JPS60183100A - Dehydration and coagulation treatment of sludge - Google Patents

Abstract

PURPOSE:To sufficiently lower the water content of dehydrated cake, by performing dehydration treatment in a dehydration part by a vacuum degree retaining member in such a state that air sucking from the outside is prevented as compared with that from the sludge adhered to the outer surface of filter cloth. CONSTITUTION:The filter cloth 3 wound around a vacuum dehydration drum 1 and a roll 2 is revolved and sludge mixture of sludge and a coagulation material is adhered to the outer surface of the revolving filter cloth 3 in a sludge adhering part 5 for immersing said filter cloth 3 in a sludge mixture bath 4 with the revolution thereof. This adhered sludge receives vacuum sucking dehydration treatment by a sheet member in a dehydration part 6 at a position where said filter cloth 3 is revolved above the sludge adhering part 5 in such a state that air sucking from the outside is prevented as compared with that from the sludge adhered to the outer surface of the filter cloth 3. Thereafter, the filter cloth 3 is revolved from the dehydration part 6 to a peeling-off part 8 and a dehydrated cake is peeled off and removed from the outer surface of the filter cloth 3.

Description

[Detailed Description of the Invention] The present invention is applicable to waste pollution as industrial waste, river pollution, etc.
Various types of sludge (hereinafter simply referred to as sludge) that will degrade the environment if left untreated, such as accumulated sludge as bottom sediment in lakes, ports, sea areas, etc., or sewage sludge discharged from sewage treatment plants, etc. In detail, the sludge mixture of sludge and solidifying material is applied to the outer surface of the rotating p-cloth in the sludge adhesion section, and the adhering sludge in step 7 is removed in the dewatering section! 2. A method for dehydrating and solidifying sludge, in which the dehydrated cake is peeled off and removed from the cloth after being subjected to suction dehydration treatment.

The dewatering and solidifying treatment method for sludge described above is characterized by adding an assimilating agent before dewatering. Also, you don't need any equipment that will last a lifetime, so it's a cost-effective option? Can it be reduced to six widths and assimilated sludge? It has the advantage of being quick.

However, although this improved sludge dehydration and assimilation treatment method has the above-mentioned advantages, the water content of the mixed sludge cannot be sufficiently lowered during the dewatering process, and the water content of the resulting dehydrated cake is limited, resulting in solidification. In order to obtain the target strength after treatment, a large amount of solidifying material is required, which makes it expensive.Also, the amount of dewatered cake to be assimilated is large compared to the solid content in the sludge, resulting in bulk. There was still room for improvement, as transportation costs for dumping increased and the waste became more expensive.

The present invention improves the sludge dehydration and solidification treatment method in which the sludge is completely added with solidification and vacuum suction dewatered before the sludge is dehydrated. The purpose of this paper is to propose a method that can sufficiently reduce the

The present invention achieves the above object in the sludge dehydration and assimilation treatment method described at the beginning, and next, in the dewatering section,
The outer surface of the cloth 1fl
The sludge is characterized by being dehydrated in a state where air is prevented from being sucked in from the outside of the sludge.

When we considered changes in sludge properties over time when vacuum suction dewatering was performed on fC mixed sludge with the addition of an assimilation agent, we found that the viscosity of the mixed sludge decreased with the addition of an assimilation agent, and that the dewatering section did not fully dewater the sludge. Before it can be removed, cracks appear in the dehydrated cake, outside air is sucked in through the cracks, and the vacuum suction force no longer acts to help itself due to dehydration.Is this the water content of the sludge? We discovered that this is the reason why the temperature could not be lowered sufficiently, and in this invention, we focused on this point, and even if cracks occur, outside air is sucked through the cracked part to maintain the full vacuum level. This has enabled the vacuum suction dehydration treatment to work effectively.

