CN103319066B - A kind of deep dehydration method for sludge - Google Patents

Abstract

The invention provides a method for deep dehydration of sludge, which comprises the steps of: adding 1 to 10% of free radical generators of sludge slurry dry weight to sludge slurry, stirring and mixing; Adding transition metal salt, magnesium salt and/or aluminum salt activators to the sludge slurry, the activation reaction generates active free radicals, and through the active free radical treatment, the conditioned sludge slurry is obtained; the conditioned sludge is Slurry is dehydrated. The sludge deep dehydration method of the present invention uses transition metal salts, magnesium salts and/or aluminum salts, etc. to react with free radical generators to produce active free radicals, on the one hand, it can effectively destroy sludge extracellular polymers, and change the surface of sludge particles It can improve the filtration performance of sludge and reduce the combined water content of sludge; on the other hand, it can activate the ions after the reaction, which can be combined with sludge particles, which can improve the floc strength of sludge, which is beneficial to the sludge dehydration process , so as to realize the deep dehydration of sludge.

Description

A method for deep dewatering of sludge

technical field

The invention belongs to the technical field of sewage sludge treatment, in particular to a sludge deep dehydration method.

Background technique

The so-called sludge is a general term for various sediments and floating objects produced in different treatment processes in water supply and urban domestic sewage treatment. There are mainly various pathogens, oxygen-consuming pollutants, plant nutrients, toxic and carcinogenic pollutants, general organic substances, and inorganic pollutants such as acids, alkalis, and salts. Due to the high content of organic matter in municipal sludge, its strong hydrophilicity and large specific surface area make it difficult to separate mud and water. At present, 83% of the sludge in our country's urban sewage treatment plants has not been effectively disposed of. Dehydration is difficult, and the efficiency of mechanical dehydration is low, which seriously affects the subsequent sludge disposal process. Therefore, sludge dewatering is the technical bottleneck of sludge treatment and disposal.

There are many factors that limit the improvement of sludge dewatering efficiency, among which the large amount of hydrophilic sludge floc structure formed by sludge extracellular polymeric substances (EPS) is a major crux of the difficulty in sludge dewatering. EPS can absorb and absorb water through selective absorption and functional group ionization, and the high degree of hydration shown is unfavorable to sludge dewatering. At the same time, the high content of organic matter in sludge is also an important factor restricting the degree of sludge dehydration. Because organic matter is easy to compress and deform under high pressure, it will block the pores of the filter cake in the later stage of filtration, that is, block the filtration channel of water, resulting in low dehydration efficiency at present. General physical and chemical conditioning can only solve the problem of removing pore water and capillary water. To achieve deep dehydration, it is necessary to destroy the highly hydrated charged floc matrix of the sludge, and improve the compressibility of the flocs, so that the sludge flocs The moisture contained in the grid must be released to the maximum extent to be effectively removed.

In the process of deep dehydration of sludge, how to change the state of bound water in sludge, how to destroy the hydrophilic structure of EPS sludge flocs in sludge, and how to solve the problem of compressibility of a large amount of organic matter in sludge are further issues. A breakthrough to improve the degree of sludge dewatering.

At present, sludge dehydration often requires conditioning treatment, generally using chemical methods, elutriation methods, heating methods and freezing methods. At present, polyacrylamide (PAM) is commonly used in sewage treatment plants for sludge dehydration. Since PAM long-chain adsorption bridges are easy to wrap a certain amount of water, the moisture content of the dehydrated cake after centrifugation or belt dehydration is as high as 80%. , the moisture in the dehydrated sludge cannot be lost, which makes subsequent disposal difficult. In addition, PAM is expensive, and the monomer is highly toxic, which is easy to cause secondary pollution. With the development of science and technology, technologies such as high-energy microelectronic radiation, microwave heating, ultrasound, electrolysis, and biological enzymes are also used to improve the dehydration performance of sludge.

The mechanical filtration method is used to dehydrate the sludge. When an external force is applied, the colloidal fine particles will block the formed filter bridge and increase the specific resistance of the filter; and because the sludge particles have certain compressibility, when the external force increases At this time, the particles are easy to cause the filter channel to collapse on the surface of the filter medium, so that the water cannot pass through, and the dehydration becomes extremely difficult, resulting in unsatisfactory results. Therefore, changing the compressibility of sludge in the filtration process is another major issue in sludge treatment efficiency.

