Equipment and method suitable for river and lake endogenous pollution bottom mud treatment

Abstract

The invention belongs to the technical field of river and lake water ecological restoration, and particularly discloses equipment and a method suitable for river and lake endogenous polluted sediment treatment, the equipment suitable for river and lake endogenous polluted sediment treatment comprises a material stirring unit and a curing granulation unit, the material stirring unit comprises a horizontal stirring machine box and is used for stirring and mixing raw materials, and the curing granulation unit is used for curing and granulating the raw materials; one side of the horizontal stirring machine box is connected with a loess spiral feeder, a bottom mud spiral feeder and a curing agent spiral feeder, and a loess crusher is connected between the loess spiral feeder and the horizontal stirring machine box. According to the method, the polluted bottom mud is efficiently converted into the ecological restoration matrix which is resistant to water flow scouring and stable in physical structure through a curing granulation process, the matrix can be directly applied to an underwater environment, and the core problem that existing ecological planting soil prepared through bottom mud recycling cannot be stabilized in a water area is solved; and a key matrix material is provided for in-situ construction of an underwater ecological system such as an underwater forest.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of river and lake water ecological restoration, and particularly relates to a device and method suitable for treatment of endogenous pollution sediment in rivers and lakes. BACKGROUND

[0002] River and lake sediment, as an accumulation and release source of pollutants, has become a core problem restricting the ecological health of water bodies. The enrichment of nitrogen, phosphorus and other pollutants in the sediment will continue to release to the overlying water, and the inorganic fine particles in the sediment are extremely easy to resuspend under disturbance. These two problems not only directly lead to the decrease of water transparency and the deterioration of water quality, but also seriously affect the survival and recovery of submerged plants, hindering the healthy recovery of the water ecological system.

[0003] For the treatment of endogenous pollution sediment in rivers and lakes, traditional dredging technology or sediment elution technology can remove part of the pollutants, but a large amount of waste sediment will be produced. The subsequent disposal of these contaminated sediments faces severe challenges: on the one hand, it is increasingly difficult and costly to find suitable disposal sites such as landfill sites; on the other hand, there are risks of leakage or dispersion of pollutant leachate during the disposal process, which in essence causes secondary transfer of pollutants and does not fundamentally solve the problem.

[0004] To promote the resource utilization of sediment, the existing technology mainly includes burning sediment into building materials, making bricks or using it for road paving, etc. In addition, some studies have also tried to use sediment to prepare ecological planting soil for land greening or riparian restoration. However, in the context of water ecological construction, the existing planting soil cannot resist hydraulic scouring due to weak particle bonding, leading to the aggravation of turbidity deterioration by resuspended particles, forming a "treatment-pollution" cycle.

[0005] The present application provides a river and lake sediment solidification and ecological restoration substrate processing integrated device. The present research uses sediment as raw material, realizes ecological restoration substrate processing through mixing with a solidifying agent and particle manufacturing through pressing, and realizes in-situ coverage through spreading of the restoration substrate to achieve endogenous "double inhibition" in rivers and lakes, i.e. inhibiting the release of in-situ endogenous sediment pollutants and inhibiting sediment resuspension, thereby simultaneously realizing resource utilization of sediment and reconstruction of water ecological substrate habitat. SUMMARY

[0006] To solve the problems raised in the background art, the present application provides a device and method suitable for treatment of endogenous pollution sediment in rivers and lakes.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solution: a device suitable for treatment of endogenous pollution sediment in rivers and lakes, comprising: The material stirring unit comprises a horizontal stirrer box for stirring and mixing raw materials, one side of the horizontal stirrer box is connected with a loess screw feeder, a bottom mud screw feeder and a curing agent screw feeder, the loess screw feeder is connected with a loess pulverizer between the horizontal stirrer box, the loess pulverizer is used for pulverizing loess raw materials entering the horizontal stirrer box, a spiral stirring paddle is installed in the horizontal stirrer box, and the spiral stirring paddle is used for mixing raw materials, a stirring paddle motor is installed on the horizontal stirrer box, the stirring paddle motor is in transmission connection with the spiral stirring paddle through a stirring paddle reducer, an electric butterfly valve for discharging is installed on the side of the horizontal stirrer box away from the loess pulverizer, a mixed material hopper for containing raw materials is installed at a position opposite to the electric butterfly valve of the horizontal stirrer box, and a transparent window is further arranged on the side wall of the horizontal stirrer box and used for observing the mixing state of the raw materials. The solidification and granulation unit is arranged at one side of the horizontal stirrer box close to the mixed material hopper and is used for granulating the mixed materials.

