CN102361829B

CN102361829B - Method for dewatering sludge and method and device for electroosmotic dewatering

Info

Publication number: CN102361829B
Application number: CN2010800131614A
Authority: CN
Inventors: 增井孝明; 正冈融
Original assignee: Kurita Water Industries Ltd
Current assignee: Kurita Water Industries Ltd
Priority date: 2009-03-30
Filing date: 2010-03-29
Publication date: 2013-07-24
Anticipated expiration: 2030-03-29
Also published as: KR20120022706A; CN102361829A; TW201107248A; TWI534100B; WO2010113846A1

Abstract

In dewatering sludge, which is formed in a process of biologically treating various industrial effluents or the like, by using an electroosmotic dewatering device, the electroosmotic dewatering treatment can be efficiently carried out while minimizing the cost for chemicals and requiring no additional element, such as a dissolution tank or a heater, or no extra energy. Concentrated salts discharged from an effluent treatment plant are added to sludge and then dewatering is carried out by using an electroosmotic dewatering device. By adding the concentrated salts discharged from the effluent treatment plant, which have been discarded as an industrial waste, to the sludge to be electroosmotically dewatered, the electrical conductivity of the sludge can be increased and the dewatering efficiency of the electroosmotic dewatering device can be increased. Thus, the water content of the dewatered sludge thus obtained can be lowered.

Description

Mud dewatering method, electroosmotic dewatering method and device

Technical field

The present invention relates to the mud that is produced in biological treatment process etc. of various industry drainings is carried out dehydration method by the electroosmotic dewatering device, particularly, relate in mud before electroosmotic dewatering modified, by using is the concentrated salt that is used as offal treatment in the prior art, with in the industrial method that advantageously obtains the low dewatered sludge of water ratio.In addition, the present invention relates to the electroosmotic dewatering method and the device that dewater in order to the hydrate of the biological treatment mud of draining, sludge of drinking water etc.

Background technology

As the method for the hydrate of mud of being produced etc. being carried out processed in the biological treatment process of draining, the known method (patent documentation 1～5, non-patent literature 1) that electroosmotic dewatering is arranged.

The electroosmotic dewatering device of patent documentation 1 is to add between the pressure zone (anode) mud is made the mode that electroosmotic dewatering handles and the device that constitutes carrying out the downside transition band (negative electrode) that endless rotates and carry out upside that endless rotates.

The electroosmotic dewatering device of patent documentation 2 is to be provided as anodic electrode rotating cylinder (drum) mutually independently to add pressure zone with upside, and holds the mode of the band under pressing under the arm and the device that constitutes through electrode rotating cylinder thus.

The electroosmotic dewatering device of patent documentation 3, be to constitute in the following manner, that is: mud be supplied to and carry out on the conveying belt that endless rotates, and between the anode unit above the negative plate of the downside of conveying belt and the conveying belt, hold the pressure hydrate under the arm, and making current is carried out electroosmotic dewatering.Anode unit, be on the conveying belt travel direction, be equipped with a plurality of.At the bottom surface sections place of each anode unit, be provided with the positive plate of level.This positive plate is to become to be depressed via air cylinder, and can be pulled on via spring.Conveying belt is under the state that makes after positive plate rises, and makes hydrate do moving of 1 span (being provided with at interval of anode unit).

The electroosmotic dewatering device of patent documentation 4,5 is to dispose 2 filter cloth between the filter plate of bipolar pair of right and left possessing.Supply with mud each other at filter cloth, hold pressure mud under the arm via filter cloth, and, between electrode, switch on, thus, mud is carried out electroosmotic dewatering and handles.After processing, filter plate is separated, then, make filter cloth separated from one another, and dehydrate is taken out.

In this kind electroosmotic dewatering method, because dehydrating amount is proportional with the energising amount, therefore, if the conductivity of mud rises, then the water ratio of dehydrated sludge cake reduces easily.Therefore,, proposed as carrying out as described in following (a)～(c) for dewatering efficiency is promoted, thus the method that the conductivity of hydrate is promoted.

(a) filtrate of will dewatering is reclaimed, and is added into mud before the dehydration, thus, comes the pH and the conductivity of the mud cake after the dehydration are adjusted (patent documentation 1).

(b) ionogen with salt or sodium sulfate, yellow soda ash etc. is added on (patent documentation 4) in the mud.

(c) will conduct electricity promoting agent is added in the mud that (which kind of material patent documentation 2 still, in patent documentation 2, is on record conduction promoting agent is concrete.)。

The mud that is produced in the biological treatment process of various industry drainings owing to include a large amount of moisture, therefore, is carrying out after the processed, as waste and processed.In the prior art, in the dehydration of mud, use has the mechanical dewatering unit of the adding pressure type water extracter of band pressurization or filter screen pressurization etc. or centrifuge etc., but, in these dewatering unit, except the mud (mud that includes the composition that is easy to dewater of a large amount of cellulosics or silt etc.) of a part, be water ratio can't to be reduced fully, the water ratio of resulting dewatered sludge, its limit are about 80%.

With respect to this, handle if carry out electroosmotic dewatering by the electroosmotic dewatering device, then be electrode to be inserted into to go forward side by side in the processed mud work, by electro-osmotic effects electronegative mud is pulled to anode side, on the other hand, make the interstitial water of mud move to cathode side, both are separated, exert pressure again meanwhile, dewater, therefore, compared to the situation of mechanical type processed, dewatering efficiency improves, and the water ratio of mud further can be reduced.

That is to say, the surface of mud particle, chargedly be-10～-20mV, and the water around it forms electrostatic double layer and positively charged.Therefore, if apply direct supply for the mud of being seized on both sides by the arms between anode and negative electrode, then with the water of positive electricity be pulled to cathode side.If exert pressure under this state, then water is discharged from as filtrate from cathode side, and the water ratio of mud reduces.

In addition, at this moment, owing at the negative electrode place reduction reaction takes place, therefore, dehydration filtrate becomes alkalescence.

Yet in various drainage treatment equipments, what have is provided with the thickening equipment of the salt in the draining being made concentrating and separating.For example, in the treatment facility of organic system draining, by active sludge treatment etc. draining is carried out a biological disposal upon, and for resulting biological treatment of water is utilized as ultrapure water again, and have: the thickening equipment by reverse osmosis membrane tripping device or vaporizer (concentrator) etc. deals with, and with biological metabolite that is contained or the pH that results from adjustment sodium hydroxide, the sodium sulfate that bodied ferric sulfate (polyferric sulfate) etc. is produced, SODIUMNITRATE, the salt of sodium-chlor etc. carries out concentrating and separating, to concentrate salt and be expelled to outside the system and take disciplinary action, and divide dried uply to be removed as treating water as industrial waste (produce useless).

The prior art document

Patent documentation

Patent documentation 1: Japanese kokai publication hei 1-189311 number

Patent documentation 2: Japanese kokai publication hei 6-154797 number

Patent documentation 3:WO2007/143840 number

Patent documentation 4: Japan special fair 7-73646 number

Patent documentation 5: No. the 3576269th, Japanese Patent

Non-patent literature

Non-patent literature 1: water treatment management brief guide (put down on September 30th, 10, ball is kind), P.339～341

In the electroosmotic dewatering method, become the positively charged ion of the motivating force of dehydration, its majority is just together to be discharged from filtrate at the dehydration first-half period.Therefore, when in processed hydrate, having added electrolytical situation in advance, dewatering between latter half, can reduce owing to cationic deficiency make the conductivity of mud, and make the equilibrium moisture content of dehydrated sludge cake be difficult to descend.If till between dehydration latter half, also keep cationic amount, in processed hydrate, add a large amount of ionogen, though then the water ratio of dehydrated sludge cake can reduce, but, in during the dehydration initial stage, meeting excess flow electric current increases energy-output ratio.

