CN106145606A

CN106145606A - Slurry dewatering technique

Info

Publication number: CN106145606A
Application number: CN201510179842.2A
Authority: CN
Inventors: L·迈莱; B·赫尔布莱特
Original assignee: Veolia Water Solutions and Technologies Support SAS
Current assignee: Veolia Water Solutions and Technologies Support SAS
Priority date: 2015-02-26
Filing date: 2015-04-16
Publication date: 2016-11-23
Also published as: FR3033164B1; SG11201706977VA; AU2016225245A1; FR3033164A1; MY189301A; WO2016135422A1; PH12017501540A1

Abstract

Slurry dewatering technique, can reach higher dried level with limited power consumption；This technique includes the chemical treatment process (S1) of mud to be drained off (10) together, in this operation, needs to add flocculant (11b) and coagulation promoter (11a) in mud (10) to；And include one electric dehydration operation (S4).

Description

Slurry dewatering technique

Technical field

This specification relates to a kind of slurry dewatering technique, can reach higher doing with limited power consumption Dry level.

This type of technique especially can be used to be dehydrated the mud from such as sewage treatment plant, in order to It can be burned or bury.

Background technology

Generally, the mud from such as sewage treatment plant must be dehydrated, and then passes through for example organic The mode of soil improvement (broadcasting sowing) or burning (burning) is recycled, or enters at the center of depositing Row is buried.In the case of burning, mud can be allowed at the end of dehydration procedure to reach drying regime, The i.e. ratio shared in mud gross mass of dry matter should be enough to automatically maintain fired state: therefore, excellent Aridity is selected to be 30% to 45%.Similarly, in the case of filling, the law of some country Require that the minimum index of aridity before mud landfill is about 40% (for giving an example).It should be understood that exploitation The importance of efficient drying technique, especially more needs in the case that this mud is the type being difficult to be dried Solve its importance, especially with the biological mud of sewage treatment plant for very.

In known technique, some technique is specifically designed to and carries out mechanical drying to mud: may relate to Centrifuging process or pressure-bearing filtering technique, it is especially desirable to use filter press or belt filter.But, this Class technique can be restricted.Such as, for the mud from sewage treatment plant, its aridity can only Reach 15% to 40%；Special effective apparatus and mud can only used for easily processing type (such as Mud with based on mineral matter) when, maximum 40% can be reached.Therefore, for some mud Speech, the biological mud of such as sewage treatment plant, it is extremely difficult to the aridity of 30%, the change to mud This aridity is inadequate.

Mud is then dehydrated by other techniques with hot dewatering type: therefore, relates to carry out mud Heating, so that it is drying regime.These techniques are largely effective: temperature and process according to heating are held The continuous time, the aridity of about 90% can be reached.But, these techniques all consume energy relatively big, row per ton Discharge water energy (kWh/tEE) the even more multi-energy of 700kWh at least to be consumed；In general, machine Tool flow process consumes the energy of at least 20kWh/tEE, (filter press, belt mistake depending on its technology type Filter or filter centrifugal).

Finally, there are the mechanical dehydration technique electrically assisting, also referred to as electric dehydration technique, it is intended to Filter with the mud to certain volume for the pressure-bearing mode, such as filter in filter press, additionally, Electric field can also be applied.This electric field adds produced hydrolysis phenomena, can disconnect water-mud key, just In solid particle, hydrone is past in the opposite direction mobile.This type of electric auxiliary then can improve the de-of mud Water efficiency, and therefore obtain several extra aridity point value.But, for some mud, this type of There is certain difficulty in technique.

In fact, during electric dehydration, mud plays a part resistance.But, at some mud Electricity mobility is relatively low and/or amount of ions less in the case of, the increase of mud resistance value can be more rapid. Therefore, under Joule effect during current constant, increasing sharply of mud resistance value is embodied in temperature rise mode. Mud is drier, and its electricity mobility is poorer, and therefore its resistance value is bigger.Meanwhile, temperature can be caused to rise, The especially anode side in arid region when electric dehydration.For this reason, it is necessary to this The duration of class electric dehydration operation is any limitation as, thus will not damage electric dewatering device.Additionally, At current constant thus in the case of voltage constant, the increase of resistance value can cause a large amount of energy loss occur.

