid valve are connected to the PLC controller.

[0006] This invention features a scientifically sound design. A nutrient solution addition module is added before the anaerobic UASB unit to activate microbial activity and reduce the subsequent Fenton oxidation load. The multi-mode switchable process adapts to the intermittent drainage characteristics of hazardous waste projects. Automatic mode switching via a PLC control system ensures that the power consumption per ton of water is ≤1.2 kWh, a 18% reduction compared to traditional processes, and a 25% reduction in energy consumption under low load conditions. Through segmented treatment, precise oxidation is achieved, effectively reducing the cost per ton of water treatment by 0.8-1.2 yuan, resulting in significant social and economic benefits. Attached Figure Description

[0007] Figure 1 This is a system block diagram of this utility model.

[0008] Figure 2 This is a schematic diagram of the connecting frame of the Fenton advanced oxidation unit of this utility model. Detailed Implementation

[0009] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings and specific circumstances.

[0010] As shown in the attached diagram, a wastewater treatment system for hazardous waste from iron and plastic drums, based on segmented oxidation and dynamic control, is described. The wastewater is divided into highly alkaline wastewater and mixed wastewater, which are treated separately. The highly alkaline wastewater enters sequentially through an inlet into a first artificial screen 1, a first oil separator 2, a highly alkaline water regulating tank 3, a pH regulating tank 4, a demulsifying tank 5, a first coagulation sedimentation tank 6, a sand filter 7, and a reclaimed water tank 8. The mixed wastewater enters sequentially through an inlet into a connected physicochemical pretreatment unit, a hydrolysis acidification tank 14, a nutrient addition tank 15, an anaerobic UASB tank 16, an AO biological treatment tank 17, a secondary sedimentation tank 18, a Fenton advanced oxidation unit 19, and an aerated biological filter 20. The first coagulation sedimentation tank... The sludge discharge ports of sedimentation tank 6, anaerobic UASB tank 16, secondary sedimentation tank 18, and Fenton advanced oxidation unit 19 are connected to the inlet of sludge tank 21, the outlet of sludge tank 21 is connected to the inlet of sludge thickening tank 22, and the outlet of sludge thickening tank 22 is connected to the inlet of plate and frame dewatering machine 23. An online TOC monitor 24 is installed on the pipeline between the physicochemical pretreatment unit and the hydrolysis acidification tank 14. A four-way solenoid valve is installed at the outlet of hydrolysis acidification tank 14. The other three valve ports of the four-way solenoid valve are connected to the inlet of nutrient tank addition tank 15, AO biological treatment tank 17, and Fenton advanced oxidation unit 19, respectively. The online TOC monitor 24 and the four-way solenoid valve are connected to the PLC controller.

[0011] To ensure better implementation results, the physical and chemical pretreatment unit consists of a second artificial bar 9, a second oil separator 10, a comprehensive equalization tank 11, a second coagulation sedimentation tank 12, and an air flotation tank 13 connected in sequence. The comprehensive wastewater is connected to the second artificial bar 9 through the inlet, and the outlet of the air flotation tank 13 is connected to the inlet of the hydrolysis acidification tank 14 through a pipeline. An online TOC monitor 24 is installed on the pipeline between the air flotation tank 13 and the hydrolysis acidification tank 14. The sludge discharge outlets of the comprehensive equalization tank 11, the second coagulation sedimentation tank 12, and the air flotation tank 13 are respectively connected to the inlet of the sludge tank 21.

[0012] The inlet of the second artificial bar 9 is equipped with a pump level gauge and an electromagnetic flow meter connected to a PLC controller.

[0013] The Fenton advanced oxidation unit 19 includes a pH adjustment tank 191, a Fenton reaction tank 192 and a sedimentation and adjustment tank 193 connected in sequence. The outlet of the sedimentation and adjustment tank 193 is connected to the inlet of the aerated biological filter 20 via a pipe. The sludge discharge outlet of the sedimentation and adjustment tank 193 is connected to the inlet of the sludge tank 21.

[0014] The pH adjustment tank 191, Fenton reaction tank 192, sedimentation and adjustment tank 193, and nutrient addition tank 15 are all equipped with a reagent addition system. The reagent addition systems of Fenton reaction tank 192 and nutrient addition tank 15 are respectively connected to a PLC controller.