In addition, when the situation of the filtrate regeneration in the patent documentation 1, at the dehydration first-half period, though can produce the high filtrate of conductivity,, the filtrate between dehydration latter half, its conductivity is low.In patent documentation 1,, therefore, be that the not high filtrate of conductivity is utilized again owing to be that the filtrate that is produced via dehydration is all done to reclaim and utilize.Therefore, causing adding amount of filtrate increases, and the mud of high-moisture percentage is carried out electroosmotic dewatering, and therefore, equilibrium moisture content is difficult to descend.

Summary of the invention

Invent problem to be solved

The present invention, be in order to solve above-mentioned the problems of the prior art point, and as the 1st purpose, a kind of method that electroosmotic dewatering is handled of carrying out is provided, it is when coming that by the electroosmotic dewatering device mud that is taken place carried out processed in biological treatment process of various industry drainings etc., the cost that can suppress medicament, and do not need the optional equipment or the additional source of energy of dissolving tank or warming-up device etc., can carry out the method that efficient electroosmotic dewatering is handled.

As the 2nd purpose, the present invention provides a kind of electroosmotic dewatering method and device, it is by add electroosmotic dewatering method and the device that ionogen or dehydration filtrate are improved the conductivity of mud and make the water ratio reduction of dehydrate in processed hydrate, wherein, can further reduce the water ratio of dehydrate effectively.

In order to solve the method for problem

The mud dewatering method of the 1st mode, it is the method for mud being carried out processed by the electroosmotic dewatering device, it is characterized in that, after the concentrated salt that will discharge from drainage treatment equipment is added into this mud, carry out processed by this electroosmotic dewatering device.

The mud dewatering method of the 2nd mode, it is in the 1st mode, it is characterized in that, aforementioned concentrated salt is more than the 1 weight % with respect to the addition of aforementioned mud.

The mud dewatering method of the 3rd mode, it is in the 1st or the 2nd mode, it is characterized in that, before aforementioned mud being carried out processed by the electroosmotic dewatering device, carry out the mechanical type processed earlier, and in resulting dehydrated sludge cake, add aforementioned concentrated salt, then, carry out processed by the electroosmotic dewatering device.

The mud dewatering method of the 4th mode, it is in the 3rd mode, it is characterized in that, the water ratio of aforementioned dehydrated sludge cake is 70～90%.

The mud dewatering method of the 5th mode, it is in any mode in the 1st to the 4th mode, to it is characterized in that, aforementioned concentrated salt is the biological treatment of water of draining to be handled by reverse osmosis membrane separating treatment or evaporation concentration concentrate resulting concentrated salt.

The mud dewatering method of the 6th mode, it is in the 5th mode, it is characterized in that, the dehydration filtrate that will obtain by the processed that aforementioned electric permeating and dewatering device is carried out is recycled in the biological treating tank of aforementioned draining, then, handles.

If mud dewatering method according to the 1st～6 mode, then be by being provided with carrying out in the mud of electroosmotic dewatering, add in the prior art is to be used as the concentrated salt of being discharged from drainage treatment equipment that industrial waste is handled, thus, improve the conductivity of mud, and make the dewatering efficiency of switching on improved efficiency and improving the electroosmotic dewatering device, can reduce the water ratio of resulting dewatered sludge.

Should concentrate salt, what be in drainage treatment equipment to be produced is to be used as the material that industrial waste is handled in the prior art, therefore, this concentrated salt is added in the mud, does not have the problem of the increase that causes new reagent cost.And,, also the amount of industrial waste can be reduced by concentrating effective utilization of salt.

Again, this concentrated salt is muddy, therefore, even directly be added in the mud, it is disperseed equably, do not need of the prior art in adding electrolytical situation needed dissolving tank.Certainly, the warming-up device or the energy of heating also are unwanted.

Shown in the 6th mode, dehydration filtrate by the alkalescence that will obtain via the processed that the electroosmotic dewatering device is carried out is recycled in the biological treating tank of draining and handles, in the processing of the filtrate of can dewatering, also can seek to be reduced in and adjust the addition of the alkaline matter of sodium hydroxide that agent adds etc. as pH in the biological treating tank.

The electroosmotic dewatering method of the 7th mode, it is to seize processed hydrate between anode and negative electrode on both sides by the arms, thereby and while squeezing the electroosmotic dewatering method of dewatering in the energising of two interpolars, and in processed hydrate, be added with chemical conditioner, it is characterized in that, chemical conditioner is added in the processed hydrate in the dehydration way.

The electroosmotic dewatering method of the 8th mode, it is in the 7th mode, it is characterized in that, chemical conditioner is to contain electrolyte solution.

The electroosmotic dewatering method of the 9th mode, it is in the 8th mode, it is characterized in that, containing electrolyte solution is the dehydration filtrate of electroosmotic dewatering device.

The electroosmotic dewatering method of the 10th mode, it is in the 8th mode, it is characterized in that, containing electrolyte solution is the dehydration filtrate at dehydration procedure initial stage.

The electroosmotic dewatering device of the 11st mode, it has: the electrode that is relative to the configuration, relatively to electrode between switch on the energising device, be configured in relatively to electrode filter material and each other or hold the pressure device of holding under the arm of the processed hydrate of pressure between the electrode filter material and a side wherein under the arm each other at this filter material, it is characterized in that having chemical conditioner is added on adding set in the processed hydrate in the dehydration way.

The electroosmotic dewatering device of the 12nd mode, it is in the 11st mode, it is characterized in that, this adding set is to reclaim the recovery adding set that dehydration filtrate is added on the dehydration filtrate in the processed hydrate then.

The electroosmotic dewatering device of the 13rd mode, it is in the 12nd mode, it is characterized in that, the recovery adding set of this dehydration filtrate is to constitute in the mode that only reclaims the dehydration filtrate at the initial stage of adding dehydration procedure.

The electroosmotic dewatering device of the 14th mode, it is in the 13rd mode, it is characterized in that, aforementioned filter material is a filter cloth belt, and this filter material dispose to carry on a shoulder pole the mode of holding processed hydrate and can move in the above on the length direction of band, downside at this filter cloth belt disposes negative electrode, above this filter cloth belt, dispose anode, this anode is that assortment has a plurality of on the length direction of this filter cloth belt, the aforementioned pressure device of holding under the arm is the device that this anode is depressed, the recovery adding set of aforementioned dehydration filtrate constitutes in the following manner: the upstream side at the travel direction of filter cloth belt partly reclaims the dehydration filtrate that has seen through filter cloth belt, and more is being added in the processed hydrate by the part in downstream side than this upstream side part.

In the 7th～14 mode, in the way of dehydration procedure, in processed hydrate, add chemical conditioner, therefore, the dewatering efficiency of dehydration procedure between latter half promotes.As mentioned above,, in processed hydrate, have a large amount of ionogen at the first-half period of dehydration procedure, therefore, the dewatering efficiency height.In the 7th～14 mode, even between the latter half that ionogen reduces gradually,, make that also dewatering efficiency uprises by the interpolation of chemical conditioner, therefore, can access the low dehydrate of water ratio.

If use dehydration filtrate as chemical conditioner, then the cost of chemical conditioner reduces.