Therefore, in the dewatering treatment of mixed sludge containing assimilated material, it is possible to avoid a decrease in vacuum paper quality due to cracks caused by the addition of assimilated material, and to sufficiently reduce the water content of the sludge, thereby increasing the moisture content of the dehydrated cake. In the dehydrated goo and ki obtained by assimilation treatment at the same time as dewatering, the required strength can be obtained satisfactorily without increasing the amount of assimilated material, and the solid content in the sludge can be kept at the same level. In terms of volume, the volume of the dehydrated cake obtained can be made smaller than before, and both the consumption of solidifying agent and the transportation cost of the dumping tank can be significantly reduced, making it possible to treat and dispose of sludge in an extremely economically advantageous manner. became.

Examples of the method of the present invention will be described below with reference to the drawings.

Vacuum dewatering drum (1) and roll (2)... Rotate the P cloth (3) wound across the drum, and accordingly, the sludge adhesion part (5) where it is immersed in the four-piece sludge bath (4). So, rotation P
A mixed sludge of sludge and an assimilating agent is attached to the outer surface of the cloth (3), and the attached sludge is removed from the sheet in the dewatering section (6) at a position rotated upward from the sludge adhering section (5). Element(
7), the sludge adhering to the outer surface of the P cloth (3) is dehydrated by vacuum suction in a state where air is prevented from being sucked in from the outside, and then the sludge is transferred from the dewatering section (6) to the stripping section (8). moved,
The dehydrated cake is peeled off and removed from the outer surface of the door cloth t31.

The dehydrated cake that has been continuously dehydrated and assimilated in this way is collected in a recovery tank (9), and then 1. The solidified material is dumped in trunks and other places in landfills.

For the mixed sludge bath (4), there is a mixed sludge storage tank (10
) is supplied and stored, and this mixed sludge storage tank (10) receives sludge from the sludge storage tank (II), flocculant storage tank (12), and solidification agent storage tank (I3), respectively. ,
A flocculant and a solidifying agent are supplied and mixed and stored.

The above flocculants include iron chloride, slaked lime, various polymers,
Alternatively, various kinds of materials such as a mixture thereof can be used. Note that if the sludge has good flocculating properties, it is not necessary to add this flocculant.

As the above-mentioned solidification material, hydraulic cement materials such as various boltland cements, blast furnace cements, high alumina cements, etc., or solidification materials mainly composed of these hydraulic cement materials, can be used. For sludge containing substances that inhibit the hydration hardening of Portland cement (for example, sugars, humins, etc.), Al2O,/wt 4 or more, 50. /jwt 4
Including the above, and Hauyne (8C
A high alumina high sulfate cement containing aO-8A1hO3.Ca5O,) as a main component can be effectively applied.

Next, details of the vacuum dehydrator shown in FIG. 1 used in the method of the present invention will be explained.

Although not shown, the inside of the vacuum dehydration drum (1) is divided into a number of chambers, and each of these chambers and seven vacuum suction pumps (14I) are operated via switching valves and piping. The switching valve is changed as the drum +11 rotates, and the suction pressure is increased only in the adsorption zone corresponding to the sludge attachment part (6) and the dewatering zone (B) corresponding to the dewatering part (6). is applied, and suction pressure is not applied in the other peeling zone (C).

At a location corresponding to the dewatering section (6)K, the drat member (7) is wound around the free rotating roll α5), and even if cracks occur in the sludge cake due to dewatering, the cracks can be removed by the sheet member. Although the sheet member (7) is blocked by (7), the P
It is configured to rotate in synchronization with the cloth (3) to prevent a drop in the suction pressure acting on the sludge in the dewatering section (6) and maintain a high degree of vacuum.

In the peeling section (8), the roll (2) is rotated 11J.
A Starepa (I6) is provided in the middle of the path, and p cloth f31
The device is configured to peel off and remove dehydrated cake attached to the surface of the device.

07) and (17) in the figure respectively jet and supply cleaning water to the P cloth (3) after peeling and removing the dehydrated cake;
A cleaning spray for cleaning and removing residual sludge is shown.

In the above-mentioned vacuum dehydrator, sludge adhesion is also performed by vacuum suction Kj, and by maintaining the degree of vacuum at a high level with the sheet member (7), it is possible to not only dehydrate sludge but also increase the suction pressure for sludge adsorption. This increases the thickness of the mixed sludge that adheres to the outer surface of the door cloth (3), that is, increases the amount of adhering mixed sludge, increases the amount of dewatering and solidification processed per unit time, and improves treatment efficiency. is made of.