Therefore, for this type of mud, and in view of the additional electrical consumption of required input, obtained Aridity relatively small and have little significance.

Therefore, just really need a kind of slurry dewatering technique, at least can partly make up the interior of previous process In shortcoming.

Content of the invention

This specification relates to a kind of slurry dewatering technique, including the chemical treatment work of one mud to be drained off Sequence, in this operation, needs to add flocculant and coagulation promoter in mud to；And include one electricity Dynamic dehydration procedure.

From the point of view of individually, flocculation aid and flocculant will not produce significantly effect to the operation of electric dehydration and efficiency Really.But, inventor it has proven convenient that in sludge treatment process a combination thereof use can produce cooperative effect, It is thus possible to be greatly enhanced the efficiency of electric dehydration operation, and then improve the final aridity of mud.

It is true that in the case of not using any composition or only use one of which composition, generally Can confirm that voltage can increase sharply on the binding post of electric dewatering device electrode, just can make voltage subsequently Keep stable, and rapid decrease or reach the maximum voltage value of operator's defined and be not further added by, from And play the effect of guard electrode.From then on, this voltage peak, actually can be in electric dehydration operation Occur immediately after startup, thus cause being dried side most and i.e. quickly raise at the mud temperature of anode side, Electric dry drying process so will be allowed to suspend in advance, and anti-locking apparatus is impaired.

Otherwise, when flocculant and flocculant aid are applied in combination, it is our surprising discovery that, usual observable To voltage peak do not occur.In contrast, the experiment of inventor shows, voltage can be in electric dehydration First drop in the first few minutes of operation and rise afterwards, then keep stable or again decline.From then on, close on The temperature delay of anode region raises, so just can temperature reach to damage the temperature levels of device with Before, extend the duration of electric dehydration operation: so can extract substantial amounts of moisture, thus reach Higher dried level.

In order to explain that this surprising phenomenon inventors herein proposes one it is assumed that be applied in combination flocculant and flocculation Auxiliary agent, in addition to can improving the filterability of mud, additionally it is possible to improves the quantity of contained ion in mud And its electric current property moved.This type of phenomenon can be used to reduce the resistance value of mud, is especially beginning to use electricity The resistance value of field, and therefore reduce voltage lift-off value, and electrode is because of heat value produced by Joule effect.

Therefore, having benefited from this technique and this specially treated flow process, test result shows, relative to routine For dewatering process, this technique can allow aridity improve 10 to 60 points, and reduces power consumption；Described The overall power consumption of technique keeps below 300kWh/tEE.

In certain embodiments, the flocculant being used is polymer.

In certain embodiments, polymer used is cationic flocculant.This base polymer can be more The mud particle assembled well, and in the range of this report, provide good filter result.

In certain embodiments, polymer used is the cation flocculation with high density and low-molecular-weight Agent.

But, other anionic flocculant, cationic flocculant or flocculant in non-ion type, with Sample can have different molecular weight according to the type of mud to be drained off.

In certain embodiments, in chemical treatment process, the net product of the flocculant in mud is added to Quality, in the dry matter of mud i.e. per ton, the quality (kgMA/tMS) of active material (MA) is 1 To 25kg, preferably 4 to 15kgMA/tMS.Inventor finds in their test process, and this is dense Degree scope can be given in terms of electric dehydration dynamics Controlling and in terms of attainable aridity and extremely make The satisfied result of people.

In certain embodiments, flocculant is mineral substance coagulating agent, such as ferric trichloride.But, equally Other mineral adjuvants or organic adjuvant can be used.

In certain embodiments, in chemical treatment process, the net product matter of the flocculant in mud is added to Amount accounts for the 0.5% to 20% of dry quality of mud fluid.Inventor finds in their test process, and this is dense Degree scope can be given in terms of electric dehydration dynamics Controlling and in terms of attainable aridity and extremely make The satisfied result of people.