[0008] Further, the solidification and granulation unit comprises an auger conveying barrel, an auger conveying driving motor, a conical hopper box, a motor and a reducer, a pair of roller rotary dies, a discharging outlet, a machine box shell, an equipment support and a finished product storage box. The conical hopper box is arranged at one side of the horizontal stirrer box close to the mixed material, the auger conveying barrel is connected between the conical hopper box and the mixed material hopper, is used for conveying the mixed raw materials in the mixed material hopper into the conical hopper box, the auger conveying driving motor is connected between the auger conveying barrel and the conical hopper box, is used for providing power for the operation of the auger conveying barrel, the pair of roller rotary dies is connected to the bottom of the conical hopper, is used for granulating the raw materials, the motor and the reducer are connected to the pair of roller rotary dies, are used for providing power for the operation of the pair of roller rotary dies, the discharging outlet is arranged at one side of the pair of roller rotary dies away from the horizontal stirrer box, is used for discharging the prepared raw material particles, the machine box shell is connected to the bottom of the pair of roller rotary dies, is used for supporting the pair of roller rotary dies, the equipment support is a frame structure, is used for providing mounting support for each component in the solidification and granulation unit, and the finished product storage box is arranged at the bottom of the discharging outlet and is used for containing the prepared raw material particles.

[0009] Further, the loess screw feeder, the bottom mud screw feeder and the curing agent screw feeder all adopt end-driven auger conveyors, the length is 10 meters, the conveying pipeline diameter is 120 mm, the motor voltage is 220 V, and the motor power is 4.5 kW.

[0010] Further, the auger conveyor adopts a middle-driven auger conveyor, the length is 16 meters, and the conveying pipeline diameter is 120 mm.

[0011] Further, the horizontal mixer box has a capacity of 2t, the motor voltage is 380V, and the motor power is 11kW.

[0012] Further, the loess crusher has a motor power of 3kW and a motor voltage of 220V.

[0013] Further, the motor and the reducer have a motor power of 22kW.

[0014] Further, the die hole diameter of the counter-roller rotary die is 5mm to 10cm.

[0015] The application also provides a use method of the equipment suitable for in-situ treatment of river and lake pollution sediment, which comprises the following steps: Step one, material conveying: when working, the loess spiral feeder, the sediment spiral feeder and the curing agent spiral feeder are started to add the three raw materials into the horizontal mixer box, and before the loess is conveyed into the horizontal mixer box, the loess crusher can crush the conveyed loess; Step two, mixing and stirring: when the three raw materials are conveyed, the spiral stirring paddle can be driven by the stirring paddle motor and the stirring paddle reducer to fully mix the three raw materials, and when it is observed through the window that the raw materials are uniformly mixed, the electric butterfly valve is opened, at this time, the mixed raw materials can slide into the mixed material hopper under the action of gravity, and then the auger conveying barrel can convey the raw materials in the mixed material hopper to the conical hopper box under the action of the auger conveying driving motor; Step three, granulation: when the motor and the reducer are started, the raw materials in the conical hopper box can be pressed into particles with a particle size of 5mm to 10cm under the action of the counter-roller rotary die, and then the pressed particles can fall into the finished product storage box under the action of gravity through the discharge outlet on the machine box shell for temporary storage; Step four, particle curing: after granulation, the water pump and the water pipe are used to spray water to the raw material particles in the finished product storage box (2.9) until the compressive strength of the raw material particles reaches the preset value (compressive strength ≥0.5MPa), and then the particles are sprayed into the river as an ecological restoration substrate for in-situ sediment covering.