[0015] The return water inlet of the recycled water tank 8 is connected to the backwash inlet of the sand filter 7; the sludge return inlet of the secondary sedimentation tank 18 is connected to the inlet of the AO biological treatment tank 17.

[0016] The working principle of this utility model is as follows:

[0017] S1. Treatment of Strong Alkaline Wastewater: Wastewater is divided into strong alkaline wastewater and general wastewater, which are treated in two separate streams. After the strong alkaline wastewater passes through the first artificial screen 1 to remove larger suspended or floating solids, it enters the first oil separator 2 for oil-water separation. Then it enters the strong alkaline water conditioning tank 3 to adjust the water quality. The water is then pumped to the pH conditioning tank 4, where acid is added to adjust the pH to 6-8. The wastewater then enters the demulsification tank 5, where 94% calcium chloride is added at a concentration of 20-30 mg / L to carry out the demulsification reaction. The wastewater then enters the first coagulation sedimentation tank 6, where PAC and PAM are added at a concentration of 50 mg / L and 1 mg / L respectively to carry out the flocculation reaction and remove organic pollutants and suspended solids. The treated sediment enters the sludge tank 21, and the wastewater is pumped into the sand filter 7 to further remove small flocs in the water. The filtered water enters the reuse water tank 8 for reuse in the plant area.

[0018] S2. Physical and chemical pretreatment of integrated wastewater: After removing larger suspended or floating solids through the second artificial screen 9, the integrated wastewater enters the second oil separator 10 for oil-water separation, and then enters the integrated equalization tank 11 for water quality and quantity adjustment. Subsequently, the wastewater is pumped to the second coagulation sedimentation tank 12, where PAC and PAM are added at a dosage of 50 mg / L and 1 mg / L to remove organic pollutants and suspended solids. The wastewater then flows by gravity into the dissolved air flotation tank 13, where PAC and PAM are added at a dosage of 20 mg / L and 1 mg / L to remove most of the suspended solids.

[0019] S3. Wastewater Treatment Mode Selection: An online TOC monitor 24 is installed on the effluent pipe of the dissolved air flotation (DAF) tank 13. The online TOC monitor 24 monitors the organic matter concentration of the wastewater in real time and transmits the data to the PLC controller. The DAF effluent enters the hydrolysis acidification tank 14, where large molecular organic matter is decomposed by hydrolytic bacteria. A four-way solenoid valve is installed at the effluent outlet of the hydrolysis acidification tank 14. Based on the data transmitted from the online TOC monitor 24 to the PLC controller, the PLC controller controls the opening and closing of the four-way solenoid valve, allowing the acidified effluent to flow to different treatment units. When the wastewater COD ≥ 2000 mg / L, the acidified effluent operates under high-load conditions, i.e., it sequentially enters the nutrient tank for feeding. The system includes a 15-tank, a 16-tank, a 17-tank, a 18-tank, a 19-tank, and an aerated biological filter. When the COD of the wastewater is less than 2000 mg / L, the acidified effluent is operated in a low-load continuous operation mode, that is, it enters the 17-tank, a 18-tank, a 19-tank, and an aerated biological filter in sequence. When the pump level gauge and electromagnetic flow meter installed at the second artificial screen 9 detect discontinuous water inflow and feed it back to the PLC controller, it means that the water volume in the workshop is small. In this case, the system is operated in an intermittent water inflow mode, that is, the effluent from the hydrolysis acidification tank 14 directly enters the Fenton advanced oxidation unit 19 for treatment.

[0020] S4, High-load operating mode: Acidified effluent enters nutrient solution addition tank 15, where carbon, nitrogen, and phosphorus sources are added at a mass ratio of C:N:P=100:5:1. It is then pumped into anaerobic UASB tank 16, where methanogenic bacteria utilize the biogas produced, degrading and removing most of the high-concentration organic matter. The effluent from anaerobic UASB tank 16 flows by gravity into AO biological treatment tank 17, where nitrification and denitrification by nitrifying bacteria remove nitrogen and phosphorus, degrading organic pollutants. The effluent from AO biological treatment tank 17 then enters secondary sedimentation tank 18 for sludge-water separation. 8. The effluent flows by gravity into Fenton Advanced Oxidation Unit 19. Within the pH range of 3-3.5, ferrous sulfate reacts with hydrogen peroxide to generate carbonyl groups, which oxidize, break chains, and de-ring recalcitrant substances, thus degrading organic matter. Then, sodium hydroxide is added to adjust the pH to 6-9, and PAC and PAM are added for precipitation and mud-water separation, further removing the remaining recalcitrant organic pollutants. The effluent from Fenton Advanced Oxidation Unit 19 is pumped into Aerated Biological Filter 20 to remove residual COD and ammonia nitrogen from the wastewater. The effluent from Aerated Biological Filter 20 meets the standards and is discharged into the municipal pipe network for further treatment at a secondary wastewater treatment plant.