In addition, in electroosmotic dewatering,, can produce the high filtrate of conductivity at the initial stage of dehydration procedure, still, the filtrate between the latter half of dehydration procedure, its conductivity is low.Therefore, preferably be recovered in the high filtrate of the conductivity that the initial stage produced of dehydration procedure, then, be added in the processed hydrate in the dehydration way.Thus, conductivity uprises, and dehydration rate promotes fully, can access the low dehydrate of water ratio.In addition, the filtrate of dehydration procedure between latter half that conductivity is low is not added in the hydrate, therefore, is accompanied by filtrate and adds the rising of the water ratio of the processed hydrate caused and diminish, and thus, can access the low dehydrate of water ratio yet.

The electroosmotic dewatering method of the 15th mode, it is to seize processed hydrate between anode and negative electrode on both sides by the arms, and while squeezing the electroosmotic dewatering method of dewatering in the energising of two interpolars, and, in processed hydrate, be added with dehydration filtrate, it is characterized in that only the dehydration filtrate with the dehydration procedure initial stage is added in the processed hydrate.

The electroosmotic dewatering method of the 16th mode, it is in the 15th mode, it is characterized in that, the dehydration filtrate in during the initial treatment time below 60% in whole treatment times of electroosmotic dewatering treatment process is added in the processed hydrate.

The electroosmotic dewatering device of the 17th mode, it has: the electrode that is relative to the configuration, relatively to electrode between switch on the energising device, be configured in relatively to each other filter material of electrode, each other or hold under the arm between the electrode filter material and a side wherein and press holding pressure device under the arm and reclaiming and dewater filtrate and be added into the recovery adding set of the dehydration filtrate in the processed hydrate of processed hydrate at this filter material, it is characterized in that the recovery adding set of this dehydration filtrate constitutes in the mode that only reclaims the dehydration filtrate of adding the dehydration procedure initial stage.

The electroosmotic dewatering device of the 18th mode, it is in the 17th mode, it is characterized in that, aforementioned filter material is a filter cloth belt, and this filter material dispose to carry on a shoulder pole the mode of holding processed hydrate and can move in the above on the length direction of band, downside at this filter cloth belt disposes negative electrode, above this filter cloth belt, dispose anode, this anode is that assortment has a plurality of on the length direction of this filter cloth belt, the aforementioned pressure device of holding under the arm is the device that this anode is depressed, and the recovery adding set of aforementioned dehydration filtrate is that the mode that the upstream side with the travel direction that is recovered in filter cloth belt has seen through the dehydration filtrate of filter cloth belt is configured.

In electroosmotic dewatering, at the initial stage of dehydration procedure, can produce the high filtrate of conductivity, still, and the filtrate between the latter half of dehydration procedure, its conductivity is low.In the 15th～18 mode, be recovered in the high filtrate of the conductivity that the initial stage produced of dehydration procedure, then, be added in the hydrate, therefore, the conductivity of hydrate uprises, and dehydration rate promotes, and can access the low dehydrate of water ratio.

In addition, the filtrate of dehydration procedure between latter half that conductivity is low is not added in the hydrate, therefore, is accompanied by filtrate and adds the rising of the water ratio of the processed hydrate caused and diminish, and thus, can access the low dehydrate of water ratio yet.

Description of drawings

Fig. 1 is the wherein system diagram of an example of the embodiment of expression mud dewatering method of the present invention.

Among Fig. 2, the longitudinal diagram of the summary when Fig. 2 a is the pressurizing and dehydrating of the electroosmotic dewatering device in the embodiment; Fig. 2 b and Fig. 2 c are along the IIB-IIB line of Fig. 2 a and the sectional view of IIC-IIC line.

Among Fig. 3, Fig. 3 a is that the electroosmotic dewatering device delivery in the embodiment is brought the longitudinal diagram that send the summary in the operation into; Fig. 3 b is the IIIB-IIIB line sectional view of Fig. 3 a.

Fig. 4 is the longitudinal diagram of summary of electroosmotic dewatering device of other embodiment.

Among Fig. 5, Fig. 5 a is the longitudinal diagram of the summary of the electroosmotic dewatering device in the embodiment; Fig. 5 b is the sectional view along the VB-VB line of Fig. 5 a.

Fig. 6 is the longitudinal diagram of the summary of the electroosmotic dewatering device in the embodiment.

Fig. 7 is the longitudinal diagram of summary of electroosmotic dewatering device of other embodiment.

Embodiment

Below, describe embodiments of the present invention in detail.

The embodiment of＜the 1～the 6th mode 〉

The mud dewatering method of the 1st～the 6th mode is characterized in that, in being provided with carrying out the mud that electroosmotic dewatering handles, adds the concentrated salt of discharging from drainage treatment equipment in advance.

As employed concentrated salt in the present invention, so long as the concentrated salt of being discharged from drainage treatment equipment gets final product, be not particularly limited, for example, can use concentrated salt cited in following (1)～(5).

(1) from concentrated salt in order to be discharged in the reverse osmosis membrane tripping device of the salt the treating water that concentrates the biological treating equipment that draining is reclaimed, utilized to organic system or the vaporizer.

(2) from seawater being carried out the concentrated salt of being discharged in the reverse osmosis membrane tripping device of the salt the treating water of tap water treatment facility of fresh water processing or the vaporizer in order to concentrate.

(3) from city's water being carried out the concentrated salt of being discharged in the reverse osmosis membrane tripping device of the salt the condensed water of the ultrapure water producing apparatus that dechlorination handles in order to concentrate.

About the electrolyte concentration of the concentrated salt of this kind, do special restriction, still, these concentrated salt, normally as electrolyte concentration be about 0.1～24.5 weight %, conductivity is the mud about 0.1～120mS/cm and be discharged from.

In the present invention, with the slimy concentrated salt of this kind, be added on and be provided with carrying out in the mud of processed.Concentrated salt, then can't obtain fully because the lifting effect of the dewatering efficiency due to the interpolation of concentrated salt again, if too much, then also can't obtain effect proportional with it, and treatment capacity increases also if very few with respect to the addition of mud.Therefore, though also exist with ... the electrolyte concentration that concentrates salt,, the addition of concentrated salt preferably is made as more than the 1 weight % with respect to mud, particularly preferably is made as about 5～15 weight %.As the addition that is scaled behind the ionogen, preferably add concentrated salt about 0.05～0.15 weight % with respect to mud again.

In addition, for mud, preferably before electroosmotic dewatering is handled, earlier the mechanical type dewatering unit of adding pressure type water extracter by band pressurization or filter screen pressurization etc. or centrifuge etc. carries out the mechanical type processed, obtain the dehydrated sludge cake of water ratio about 70～90%, again in this dehydrated sludge cake, become the mode of aforesaid ratio with addition with respect to the mud before the dehydration, add concentrated salt, and carry out electroosmotic dewatering and handle, by carrying out that so mechanical type processed and electroosmotic dewatering treatment combination can be carried out more efficient processed.

When carrying out this mechanical type processed, also can add inorganic agglutinant commonly known in the art or polymer coagulant, in this case, as inorganic agglutinant, the iron that can use ferric sulfate (also comprising polyiron sulfate), ferrous sulfate, iron(ic) chloride, iron protochloride, iron-silicon oxide inorganic polymer agglutinant etc. be in the inorganic agglutinant more than a kind or 2 kinds.Iron is the addition of inorganic agglutinant with respect to mud, no matter be too much or very few, all can't obtain the fully low dewatered sludge of water ratio, therefore, the addition that converts as Fe with respect to the SS of the mud that carries out processed, preferably 5～20 weight %, especially preferably 7～15 weight %.