[0016] The technical effects and advantages of the application are as follows: 1. The application can efficiently convert the pollution sediment into ecological restoration substrate particles with water flow erosion resistance and stable physical structure through the solidification and granulation process, the particles can be directly applied to the underwater environment, and the core problem that the existing ecological planting soil prepared by sediment resourceization cannot stably exist in the water area is solved, which provides key substrate materials for in-situ construction of underwater forest and other water ecological systems. 2, The application utilizes the prepared ecological restoration substrate particles to carry out in-situ covering, forms a stable physical barrier on the surface of the river and lake sediment, the layer of barrier can simultaneously and efficiently inhibit the release of nitrogen, phosphorus and other pollutants in the underlying polluted sediment to the overlying water body, and can effectively prevent the resuspension of the underlying inorganic fine particles under the disturbance of water flow, the "double inhibition" effect significantly improves the water transparency, improves the water quality, creates favorable conditions for the planting and growth of submerged vegetation and other aquatic organisms, and plays a fundamental and positive role in the restoration and health maintenance of water ecological system; 3, The application patent technology is matched with a highly integrated solidification and granulation equipment, realizes the continuous and automatic production from the sediment raw material to the finished product particles, the integrated system significantly reduces the manual operation strength and cost input, and greatly improves the production efficiency, and the production capacity can reach 80 tons / day. The high efficiency and large-scale processing capacity provides strong technical equipment support for the large-scale resource utilization of the polluted sediment and the rapid implementation of the river and lake treatment project. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the whole structure diagram of the sediment solidification and ecological restoration substrate processing integrated equipment of the application; Figure 2 It is the whole structure diagram of the material stirring unit; Figure 3 It is the whole structure diagram of the solidification and granulation unit; Figure 4 It is the comparison diagram of the compressive strength of different solidification agent content planting bases; Figure 5 It is the overlying water pollutant concentration change: TOC (a), NH4+-N (b), TN (c) and TP (d); Figure 6 It is the change of the pollutant concentration of the ecological restoration substrate: TOC (a), NH4+-N (b), TN (c) and AVS (d); Figure 7 It is the comparison diagram of the inhibition effect of different planting base covering depths on ammonia nitrogen and TOC; Figure 8 It is the comparison diagram of the inhibition effect of different planting base covering depths on turbidity.

[0018] In the figure: 1, material stirring unit; 1.1, loess screw feeder; 1.2, bottom mud screw feeder; 1.3, curing agent screw feeder; 1.4, loess crusher; 1.5, horizontal stirrer box; 1.6, spiral stirring paddle; 1.7, stirring paddle reducer; 1.8, stirring paddle motor; 1.9, electric butterfly valve; 1.10, mixed material hopper; 1.11, window; 2, solidification and granulation unit; 2.1, auger conveying barrel; 2.2, auger conveying drive motor; 2.3, conical hopper box; 2.4, motor and reducer; 2.5, double-roller rotary mold; 2.6, machine box shell; 2.7, equipment support; 2.8, discharge outlet; 2.9, finished product storage box. DETAILED DESCRIPTION

[0019] Example 1: Equipment operation and start-up In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described clearly and completely below in conjunction with the embodiments.