Only using cationic polymers for sludge dehydration will result in high moisture content in the mud cake; using high-energy microelectronic radiation, microwave heating, ultrasonic, electrolysis, biological enzymes and other technologies for sludge dehydration, the entire reaction process has a great impact on the operation process. Strict control requirements make the operation cost of sludge treatment high; if industrial raw materials or waste residues are used alone, the bound water in the sludge cannot be removed due to their inherent properties, which will increase the volume of sludge before and after treatment. If the volume increases If it is too large, the post-treatment cost will be significantly increased, which is not conducive to the later sludge disposal.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, and provide a deep sludge dehydration method that can effectively destroy extracellular polymers in sludge, reduce the compressibility of organic matter, and greatly improve sludge dewatering performance.

In order to realize the above-mentioned purpose of the invention, the technical scheme of the present invention is as follows:

A method for deep dewatering of sludge, comprising the steps of:

Adding 1 to 10% of free radical generators by dry basis weight of the sludge slurry to the sludge slurry, stirring and mixing;

Add transition metal salt, magnesium salt and/or aluminum salt activator of 2 to 12% of the dry weight of the sludge slurry to the sludge slurry containing free radical generators, activate the reaction to generate active free radicals, and pass the active free radicals Based active treatment to obtain conditioned sludge;

The conditioned sludge slurry is dewatered.

The mud deep dehydration method of the present invention uses transition metal salts, magnesium salts and/or aluminum salts, etc. to react with free radical generators to generate active free radicals. Through the action of active free radicals, on the one hand, it can effectively destroy sludge extracellular polymers, Change the surface properties of the sludge particles, improve the filtration performance of the sludge, and reduce the bound water content of the sludge; on the other hand, it can activate the ions after the reaction is completed, which can be combined with the sludge particles, and can increase the floc strength of the sludge. It is beneficial to the sludge dewatering process, so as to realize the deep dehydration of sludge. In addition, the sludge deep dehydration method has low requirements on the pH of the sludge system, and can be treated in a wide range of pH, such as a pH of 2 to 10. The process is simple and the conditions are easy to control, which shortens the sludge dehydration time , improve the efficiency of sludge treatment, reduce the cost of sludge treatment, and realize the large-scale treatment of sludge.

Description of drawings

Fig. 1 is a schematic diagram of the technical process of the sludge deep dehydration method of the embodiment of the present invention;

Fig. 2 is a schematic diagram of another process flow of the sludge deep dehydration method of the embodiment of the present invention;

Fig. 3 is a schematic diagram of the effect of the incompressible mud cake and the traditional compressible mud cake after the sludge deep dehydration method according to the embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The embodiment of the present invention provides a deep sludge dehydration method that can effectively destroy extracellular polymers in sludge, reduce the compressibility of organic matter, and greatly improve sludge dewatering performance. The process flow of the method is shown in Figure 1 . The sludge deep dewatering method comprises the following steps:

S01: Obtaining sludge containing free radical generators: adding 1 to 10% of free radical generators by dry weight of the sludge slurry to the sludge slurry, stirring and mixing;

S02: Obtain the conditioned sludge slurry: add transition metal salt, magnesium salt and/or aluminum salt activator of 2 to 12% of the dry weight of the sludge slurry to the sludge slurry containing free radical generators in step S01, The activation reaction generates active free radicals, and the conditioned sludge slurry is obtained through active free radical treatment;

S03: sludge dehydration treatment: dehydration treatment is performed on the conditioned sludge slurry in step S02.

Specifically, in the above step S01, the sludge slurry can be sludge from different sources and with different mud qualities, including mixed sludge (with a water content of 95% to 99%), dewatered sludge (with a water content of about 80%), papermaking sludge, etc. sludge, municipal sludge, etc. In order to make the free radical generators in step S01 more fully mix and react with the sludge, when the selected sludge has a low water content, such as PAM dewatered sludge, belt filter press with a solid content of 75% to 85% When dewatering the cake with a machine or a centrifuge, the sludge can be slurried with water first, and the water content of the sludge slurry can be adjusted to 87wt% to 99wt%.