In addition, can be that inorganic agglutinant adds polymer coagulant also together with iron, at this moment, and as polymer coagulant, not special qualification the, but the preferred Amphiphatic high polymer agglutinant (amphiphilic polymers) that uses.As the Amphiphatic high polymer agglutinant, preferably have monomer, (methyl) acrylamide and (methyl) vinylformic acid of amido or ammonium salt base or the multipolymer of its salt, as monomer, can enumerate: (methyl) acryloxy ethyl-trimethyl salmiac, (methyl) acryloxy ethyl dimethyl benzene ammonio methacrylate, (methyl) acryl oxygen base-(methyl) acryloxyalkyl quaternary ammonium salts such as 2-hydroxypropyl-trimethyl ammonium chloride with amido or ammonium salt base; (methyl) acryloxyalkyl tertiary ammonium salts such as (methyl) acryloxy ethyl dimethylamine vitriol or hydrochloride, (methyl) acryloxy propyl group dimethylamine hydrochloride; (at this, " (methyl) vinylformic acid " is meant " vinylformic acid and/or methacrylic acid " to (methyl) acryl amido alkyl quaternary ammonium saltss such as (methyl) acryl aminocarbonyl propyl trimethyl ammonium chloride, (methyl) acryl aminocarbonyl propyl TMA (TriMethylAmine) methylsulfuric acid ester etc." (methyl) acryl " also is same expression.)。These monomers can use a kind separately, and use perhaps also capable of being combined is more than 2 kinds.Among these, (methyl) acryloxyalkyl quaternary ammonium salt is because the dehydrating effect excellence so can be suitable for using, especially can be suitable for using acryloxy ethyl-trimethyl salmiac and methacryloxyethyl trimethyl ammonium chloride.

In addition, as (methyl) vinylformic acid or its salt, for example can enumerate (methyl) vinylformic acid, (methyl) sodium acrylate, (methyl) ammonium acrylate, (methyl) calcium acrylate etc.Among these, especially can be suitable for using vinylformic acid and sodium acrylate.

In the Amphiphatic high polymer agglutinant, can be in addition and other comonomer copolymerizations.As other comonomers, can enumerate for example vinyl pyrrolidone, toxilic acid, methyl acrylate etc.These copolymerization of copolymerization monomer amounts are preferably 20 moles below the % usually, more preferably 10 moles below the %.

These Amphiphatic high polymer agglutinant can use separately a kind, also can will also use more than 2 kinds.

By with this kind polymer coagulant and usefulness, and in iron is mud after inorganic agglutinant adds, add polymer coagulant, can form strong mud throw out, can seek further to reduce water ratio.

The addition of this kind polymer coagulant, preferably the SS with respect to the mud that carries out processed is made as about 0.2～1 weight %.

In addition, when before the mechanical type processed, when in mud, adding these the situation of agglutinant, preferably, adding iron in mud is inorganic agglutinant, preferably handles with 1～5 minute residence time by steel basin rapidly, in addition, in the interpolation of polymer coagulant, preferably handle with 1～10 minute residence time by steel basin at a slow speed.

So carry out, after adding agglutinant as required and mud carried out the mechanical type processed, add concentrating salt, then, carry out electroosmotic dewatering by the electroosmotic dewatering device and handle.

Usually, in the electroosmotic dewatering device of being peddled on the market, owing to also exist the electroosmotic dewatering device that possesses the pattern that mechanical type dehydration portion and electroosmotic dewatering portion are arranged, therefore, can use common electroosmotic dewatering device to carry out mechanical type dehydration and electroosmotic dewatering processing, between mechanical type dehydration portion and electroosmotic dewatering portion, concentrate the interpolation of salt.

In the treatment condition of this mechanical type dehydration and electroosmotic dewatering, not special restriction still, for example, can be adopted following condition.

＜mechanical type processed condition 〉

Plus-pressure during the situation of adding pressure type dehydration: 50～1000kPa

Centrifugal force during the situation of centrifuge dehydration: 1000～2500G

Dewatering time: 1～60 minute

＜electroosmotic dewatering treatment condition 〉

Plus-pressure: 0.1～200kPa

Energising amount: DC20～100V

Dewatering time: 5～60 minutes

If according to the present invention, then plant processed thus, can access water ratio below 70%, for example the dehydrated sludge cake of the low-water-content of water ratio about 50～70%.

In addition, as the mud that carries out processed by mud dewatering method of the present invention, not special restriction, the present invention applicable to the mud that in the biological treatment process of various industry drainings etc., is produced or other pressurization from the motor-car draining floating in the various mud of mud etc.

In addition, in processed of the present invention, mud includes concentrated salt, therefore, can produce the dehydration filtrate of the alkalescence about pH12 (pH10～13 usually).This filtrate of dewatering, preferably be fed in the biological treating tank of draining and handle, thus, in the processing of the filtrate of can dewatering, the addition that also can will adjust agent as pH and be added into the alkaline matter of sodium hydroxide in the biological treating tank etc. reduces, thereby preferred.Particularly, when the filtrate of will dewatering was fed into situation about handling in the biological treating tank when so carrying out, it was favourable being recycled to it in the biological treating tank as the drainage treatment equipment in the generation source that concentrates salt.

Fig. 1 is that expression is recycled to the dehydration filtrate of electroosmotic dewatering device for so carrying out as in the biological treating tank of the drainage treatment equipment in the generation source of concentrated salt and the system diagram of situation about handling.Former water is carried out biological treatment by biological treating tank 61, and biological treatment of water is carried out processing by thickening equipment 62, and the treating water after salt is concentrated and removes is discharged to outside the system.On the other hand, a part that concentrates salt is used as industrial waste and handles, and remainder is added in the mud or dehydrated sludge cake of giving electroosmotic dewatering equipment 63.Be added mud or dehydrated sludge cake after the concentrated salt, carried out electroosmotic dewatering by electroosmotic dewatering equipment 3 and handle, resulting dehydrated sludge cake is discharged to outside the system and is carried out processing.On the other hand, dehydration filtrate is recycled in the biological treating tank 61 and is carried out processing.

Dehydration filtrate is recycled in the biological treating tank 61 by so carrying out, can seeks further efficient activity.

Below, list embodiment and comparative example, and make more specific description for the present invention.

＜embodiment 1 〉

(MLSS8 adds polymkeric substance in 000mg/L), carries out the mechanical type processed at the excess sludge of organic system draining, obtain the dehydrated sludge cake of water ratio 82%, in this dehydrated sludge cake, the mud that following concentrated salt is preceding with respect to dehydration adds 10 weight %, and has carried out the electroosmotic dewatering processing.

At this moment, the treatment condition of mechanical type processed and electroosmotic dewatering processing are as described below.

＜concentrated salt 〉

By activated sludge process to organic system draining carry out a biological disposal upon, then, biological treatment of water is concentrated and the concentrated salt mud of being discharged in the reverse osmosis membrane separating device with the ionogen concentrating and separating by film.

Electrolyte concentration: 1.3～1.5 weight %, conductivity: 15～17mS/cm.

＜mechanical type dehydration (centrifuge dehydration) treatment condition 〉

Rotation number: 2000/min

Centrifugal effect: 1000G

Dewatering time: 5m ³(with SS8, the excess sludge of 000mg/L is with 5m for/hr ³/ hr dewaters)

The polymkeric substance addition: with respect to SS is 1 weight %

＜electroosmotic dewatering treatment condition 〉

Plus-pressure: 0.16kgf/cm ²(15.7kPa)

Energising amount: DC60V

Dewatering time: 10 minutes

The water ratio of resulting dehydrated sludge cake is 65%.