[0020] The present application provides a device suitable for treating river and lake internal source pollution bottom mud, as shown in Figures 1 to 8 The device comprises a material stirring unit 1 and a solidification and granulation unit 2. The material stirring unit 1 comprises a horizontal stirrer box 1.5 for stirring and mixing raw materials. The horizontal stirrer box 1.5 is connected on one side with a loess screw feeder 1.1, a bottom mud screw feeder 1.2 and a curing agent screw feeder 1.3. The loess screw feeder 1.1 is connected with the horizontal stirrer box 1.5 through a loess crusher 1.4 for crushing loess raw materials entering the horizontal stirrer box 1.5. The horizontal stirrer box 1.5 is provided with a spiral stirring paddle 1.6 for mixing raw materials. The horizontal stirrer box 1.5 is provided with a stirring paddle motor 1.8. The stirring paddle motor 1.8 is drivingly connected with the spiral stirring paddle 1.6 through a stirring paddle reducer 1.7. The side of the horizontal stirrer box 1.5 away from the loess crusher 1.4 is provided with an electric butterfly valve 1.9 for discharging. The horizontal stirrer box 1.5 is provided opposite the electric butterfly valve 1.9 with a mixed material hopper 1.10 for receiving raw materials. The side wall of the horizontal stirrer box 1.5 is further provided with a transparent window 1.11 for observing the mixing condition of raw materials. The loess screw feeder 1.1, the bottom mud screw feeder 1.2 and the curing agent screw feeder 1.3 are all end-driven auger conveyors with a length of 10 meters, a conveying pipe diameter of 120 mm, a motor voltage of 220 V and a motor power of 4.5 KW. The capacity of the horizontal stirrer box 1.5 is 2 t, the motor voltage is 380 V and the motor power is 11 KW. The motor power of the loess crusher 1.4 is 3 KW and the motor voltage is 220 V. The solidification granulation unit 2 is arranged on one side of the horizontal mixer box 1.5 close to the mixture hopper 1.10, and is used for granulating the mixed material; In use, the loess spiral feeder 1.1 conveys raw material loess, which is crushed by the loess crusher 1.4 and then enters the horizontal mixer box 1.5, the bottom mud spiral feeder 1.2 conveys bottom mud (water content 35% to 40%) into the horizontal mixer box 1.5, and the solidification agent spiral feeder 1.3 conveys bottom mud solidification agent (silicate solidification agent and heavy metal adsorbent) into the horizontal mixer box 1.5, and different planting bases can be prepared according to the ratio of the three raw materials (different solidification agent contents), for example, bottom mud:solidification agent:loess=5:1:4, 5:1.5:3.5, 5:2:3, 5:2.5:2.5, when the three raw materials are conveyed into the horizontal mixer box 1.5, the spiral stirring paddle 1.6 can be driven by the stirring paddle motor 1.8 and the stirring paddle reducer 1.7 to fully mix the three raw materials, when the raw materials are observed to be uniformly mixed through the window 1.11, the electric butterfly valve 1.9 is opened, at this time, the mixed raw materials can slide into the mixture hopper 1.10 under the action of gravity, and then the solidification granulation unit 2 can suck the mixed raw materials into its interior for granulation operation, when the granulation is completed, a water pump and a water pipe are used to spray water on the raw material particles for curing until the compressive property of the raw material particles reaches a preset value (compressive strength ≥0.5MPa), and the raw material particles are used as ecological restoration substrates for in-situ bottom mud covering.

[0021] The present application surrounds the efficient preparation of ecological restoration substrate particles suitable for underwater environment and water ecological restoration target, from the aspect of equipment, the integration breaks the capacity and efficiency limit, from the aspect of water ecological restoration strategy: with the double inhibition mechanism of "covering and repairing", the in-situ water ecological management and resource cycle closed loop has the following beneficial effects: (1) The full-process integrated equipment system realizes efficient resource conversion of contaminated bottom mud By developing the "solidification-pressing molding-granulation" integrated equipment, the traditional dispersed bottom mud treatment processes (solidification agent adding, mixing and stirring, dewatering, molding) are integrated into a single continuous production line. The equipment adopts modular series design (feeding and crushing module→precise metering and mixing module→high-pressure pressing and molding module→curing module), realizing the non-interrupted automatic production of contaminated bottom mud from raw material to finished product particles. This design breaks through the traditional technology and equipment dispersion, long process and multiple manual intervention, and significantly improves the production capacity to 80 tons / day, providing equipment support for large-scale water ecological restoration engineering; (2) Double inhibition synergistic repair mechanism of in-situ covering type ecological restoration substrate The application creatively proposes an in-situ covering strategy of "waste treatment with waste": the bottom mud resource product (ecological restoration matrix granules) is directly spread on the surface of the contaminated bottom mud to simultaneously achieve the physical barrier and biochemical stability effects. ①Physical inhibition of particle resuspension: the high mechanical strength (compressive strength ≥ 0.5 MPa) and optimized particle size distribution (5 mm-10 cm) of the granules form a dense covering layer, effectively resisting water flow erosion and blocking the upward floating of inorganic fine particles in the bottom mud; ②Biochemical inhibition of pollutant release: the "bacteria-algae symbiosis" biofilm on the surface of the granules adsorbs and degrades nitrogen and organic pollutants, blocking their diffusion to the overlying water. The synergistic effect of double inhibition significantly improves water transparency, creating a stable substrate environment for the colonization of submerged plants, directly driving the ecological reconstruction of "underwater forest", and breaking through the bottleneck that existing resource products cannot be applied underwater.

