Phosphorus adsorbent prepared from rainwater pipe sludge and application thereof

Abstract

The invention provides a phosphorus adsorbent prepared from rainwater pipe sludge and application of the phosphorus adsorbent, and belongs to the technical field of water treatment adsorption materials. The phosphorus adsorbent is prepared by the following steps: S100, collecting rainwater pipeline dredging sludge, grinding, drying, filtering through a screen, and storing in a drying cabinet; and S200, pyrolyzing the rainwater pipeline dredging sludge treated in the step S100 to obtain the phosphorus adsorbent. During application, the phosphorus adsorbent prepared from the rainwater pipe sludge is put into phosphorus-containing wastewater to adsorb phosphate in the wastewater. Resource utilization of the rainwater pipeline dredging sludge and convenient obtaining of the phosphorus removal adsorbent can be achieved, and the phosphorus removal adsorbent prepared from the rainwater pipeline dredging sludge is high in phosphate removal rate. Compared with some phosphorus adsorbents prepared from industrial sludge, the application range is wider, and the phosphorus adsorbents are contained in the adsorption box, so that the phosphorus adsorbents are conveniently and rapidly recycled in the follow-up process.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment adsorption materials, and in particular relates to a phosphorus adsorbent prepared from rainwater pipe sludge and application thereof. Background Art

[0002] Stormwater pipe sludge is a mixture of mud and sand containing a large amount of organic and inorganic pollutants produced in the urban rainwater discharge network. Its main components include organic matter, silicon, calcium and other elements, and also contain a small amount of iron. Organic matter is the main component in stormwater pipe sludge, with a content of more than 50%. Stormwater pipe sludge also contains a large number of microorganisms, such as bacteria and viruses. If it is not properly disposed of, it will cause environmental pollution. At present, the treatment methods for stormwater pipe sludge include filter pressing, drying, composting, incineration, etc. These methods have some defects and problems, such as occupying land resources and causing secondary pollution. Therefore, finding a treatment method that can achieve the reduction, harmlessness and resource utilization of stormwater pipe sludge is an urgent need for current urban environmental management. Summary of the invention

[0003] In order to solve the above-mentioned defects of the prior art, the present application provides a phosphorus adsorbent prepared from rainwater pipe sludge and its application, which can realize the resource utilization of rainwater pipe ditch sludge and the convenient acquisition of phosphorus removal adsorbent.

[0004] In order to achieve the above object, the present invention adopts the following technologies: A phosphorus adsorbent prepared from rainwater pipe sludge is prepared by the following method, the steps comprising: S100, collecting sludge from the rainwater pipes, grinding and drying it, filtering it through a sieve, and then storing it in a drying cabinet; S200, pyrolyzing the rainwater pipe ditch sludge treated in step S100 to obtain a phosphorus adsorbent.

[0005] Furthermore, in step S200, the rainwater pipe ditch sludge is pyrolyzed in a continuous nitrogen environment.

[0006] Furthermore, the pyrolysis temperature in step S200 is 800° C., and the pyrolysis time is 2 hours.

[0007] An application of a phosphorus adsorbent prepared from rainwater pipe sludge, wherein the phosphorus adsorbent prepared from rainwater pipe sludge is added into a phosphorus-containing water body.

[0008] Furthermore, the phosphorus adsorbent is first placed in an adsorption box with multiple adsorption holes, and then the porous adsorption box is placed in the phosphorus-containing water body; a filter cloth is provided in the adsorption holes to prevent the phosphorus adsorbent placed in the adsorption box from leaking into the phosphorus-containing water body.

[0009] Furthermore, a screen is provided in the adsorption hole, and the screen is provided on the outside of the filter cloth.

[0010] Furthermore, the adsorption box includes a box body and a cover plate. The cover plate and the bottom of the box body are both provided with a plurality of adsorption holes. The cover plate is arranged on the top of the box body and is connected to the box body by a snap buckle.

[0011] Furthermore, a plurality of adsorption boxes filled with phosphorus adsorbents are connected in series on a connecting rope, and both ends of the connecting rope are hung on both sides of the phosphorus-containing water body, and the adsorption boxes are all immersed in the phosphorus-containing water body.

