CN204769857U - Get rid of drip washing device of soil heavy metal - Google Patents

Abstract

The utility model discloses a get rid of drip washing device of soil heavy metal, it includes soil crushing and screening equipment, multistage screening equipment, stirring drip washing equipment, the mud buffer pool, the leachate storage tank, the multistage screening equipment's of export termination of soil crushing and screening equipment entry end, multistage screening equipment's the exit end and the output of leachate storage tank insert the entry of stirring drip washing equipment, the exit linkage mud buffer pool of stirring drip washing equipment, the mud export of mud buffer pool is connected with filter press through the sediment stuff pump, the supernatant export of mud buffer pool is connected with leachate clarification plant's entry end, leachate clarification plant's exit end is connected through peristaltic pump and leachate storage tank. The utility model discloses major parameters such as churning time, stirring speed, water and soil proportion and the selection of soil particle diameter can suitably be adjusted to the device, are favorable to carrying on the drip washing processing of optimization to heterogeneity soil at the actual operation in -process.

Description

Leaching device for removing heavy metals from soil

technical field

The utility model relates to the field of industrial solid waste heavy metal pollution control, in particular to a leaching device for removing heavy metals from soil.

Background technique

Soil heavy metal leaching technology can be classified according to different remediation principles: in-situ chemical leaching and ex-situ chemical leaching. In the field restoration process, soil leaching is to use leaching agent to transfer the heavy metals adsorbed on the soil to the liquid phase, and then collect the waste liquid for treatment. Chemical leaching is more effective for remediation of small areas of heavily polluted soil.

In-situ leaching technology is suitable for sandy soil with strong water permeability, and the pollutant layer should be located above the impermeable layer to ensure that the eluent will not pollute the groundwater. Then the eluent is pumped out from the collection well, and the eluent is collected for the removal of heavy metals and the recycling of the eluate. This technology has low cost and simple process, but the repair efficiency is low, and it is easy to cause pollution to groundwater, and it is not suitable for application in karst cave areas.

Soil ectopic chemical leaching needs to go through steps such as excavation and migration, and then be concentrated in the leaching device for centralized treatment. The pollutants in the eluent need to be harmlessly treated, and the treated soil needs to be backfilled. Ectopic leaching techniques include soil column leaching, oscillation leaching, and stirring leaching. The soil column leaching method mainly removes heavy metals in polluted soil through soil column leaching. The ectopic leaching technology will not pollute the groundwater. The agitation leaching is to make the eluent and the soil fully in the shaking or stirring reactor for a long time. Mixing to remove heavy metals in the eluent, this technology has high repair efficiency and low risk of secondary pollution, but the cost is also high.

At present, there are no relevant reports on a leaching device for removing heavy metal zinc from soil that can self-adjust the leaching conditions, improve the removal rate of heavy metals, and solve the problems of eluent recovery and treatment.

Utility model content

The technical problem to be solved by this utility model is to provide a new leaching device for removing heavy metals from soil, which can effectively remove heavy metals in polluted soil, and can self-adjust leaching conditions to treat polluted soil, improve the removal rate of heavy metals, and solve the problem of The problem of eluent recovery and disposal is solved, and soil fertility is preserved.

The utility model solves the above technical problems with the following technical solutions:

The utility model is a leaching device for removing heavy metals in soil, which includes soil crushing and screening equipment, multi-stage screening equipment, stirring and rinsing equipment, mud buffer pool, leaching liquid storage tank, and the outlet terminal of the soil crushing and screening equipment is multi-connected. The inlet of the multi-stage screening equipment, the outlet of the multi-stage screening equipment and the output of the eluent storage tank are connected to the inlet of the stirring and washing equipment, and the outlet of the stirring and washing equipment is connected to the mud buffer tank, and the mud in the mud buffer tank The outlet is connected to the plate and frame filter press through the slurry pump, the supernatant outlet of the mud buffer tank is connected to the inlet of the eluent purification equipment, and the outlet of the eluent purification equipment is connected to the eluent storage tank through a peristaltic pump . The inlet end of the eluent storage tank is connected in parallel with acid solution adding equipment.

The multi-stage screening equipment includes a first-stage screen and a second-stage screen arranged up and down. The first-stage screen is smaller than the screen aperture of the soil crushing and screening equipment and larger than the second-stage screen aperture.