[0022] As shown in Figure 1 and Figure 3 , the solidification and granulation unit 2 includes an auger conveying barrel 2.1, an auger conveying drive motor 2.2, a conical hopper box 2.3, a motor and reducer 2.4, a pair of roller rotating dies 2.5, a discharge outlet 2.8, a machine box shell 2.6, a device support 2.7, and a finished product storage box 2.9; The conical hopper box 2.3 is arranged on the side close to the mixed material of the horizontal mixer box 1.5, the auger conveying barrel 2.1 is connected between the conical hopper box 2.3 and the mixed material hopper 1.10, for conveying the mixed raw materials in the mixed material hopper 1.10 to the conical hopper box 2.3, the auger conveying drive motor 2.2 is connected between the auger conveying barrel 2.1 and the conical hopper box 2.3, for providing power for the operation of the auger conveying barrel 2.1, the pair of roller rotating dies 2.5 is connected to the bottom of the conical hopper, for granulating the raw materials, the motor and reducer 2.4 is connected to the pair of roller rotating dies 2.5, for providing power for the operation of the pair of roller rotating dies 2.5, the discharge outlet 2.8 is arranged on the side away from the horizontal mixer box 1.5 of the pair of roller rotating dies 2.5, for discharging the prepared raw material particles, the machine box shell 2.6 is connected to the bottom of the pair of roller rotating dies 2.5, for providing support for the pair of roller rotating dies 2.5, the device support 2.7 is a frame structure, for providing installation support for each component in the solidification and granulation unit 2, the finished product storage box 2.9 is arranged at the bottom of the discharge outlet 2.8, for receiving the prepared raw material particles, the motor power of the motor and reducer 2.4 is 22 kW, and the die hole diameter of the pair of roller rotating dies 2.5 is 5 mm to 10 cm; When the mixed raw materials slide into the mixing hopper 1.10 under the action of gravity, the auger conveying barrel 2.1 can convey the raw materials in the mixing hopper 1.10 to the conical hopper box 2.3 under the action of the auger conveying drive motor 2.2, and then the raw materials in the conical hopper box 2.3 can be pressed into an elliptical particle planting base with a particle size of 5mm to 10cm under the action of the counter-roller rotary die 2.5 after the motor and reducer 2.4 are started, and then the pressed particles can fall into the finished product storage box 2.9 through the discharge outlet 2.8 on the machine box shell 2.6 under the action of gravity.

[0023] Water is sprayed on the raw material particles in the finished product storage box 2.9 using a water pump and a water pipe until the compressive strength of the raw material particles reaches a preset value. After the granulation is completed, the prepared raw material particles are sprayed and maintained every day using a water pump and a water pipe, and the continuous maintenance is 14 days, and when the compressive strength of the prepared raw material particles reaches 0.20-0.35Mpa, the in-situ river bottom mud covering operation can be performed, and the covering thickness is 5-15cm.

[0024] The application also provides a use method of the equipment suitable for river and lake internal source pollution bottom mud treatment, which comprises the following steps: Step one, material conveying: when working, the loess screw feeder 1.1, the bottom mud screw feeder 1.2 and the curing agent screw feeder 1.3 are started at the same time to add the three raw materials into the horizontal mixer box 1.5, and the loess pulverizer 1.4 can pulverize the transported loess before the loess is transported into the horizontal mixer box 1.5. Step two, mixing and stirring: when the three raw materials are transported, the spiral stirring paddle 1.6 can be driven by the stirring paddle motor 1.8 and the stirring paddle reducer 1.7 to fully mix the three raw materials after the stirring paddle motor 1.8 and the stirring paddle reducer 1.7 are started, and when it is observed through the window 1.11 that the raw materials are uniformly mixed, the electric butterfly valve 1.9 is opened, and then the mixed raw materials can slide into the mixing hopper 1.10 under the action of gravity, and then the auger conveying barrel 2.1 can convey the raw materials in the mixing hopper 1.10 to the conical hopper box 2.3 under the action of the auger conveying drive motor 2.2. Step three, particle pressing: the raw materials in the conical hopper box 2.3 can be pressed into particles with a particle size of 5mm or 10mm under the action of the counter-roller rotary die 2.5 after the motor and reducer 2.4 are started, and then the pressed particles can fall into the finished product storage box 2.9 through the discharge outlet 2.8 on the machine box shell 2.6 under the action of gravity. Step four, granule maintenance: when the granulation is completed, the water pump and water pipe are used to spray water on the prepared raw material granules for daily maintenance, and the maintenance is continued for 14 days, waiting for the prepared raw material granules to reach a compressive strength of 0.20-0.35 MPa, and then the granules can be subjected to in-situ bottom sediment covering operation.

