Papermaking Fenton sludge and treatment method thereof

Abstract

The invention provides papermaking Fenton sludge and a treatment method thereof. The treatment method comprises the following steps: performing concentration treatment on the Fenton sludge, wherein the concentration of the concentrated Fenton sludge is 3-4%; the concentrated Fenton sludge is conditioned, and polyaluminum chloride and an organic coagulant are added in the conditioning process. The papermaking Fenton sludge treatment method provided by the embodiment of the invention has the advantages of improving the solid content of the sludge, improving the heat value of the sludge and improving the sludge treatment efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of sludge treatment, in particular to a papermaking Fenton sludge and a treatment method thereof. BACKGROUND

[0002] The pretreatment method for sludge deep dewatering is mainly chemical conditioning. However, it is difficult to achieve good conditioning effect and reduce treatment cost by using a single conditioning method. In production practice, the method of combining inorganic flocculants and organic polymer flocculants with high-pressure dewatering equipment is generally used, and the water content is dewatered to below 60%, which is a mature sludge conditioning deep dewatering technology. However, the addition amount of inorganic conditioning agent is large, which is equivalent to increasing the dry weight of sludge, and the organic matter content and heat value of sludge are correspondingly reduced, the dewatering cost is high, and it is not conducive to the subsequent resource utilization of sludge. SUMMARY

[0003] The first aspect of the embodiment of the application provides a treatment method of papermaking Fenton sludge, and the treatment method comprises the following steps:

[0004] The Fenton sludge is concentrated, and the concentration of the concentrated Fenton sludge is 3%-4%;

[0005] The concentrated Fenton sludge is conditioned, wherein polyaluminum chloride and an organic coagulant are added in the conditioning process.

[0006] In some optional embodiments, in the step of concentrating the Fenton sludge, an amphoteric flocculant is added for concentration.

[0007] In some optional embodiments, the addition amount of the amphoteric flocculant is 50-120 ppm.

[0008] In some optional embodiments, in the step of conditioning the concentrated Fenton sludge, the addition amount of the polyaluminum chloride is 8000-16000 ppm.

[0009] In some optional embodiments, in the step of conditioning the concentrated Fenton sludge, the addition amount of the organic coagulant is 200-800 ppm.

[0010] In some optional embodiments, the organic coagulant is a low-molecular-weight organic polymer.

[0011] In some optional embodiments, the organic coagulant comprises any one or a combination of chloropropylene, acrylonitrile and dimethyl quaternary ammonium salt.

[0012] In some optional embodiments, in the step of conditioning the concentrated Fenton sludge, cationic polyacrylamide is also added, and the addition amount is 80-120 ppm.

[0013] In some optional embodiments, the treatment method further comprises mixing the concentrated Fenton sludge with primary sludge before the step of conditioning the concentrated Fenton sludge, wherein the ratio of the primary sludge is 0-20%.

[0014] In a second aspect, the embodiments of the present application provide a papermaking Fenton sludge, which is treated by the treatment method described in the above embodiments.

[0015] The treatment method of the papermaking Fenton sludge provided by the embodiments of the present application has the advantages of improving the solid content of the sludge, improving the heat value of the sludge, and improving the sludge treatment efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 is a flowchart of an embodiment of the treatment method of the papermaking Fenton sludge of the present application;

[0018] Figure 2 is a flowchart of another embodiment of the treatment method of the papermaking Fenton sludge of the present application. DETAILED DESCRIPTION

[0019] The present application will be further described in detail below in combination with the drawings and embodiments. It is particularly pointed out that the following embodiments are only used to illustrate the present application, but do not limit the scope of the present application. Similarly, the following embodiments are only some embodiments of the present application, not all embodiments, and all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] The terms "first", "second", "third", etc. in the embodiments of the present application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly. The terms "include" and "have" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or components inherent to the process, method, product or device.

[0021] Reference herein to "embodiments" means that a particular feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor does it necessarily refer to a separate or alternative embodiment in isolation or in combination with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] The wastewater COD of the mechanical pulp wastewater entering the Fenton deep treatment link of our company is about 1500 mg / L, and the Fenton sludge yield is large. Therefore, it is necessary to study a method for reducing the dosage of the conditioning agent, reducing the cost, having strong dewatering effect, and no secondary pollution. The present application provides a conditioning method for treating papermaking Fenton sludge.