[0021] In the Fenton advanced oxidation unit 19, the wastewater specifically flows as follows: effluent from the secondary sedimentation tank 18 flows by gravity into the pH adjustment tank 191, where 98% sulfuric acid is added to adjust the pH. The effluent from the pH adjustment tank 191 then enters the Fenton reactor 192, where ferrous sulfate and hydrogen peroxide are added. The hydrogen peroxide and ferrous sulfate contain Fe...2+ The mass ratio is 1:1.5~1:3, and the dosage of ferrous ions is 95-100 mg / L to oxidize, break chains, and decirculate recalcitrant substances, thereby degrading organic matter. The effluent from Fenton reactor 192 enters sedimentation and return tank 193. 95% sodium hydroxide, PAC and PAM are added to sedimentation and return tank 193. The dosage of 95% sodium hydroxide is 150 mg / L, the dosage of PAC is 100 mg / L, and the dosage of PAM is 1 mg / L to further remove the remaining recalcitrant organic pollutants. The sludge from sedimentation and return tank 193 is discharged to sludge tank 21, and the effluent from sedimentation and return tank 193 is pumped into aerated biological filter 20.

[0022] S5. Sludge Treatment: The sludge from the first coagulation sedimentation tank 6, the comprehensive equalization tank 11, the second coagulation sedimentation tank 12, the dissolved air flotation tank 13, the anaerobic UASB tank 16, the secondary sedimentation tank 18, and the Fenton advanced oxidation unit 19 is discharged to the sludge tank 21, and then enters the sludge thickening tank 22 to thicken the sludge and reduce its water content. Subsequently, it is lifted by a lift pump to the plate and frame dewatering machine 23 for dewatering. The dewatered sludge cake is transported off-site, and the supernatant of the sludge thickening tank 22 and the drainage of the plate and frame dewatering machine 23 flow back to the comprehensive equalization tank 11 by gravity.

[0023] This utility model is scientifically and rationally designed, and has the following advantages compared with the prior art:

[0024] 1. This utility model adds a nutrient solution dosing module before the anaerobic UASB unit to activate microbial activity, preferentially degrade biodegradable COD in the raw water (removal rate ≥85%), and reduce the subsequent Fenton oxidation load.

[0025] 2. This invention places the Fenton unit after A / O biochemical treatment, and uses an online TOC monitor (detection accuracy ±0.5mg / L) to identify the concentration of recalcitrant organic matter in real time, dynamically adjusting the H2O2 and Fe... 2+ By adjusting the dosage ratio, the amount of pesticide used can be reduced by 25%-30%.

[0026] 3. This utility model features a multi-mode switchable process flow, adapting to the intermittent drainage characteristics of hazardous waste projects. The PLC control system automatically switches modes to ensure that the power consumption per ton of water is ≤1.2kWh, which is 18% lower than the traditional process, and energy consumption is reduced by 25% under low load.

[0027] 4. Wastewater from crushed iron or plastic drums, after pretreatment via air flotation and filtration, has a COD reduced from 2000 mg / L to ≤500 mg / L. This wastewater is then pumped through pipelines to the iron or plastic drum washing line, replacing 50% of the fresh water for reuse in the industrial cleaning process. The reuse rate is ≥70%, reducing fresh water consumption by 30%, lowering water costs for the washing line by 40%, and saving ≥5000 m³ of water annually. 3 This reduces the COD load of raw water by 15%-20%.

[0028] 5. Through segmented treatment, Fenton reagent only acts on recalcitrant COD (accounting for ≤20%), achieving precise oxidation and effectively reducing the cost of water treatment by 0.8-1.2 yuan per ton, resulting in significant social and economic benefits.

[0029] It should be noted that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Any person skilled in the art who can make changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model's technical solution shall fall within the protection scope of the present utility model.