In this step S01, the free radical generator is preferably peroxide or/and persulfide. Wherein, the peroxide is one or more of peroxyformic acid, peracetic acid, hydrogen peroxide, and monoperoxyhydrogensulfate, and monoperoxyhydrogensulfate is a water-soluble monoperoxygen commonly used in the art. Bisulfate; persulfide is preferably one or more of persulfate and peroxodisulfate, which are water-soluble peroxosulfate commonly used in the art. The oxide or/and persulfide can generate active free radicals under the action of the activator, and the rate of generating active free radicals is high and the amount is large.

The inventor also found that when the addition of the free radical generator is preferably 2 to 5% of the dry base of the sludge slurry, the ratio of the active free radicals produced to the dry base of the sludge can fully destroy the extracellular polymers of the sludge and change the The surface properties of sludge particles can improve the filtration performance of sludge, increase the floc strength of sludge, reduce the combined water content of sludge, save the amount of free radicals, and reduce the cost of sludge treatment.

In this step S01, after the free radical generator is added to the sludge slurry, the free radical generator should be mixed evenly with the sludge slurry. For example, the free radical generator can be added to the sludge slurry together, and then stirred, or the free radical generator can be stirred while adding the free radical generator, so that the free radical generator can be evenly dispersed in the sludge.

In this step S01, since the sludge generally contains transition metal ions, such as Fe ²⁺ , Zn ²⁺ , o ²⁺ , Mn ²⁺ , Cu ²⁺ , after adding free radical generators, the free radicals After the activation of the transition metal ions present in the sludge itself, the product can generate some active free radicals, which can activate the sludge and destroy the extracellular polymer (EPS) part of the sludge. .

In the above step S02, the addition of transition metal salts, magnesium salts and/or aluminum salts can make the free radical generators in the sludge slurry in the step fully generate active free radicals. On the one hand, the active free radicals can further effectively destroy the sludge EPS can also change the surface properties of sludge particles, improve the filtration performance of sludge, and reduce the combined water content of sludge. On the other hand, the ions after the activation reaction can be combined with the sludge particles, which can increase the floc strength of the sludge to a certain extent, which is beneficial to the sludge dehydration process. Wherein, the transition metal salt activator is preferably one or more of manganese salts, iron salts, cobalt salts, copper salts, and zinc salts. The manganese salt, iron salt, cobalt salt, copper salt, zinc salt, magnesium salt and/or aluminum salt are water-soluble salts commonly used in the art. The preferred transition metal salt activator enables a higher rate of active free radical generation. In order to make free radical generators fully produce activated sludge, reduce the amount of activator, improve sludge treatment efficiency, and save sludge treatment costs, the addition of the transition metal salt, magnesium salt and/or aluminum salt activator is preferably 6-10%.

The mechanism that above-mentioned active free radical produces can be expressed with following reaction formula:

Under the action of activators such as transition metal salts, free radical generators generate active free radicals.

X ₁ +Me ⁿ⁺ → X ^m- +Me( ^n+m) ++X ₂

In the formula: X ₁ is a free radical generator

Me ⁿ⁺ is an activator such as a transition metal salt

·X ^m -active free radical

Me( ^n+m)+ and X ₂ are by-products

·X ^m- can react with the carbon chain of organic matter in the sludge. It can also further deeply oxidize organic matter by attracting protons to generate organic free radicals R·.

RH+·X ^m- →H ₂ O+R·→deep oxidation

In the formula: RH is the organic matter in the sludge

In this step S02, after the transition metal salt, magnesium salt and/or aluminum salt activator is added to the sludge slurry, the transition metal salt, magnesium salt and/or aluminum salt activator and the free radical generator should be fully dispersed. For example, the transition metal salt, magnesium salt and/or aluminum salt activator can be added to the sludge slurry, and then stirred; or the activator can be stirred while adding the activator, so that the activator and free radicals can be produced in the sludge. Disperse evenly and keep the two in full contact.

In this step S02, the time for active free radicals to activate the sludge is preferably 5-20 minutes. During this time, the active free radicals can fully interact with the EPS in the sludge, fully destroy the EPS and change the surface properties of the sludge particles, maximize the filtration performance of the sludge and the floc strength of the sludge, and reduce the Sludge bound water content.