In certain embodiments, this electric dehydration operation can be implemented in filter press；Electric dehydration operation exists Filter press is carried out；This filter press at least includes a chamber being made up of two pallets；Each pallet is extremely It is equipped with an electrode less；And at least one pallet is provided with filter, preferably a filter cloth.Each chamber Including a pallet being equipped with anode and a pallet being equipped with negative electrode, in order to application electric field.This type of Press filtration function is first pointed to the mud of the certain volume between two pallets and carries out filtering and then pressing Contracting, in order to extract water by the filter cloth being placed in pallet.Second step, when mud is still in compression During, electrode can produce electric field between pallet, in order to mobile pallet, thus will by filter cloth Water is discharged.

In certain embodiments, at least one pallet of pressure filter need to be equipped with and can compressed fluid compressive strain When use film, in order to the mud in filter press can be compressed.

In certain embodiments, the pressure applied in compression process is 5 to 20 bars, preferably 10 to 13 bars.

In certain embodiments, electric dehydration operation should at least originally be carried out under constant current strength. In fact, this shaping modes can be easy to carry out fast dewatering to mud.

In certain embodiments, current strength used is 5 to 200A/m²。

In certain embodiments, in electric dehydration process, when meeting pre-conditioned, abandon into Row constant current is regulated, with constant voltage regulative mode instead.In fact, this shaping modes can limit Temperature on electrode processed rises.Therefore, magnitude of voltage when constant voltage values used preferably meets pre-conditioned.

In certain embodiments, in electric dehydration process, when voltage reaches voltage threshold, put Abandon and carry out constant current regulation, with constant voltage regulative mode instead.Operator is determined this voltage Threshold value, in order to electrode can be used under the voltage conditions less than breakdown voltage.

In other embodiments, when the temperature closing on electrode zone reaches threshold temperature, abandon carrying out perseverance Determine electric current regulation, with constant voltage regulative mode instead.So, lower temperature is being kept, and in perseverance When determining to run under current strength and high dewatering efficiency operating mode, once reach temperature threshold, just can turn rapidly Change to constant voltage mode to run, in order to suspend temperature rise, thus do not become too high in temperature and jeopardize electronic Extend the dehydration duration before dehydration device.

In certain embodiments, when the temperature of anode reaches temperature threshold 50 to 65 DEG C, abandon carrying out Constant current is regulated, with constant voltage regulative mode instead.In fact, so not only contribute to as far as possible Extend the time limit being dehydrated in an efficient manner under constant current strength, and once reach this temperature threshold Value, can also extend the dehydration time limit under constant voltage regulation as far as possible.

In certain embodiments, in electric dehydration process, the electrode temperature near mud is less than Limiting temperature, when i.e. less than or equal to 150 DEG C, preferably lower than or equal to 80 DEG C, and preferably smaller than or Equal to 70 DEG C.So, the damaged risk of device can just be reduced.Once reach this peak temperature, just may be used Preferential time-out electric dehydration operation.

In certain embodiments, electric dehydration operation at least continues 45 minutes, and preferably at least persistently 60 Minute, and preferably at least continue 100 minutes.This duration that this technique allows, mud can be allowed Reach the higher aridity than conventional electric dehydration technique.

In certain embodiments, after electric dehydration operation, the aridity of mud is more than 30%, preferably greatly In 40%, and preferably greater than 50%.

In certain embodiments, one mistake that this technique is implemented before being additionally included in electric dehydration operation in addition Filter operation.This filter progress can carry out initial filter before application electric field, thus dispose in mud and produced Most of free water.This filter progress is preferably carried out after treatment process.

In certain embodiments, the pressure together that this technique is implemented before being additionally included in electric dehydration operation in addition Contracting operation.This independent compression section, mechanically can extract in the case of without electric auxiliary Go out remaining free water.So just neither consuming electric dehydration institute's subfam. Spiraeoideae nor electrode temperature can be raised In the case of extract the free water in mud.Preferably, this operation can be by press filtration after filter progress Machine completes.Compression pressure can be 5 to 20 bars, preferably 10 to 13 bars.