＜comparative example 1 〉

In embodiment 1, using sodium sulfate is the concentrated salt of aqueous solution replacement of 10 weight %, and add with respect to the mode that the addition of the SS in the dehydrated sludge cake becomes 1.4 weight % with sodium sulfate, in addition, carried out processed with identical condition, consequently, the water ratio of resulting dehydrated sludge cake is 67%.

＜comparative example 2 〉

In embodiment 1, except not adding concentrated salt, carried out processed with identical condition, consequently, the water ratio of resulting dehydrated sludge cake is 73%.

Can learn by above result, if according to the present invention, then can effectively utilize the concentrated salt of discharging from drainage treatment equipment that is used as industrial waste punishment in the prior art, can improve the dewatering efficiency in electroosmotic dewatering is handled significantly.

The embodiment of＜the 7～the 14th mode 〉

Fig. 2 a and Fig. 3 a are the longitudinal diagrams along the length direction of the electroosmotic dewatering device of the embodiment of the 7th～14 mode (band turning direction), Fig. 2 b, 2c are the IIB-IIB line along Fig. 2 a, the sectional view of IIC-IIC line, and Fig. 3 b is the sectional view along the IIIB-IIIB line of Fig. 3 a.In addition, Fig. 2 a, 2b are the apperances of expression dehydration procedure, and Fig. 3 a, 3b are that this electroosmotic dewatering device delivery of expression is brought the apperance of sending operation into.

By connections of building bridge of conveying belt 1 that filter cloth constituted endless ground between roller 2,3, and be set as and carry out the endless rotation.

The upper face side of this conveying belt 1 becomes the carrying side of mud, below side become the loopback side.Below the carrying side of conveying belt 1, be configured with tabular negative electrode 4.This negative electrode 4 is the tabular components that electro-conductive material constituted by metal etc., and possesses the hole that the majority that connects above-below direction is arranged.Negative electrode 4 is to exist near roller 3 from nearby extending of roller 2 always.

Be provided with funnel 5 in the mode of supplying with processed hydrate (being mud S in this embodiment) at the upstream portion of this carrying direction above conveying belt 1.

Be equipped with the

pallet

6,7 that filtrate work that the aforementioned apertures by negative electrode 4 is fallen is accepted at the downside of negative electrode 4.

Pallet 6 is configured in the carrying direction upstream side place of conveying belt 1, and pallet 7 is configured in than this pallet 6 and more by place, carrying direction downstream side.In this embodiment, as aftermentioned, assortment has anode unit 21～25 on the carrying direction of conveying belt 1, the downside of half side anode unit 21～23 before pallet 6 is configured in, and pallet 7 is configured in the downside of the half

side anode unit

24,25 in back.

Be fed in the filtrate storage tank 8 by pallet 6 collected filtrates, and can be supplied to spray nozzle described later 12 places via pump and pipe arrangement (omitting diagram).

Be sent to the water treating equipment place by pallet 7 collected filtrates via pipe arrangement 11.

Above the trucking department of conveying belt 1, be provided with

anode unit

21,22,23,24,25.In addition, shown in Fig. 2 b, 2c, on the both sides of the trucking department of conveying belt 1, erect and be provided with the sidewall 20 that is constituted by the electrical insulating property material, constitute the mud that can not make on the conveying belt 1 and ooze out into the place, side.Anode unit 21～25 is configured between the

sidewall

20,20.

In this embodiment, on conveying belt carrying direction, dispose 5 anode units, still, be not defined to this.Usually, as long as on conveying belt carrying direction, dispose about 2～5 of anode units.

Each anode unit 21～25 possesses to have and is fixed then in positive plate of locating below 33 and air cylinder (omitting diagram).Air cylinder, its upper end is the body place that is fixed on the electroosmotic dewatering device, if supply air in the air cylinder, then positive plate 33 is to move towards the below.If from air cylinder air is discharged, then positive plate 33 is pulled on and is risen.

The upper end of air cylinder is installed in as the beam of the body of electroosmotic dewatering device (omitting diagram) and locates.This beam is fixedly installed on the top of conveying belt 1.

Positive plate 33 for each anode unit 21～25 is connected with galvanic current from continuous-current plant (omitting diagram).

Between anode unit 23 and anode unit 24, be configured with spray nozzle 12, constitute and the dehydration filtrates in the groove 8 are sprayed with respect to the mud on the conveying belt 1 and added.In this embodiment, spray nozzle 12 is that the wide cut direction of conveying belt 1 is provided with 2, still, also can be provided with 1 or be provided with 3.Also can be arranged on the spray nozzle that has long finedraw shape fog nozzle on the conveying belt wide cut direction again.

When the electroosmotic dewatering device via formation like this carries out the processed of mud, the mud S that is supplied in the funnel 5 is sent to conveying belt 1, and to each anode unit 21～25 perfectly straight stream electric current, and, to the air cylinder air supply of each anode unit 21～25, the positive plate 33 by anode unit 21～25 pushes from the top for this mud.

Voltage is so that anode unit 21～25 is just becoming and make negative plate 4 become negative mode applies.Become from the running management that makes device and to be easy to viewpoint, preferably apply identical voltage, still, also can be made as highly more by carrying direction downstream side voltage more, or be made as low more by carrying direction downstream side voltage more on the contrary for each anode unit 21～25.Again, also can be so that the current value of each anode unit becomes the control of switching on of identical mode.

Can supply with the air of uniform pressure to the air cylinder of each anode unit 21～25, the anode unit that also can be made as leaning on the downstream side more is made as the air supply pressure big or more little more.

So carry out, energising and the positive plate 33 by anode unit 21～25 come mud is pushed between anode unit 21～25 and negative plate 4, and thus, mud is by electroosmotic dewatering.Then, dehydration filtrate sees through conveying belt 1, and passes through the hole of negative plate 4, falls on the pallet 6,7.Fall to the filtrate on the pallet 6, because the conductivity height, therefore, be stored in the storage tank 8 being used for and be added on the conveying belt 1 from spray nozzle 12.

Shown in Fig. 2 a～2c, when coming mud pushed to 21～25 energisings of each anode unit and via anode unit 21～25, conveying belt 1 stops.After the extruding of having carried out the specified time via anode unit 21～25 and energising, from the air cylinder of each anode unit 21～25 air is discharged, and positive plate 33 is risen.Then, make the distance of a pitch of the assortment pitch of conveying belt 1 moving anode unit 21～25.Thus, the position is sent as dewatered sludge at the mud of the downside of anode unit 25, and the position is at the mud of the downside of each anode unit 21～24, does moving of 1 pitch towards the downside of the anode unit 22～25 in downstream side respectively.Again, processed mud is not the downside that is fed to anode unit 21 from funnel 5.

In this embodiment, make conveying belt 1 do 1 pitch amount feed mobile during in, from spray nozzle 12 the dehydration filtrates in the storage tank 8 are sprayed, be added among the mud S on the conveying belt 1.

Make conveying belt 1 done 1 pitch amount feed move after, the spraying of the dehydration filtrate that stops from spray nozzle 12 and come then, is depressed the positive plate 33 of each anode unit 21～25, and energising between each anode unit 21～25 and negative electrode 4 is carried out the electroosmotic dewatering of mud and is handled.Below, by carrying out this operation repeatedly, carry out electroosmotic dewatering for mud and handle.

By being somebody's turn to do from the high filtrate of the conductivity of pallet 6 is added into processed mud S the dehydration way, conductivity at the processed mud of dehydration procedure between latter half uprises, the conductivity of the mud between

anode unit

24,25 and negative plate 4 uprises, and dehydration property gets a promotion.Thus, the water ratio of resulting dewatered sludge reduces.