The screen mesh aperture of the soil crushing and screening equipment is 5-15mm, the first-stage screen mesh aperture of the multi-stage screening equipment is 2mm-4mm, and the second-stage screen mesh aperture is 0.5mm-0.8mm.

The inlet end of the eluent purification equipment is connected in parallel with the water outlet of the plate and frame filter press.

The feeding of the stirring and washing equipment is controlled by a metering pump.

The utility model device can effectively remove the heavy metal zinc in the polluted soil, and can self-adjust the leaching conditions to treat the polluted soil, improve the removal rate of the heavy metal, and the treated soil can continue to be used as agricultural or commercial land to achieve harmless treatment, and at the same time solve the problem of Eluent recovery and disposal issues.

Description of drawings

Fig. 1 is the structure schematic diagram of the rinsing device of the utility model for removing soil heavy metals.

In the figure: soil crushing and screening equipment 1, multi-stage screening equipment 2, first-level screen 2-1, second-level screen 2-2, stirring and washing equipment 3, stirring motor 3-1, stirring paddle 3 -2, mud buffer tank 4, plate and frame filter press 5, eluent storage tank 6, eluent purification equipment 7, Na ₂ S purification 7-1, activated carbon purification 7-2, metering pump 8, peristaltic pump 9 , acid liquid adding equipment 10, slurry pump 11.

Detailed ways

As shown in Figure 1, the utility model device consists of soil crushing and screening equipment 1, multi-stage screening equipment 2, stirring and washing equipment 3, mud buffer tank 4, plate and frame filter press 5, eluent storage tank 6, The eluent purification equipment 7, the metering pump 8, the peristaltic pump 9, the acid liquid addition equipment 10 and the slurry pump 11 are composed of components, among which the soil crushing and screening equipment 1 adopts a hammerstone crushing and screening machine, and the multi-stage screening equipment 2 is equipped with There are a first-stage screen 2-1 and a second-stage screen 2-2 arranged up and down, the pores of the first-stage screen 2-1 are larger than the pores of the second-stage screen 2-2, and smaller than the soil crushing screen Sub-device 1 porosity. The pore size of the screen for soil crushing and screening equipment 1 is required to be 5-15mm, the pore size of the first-stage screen for multi-stage screening equipment is required to be 2mm-4mm (5-10 mesh, the pore size of the second-stage screen is required to be 0.5mm- 0.8mm (20-35 mesh).

The porosity of the soil crushing and screening equipment 1 in this example is 10mm, and the porosity of the first-stage screen cloth 2-1 is 8 orders (2.4mm) in the multistage screening equipment, and the porosity of the second-stage screen cloth is 20 orders ( 0.8mm).

The connection structure of each part of the utility model is shown in Figure 1, the outlet end of the soil crushing and screening equipment 1 is connected to the inlet end of the multi-stage screening equipment 2, the outlet end of the multi-stage screening equipment 2 and the eluent storage tank 6 The output end of the mixer is connected to the entrance of the stirring and washing equipment 3, and the material entering of the stirring and washing equipment 3 is controlled by the metering pump 8. In the stirring and washing equipment 3, the stirring motor 3-1 drives the stirring paddle 3-2 to rotate the mixed material, stirring The outlet of the washing equipment 3 is connected to the mud buffer tank 4, the mud outlet of the mud buffer tank 4 is connected to the plate and frame filter press 5 through the slurry pump 11, and the supernatant liquid outlet of the mud buffer tank 4 is connected to the eluent purification device 7. The inlet end is connected, and the outlet end of the eluent purification equipment 7 is connected to the eluent storage tank 6 through a peristaltic pump 9, and the inlet end of the eluent storage tank 6 is connected in parallel with the acid solution addition device 10; the eluent purification equipment 7 The inlet end is connected in parallel with the water outlet of the plate and frame filter press 5 .

The main function of the soil crushing and screening equipment 1 is to crush the contaminated soil. During the crushing process, the materials can be uniformly entered into the stirring type washing equipment, so as to reduce the mechanical failure caused by the uneven particle size of the materials during the stirring process. .