[0025] Example two: compressive strength of planting base Take 4 different curing agent contents (10%, 15%, 20% and 25%) of ecological restoration substrate products, and take 8 kg of planting base for each group into four water tanks with specifications of 54x42x30 cm, and sprinkle 3 to 4 cm of river sand on the bottom of the tank. The well-maintained planting base is laid on the river sand, 40 L of tap water is added to the experimental water tank, and a 42-day static water test is conducted. The compressive strength is monitored every 7 days during the test.

[0026] From Figure 4 It can be seen that the compressive strength of the planting base with 4 different curing agent contents shows a gradually increasing trend. At the same time, with the increase of the content of Portland cement in the mixed material, the compressive strength of the planting base gradually increases, and the compressive strengths of the first to fourth groups all reach the peak value at 21 d and remain stable during the remaining curing period. In the fourth group, the raw material ratio of Portland cement: loess: bottom sediment is 5:2.5:2.5, and the unconfined compressive strength of the planting base is the highest at 0.5 MPa after 28 days of curing.

[0027] Table 1: mass mixing ratio of contaminated bottom sediment and curing agent Example three: pollutant release characteristics On the basis of the batch test of example two, the changes of nitrogen and phosphorus nutrients, sulfur compounds and organic pollutants in the overlying water and planting base are monitored every 7 days during the test, so as to characterize the release rate of pollutants from the planting base to the water body.

[0028] From Figure 5 It can be seen that the contents of TOC, NH4 + -N, TN and TP in the overlying water all show a trend of first increasing and then decreasing. The peak concentrations of NH4 + -N and TP are at 7 days, the peak concentration of TOC is at 14 days, and the peak concentration of TN in the first group is at 7 days, while the peak concentrations of the experimental groups are at 14 days. Thereafter, the pollutant indicators of each group show a downward trend, and show the rule that "the higher the cement content, the lower the concentration of pollutants in the overlying water". At 42 days, the TOC, NH4 +The concentrations of -N, TN, and TP were only 60.9%, 50.0%, 46.3%, and 15.1% of the pollutant concentrations in the overlying water of Group 1, respectively. Before the pollutants in the overlying water reached their peak concentration, the large specific surface area of ​​the planting substrate and the difference in mud-water concentration caused the pollutants to be rapidly released into the overlying water, and the cumulative concentration of pollutants in the water phase gradually increased. Subsequently, due to the synergistic and balanced effect of the degradation and transformation of pollutants by bacteria and algae attached to the surface of the planting substrate and the slow release rate of pollutants by cement in the planting substrate, the concentration of pollutants in the overlying water of the experimental group was lower than that of Group 1.

[0029] During the experimental period, the pollutant content in the sediment of all four planting substrates showed a continuous decreasing trend. Furthermore, with the increase of solidifying agent content, the release of various pollutant indicators from the sediment decreased, indicating that the solidifying agent slowed down the pollutant release rate. On day 42, compared to group 1, the levels of TOC and NH4 in the planting substrates of groups 2-4 were significantly lower. + The release rates of -N, TN, and AVS decreased by 7.23 times, 2.95 times, 1.72 times, and 2.12 times, respectively. After day 14, the concentration of pollutants in the sediment showed a significant and continuous decrease, while the concentration of pollutants in the overlying water gradually decreased, specifically the concentrations of TOC and NH4+ in the sediment-water system. + The total amounts of -N, TN, and AVS gradually decreased, indicating that the planting substrate had a significant inhibitory effect on the release of various pollutants.