Again, about falling to the low filtrate of conductivity on the pallet 7, owing to be not added in the mud, therefore, the water ratio of processed mud rises and also is suppressed, and thus, the water ratio of resulting dewatered sludge also can step-down.

And then, in this embodiment, owing to, therefore, also prevented excessive energising at the dehydration procedure first-half period not for the processed mud interpolation dehydration filtrate of dehydration procedure first-half period.But, in the present invention, when the conductivity of the processed mud in being fed to funnel 5 hangs down, also can be with the part of the dehydration filtrate in the storage tank 8, in the mud before being added into electroosmotic dewaterings in the funnel 5 and handling or be added into than it and more in the mud of prime, improve with conductivity with processed mud.

In this embodiment, between

anode unit

23,24, be configured with spray nozzle 12.Near this spray nozzle 12, since mud be carried out to a certain degree dehydration and the water ratio step-down, therefore, after dehydration filtrate having been carried out the spraying interpolation from spray nozzle 12, even come mud is pushed, do not have the situation that mud spills from the space of 23,24 of anode units by anode unit yet.

In the present invention, the conductivity that is added into the filtrate the mud on the conveying belt 1 from spray nozzle 12 is preferably more than the 500mS/m, especially preferably more than the 1000mS/m, again, usually preferably below the 2500mS/m, especially preferably below the 2000mS/m.When the situation that is made as 100% the fully dehydrating treatment time, usually, preferably reclaim initial 60% below, particularly the time below 40% be with in resulting dehydration filtrate, and be added in the processed mud via spray nozzle 12.The allocation position of spray nozzle 12 in this embodiment, is between the 3rd and the 4th 's

anode unit

23,24, still, is not defined to this.When the situation that will be made as 100% from the length of the fully dehydrating portion of leading section till the terminal part of the anode unit in downstream side of the anode unit of upstream side, the position of spray nozzle 12, preferably be made as from upstream side 50% after, for example be made as 50～80%, especially preferably be made as 50～70%.

Be added on the amount of the filtrate in the mud on the conveying belt 1, preferably with respect to be present in than spray nozzle 12 more the mud weight on the conveying belt 1 in downstream side become more than the 5 weight %, especially preferably become more than the 10 weight %, in addition, usually, preferably below the 20 weight %, especially preferably below the 15 weight %.

In the electroosmotic dewatering device of above-mentioned embodiment, configuration spray nozzle 12 between

anode unit

23,24, still, also can be as shown in Figure 4,20 places are provided with spray nozzle 13 at the side walls plate, and are made as from each spray nozzle 13 to come the spraying of the mud S on the conveying belt 1 interpolation dehydration filtrate.

If be made as this kind formation, then

anode unit

23,24 space to each other can be dwindled, can prevent the situation of mud when mud pushes from spilling between this

anode unit

23,24.

In the present invention, also can as between

anode unit

23 and 24 and between

anode unit

24 and 25 usually at the complex field configuration spray nozzle of living in of the carrying direction of conveying belt 1.

In the above-described embodiment, be made as via anode unit 21～25 and conveying belt 1 and negative electrode 4 to come mud is carried out electroosmotic dewatering, still, the present invention is also applicable in the electroosmotic dewatering device of other patterns.For example, the present invention is also applicable to mud S being held under the arm the electroosmotic dewatering device that is pressed between the conveying belt that anode rotating cylinder and double as are negative electrode.Again, the present invention is also applicable to object being treated being held under the arm the electroosmotic dewatering device that is pressed in filter material pattern each other.For example, the present invention is also applicable to coming mud is held under the arm the pressurization squeeze type electroosmotic dewatering device of pressure via squeezing film and electrode shown in patent documentation 4 as described above (the special fair 7-73646 of Japan), patent documentation 5 (Japanese Patent the 3576269th), the non-patent literature 1 (water treatment management brief guide is table 86 P.340) between 1 pair filter plate.

In the electroosmotic dewatering method of the electroosmotic dewatering device of the also applicable pattern beyond use has diagram of the present invention.

In the present invention, also can be made as the electrolyte solution of dehydration beyond the filtrate is added in the processed hydrate in the dehydration way.As this kind electrolyte solution, but illustration has: the solution of the salt of sodium-chlor, sodium sulfate, yellow soda ash, sodium bicarbonate, Repone K etc.; Or the solution of the acid of hydrochloric acid, sulfuric acid, nitric acid etc.The concentration of the salt of this solution is so that conductivity becomes the mode of aforesaid proper range and selectes.Salt is dissolved in the dehydration filtrate, and this is added in the processed hydrate in the dehydration way.

Below, describe at embodiment and comparative example.

Use the electroosmotic dewatering device shown in Fig. 4, the water drain of water ratio 78% is handled mud carry out the electroosmotic dewatering processing.Operating condition, as follows.

The assortment number of anode unit on conveying belt carrying direction: 4

The position of spray nozzle 13: between the 2nd and the 3rd 's the anode unit

Mud feed speed: 12L/hr

The voltage that applies for anode unit: 60V

＜comparative example 3 〉

Do not add chemical conditioner, and carry out the electroosmotic dewatering processing of mud by above-mentioned condition.About dehydration filtrate, it is all delivered to the water treating equipment place.Its result, the water ratio of dewatered sludge is 67.1%, consumed power is 1429WH.

＜comparative example 4 〉

In above-mentioned comparative example 1, from spray nozzle 13 being that the ratio of 2 volume % is added Na with respect to the mud in the funnel 5 ₂SO ₄The aqueous solution (concentration 120g/L).Its result, the water ratio of dewatered sludge is 62.4%, consumed power is 1651WH.

＜embodiment 2 〉

In above-mentioned comparative example 2, only the anode unit spray nozzle 13 to each other from the 2nd and the 3rd adds Na when feeding of conveying belt 1 is mobile ₂SO ₄The aqueous solution.Addition be with respect to than the position of spray nozzle 13 more the mud on the conveying belt 1 in downstream side be 2 volume %.Its result, the water ratio of dewatered sludge is 61.3%, consumed power is 1379WH.

Above result is summarized, be shown in the following table 1.

Table 1

	Equilibrium moisture content (%)	Consumed power (WH)
			Comparative example 1	67.1	1429
Comparative example 2	62.4	1651
			Embodiment 1	61.3	1379

＜investigate

Shown in embodiment 2,, equilibrium moisture content and consumed power are reduced by in the electroosmotic dewatering way, adding chemical conditioner.

In comparative example 3, can think that between dehydration latter half, because the positively charged ion deficiency, and can't obtain the effect of osmosis fully, therefore, equilibrium moisture content is unsatisfactory.

In addition, in comparative example 4, need big consumed power.This can think following reason: although contain more positively charged ion in the mud in dehydration during the initial stage, still added auxiliary agent, therefore, flowing is necessary above too much electric current.In addition, in comparative example 4, by the effect of chemical conditioner, equilibrium moisture content has had lifting compared to comparative example 3, still, remains the water ratio higher than embodiment 2.Can think following reason: owing to be to be added with chemical conditioner in inlet mud, therefore, between the latter half of dehydration procedure, the positively charged ion quantitative change gets not enough.

The embodiment of＜the 15～the 18th mode 〉

Fig. 5 a and Fig. 6 are the longitudinal diagrams of the length direction (band turning direction) of the electroosmotic dewatering device in the embodiment of the 15th～18 mode, and Fig. 5 b is the sectional view along the VB-VB line of Fig. 5 a.In addition, Fig. 5 a, 5b are the apperances of expression dehydration procedure, and Fig. 6 is that this electroosmotic dewatering device delivery of expression is brought the apperance of sending operation into.