When using the device of the utility model, the prepared eluent is added into the eluent storage tank 6 and enters the stirring and eluting equipment 3 downstream. The rinsing mixing device 3 is circular, and the washing liquid and the polluted soil are fully mixed with mud and water in the mixing device. The proportion of water and soil can be controlled by the material passing through the metering pump 8, and a butterfly valve is installed at the lower end of the washing and stirring equipment to control the sludge entering the mud buffer tank 4. Under the control of the metering pump 8, the quality of the materials entering the rinsing equipment can be scientifically controlled to ensure the ratio of water to soil.

The main function of the washing buffer pool 4 is to initially separate the mud and water. When the butterfly valve under the washing equipment is opened, the mud enters the washing buffer pool 4 and is sent into the plate and frame pressure by the slurry pump 11 at its lower end. The filter 5 separates the mud and water, and the supernatant in the upper layer enters the eluent purification equipment 7 .

The eluate purification equipment 7 is composed of a Na ₂ S purification device 7-1 and an activated carbon purification device 7-2 connected in series, and the main function of the eluent purification equipment 7 is to store and recover the eluent after the mud-water separation, and Connect to the eluent buffer tank 4, recover the eluent, and enter the eluent purification equipment for purification and regeneration, and finally re-enter the eluent storage tank 6.

The mud buffer tank 4 that the utility model adopts has a diameter of 2.5m and a height of 4m. A pipeline with a valve is provided at the middle end of the buffer pool to connect with the eluent purification equipment 7, and the bottom is connected with the water inlet of the plate and frame filter press 5 by a slurry pump 11.

The main function of the plate and frame filter press 5 is to separate water and soil from the mud at the port of the mud buffer tank. In the plate and frame filter press, the mud water is fed from the feed hole of the tail plate by the feed pump at a certain pressure. With the help of the pressure provided by the feed pump, the pressure difference formed on both sides of the filter medium realizes solid-liquid separation, dewaters the sludge to a moisture content of about 20%, and obtains a filter cake of clean soil.

In the feed screening process of the device of the utility model, the soil smaller than the pores of the graded vibrating screen enters the leaching equipment, and after leaching, the clean soil is dehydrated and backfilled or used for other purposes, while the leaching liquid enters the purification equipment for recycling and reuse. , so as to complete the treatment of polluted soil.

The device of the utility model can properly adjust main parameters such as stirring time, stirring speed, water-soil ratio and soil particle size selection, and is beneficial to optimize leaching treatment for soils with different properties during the actual operation process.

Claims (6)

1. The leaching device for removing heavy metals from soil is characterized in that it includes soil crushing and screening equipment, multi-stage screening equipment, stirring and leaching equipment, mud buffer tank, eluent storage tank, and the outlet of soil crushing and screening equipment The terminal is connected to the inlet of the multi-stage screening equipment, the outlet of the multi-stage screening equipment and the output of the eluent storage tank are connected to the inlet of the stirring and washing equipment, and the outlet of the stirring and washing equipment is connected to the mud buffer pool. The mud outlet of the tank is connected to the plate and frame filter press through the slurry pump, the supernatant outlet of the mud buffer tank is connected to the inlet of the eluent purification equipment, and the outlet of the eluent purification equipment is connected to the eluent through a peristaltic pump. Tank connection. 2. The leaching device for removing heavy metals from soil according to claim 1, characterized in that: the inlet end of the eluent storage tank is connected in parallel with acid solution adding equipment. 3. According to claim 1 or 2, the leaching device for removing heavy metals from soil is characterized in that: the multi-stage screening equipment includes a first-stage screen cloth and a second-stage screen cloth arranged up and down, and the first-stage screen cloth It is smaller than the sieve hole of the soil crushing and screening equipment, and larger than the second stage sieve hole. 4. according to claim 3, remove the leaching device of soil heavy metal, it is characterized in that, the sieve mesh aperture of described soil crushing and screening equipment is 5-15mm, and the first stage sieve mesh aperture of multistage screening equipment is 2mm -4mm, the aperture of the second stage screen is 0.5mm-0.8mm. 5. The leaching device for removing heavy metals from soil according to claim 1 or 2, characterized in that: the inlet end of the eluent purification equipment is connected in parallel to the water outlet of the plate-and-frame filter press. 6. The leaching device for removing heavy metals from soil according to claim 1 or 2, characterized in that: the feeding of the stirring and rinsing equipment is controlled by a metering pump.