In the above step S03, after the sludge slurry is conditioned in the above steps S01 and S02, the EPS in the sludge is destroyed, the surface properties of the sludge particles are changed, the filtration performance of the sludge is improved, and the ability to bind water is reduced. The floc strength of the sludge was improved. Therefore, the conditioned sludge slurry in step S02 can be directly dehydrated. The dehydration treatment method can adopt conventional methods in the art, such as mechanical dehydration methods such as pressure filtration and centrifugation. The moisture content of the dewatered sludge can reach below 55%, the dehydration efficiency is greatly improved, and the mud cake can be directly used for landfill, compost, incineration or building material utilization.

Further, on the basis of the above-mentioned sludge deep dehydration method as shown in Figure 1, between the above steps S02 and S03, it also includes adding 0.04 to 30% of the dry weight of the sludge slurry to the conditioned sludge slurry. The auxiliary modifier step S02' is the process flow shown in FIG. 2 .

In this step S02', the amount of the auxiliary modifying agent added is preferably 5-30% of the dry weight of the sludge slurry, more preferably 10-30%, and the auxiliary modifying agent is preferably industrial waste residue and/or a surfactant. Among them, the industrial waste residue is preferably any one or several powders of pulverized coal, coal gangue, slag, biomass, lime and their substitutes with a particle size of ≤1.0mm; the surfactant is preferably a cationic surfactant, One or more of nonionic surfactants and amphoteric surfactants. The cationic surfactant can be rosin-based bis-trimethyl ammonium chloride, ethylene group dioctadecyl dimethyl ammonium bromide, ethylene group bis(dodecyl dimethyl ammonium bromide) At least one of the non-ionic surfactants can be at least one of octylphenol ethoxylates, Span-20, Span-40, Span-60, Span-80, and the amphoteric surfactants can be iso Alcohol polyoxyethylene polyoxypropylene ether, Gemin type betaine at least one.

In this step S02', after adding the auxiliary modifying agent, it should be fully stirred and mixed, so that the added auxiliary modifying agent can be uniformly dispersed in the sludge. The mixing time is preferably 5 minutes to 15 minutes. The preferred mixing time can make the auxiliary modifier fully interact with the sludge, fully destroy the floc structure in the sludge, and form a large number of stable skeleton structures.

After the above-mentioned preferred content and type of auxiliary modifiers are added to the sludge, they can become the skeleton structure of the sludge, which can make the sludge form a hard mesh porous structure during the filtration process, maintain the filtration channel of the water, and solve the problem of sludge in the sludge. Organic matter compressibility problem. Fig. 3 is a schematic diagram of the effect of the sludge cake treated by adding auxiliary modifiers in the embodiment of the invention and the sludge cake treated by the traditional method. Among them, Fig. 3(a) is a schematic diagram of the effect of the sludge cake after being treated by adding auxiliary modifiers according to the embodiment of the present invention, and Fig. 3(b) is a schematic diagram of the effect of the sludge cake after being treated by the traditional method. It can be seen from Fig. 3 that during the compression process of the treated sludge in the embodiment of the invention, the skeleton structure formed in the sludge effectively ensures the smooth flow of the water outflow channel in the sludge, so that the water can be removed to the maximum extent, and the sludge is decomposed. Deep dehydration; In the compression process of sludge treated by traditional methods, the organic matter is compressed and deformed, which blocks the water filtration channel and prevents water from flowing out. According to the test, after the sludge is conditioned and dehydrated through the above steps, the SRF of the sludge can be reduced by three orders of magnitude, and the CST has dropped significantly, and the CST reduction rate is higher than 50%, which greatly improves the filtration performance of the sludge. Dehydration moisture content can reach below 55%.

The sludge deep dehydration method in the embodiment of the present invention uses transition metal salts, magnesium salts and/or aluminum salts to react with free radical generators to generate active free radicals. Through the action of active free radicals, on the one hand, it can effectively destroy the sludge extracellular Polymers can change the surface properties of sludge particles, improve the filtration performance of sludge, and reduce the bound water content of sludge; on the other hand, they can activate the ions after the reaction is completed, which can be combined with sludge particles, and can improve the flocculation of sludge. The body strength is beneficial to the sludge dewatering process, so as to realize the deep dehydration of the sludge. In addition, the sludge deep dehydration method has low requirements on the pH of the sludge system, and can be treated in a wide range of pH, such as a pH of 2 to 10. The process is simple and the conditions are easy to control, which shortens the sludge dehydration time , improve the efficiency of sludge treatment, reduce the cost of sludge treatment, and realize the large-scale treatment of sludge.