[0012] The beneficial effects of the present invention are: 1. It can realize the resource utilization of rainwater pipe ditch sludge and the convenient acquisition of phosphorus removal adsorbents. The raw materials for the preparation of phosphorus adsorbents only require rainwater pipe ditch sludge. The preparation method is simple. The phosphorus adsorbent prepared by rainwater pipe ditch sludge has a high phosphate removal rate and a high phosphorus adsorption capacity. Compared with some phosphorus adsorbents prepared with industrial sludge, it has a wider range of applications.

[0013] 2. By setting up an adsorption box and placing the phosphorus adsorbent in a hanging manner, the phosphorus adsorbent put into the phosphorus-containing wastewater can be quickly taken out, which is convenient for the subsequent recovery of the adsorption capacity and multiple uses. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the elemental analysis diagram of the phosphorus adsorbent 800N in this application.

[0015] Figure 2 This is a diagram showing the adsorption effects of multiple groups of phosphorus adsorbents in this application.

[0016] Figure 3 This is a diagram showing the adsorption effects of different dosages of the phosphorus adsorbent 800N in this application.

[0017] Figure 4 This is a diagram showing the adsorption effect of the phosphorus adsorbent 800N in this application under different pH conditions.

[0018] Figure 5 This is the ZATA potential diagram of the phosphorus adsorbent 800N in this application under different pH conditions.

[0019] Figure 6 This is the overall structural diagram of the adsorption box in this application.

[0020] Figure 7 It is a top view of the adsorption box in this application.

[0021] Figure 8 This is a schematic diagram of the adsorption box in this application being suspended on both sides of a water body by connecting ropes.

[0022] Figure numerals: adsorption box-1, adsorption hole-101, filter cloth-2, filter screen-3, box body-102, cover plate-103, buckle-104, connecting rope-4. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the implementation modes of the present invention are described in detail below with reference to the accompanying drawings. However, the embodiments described in the present invention are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] The present invention provides a phosphorus adsorbent prepared from rainwater pipe sludge, and the preparation steps include: S100, collecting rainwater pipe ditch sludge, grinding and drying it, filtering it through a screen, and then storing it in a drying cabinet; S200, pyrolyzing the rainwater pipe ditch sludge treated in step S100 to obtain a phosphorus adsorbent.

[0025] The following describes in detail a method for preparing a phosphorus adsorbent using rainwater pipe sludge provided by the present invention through multiple embodiments.

[0026] Example 1 (1) Collect the sludge from the rainwater pipes, place and grind it, dry it in an oven at 60°C for 48 hours until it reaches constant weight, then filter the resulting dried product through a 100-mesh sieve, store it in a drying cabinet, and mark and seal it.

[0027] (2) A tubular furnace was used to pyrolyze the ditch sludge in an air environment, and the pyrolysis was carried out at 600°C, 700°C, 800°C, and 900°C for 2 hours to obtain multiple groups of phosphorus adsorbents. Specifically, the initial temperature of the tubular furnace was set to 20°C, and the heating rate was 5°C / min.

[0028] Example 2 (1) Collect the sludge from the rainwater pipes, place and grind it, dry it in an oven at 60°C for 48 hours until it reaches constant weight, then filter the resulting dried product through a 100-mesh sieve, store it in a drying cabinet, and mark and seal it.

[0029] (2) A tubular furnace was used to pyrolyze the ditch sludge in a continuous nitrogen environment, and the pyrolysis was carried out at 600°C, 700°C, 800°C, and 900°C for 2 hours to obtain multiple groups of phosphorus adsorbents. Specifically, the initial temperature of the tubular furnace was set to 20°C, and the heating rate was 5°C / min.

[0030] The phosphate adsorption performance of the multiple groups of phosphorus adsorbents obtained in Example 1 and Example 2 was tested, and the phosphate adsorption effect of the phosphorus adsorbent on phosphorus was obtained after adding 1 g / L of phosphorus adsorbent to phosphorus-containing wastewater with a phosphate concentration of 20 mg / L and a pH of 6 for 24 hours. The experimental results are as follows: Figure 2As shown, the left vertical axis represents the amount of phosphate adsorbed by each gram of phosphorus adsorbent in phosphorus-containing wastewater, and the right vertical axis represents the removal rate of phosphorus in phosphorus-containing wastewater by the phosphorus adsorbent. 600A, 700A, 800A, and 900A respectively represent that the sludge from the rainwater pipe ditch is in an air environment, and is pyrolyzed for 2 hours at a temperature of 600°C, 700°C, 800°C, and 900°C to obtain the phosphorus adsorbent, and 600N, 700N, 800N, and 900N respectively represent that the sludge from the rainwater pipe ditch is in a continuous nitrogen environment, and is pyrolyzed for 2 hours at a temperature of 600°C, 700°C, 800°C, and 900°C to obtain the phosphorus adsorbent. Figure 2 It can be compared that the best adsorption effect of phosphorus adsorbent (800N) is obtained when the sludge from the rainwater pipe is placed in a continuous nitrogen environment and pyrolyzed at 800°C for 2 hours.