By connections of building bridge of conveying belt 1 that filter cloth constituted endless ground between roller 2,3, and can carry out the endless rotation.

The upper face side of this conveying belt 1 becomes the carrying side of mud, below side become the loopback side.Below the carrying side of conveying belt 1, dispose tabular negative electrode 4.This negative electrode 4 is the tabular components that electro-conductive material constituted by metal etc., and possesses the hole that the majority that connects above-below direction is arranged.Negative electrode 4 is to exist near roller 3 from nearby extending of roller 2 always.

Be provided with funnel 5 in the mode that processed hydrate (being mud S in this embodiment) is supplied to the upstream portion of the carrying direction on this conveying belt 1.

Be provided with the

pallet

6,7 that filtrate that the aforementioned apertures by negative electrode 4 is fallen is accepted at the downside place of negative electrode 4.

Pallet 6 is configured in the carrying direction upstream side place of conveying belt 1, and pallet 7 is configured in than this pallet 6 more by place, carrying direction downstream side.In this embodiment, as described later, assortment has anode unit 21～25 on the carrying direction of conveying belt 1, and pallet 6 is configured in the downside of anode unit 21～23, and pallet 7 is configured in the downside of

anode unit

24,25.

Be fed in the filtrate storage tank 8 by pallet 6 collected filtrates, and can be via pump 9 and pipe arrangement 10 and be supplied to funnel 5.

Be sent to water treating equipment by pallet 7 collected filtrates via pipe arrangement 11.

Above the trucking department of conveying belt 1, be provided with

anode unit

21,22,23,24,25.In addition, shown in Fig. 5 b, erect in the both sides of the trucking department of conveying belt 1 and to be provided with sidewall 20, constitute the mud that can not make on the conveying belt 1 and ooze out into the place, side.Anode unit 21～25 is configured between the

sidewall

20,20.

In this embodiment, anode unit is configured with 5 on conveying belt carrying direction, still, be not defined to this.Anode unit is usually as long as dispose about 2～5 on conveying belt carrying direction.

Each anode unit 21～25 possesses to have and is fixed then in positive plate of locating below 33 and air cylinder (omitting diagram).Air cylinder, its upper end is fixed on the body place of electroosmotic dewatering device, if supply air in the air cylinder, then positive plate 33 is to move towards the below.If from air cylinder air is discharged, then positive plate 33 is pulled on and is risen.

The upper end of air cylinder is installed in as on the beam of the body of electroosmotic dewatering device (omitting diagram).This beam is fixedly installed on the top of conveying belt 1.

Positive plate 33 to each anode unit 21～25 is connected with galvanic current from continuous-current plant (omitting diagram).

When the electroosmotic dewatering device via formation like this carries out the processed of mud, the mud S that is supplied in the funnel 5 is sent to conveying belt 1, and to each anode unit 21～25 perfectly straight stream electric current, and, to the air cylinder air supply of each anode unit 21～25, the positive plate 33 by anode unit 21～25 comes this mud is pushed from the top.

Voltage is so that anode unit 21～25 is just becoming and make negative plate 4 become negative mode applies.Become from the running management that makes device and to be easy to viewpoint, preferably each anode unit 21～25 is applied identical voltage, still, can be made as also that then voltage is high more by carrying direction downstream side more, or be made as on the contrary that then voltage is low more by carrying the direction downstream side more.Again, also can be so that the current value of each anode unit becomes the control of switching on of identical mode.

Can supply with the air of uniform pressure to the air cylinder of each anode unit 21～25, also can be made as to more by the anode unit in downstream side and with air supply press be made as big or more little more.

Energising and the positive plate 33 by anode unit 21～25 come mud is pushed between anode unit 21～25 and negative plate 4 by so carrying out, and mud is by electroosmotic dewatering.Then, dehydration filtrate sees through conveying belt 1, and passes through the hole of negative plate 4, falls on the pallet 6,7.Fall to the filtrate on the pallet 6, because the conductivity height, therefore, be stored in the storage tank 8, and be added in the mud in the funnel 5 via pump 9, pipe arrangement 10.Be added in the funnel 5 by the filtrate that this conductivity that comes from pallet 6 is high, the conductivity of processed mud uprises, and the conductivity of the mud between anode unit 21～25 and negative plate 4 uprises, and dehydration property promotes.Thus, the water ratio of resulting dewatered sludge reduces.

Again, fall to the low filtrate of conductivity on the pallet 7, be not added in the mud, therefore, the rising of the water ratio of processed mud also is suppressed, and thus, the water ratio of resulting dewatered sludge also can step-down.

When coming mud pushed to 21～25 energisings of each anode unit and via anode unit 21～25 shown in Fig. 5 a, 5b, conveying belt 1 stops.After the extruding of having carried out the specified time via anode unit 21～25 and energising, from the air cylinder of each anode unit 21～25 air is discharged, and positive plate 33 is risen.Then, make the distance of a pitch of the assortment pitch of conveying belt 1 moving anode unit 21～25.Thus, the position is sent as dewatered sludge at the mud of the downside of anode unit 25, and the position is at the mud of the downside of each anode unit 21～24, does moving of 1 pitch towards the downside of the anode unit 22～25 in downstream side respectively.Again, processed mud is not the downside that is fed to anode unit 21 from funnel 5.Then, the positive plate 33 of each anode unit 21～25 is depressed, and energising between each anode unit 21～25 and negative electrode 4, carry out the electroosmotic dewatering of mud and handle.Below, by carrying out this operation repeatedly, mud is carried out electroosmotic dewatering handle.

In the present invention, the conductivity of the filtrate the mud in pipe arrangement 10 is added into funnel 5, preferably more than the 500mS/m, especially preferably more than the 1000mS/m, again, usually preferably below the 2500mS/m, especially preferably with below the 2000mS/m.When the situation that is made as 100% the fully dehydrating treatment time, usually preferably will be initial below 60%, particularly the time below 40% be with in resulting dehydration filtrate be added in the processed mud.

Being added on the amount of the filtrate in the mud in the funnel 5, is more than the 5 weight % with respect to mud weight preferably, especially preferably more than the 10 weight %, in addition, usually preferably below the 20 weight %, especially preferably below the 15 weight %.

In Fig. 5 a, 5b, 6, the dehydration filtrates in the storage tank 8 are added in the mud before electroosmotic dewaterings in the funnel 5 are handled, but also can be in that more the mud storage tank of preceding-stage side or mud supplying tubing etc. be located to make an addition in the mud than funnel 5.

In the electroosmotic dewatering device of above-mentioned embodiment, come mud is carried out electroosmotic dewatering via anode unit 21～25 and conveying belt 1 and negative electrode 4, still, the present invention is also applicable in the electroosmotic dewatering device of other patterns.For example, the present invention is also applicable to as shown in Figure 7 mud S being held under the arm the electroosmotic dewatering device 40 that is pressed between the conveying belt 42 that anode rotating cylinder 41 and double as are negative electrode.In the case, the filtrate at the initial stage of will dewatering is too reclaimed by pallet 43, and is added among the processed mud S.The point of addition for processed mud of dehydration filtrate is arbitrarily.The filtrate of dehydration procedure between latter half is recovered by pallet 44, and is sent to water treating equipment.