Furthermore, when the auxiliary modifier is added to the sludge conditioned by active free radicals, the sludge can become a skeleton structure, which can make the sludge form a hard mesh porous structure during the filtration process, and keep the water Filter channel to solve the problem of compressibility of organic matter in sludge. According to the test, after conditioning and dehydrating the sludge with auxiliary modifiers, the SRF of the sludge can be reduced by three orders of magnitude, and the CST has dropped significantly, and the CST reduction rate is higher than 50%, which greatly improves the filtration performance of the sludge. The moisture content of plate and frame dehydration can reach below 55%.

The present invention will be further described in detail by taking the concrete sludge dehydration composite conditioner and its application method as an example.

Example 1

A method for deep dewatering of sludge, the process steps are as follows:

S11: Starting from the remaining sludge with an organic matter content of 55.2wt% and a moisture content of 97wt%, add peracetic acid free radical generators of 5wt% on a dry basis to the sludge, and stir thoroughly;

S12: Add 5 wt% manganese salt transition metal salt on a dry basis to the sludge treated in step S11, and stir for 10 minutes to complete sludge conditioning;

S13: dehydrating the sludge conditioned in step S12 through plate and frame dehydration.

After testing, the sludge filtration specific resistance decreased from the original 1.88×10 ¹³ m/kg to 1.24×10 ¹¹ m/kg, the capillary water absorption time of the sludge decreased from 156.2s to 42.5s from the original sludge, and the conditioned sludge After plate and frame dehydration, the water content is 55.2%, and the organic matter of the mud cake is 52.4%.

Example 2

A method for deep dewatering of sludge, the process steps are as follows:

S21: Starting from the remaining sludge with an organic matter content of 55.2wt% and a water content of 97.1wt%, add hydrogen peroxide and peroxodisulfate with a mass ratio of 1:1 to the sludge at 5wt% on a dry basis Mixture free radical generator, stir well;

S22: Add 10wt% cobalt salt transition metal salt on a dry basis to the sludge treated in step S21, and after stirring for 10 minutes, add 10wt% slag powder with a particle size ≤ 1.0mm on a dry basis Auxiliary modifier, stirring to fully complete sludge conditioning

S23: dehydrating the sludge conditioned in step S22 through plate and frame dehydration.

After testing, the sludge filtration specific resistance decreased from the original 1.88×10 ¹³ m/kg to 3.12×10 ¹⁰ m/kg, the capillary water absorption time of the sludge decreased from 156.2s to 30.6s from the original sludge, and the conditioned sludge After plate and frame dehydration, the water content is 50.1%, and the mud cake organic matter is 50.3%.

Example 3

S31: Starting from the centrifuge dewatered cake with an organic content of 50.6wt% and a water content of 82.2wt%, adding water to slurry it to a water content of 93wt%, and then adding 10wt% of the sludge on a dry basis to the sludge Peroxobisulfate free radical generator, fully stirred;

S32: Add 10%wt aluminum salt transition metal salt on a dry basis to the sludge treated in step S31, and after stirring for 15min, add 5wt% isomeric alcohol polyoxyethylene polyoxypropylene ether to assist in improving Active agent, stirring to fully complete the sludge conditioning;

S33: dehydrating the sludge conditioned in step S32 through plate and frame.

After testing, the sludge filtration specific resistance decreased from 2.82×10 ¹³ m/kg when the slurry moisture content was 93% to 6.5×10 ¹¹ m/kg, and the sludge capillary water absorption time decreased from 2.82×10 13 m/kg when the slurry moisture content was 93%. 194.5s down to 34.5s. After the conditioned sludge is dehydrated by the plate and frame, the water content is 48.5%, and the organic matter of the mud cake is 45.1%.

Example 4

S41: After the organic matter content is 55.2wt% and the water content is 96.5wt%, add peroxymonosulfate radical generators of 5wt% on a dry basis to the sludge, and stir fully;

S42: To the sludge treated in step S41, add 5wt% of the sludge dry basis to the mass ratio of 1:2 iron salt and magnesium salt mixture activator, after stirring for 10min, add 0.04wt% octylphenol Polyoxyethylene ether non-ionic surfactant, stirring fully to complete the sludge conditioning;

S43: dehydrating the sludge conditioned in step S42 through plate and frame dehydration.