[0030] Example 4: Effect of Substrate Coverage Five water tanks, each measuring 54×42×30cm, were used. A 10cm layer of black, foul-smelling sediment was spread at the bottom of each tank, and the tanks were numbered 1-5. Group 1 served as a blank control group. Groups 2-4 were then equipped with 5mm particle size ecological restoration substrate products with particle sizes of 2cm, 5cm, 10cm, and 20cm, respectively, followed by the addition of 40L of overlying water. NH4 levels in the overlying water were measured every 12 hours. + -N, TOC, and turbidity were measured continuously for 7 days, and NH4 was calculated separately. + -N and TOC release rates were assessed to evaluate the impact of planting substrate cover thickness on pollutant release rates.

[0031] Depend on Figure 7 It can be seen that as the cover thickness increases, the release rates of dissolved ammonia nitrogen and TOC gradually decrease, and the pollutant release rates tend to reach equilibrium when the cover depth is 10cm-20cm. Therefore, considering both economic efficiency and pollutant suppression effectiveness, 10cm is the optimal cover depth for the planting substrate (at which point NH4+...). + -N release rate is 2 mg / (m 2 ·d), TOC release rate is 5 mg / (m³) 2 ·d)).

[0032] Depend on Figure 8It can be seen that the turbidity of the planting base test group is significantly lower than that of the control group. When the covering depth is 5 cm or 10 cm, the turbidity of the overlying water is 4.5 NTU and 4 NTU, respectively. It is proved that the planting base can stabilize the mud-water interface and inhibit the resuspension of fine particles. In summary, the planting base has a "double inhibition" effect of inhibiting pollutant release and inhibiting particle resuspension, which can significantly improve the transparency of the water body.

[0033] The above examples are only used to illustrate the technical solutions of the present application, but not limit it.

Claims

1. A device suitable for in-situ treatment of polluted sediment in rivers and lakes, characterized in that, It comprises: The material stirring unit (1) comprises a horizontal mixer box (1.5) for stirring mixed raw materials, a loess screw feeder (1.1), a bottom mud screw feeder (1.2) and a curing agent screw feeder (1.3) connected to one side of the horizontal mixer box (1.5), a loess crusher (1.4) connected between the loess screw feeder (1.1) and the horizontal mixer box (1.5) for crushing loess raw materials entering the horizontal mixer box (1.5), a spiral stirring paddle (1.6) installed in the horizontal mixer box (1.5) for mixing raw materials, a stirring paddle motor (1.8) installed on the horizontal mixer box (1.5), the stirring paddle motor (1.8) and the spiral stirring paddle (1.6) being drivingly connected together through a stirring paddle reducer (1.7), an electric butterfly valve (1.9) installed on the side of the horizontal mixer box (1.5) away from the loess crusher (1.4) for unloading, a mixed material hopper (1.10) installed opposite the electric butterfly valve (1.9) for receiving raw materials, and a transparent window (1.11) provided on the side wall of the horizontal mixer box (1.5) for observing the mixing condition of the raw materials; The solidification and granulation unit (2) is arranged on the side of the horizontal mixer box (1.5) close to the mixed material hopper (1.10) for granulating the mixed materials.

2. The device suitable for in-situ pollution sediment treatment in rivers and lakes according to claim 1, characterized in that, The solidification and granulation unit (2) comprises an auger conveying barrel (2.1), an auger conveying drive motor (2.2), a conical hopper box (2.3), a motor and reducer (2.4), a pair of roller rotary dies (2.5), an unloading outlet (2.8), a machine box shell (2.6), an equipment support (2.7) and a finished product storage box (2.9). The conical hopper box (2.3) is arranged on the side of the horizontal mixer box (1.5) close to the mixed material, the auger conveying barrel (2.1) is connected between the conical hopper box (2.3) and the mixed material hopper (1.10), which is used to convey the mixed raw materials in the mixed material hopper (1.10) to the conical hopper box (2.3), the auger conveying drive motor (2.2) is connected between the auger conveying barrel (2.1) and the conical hopper box (2.3), which is used to provide power for the operation of the auger conveying barrel (2.1), the pair of roller rotary die (2.5) is connected to the bottom of the conical hopper, which is used for granulating the raw materials, the motor and reducer (2.4) is connected to the pair of roller rotary die (2.5), which is used to provide power for the operation of the pair of roller rotary die (2.5), the discharge outlet (2.8) is arranged on the side of the pair of roller rotary die (2.5) away from the horizontal mixer box (1.5), which is used to discharge the prepared raw material particles, the machine box shell (2.6) is connected to the bottom of the pair of roller rotary die (2.5), which is used to support the pair of roller rotary die (2.5), the equipment support (2.7) is a frame structure, which is used to provide installation support for each component in the solidification and granulation unit (2), and the finished product storage box (2.9) is arranged at the bottom of the discharge outlet (2.8), which is used to receive the prepared raw material particles.