[0023] Please refer to Figure 1 , Figure 1 is a flowchart of an embodiment of the papermaking Fenton sludge treatment method of the present application, which includes but is not limited to the following steps.

[0024] Step S100, the Fenton sludge is concentrated.

[0025] In this step, specifically in the Fenton sludge concentration tank, cationic (such as cationic polyacrylamide PAM) or amphoteric flocculant (such as amphoteric polyacrylamide) is used for concentration, the Fenton sludge concentration is increased from 2% to 3%-4%, the Fenton sludge volume is reduced, and the Fenton sludge treatment efficiency is improved. The dosage of amphoteric flocculant is 50-120 ppm, specifically 50 ppm, 55 ppm, 60 ppm, 70 ppm, 80 ppm, 88 ppm, 90 ppm, 93 ppm, 100 ppm, 120 ppm, etc.

[0026] Step S200, the concentrated Fenton sludge is conditioned.

[0027] Optionally, step S200 can be performed in the Fenton sludge conditioning tank. This step can specifically add polyaluminum chloride and organic coagulant for conditioning. Through the adsorption, wrapping, bridging, etc. of cationic polyacrylamide, large particle flocculation bodies are formed. The addition amount of polyaluminum chloride (PAC) is 8000-16000 ppm, specifically 8000 ppm, 8500 ppm, 9000 ppm, 10000 ppm, 11000 ppm, 12000 ppm, 15000 ppm, 16000 ppm, etc. The addition amount of organic coagulant is 200-800 ppm, specifically 200 ppm, 250 ppm, 300 ppm, 400 ppm, 500 ppm, 550 ppm, 600 ppm, 700 ppm, 800 ppm, etc.

[0028] The organic coagulant is a low molecular weight organic polymer, including any one or a combination of chloropropylene, acrylonitrile, dimethyl quaternary ammonium salt.

[0029] In addition, cationic polyacrylamide (PAM) can also be added during conditioning, the addition amount is 80-120 ppm, specifically 80 ppm, 85 ppm, 88 ppm, 90 ppm, 95 ppm, 100 ppm, 120 ppm, etc.

[0030] Please refer to Figure 2 , Figure 2 is a flow diagram of another embodiment of the papermaking Fenton sludge treatment method of the present application, which includes but is not limited to the following steps.

[0031] It should be noted that the papermaking Fenton sludge treatment method in this embodiment includes the following equipment: Fenton sludge concentration tank, sludge pump, Fenton sludge conditioning tank, PAC dosing system, organic coagulant dosing system, PAM dosing system, stirrer, high-low pressure pump, plate and frame filter press, etc.

[0032] Step S100, the Fenton sludge is concentrated.

[0033] In this step, specifically in the Fenton sludge concentration tank, cation (such as cationic polyacrylamide PAM) or amphoteric flocculant (such as amphoteric polyacrylamide) is used for concentration, the Fenton sludge concentration is increased from 2% to 3%-4%, the Fenton sludge volume is reduced, and the Fenton sludge treatment efficiency is improved. The dosage of the amphoteric flocculant is 50-120 ppm, and specifically can be 50 ppm, 55 ppm, 60 ppm, 70 ppm, 80 ppm, 88 ppm, 90 ppm, 93 ppm, 100 ppm, 120 ppm, etc.

[0034] Please continue to refer to Figure 2 Unlike the foregoing embodiments, the treatment method in this embodiment further includes step S300 of mixing the concentrated Fenton sludge with primary sludge.

[0035] The proportion of the primary sludge is 0-20% (percentage of the total amount of mixed sludge), and specifically can be 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, etc.

[0036] Step S200, the concentrated Fenton sludge is conditioned.

[0037] Optionally, step S200 can be performed in a Fenton sludge conditioning tank. This step can specifically be conditioning by adding polyaluminum chloride and organic coagulant. Through the adsorption, wrapping, bridging, etc. of cationic polyacrylamide, large-particle flocculation bodies are formed. The addition amount of polyaluminum chloride (PAC) is 8000-16000 ppm, and specifically can be 8000 ppm, 8500 ppm, 9000 ppm, 10000 ppm, 11000 ppm, 12000 ppm, 15000 ppm, 16000 ppm, etc. The addition amount of organic coagulant is 200-800 ppm, and specifically can be 200 ppm, 250 ppm, 300 ppm, 400 ppm, 500 ppm, 550 ppm, 600 ppm, 700 ppm, 800 ppm, etc.