Next, we will discuss the case of the method of the present invention carried out using a dehydrator (denoted as the developed method) and the case of the method carried out by removing the sheet member (7) from the vacuum dehydrator (denoted as the conventional method). ) Comparison of eyelid results for each Vζ is shown.

The sludge used in this experiment was standard activated sludge T).
F! It is mixed sludge processed by law, and the thickened sludge water treatment rate is approximately 98.
．． 5% and ignition wave attenuation of 82.5 was used.

The solidification addition rate was expressed as the ratio of the same type of sludge added to the dry base.

From the above results, the method of the present invention can easily set and obtain a high degree of vacuum in both the adsorption zone prisoner and the dehydration section (6), and accordingly, the water content of the dehydrated cake can be sufficiently reduced, and It is clear that a dehydrated cake of sufficient strength can be obtained.

Figure 2 shows an embodiment of a vacuum dehydrator pond used to carry out the method of the present invention, in which one cloth (3) is rotatably provided.
The upper sutra sutra lol! ! 2, a partition arm is provided on the upper side in the forward direction, and the partition wall, barrel and both side walls (figure omitted)
In addition, a receiving part 4 for the mixed sludge is formed by the p-cloth (3), and as the p-cloth (3) rotates, the mixed sludge is placed and adhered to the outer surface of the p-cloth (3). Sludge adhesion part (6)
is configured.

In addition, in the sludge adhesion part (5) on the lower side between the front parts of the L95P cloth (3), there is an airtight chamber connected to the vacuum suction pump +1 below the P cloth (3). A dewatering section (6) is provided for dehydrating the sludge by vacuum suction. Above this dewatering section (6), a pair of idler rolls,
u5) over the outer surface of the sludge on the P cloth (3) gold drJ
A sheet member (7) is wound around the L side that is in contact with the K, and is configured to maintain a high degree of vacuum in the dewatering section (6).

The sheet member (7) for maintaining a high degree of vacuum in the above-mentioned dehydration step 5 (6) may be made of a material with low air permeability similar to the P cloth (3), or may be made of vinyl chloride. A non-porous sheet member may also be used, and furthermore, the sludge and P cloth (3) can be placed on the outer side of the sludge adhered to the outer surface of the P cloth (3) in correspondence with the dewatering section (6). Various modifications can be made as long as they can prevent the vacuum level (
7) collectively referred to as 0

[Brief explanation of drawings]

FIG. 1 is an overall schematic longitudinal sectional view of a vacuum dehydrator used in the method of the present invention, and FIG. 8 is an overall schematic longitudinal sectional view showing an embodiment of a pond of the vacuum dehydrator used in the method of the present invention. (3)...tpJ, (6)...sludge adhesion section, (6)...dewatering section, (7)...
Vacuum maintenance parts and sheet parts. Agent Patent Attorney Osamu Kitamura

Claims (1)

[Claims] ■ Mixed sludge of sludge and solidifying material was attached to the outer surface of #Fi131 in the sludge attachment section (6), and subjected to vacuum suction dewatering in the sludge total dewatering section +61 in step 7. The dehydration and assimilation treatment method for sludge includes peeling off and removing the dehydration bag No. 7 from the rp*ts+, in which in the dewatering section 161 K', the vacuum degree maintaining member (7) is attached to the p cloth. A method for dewatering and solidifying sludge, characterized in that the sludge adhering to the outer surface of the sludge is dehydrated while preventing flL air from outside. ■ As the member for maintaining the degree of vacuum, a sheet member with low air permeability, which was previously provided in-house in conjunction with the P cloth T8J, was used.
The method for dewatering and solidifying sludge according to item (2) above, which uses ice. (2) The dehydration and assimilation treatment of sludge according to claim (2), wherein a non-breathable sheet member previously provided in-house in conjunction with the P cloth 13J is used as the vacuum degree maintaining member. Method. ■ The sludge dehydration and solidification treatment method according to any one of claims 1 to 3, wherein the sludge is sewage sludge, and is used as a solidification material in high alumina high sulfate cement. .