[0031] Figure 1 The EDS graph of 800N was presented, and the results showed that 800N mainly contained C, O, Si, Ca elements, some Fe elements and trace amounts of Zn elements, but did not contain arsenic, lead, cadmium and other heavy metal elements that are harmful to the human body. Compared with some phosphorus adsorbents prepared from industrial sludge, 800N has a wider range of applications.

[0032] In order to evaluate the effect of 800N dosage on phosphate adsorption performance, experimental tests were conducted at dosages of 0.6g / L, 0.8g / L, 1g / L, 1.2g / L, 1.4g / L, 1.6g / L, 1.8g / L, and 2g / L. The phosphate concentration of phosphorus-containing wastewater used in the experiment was 20mg / L, and the pH of phosphorus-containing wastewater was 6. The experimental results are shown in Figure 2. Figure 3 As shown in the figure, it can be seen that increasing the amount of 800N within a certain range provides more adsorption active sites, and the phosphate adsorption efficiency is significantly improved within a certain range. When the amount of 800N reaches a certain value, too much adsorbent leads to the appearance of idle adsorption sites, which leads to a decrease in adsorption efficiency and a waste of resources. Figure 3 It can be seen that when 800N is added at a rate of 1g / L, the removal rate of phosphate reaches 80%, tends to be stable, and the adsorption amount reaches 16.1mg / g. Considering the adsorption effect and economy, the optimal amount is selected to be around 1g / L.

[0033] In order to evaluate the effect of solution pH on the adsorption performance of phosphate, the adsorption effect of 800N was tested experimentally under pH conditions of 4-11. The phosphate concentration of phosphorus-containing wastewater used in the experiment was still 20 mg / L, and 800N was added at a rate of 1 g / L. The experimental results are shown in Figure 2. Figure 4As shown in the figure, the adsorption of phosphate by 800N increased continuously during the pH change from 4 to 8. When the pH was 8, the adsorption effect was the best, with the adsorption amount and removal rate being 19.32 mg / g and 87.75%, respectively. During the pH change from 8 to 10, the adsorption amount decreased, and when the pH changed from 10 to 11, the adsorption amount continued to increase. At pH = 11, a removal rate of 83.99% was obtained. Figure 5 The relationship between the pH of the phosphate solution and the Zeta potential of the added 800N is shown. When the pH of the phosphate solution is 4-11, the adsorbent surface is negatively charged. Figure 4 It can be seen that when the pH of the phosphate solution is less than 5, the adsorption effect of 800N is poor. When the pH is 5-11, the existence state of phosphate is mainly HPO4 2- and H2PO 4- When the pH value changes from 8 to 10, the adsorption effect tends to decrease, indicating that in an alkaline environment, the high concentration of hydroxide ions in the phosphorus solution will react with H2PO4. 4 - Competitive adsorption occurs, thereby reducing the amount of phosphorus adsorption. When pH=11, PO4 3- At this time, the removal rate increased significantly, indicating that the adsorbent has a strong effect on PO4 3- Considering the adsorption effect and economy, the pH of phosphorus-containing wastewater was adjusted to 8 before adding 800N, which had the best effect.

[0034] Considering the convenience of removing the phosphorus adsorbent from the phosphorus-containing wastewater after use, and the recycling of the phosphorus adsorbent. In one embodiment, when 800N is added, the phosphorus adsorbent is first placed in an adsorption box 1 having multiple adsorption holes 101, and then the porous adsorption box 1 is placed in the phosphorus-containing wastewater; for details, refer to Figure 7 , a filter cloth 2 is provided in the adsorption hole 101 to prevent the phosphorus adsorbent placed in the adsorption box 1 from leaking into the phosphorus-containing wastewater. After the phosphorus adsorbent adsorbs phosphate in the phosphorus-containing wastewater to saturation, the adsorption box 1 is taken out to facilitate the subsequent recovery of the adsorption capacity and multiple uses. For details, refer to Figure 6 , Figure 7 A filter screen 3 is also provided in the adsorption hole 101. The filter screen 3 is provided on the outside of the filter cloth 2 to prevent the impurities in the phosphorus-containing wastewater from directly contacting the filter cloth 2 and prevent the filter cloth 2 from being blocked or scratched. Specifically, a 500-mesh screen 3 can be selected. For more details, refer to Figure 6 The adsorption box 1 includes a box body 102 and a cover plate 103. The cover plate 103 and the bottom of the box body 102 are both provided with a plurality of adsorption holes 101. The cover plate 103 is arranged on the top of the box body 102 and is connected to the box body 102 by a buckle 104, which is convenient for disassembly and taking in and out the phosphorus adsorbent.