[0038] The organic coagulant is a low-molecular-weight organic polymer, including any one or a combination of chloropropylene, acrylonitrile, and dimethyl quaternary ammonium salt.

[0039] In addition, cationic polyacrylamide (PAM) can also be added during conditioning, and the addition amount is 80-120 ppm, and specifically can be 80 ppm, 85 ppm, 88 ppm, 90 ppm, 95 ppm, 100 ppm, 120 ppm, etc.

[0040] The papermaking Fenton sludge treatment method in the embodiment of the application proposes a conditioning method for treating papermaking Fenton sludge, a Fenton sludge pretreatment tank is added, a cationic or amphoteric flocculating agent is used for pretreatment, and the Fenton sludge concentration is increased. In the sludge conditioning tank, a certain proportion of primary sludge is added, and an organic coagulant, an inorganic salt coagulant and a cationic flocculating agent are used for conditioning. The application has the advantages of improving the sludge solid content, improving the sludge heat value and improving the sludge treatment efficiency.

[0041] The following table lists several specific examples for comparative analysis.

[0042]

[0043]

[0044] Among them, compared with example 2, it can be seen that the organic coagulant is combined with PAC, and the sludge dryness is increased from 30.4% to 34.9%.

[0045] Compared with example 3, it can be seen that after adding the organic coagulant, the addition amount of PAC can be reduced, and the sludge dryness has no obvious influence, and the organic matter content and heat value of the sludge are improved.

[0046] Compared with example 3, example 4 and example 5, it can be seen that with the increase of the proportion of primary sludge, the amount of PAM is reduced, and the sludge dryness is increased.

[0047] Example 5 has the best effect, compared with example 1, the sludge dryness is increased from 30.4% to 39.7%, the average plate frame feeding amount is increased from 41m 3 to 49.5m 3 , and the sludge dryness is increased.

[0048] Compared with the prior art, the application has the advantages of improving the sludge solid content, improving the sludge heat value and improving the sludge treatment efficiency. The papermaking Fenton sludge treatment method in the embodiment of the application adds a Fenton sludge concentration tank, reduces the volume of Fenton sludge, and improves the Fenton sludge treatment efficiency. In the sludge conditioning link, the primary sludge is added, the skeleton effect of the fiber is used to improve the sludge dryness, and the electric neutralization and coagulation effect of PAC+organic coagulant are used, so that the sludge dryness is obviously improved.

[0049] The above only describes some embodiments of the application, and does not limit the protection scope of the application, and any equivalent device or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A method for treating papermaking Fenton sludge, characterized by, The treatment method comprises: The Fenton sludge is concentrated, and the concentration of the concentrated Fenton sludge is 3%-4%; The concentrated Fenton sludge is conditioned, wherein polyaluminum chloride and an organic coagulant are added in the conditioning process.

2. The treatment method according to claim 1, characterized in that, In the step of concentrating the Fenton sludge, an amphoteric flocculant is added for concentration.

3. The treatment method according to claim 2, characterized in that, The addition amount of the amphoteric flocculant is 50-120 ppm.

4. The treatment method of claim 1, wherein In the step of conditioning the concentrated Fenton sludge, the addition amount of the polyaluminum chloride is 8000-16000 ppm.

5. The treatment method according to claim 4, characterized in that, In the step of conditioning the concentrated Fenton sludge, the addition amount of the organic coagulant is 200-800 ppm.

6. The treatment method of claim 1, wherein The organic coagulant is a low-molecular-weight organic polymer.

7. The treatment method according to claim 6, characterized in that, The organic coagulant comprises any one or a combination of chloropropylene, acrylonitrile, and dimethyl quaternary ammonium salt.

8. The treatment method of claim 1, wherein, In the step of conditioning the concentrated Fenton sludge, cationic polyacrylamide is also added, and the addition amount is 80-120 ppm.

9. The treatment method of claim 1, wherein, The treatment method further comprises mixing the concentrated Fenton sludge with primary sludge before the step of conditioning the concentrated Fenton sludge, wherein the proportion of the primary sludge is 0-20%.

10. A papermaking Fenton sludge, characterized in that, The papermaking Fenton sludge is treated by the treatment method according to any one of claims 1-9.

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