In other embodiments, this technique will not be compressed operation before electric dehydration operation.Actual On, inventor finds in its test process, electrically processes immediately after at filter progress and is disappeared The energy of consumption is little；And especially such as only carry out in the case of greatly in the very difficult dehydration of mud and resistance value It is just not highly beneficial that this type of shifts to an earlier date compression section.

In certain embodiments, the biological mud that mud is that sewage treatment plant produces need to be dehydrated, especially need The mud that oxygen biological purifying process produces.Being characterized in that of such mud, comprises the knot of enormous proportions Heshui.But, certainly, the content in this specification can be used for other kinds of mud.

Preceding feature and advantage and other guide all detailed by after investing suggestion process implementing example Explanation is enumerated.This detailed description refers to appended drawing.

Brief description

Appended drawing is schematic diagram, for enumerating the cardinal principle of this invention.

In these drawings, all use identical reference marker come in each figure identical element (or want Element part) it is labeled.

Fig. 1 is the process example block diagram according to this invention.

Fig. 2 uses filter press principle schematic for meeting technique needs.

Fig. 3 is for than more conventional electric dehydration operation with according to electric dehydration operation described in this invention In the curve map of voltage change situation.

Fig. 4 is for than more conventional electric dehydration operation with according to electric dehydration operation described in this invention In the curve map of temperature variations.

Fig. 5 is the parameter temporal tracing figure of the conventional electric dehydration operation of heavy current.

Fig. 6 is the parameter temporal tracing figure of the conventional electric dehydration operation compared with weak current.

Detailed description of the invention

In order to make this invention more realistic, hereinafter the example of dewatering process is described in detail, Refer to accompanying drawing.It is noted that this invention is not limited only to type described in this example.

Fig. 5 gives by inventor according to this invention implement in the case of not processing electronic The time tracking curve of the different parameters of dehydration procedure.Test is to enter under higher current strength for the first time Row.In this case it is desirable to being difficult to be dehydrated, there is high electrical resistance value and constant current strength is 16A It (is i.e. about 70A/m²) and mud that limiting voltage is 110V carry out electric dehydration, in order to be not up to The breakdown voltage of system.

As it is shown in figure 5, because mud resistance value is bigger, voltage 82 (thick dashed line) increases sharply, In order to its maximum 110V at least can be reached in one minute.Constant current regulation shape can not be kept again State；Current strength 81 (heavy line) began to decline before keeping stablizing, and voltage 82 is maintained at 110V. Verified, anode 83 (fine line) side temperature quickly raises, and reaches 70 DEG C within 15 minutes, this Shi Yaoqiu stops test.Otherwise it is emphasized that, negative electrode 84 side (fine dotted line) temperature rise then slow to obtain Many, so just anode-side temperature can be defined as limit the parameter of this type of electric dehydration operation.

Therefore, when test for the first time is provided without the technique described in this invention, it can be verified that entirely locate The reason duration is less than 15 minutes.Thus, it can be understood that, dryness level is less than satisfactory.

Second time test requires to carry out in the case of without any process according to this invention, inventor It is intended to reduce current strength required when carrying out electric dehydration operation.In the case, can use 9A's Constant current strength carries out this electric dehydration operation, i.e. intensity is about 40A/m²。

As shown in Figure 6, voltage 92 (thick dashed line) extremely rapid increases in former seconds of test, Then increased lentamente before its safety value reaches 110V when the about the 3rd minute.Can not keep permanent again Determine current regulating state；Current strength 91 (heavy line) begins to decline, and voltage 92 is maintained at 110V. But, confirming equally, anode 93 (fine line) side temperature quickly raises, and reaches within about ten minutes 70 DEG C, now require to stop test.Now, the temperature rise than anode 93, can be by negative electrode 94 side The temperature rise of (fine dotted line) is omitted.