[0035] Preferably, when 800N is applied, refer to Figure 8, multiple adsorption boxes 1 filled with phosphorus adsorbents are connected in series on a connecting rope 4, and the two ends of the connecting rope 4 are suspended on both sides of the phosphorus-containing water body, and the adsorption boxes 1 are all immersed in the phosphorus-containing water body. In this way, the adsorption box 1 can be suspended in the phosphorus-containing wastewater to prevent the phosphorus-containing wastewater from sinking to the bottom of the phosphorus-containing wastewater, causing the adsorption holes 101 at the bottom of the adsorption box 1 to be close to the bottom of the phosphorus-containing wastewater, affecting the phosphorus-containing wastewater from entering and exiting the adsorption box 1, thereby avoiding the situation that affects the adsorption effect. When taking out the adsorption box 1, multiple adsorption boxes 1 can be taken out at one time by pulling up the connecting rope 4, thereby improving the efficiency of taking out the adsorption box 1.

[0036] The above description is only a preferred embodiment of the present invention, and is not intended to be the only one or to limit the present invention. Those skilled in the art should understand that various changes or equivalent substitutions made to the present invention without departing from the scope of the present invention are within the scope of protection of the present invention.

Claims

1. A phosphorus adsorbent prepared from rainwater pipe sludge, characterized in that: Prepared by the following method, the steps include: S100, collecting sludge from the rainwater pipes, grinding and drying it, filtering it through a sieve, and then storing it in a drying cabinet; S200, pyrolyzing the rainwater pipe ditch sludge treated in step S100 to obtain a phosphorus adsorbent.

2. The phosphorus adsorbent prepared from rainwater pipe sludge according to claim 1, characterized in that: In step S200, the stormwater pipe ditch sludge is pyrolyzed in a continuous nitrogen environment.

3. The phosphorus adsorbent prepared from rainwater pipe sludge according to claim 1, characterized in that: The pyrolysis temperature in step S200 is 800° C. and the pyrolysis time is 2 hours.

4. An application of a phosphorus adsorbent prepared from rainwater pipe sludge, characterized in that: A phosphorus adsorbent prepared from rainwater pipe sludge as described in any one of claims 1 to 3 is added to a phosphorus-containing water body.

5. The use of a phosphorus adsorbent prepared from rainwater pipe sludge according to claim 4, characterized in that: First, a phosphorus adsorbent is placed in an adsorption box (1) having a plurality of adsorption holes (101), and then the porous adsorption box (1) is placed in a phosphorus-containing water body; a filter cloth (2) is provided in the adsorption holes (101) to prevent the phosphorus adsorbent placed in the adsorption box (1) from leaking into the phosphorus-containing water body.

6. The use of a phosphorus adsorbent prepared from rainwater pipe sludge according to claim 5, characterized in that: A filter screen (3) is also provided in the adsorption hole (101), and the filter screen (3) is provided on the outside of the filter cloth (2).

7. The use of a phosphorus adsorbent prepared from rainwater pipe sludge according to claim 5, characterized in that: The adsorption box (1) comprises a box body (102) and a cover plate (103); a plurality of adsorption holes (101) are provided on the cover plate (103) and the bottom of the box body (102); the cover plate (103) is arranged on the top of the box body (102) and is connected to the box body (102) via a buckle (104).

8. The use of a phosphorus adsorbent prepared from rainwater pipe sludge according to claim 5, characterized in that: A plurality of adsorption boxes (1) containing phosphorus adsorbents are connected in series on a connecting rope (4), the two ends of the connecting rope (4) are suspended on both sides of a phosphorus-containing water body, and the adsorption boxes (1) are all immersed in the phosphorus-containing water body.

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