In addition, though also not shown, still, the present invention is also applicable to object being treated being held under the arm the electroosmotic dewatering device that is pressed in filter material pattern each other.For example, the present invention also is shown in the pressurization squeeze type electroosmotic dewatering device of holding pressure mud between 1 pair filter plate via squeezing film and electrode under the arm applicable to foregoing patent documentation 4 (Japan special fair 7-73646), patent documentation 5 (Japanese Patent the 3576269th), non-patent literature 1 (water treatment management brief guide is table 86 P.340) institute.In the electroosmotic dewatering treatment process of the electroosmotic dewatering device of this kind batch, as long as be recovered in the effusive dehydration filtrate of initial stage of dehydration procedure, and be added in the processed mud (former mud), and with this former mud that has added filtrate next batch or its later batch treatment process in carry out electroosmotic dewatering and handle and get final product.

Below, explain at embodiment and comparative example.

Use the electroosmotic dewatering device shown in Fig. 5 a, the 5b, 6, the water drain of water ratio 82% is handled mud carry out the electroosmotic dewatering processing.Operating condition, as described below.

The assortment number of anode unit on conveying belt carrying direction: 5

Mud feed speed: 12L/hr

The voltage that applies for anode unit: 60V

＜comparative example 5 〉

Carry out the electroosmotic dewatering of mud handles by above-mentioned condition.About dehydration filtrate, be that it has all been delivered to water treating equipment.Consequently, the water ratio of dewatered sludge is 74%.

Take the filtrate that falls from the downside of each anode unit 21～25, conductivity, Na ionic concn and pH are measured, consequently, as shown in the table 2.

Table 2

＜embodiment 3 〉

In above-mentioned comparative example 5, reclaim the dehydration filtrate of downside of the anode unit 21～23 of 3 grades of upstream sides, and add this dehydration filtrate (conductivity 1070mS/m) of 10 weight % with respect to former mud.Consequently, the water ratio of dewatered sludge is 65%.

＜comparative example 6 〉

In above-mentioned comparative example 5, reclaim the dehydration filtrate (conductivity 258mS/m) of downside of the anode unit 25 in downstream side, and add this dehydration filtrate of 10 weight % with respect to former mud.Consequently, the water ratio of dewatered sludge is 72%.

＜comparative example 7 〉

In above-mentioned comparative example 5, reclaim the dehydration filtrate of the downside of all anode units 21～25, and add this dehydration filtrate (conductivity 820mS/m) of 10 weight % with respect to former mud.Consequently, the water ratio of dewatered sludge is 68%.

According to above embodiment and comparative example,, can confirm that then the water ratio of dewatered sludge is reduced if according to the present invention.

Though use specific mode that the present invention has been done detailed description,, to those skilled in the art, clearly, under the prerequisite that does not break away from the intent of the present invention and scope, the present invention can carry out various changes.

In addition, the application is as basic with the Japanese patent application of being applied in the Japanese patent application of being applied on March 30th, 2009 (special be willing to 2009-082568), on September 1st, 2009 (the special 2009-201799 of hope) and the Japanese patent application (the special 2010-057589 of hope) applied on March 15th, 2010, at this, quote its all content by reference.

Claims

1. mud dewatering method, it is by the electroosmotic dewatering device mud to be carried out the method for processed, it is characterized in that,

After the concentrated salt that will discharge from drainage treatment equipment is added into this mud, carry out processed by this electroosmotic dewatering device,

And aforementioned concentrated salt is the biological treatment of water of draining to be handled by reverse osmosis membrane separating treatment or evaporation concentration concentrate resulting concentrated salt.

2. mud dewatering method as claimed in claim 1 is characterized in that, aforementioned concentrated salt is more than the 1 weight % with respect to the addition of aforementioned mud.

3. mud dewatering method as claimed in claim 1 or 2, it is characterized in that, before aforementioned mud being carried out processed by the electroosmotic dewatering device, carry out the mechanical type processed earlier, and in resulting dehydrated sludge cake, add aforementioned concentrated salt, then, carry out processed by the electroosmotic dewatering device.

4. mud dewatering method as claimed in claim 3 is characterized in that the water ratio of aforementioned dehydrated sludge cake is 70～90%.

5. mud dewatering method as claimed in claim 1 is characterized in that, the dehydration filtrate that will obtain by the processed that aforementioned electric permeating and dewatering device is carried out is recycled in the biological treating tank of aforementioned draining, then, handles.

6. electroosmotic dewatering method, it is to seize processed hydrate between anode and negative electrode on both sides by the arms, while thereby and squeeze the electroosmotic dewatering method of dewatering in the energising of two interpolars, and in processed hydrate, be added with chemical conditioner, it is characterized in that

Chemical conditioner is added in the processed hydrate in the dehydration way,

And aforementioned chemical conditioner is to contain electrolyte solution,

And, aforementionedly contain the dehydration filtrate that electrolyte solution is the dehydration procedure initial stage.

7. electroosmotic dewatering device, it has:

The electrode that is relative to the configuration,

Relatively to electrode between switch on the energising device,

Be configured in relatively to electrode each other filter material and

At this filter material each other or at filter material and wherein hold the pressure device of holding under the arm of pressing processed hydrate between a side the electrode under the arm,

It is characterized in that,

It has chemical conditioner is added on adding set in the processed hydrate in the dehydration way,

This adding set is to reclaim the recovery adding set that dehydration filtrate is added on the dehydration filtrate in the processed hydrate then,

And the recovery adding set of aforementioned dehydration filtrate is to constitute in the mode that only reclaims the dehydration filtrate at the initial stage of adding dehydration procedure,

And aforementioned filter material is a filter cloth belt, and this filter material is held processed hydrate with load in the above and the mode that can move on the length direction of band dispose,

Downside at this filter cloth belt disposes negative electrode, disposes anode above this filter cloth belt,

This anode be on the length direction of this filter cloth belt assortment have a plurality of,

The aforementioned pressure device of holding under the arm is the device that this anode is depressed,

And, the recovery adding set of aforementioned dehydration filtrate constitutes in the following manner: the upstream side at the travel direction of filter cloth belt partly reclaims the dehydration filtrate that has seen through filter cloth belt, and more is being added in the processed hydrate by the part in downstream side than this upstream side part.

8. electroosmotic dewatering method, it is to seize processed hydrate between anode and negative electrode on both sides by the arms, and while squeezing the electroosmotic dewatering method of dewatering in the energising of two interpolars, and, in processed hydrate, be added with dehydration filtrate, it is characterized in that only the dehydration filtrate with the dehydration procedure initial stage is added in the processed hydrate.

9. electroosmotic dewatering method as claimed in claim 8 is characterized in that, the dehydration filtrate in during the initial treatment time below 60% in whole treatment times of electroosmotic dewatering treatment process is added in the processed hydrate.

10. electroosmotic dewatering device, it has:

The electrode that is relative to the configuration,

Relatively to electrode between switch on the energising device,

Be configured in relatively to each other filter material of electrode,

This filter material each other or at filter material and wherein hold under the arm between a side the electrode press processed hydrate hold under the arm pressure device and

Reclaim dehydration filtrate and be added into the recovery adding set of the dehydration filtrate in the processed hydrate,

It is characterized in that the recovery adding set of this dehydration filtrate constitutes in the mode that only reclaims the dehydration filtrate of adding the dehydration procedure initial stage.

11. electroosmotic dewatering device as claimed in claim 10 is characterized in that,

Aforementioned filter material is a filter cloth belt, and this filter material is held processed hydrate with load in the above and the mode that can move on the length direction of band dispose,

The recovery adding set of aforementioned dehydration filtrate is that the mode that the upstream side with the travel direction that is recovered in filter cloth belt has seen through the dehydration filtrate of filter cloth belt is configured.