Therefore, in the case that second time test is provided without the technique described in this invention, it can be verified that The process duration under constant current strength is slightly long, but not over four minutes.Additionally, entirely locate The reason duration is less than ten minutes.Thus, it can be understood that, dryness level still less makes us full Meaning.

It in order to improve dehydration conditions, is described to according to the technique described in this invention now.It is overall Situation is described by FIG.

In this processing range, the mud 10 that need to process is the biological mud from sewage treatment plant.Such Mud is from the membrane bioreactor directly running in the former water of trash rack.

Mud 10, its original aridity is about 0.9% in this example, contains in i.e. every liter liquid mud 9g dry matter, it is necessary first to carry out chemical treatment process S1；In this operation, some chemical composition Can be added in mud 10, consequently facilitating carry out processing and being dehydrated to it.In these compositions, Need to add coagulation promoter (11a) and flocculant (11b).

In this example, coagulation promoter (11a) used is ferric trichloride.Mud ditch adds quite In this coagulation promoter being dried mud material mass 15%.Flocculant (11b) used is then Flopam EM 640TBD polymer.Systematically inject this flocculant, make the net products mesh in dry matter per ton Mark concentration reaches 4.6kg (4.6kgMA/tMS).

Booster pump is used to inject the mud 10 processing in filter press 20.

This filter press 20 is illustrated in fig. 2.It including three pallets 21a, 21b, is used for Determine two chambers 22 importing needed for mud 10.Each wall of pallet 21a, 21b can determine that The edge extent of chamber 22；Each wall is equipped with electrode 23a, 23b: therefore, and lateral pallet 21a needs It is equipped with the electrode being made up of anode 23a；Every face of central tray 21b is both needed to be equipped with and is made up of negative electrode 23b Electrode.

The inwall of each lateral pallet 21a is additionally equipped with filter cloth 24；This filter cloth should be arranged in and be examined Consider the front of electrode 23a.As for intermediate tray 21b, each of which wall all should install film 25, by thin Film is arranged in considered electrode 23b rear；And filter cloth 24 is installed, filter cloth is arranged on and is considered Electrode 23b front.

Three pallets 21a, 21b of filter press 20, use hydraulic jack 26 mutually to be fastened； This jack is for ensureing the sealing of filtering chamber 22.Under the crunch of jack 26, pallet Mutually draw close, thus keep allowing the mud of certain volume enter in chamber 22.It will of course be understood that be, The module of several pallets 21a, 21b can be prepared in jack 26 front.

Each pallet 21a and 21b all should be equipped with the first outlet, is used for discharging filtrate 12, and is equipped with the Two outlet 13a and 13b, are used for discharging issuable gas.

During filter progress S2, booster pump can produce the mechanical pressure of 8 bars in mud 10；Should Mud then can use filter cloth 24 to filter.When the flow of the filtrate 12 of discharge from pallet 21 reaches During to the determined threshold preset, suspend this operation S2.This operation S2 can be removed with relatively low energy ezpenditure Fall the free water of mud surface.

Once filter in the chamber 22 that mud 10 enters filter press 20, just need to enter in filter press 20 This independent compression section S3 of row.Compressed air supercharger can allow the film 25 of filter press 20 expand, Thus be compressed the mud in chamber 22, until the pressure in chamber 22 reaches about 11 to 12 bars. Therefore, compression section needs to continue 10 minutes.Can not use any electrically auxiliary during this operation S3 Assistant's section.

The mud 10 of filtrate 12 shape that this independent compression section S3 can will go out from pallet 21 outlet drain Interior residual ionization water extracts.

In this independent compression section S3, need to keep pressure and start electric supplementary means, thus opening Dynamic electric dehydration operation S4.

Engine then can apply electric current between electrode group 23a of each chamber 22,23b.Originally, need Carry out constant current regulation.In this example, selected current strength is about 9A, i.e. about 40A/m²。

In this process, the water that extracts from mud 10 by with the form of filtrate 12 from pallet 21a Go out with the outlet drain of 21b.Additionally, the gas producing during this operation S4, and originally show In example, oxygen and hydrogen because of hydrolysis generation all can discharge from second pallet exit 13a and 13b Go out.