After testing, the sludge filtration specific resistance decreased from the original 1.67×10 ¹³ m/kg to 1.1×10 ¹² m/kg, the sludge capillary water absorption time decreased from the original 163.4s to 45.4s, and the conditioned sludge passed through the plate After frame dehydration, the water content is 52.4%, and the mud cake organic matter is 49.8%.

Example 5

A method for deep dewatering of sludge, the process steps are as follows:

S51: Starting from the remaining sludge with an organic matter content of 55.2wt% and a water content of 97wt%, add 1wt% of the dry basis of the sludge to the sludge, and stir fully;

S52: Add 2wt% aluminum chloride on a dry basis to the sludge treated in step S51, stir for 10 minutes, add 2wt% lime, and stir to fully complete the sludge conditioning;

S53: dehydrating the sludge conditioned in step S52 through plate and frame.

After testing, the sludge filtration specific resistance decreased from the original 1.88×10 ¹³ m/kg to 1.31×10 ¹¹ m/kg, the capillary water absorption time of the sludge decreased from 156.2s to 44.5s from the original sludge, and the conditioned sludge After plate and frame dehydration, the water content is 53.9%, and the organic matter of the mud cake is 53.4%.

Example 6

A method for deep dewatering of sludge, the process steps are as follows:

S61: Starting from the remaining sludge with an organic matter content of 55.2wt% and a moisture content of 97wt%, add a monoperoxyhydrogensulfate free radical generator of 10wt% on a dry basis to the sludge, and stir fully;

S62: Add 12wt% aluminum chloride on a dry basis to the sludge treated in step S61, stir for 10 minutes, add 4wt% biomass, and stir to fully complete the sludge conditioning;

S63: dehydrating the sludge conditioned in step S62 through plate and frame.

After testing, the sludge filtration specific resistance decreased from the original 1.88×10 ¹³ m/kg to 1.18×10 ¹¹ m/kg, the capillary water absorption time of the sludge decreased from 156.2s to 40.1s from the original sludge, and the conditioned sludge After plate and frame dehydration, the moisture content is 49.9%, and the organic matter of the mud cake is 46.4%.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (9)

1. a deep dehydration method for sludge, comprises the steps:

The free radical adding the dry base weight 1��10% of sludge slurry in sludge slurry produces thing, is uniformly mixed; Wherein, described free radical produce thing be superoxide or/and persulfide, the water ratio of sludge slurry is 87wt%��99wt%, and described superoxide is one or more in peroxyformic acid, Peracetic Acid, single peroxosulphuric hydrogen salt;

Adding the transition metal salt of the dry base weight 2��12% of sludge slurry, magnesium salt and/or aluminium salt activator in the described sludge slurry producing thing containing free radical, priming reaction generates living radical, and by living radical activity process, obtains the sludge slurry through conditioning;

The described sludge slurry through conditioning is carried out processed.

2. deep dehydration method for sludge according to claim 1, it is characterised in that: it is the 2��5% of the dry base of sludge slurry that described free radical produces the add-on of thing.

3. deep dehydration method for sludge according to claim 1, it is characterised in that: described persulfide is one or more in peroxy-monosulfate, peroxydisulfate.

4. deep dehydration method for sludge according to claim 1, it is characterised in that: the add-on of described transition metal salt activator is the 2��12% of the dry base weight of sludge slurry.

5. deep dehydration method for sludge according to claim 1 or 4, it is characterised in that: described transition metal salt activator is one or more in manganese salt, molysite, cobalt salt, mantoquita, zinc salt.

6. deep dehydration method for sludge according to claim 1, it is characterized in that: obtain after the sludge slurry step of conditioning described, before dehydration process steps, also comprising and add Aided Modification medicament step to the sludge slurry through conditioning, the add-on of described Aided Modification medicament is the 0.04��30% of the dry base weight of sludge slurry.

7. deep dehydration method for sludge according to claim 6, it is characterised in that: described Aided Modification medicament is industrial residue and/or tensio-active agent.

8. deep dehydration method for sludge according to claim 7, it is characterised in that: described industrial residue is any one or a few the powder body in the surrogate of the fine coal of granularity��1.0mm, coal gangue, slag, biomass, lime and fine coal, coal gangue, slag, biomass or lime.

9. deep dehydration method for sludge according to claim 7, it is characterised in that: described tensio-active agent is one or more in cationic surfactant, nonionic surface active agent, amphoterics.