Claims

1. A wastewater treatment system for hazardous waste from iron and plastic drums, based on segmented oxidation and dynamic control, wherein the wastewater is divided into strongly alkaline wastewater and mixed wastewater, and treated separately in two streams, characterized in that... The highly alkaline wastewater enters sequentially through the inlet into the first artificial screen (1), the first oil separator (2), the highly alkaline water conditioning tank (3), the pH conditioning tank (4), the demulsification tank (5), the first coagulation sedimentation tank (6), the sand filter (7), and the recycled water tank (8). The combined wastewater enters sequentially through the inlet into the connected physicochemical pretreatment unit, the hydrolysis acidification tank (14), the nutrient addition tank (15), the anaerobic UASB tank (16), the AO biological tank (17), the secondary sedimentation tank (18), the Fenton advanced oxidation unit (19), and the aerated biological filter (20). The first coagulation sedimentation tank (6), the anaerobic UASB tank (16), the secondary sedimentation tank (18), and the Fenton advanced oxidation unit (20) also enter sequentially through the inlet. The sludge discharge port of the oxidation unit (19) is connected to the inlet of the sludge tank (21), the outlet of the sludge tank (21) is connected to the inlet of the sludge thickening tank (22), and the outlet of the sludge thickening tank (22) is connected to the inlet of the plate and frame dewatering machine (23). An online TOC monitor (24) is installed on the pipeline between the physicochemical pretreatment unit and the hydrolysis acidification tank (14). A four-way solenoid valve is installed at the outlet of the hydrolysis acidification tank (14). The other three valve ports of the four-way solenoid valve are connected to the nutrient tank addition tank (15), the AO biochemical tank (17), and the inlet of the Fenton advanced oxidation unit (19), respectively. The online TOC monitor (24) and the four-way solenoid valve are connected to the PLC controller.

2. The wastewater treatment system for hazardous waste such as iron drums and plastic drums based on segmented oxidation and dynamic control according to claim 1, characterized in that, The physical and chemical pretreatment unit consists of a second artificial bar (9), a second oil separator (10), a comprehensive equalization tank (11), a second coagulation sedimentation tank (12), and an air flotation tank (13) connected in sequence. The comprehensive wastewater is connected to the second artificial bar (9) through the inlet. The outlet of the air flotation tank (13) is connected to the inlet of the hydrolysis acidification tank (14) through a pipeline. An online TOC monitoring instrument (24) is installed on the pipeline between the air flotation tank (13) and the hydrolysis acidification tank (14). The sludge discharge outlets of the comprehensive equalization tank (11), the second coagulation sedimentation tank (12), and the air flotation tank (13) are respectively connected to the inlet of the sludge tank (21).

3. The wastewater treatment system for hazardous waste from iron and plastic drums based on segmented oxidation and dynamic control according to claim 2, characterized in that, The inlet of the second artificial bar (9) is equipped with a pump level gauge and an electromagnetic flow meter connected to the PLC controller.

4. The wastewater treatment system for hazardous waste from iron and plastic drums based on segmented oxidation and dynamic control according to claim 1, characterized in that, The Fenton advanced oxidation unit (19) includes a pH adjustment tank (191), a Fenton reaction tank (192), and a sedimentation and settling tank (193) connected in sequence. The outlet of the sedimentation and settling tank (193) is connected to the inlet of the aerated biological filter (20) via a pipeline. The sludge discharge outlet of the sedimentation and settling tank (193) is connected to the inlet of the sludge tank (21).

5. The wastewater treatment system for hazardous waste from iron and plastic drums based on segmented oxidation and dynamic control according to claim 4, characterized in that, The pH adjustment tank (191), Fenton reaction tank (192), sedimentation and adjustment tank (193), and nutrient addition tank (15) are all equipped with a reagent addition system. The reagent addition systems of Fenton reaction tank (192) and nutrient addition tank (15) are respectively connected to a PLC controller.

6. The wastewater treatment system for hazardous waste such as iron drums and plastic drums based on segmented oxidation and dynamic control according to claim 1, characterized in that, The return water inlet of the recycled water tank (8) is connected to the backwash inlet of the sand filter (7); the sludge return inlet of the secondary sedimentation tank (18) is connected to the inlet of the AO biochemical tank (17).

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