3. The device suitable for in-situ pollution sediment treatment in rivers and lakes according to claim 2, characterized in that, The loess spiral feeder (1.1), the bottom mud spiral feeder (1.2) and the curing agent spiral feeder (1.3) all adopt end-driven auger conveyors, with a length of 10 meters, a conveying pipe diameter of 120mm, a motor voltage of 220V and a motor power of 4.5kW.

4. The device suitable for in-situ remediation of lake and river sediment pollution according to claim 3, characterized in that, The auger conveyor (3.1) adopts a middle-driven auger conveyor, with a length of 16 meters and a conveying pipe diameter of 120mm.

5. The device suitable for in-situ remediation of lake and river sediment pollution according to claim 4, characterized in that, The capacity of the horizontal mixer box (1.5) is 2t, the motor voltage is 380V, and the motor power is 11kW.

6. The device suitable for in-situ remediation of polluted sediment in rivers and lakes according to claim 5, characterized in that, The motor power of the loess pulverizer (1.4) is 3kW, and the motor voltage is 220V.

7. The device suitable for in-situ remediation of lake and river sediment pollution according to claim 6, characterized in that, The motor power of the motor and reducer (2.4) is 22kW.

8. The device suitable for in-situ remediation of lake and river sediment pollution according to claim 7, characterized in that, The die hole diameter of the pair of roller rotary die (2.5) is 5mm to 10cm. 9.The use of the device for treating the in-situ pollution of the sediment in rivers and lakes according to claim 8, characterized in that, The method comprises the following steps: Step one, material conveying: when working, the loess spiral feeder (1.1), the bottom mud spiral feeder (1.2) and the curing agent spiral feeder (1.3) are started at the same time to add three kinds of raw materials into the horizontal mixer box (1.5), and before the loess is conveyed into the horizontal mixer box (1.5), the loess pulverizer (1.4) can perform pulverizing operation on the conveyed loess; Step two, mixing and stirring: different planting bases can be prepared according to the ratio of the three raw materials (different content of curing agent), for example, the ratio of sediment, curing agent and loess is 5:1:4, 5:1.5:3.5, 5:2:3 and 5:2.5:2.

5. When the three raw materials are transported, the spiral stirring paddle (1.6) can be driven by the stirring paddle motor (1.8) and the stirring paddle reducer (1.7) to mix the three raw materials thoroughly. When the raw materials are observed to be uniformly mixed through the window (1.11), the electric butterfly valve (1.9) is opened, and the mixed raw materials can slide into the mixed material hopper (1.10) under the action of gravity. Then the auger conveying barrel (2.1) can convey the raw materials in the mixed material hopper (1.10) to the conical hopper box (2.3) under the action of the auger conveying drive motor (2.2); Step three, granulation: when the motor and reducer (2.4) are started, the raw materials in the conical hopper box (2.3) can be pressed into particles with a particle size of 5mm to 10cm under the action of the counter-roller rotary die (2.5). Then the pressed particles can fall into the finished product storage box (2.9) through the discharge outlet (2.8) on the machine box shell (2.6) under the action of gravity for temporary storage; Step four, particle curing: after granulation, water is sprayed on the raw material particles in the finished product storage box (2.9) using a water pump and a water pipe for curing until the compressive strength of the raw material particles reaches the preset value. Then the particles are recycled.

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