Keep carrying out constant current regulation, until using what the kind equipment of such as thermocouple recorded to close on anode Till the temperature in 23a region reaches 60 DEG C: when meeting this condition, abandon carrying out constant current regulation, With constant voltage regulative mode instead.Carry out the selected magnitude of voltage of this constant voltage regulation for maximum safe voltage Value, is 110V in this example.

Then keep carrying out constant voltage electrically to assist, until the temperature closing on anode 23a region reaches 70 DEG C be Only: when meeting this condition, suspend electrically process, discharge pressure.

During mud cake 14 removal process S5, needs take out de-from the chamber 22 of filter press 20 The mud cake 14 of water.The dry angle value that these mud cakes 14 are obtained averagely is about 38.3%.

These mud cakes 14 can be carried out subsequently filling or carry out recycling with organic soil improvement or Carry out reusing of energy source.

Some series of tests will be illustrated now, in order to illustrate this invention compared with old process The different content being added.

In all these tests, it is possible to use the mud 10a of same type: in fact relate to from dirt The biological mud of water treatment plant.More specifically, the film running in relating to the former water of comfortable trash rack Mud in bioreactor.The initial aridity of such mud is less than 1%, i.e. 10g/L.

The operating condition of test T0 is as follows:

The FLOPAM EM 640TBD polymer of-about 8.95kg/tMS, i.e. 3.8kg MA/tMS；

-without coagulating agent；

Independent filtration under-8 bar pressures；

-continue individually to compress under 11 to 12 bar pressures for 10 minutes；

-be compressed under 11 to 12 bar pressures+under 9A electric current, carry out electric dehydration (i.e. about For 40A/m²), it is changed into suddenly constant voltage when anode-side temperature is more than 60 DEG C.

The operating condition of test T1 is as follows:

The FLOPAM EM 640TBD polymer of-about 12.8kg/tMS, i.e. 5.4kg MA/tMS；

-account for being dried the coagulating agent ferric trichloride of quality of mud fluid 15%；

Independent filtration under-8 bar pressures；

-without independent compression section；

-be compressed under 11 to 12 bar pressures+under 9A electric current, carry out electric dehydration (i.e. about For 40A/m²), constant voltage will not be changed into suddenly when anode-side temperature is more than 60 DEG C.

Fig. 3 and Fig. 4 is for taking off than more conventional electric dehydration operation with according to electronic described in this invention The curve map of the voltage change situation in water conservancy project sequence.

Accordingly, it would be desirable to voltage the 31st, 36 and temperature of anode in these electric dehydration operations tested 32nd, it 37 is tracked: the curve related to test T0 is dotted line, and the curve related to test T1 is Solid line.

In the range of test T0, coagulating agent is not used to process；Confirming according to Fig. 3, voltage 31 is first Increase sharply, and the voltage peak 31a of about 81V occurs in the first few minutes of test；Subsequently, voltage Again decline, in order to can start stable at about about 50V from the tenth minute.

It should be noted that the voltage recording in the range of test T1, its processing procedure uses simultaneously Coagulating agent and polymer；Then, the entire change contrary with test T0 voltage 31 occurs；Because, After producing electric field, voltage 36 used by T1 for the test begins to decline from initial value, without occurring as surveying That increase situation described in T0 for the examination.Now voltage 36 reaches minimum about 40V, starts after a moment Notable raise, after test 30 minutes, rise to a plateau value 36a about 50V until about 40 minutes, Then magnitude of voltage tends to be steady and is maintained between 30 to 40V.

Now, according to Fig. 4 it can be confirmed that the temperature of the anode 32 of test T0 is than the anode testing T1 37 temperature ramp-up rate faster because playing temperature of anode when self-test T0 starts just can reach 40 DEG C, and The temperature of the anode 37 of test T1 is then square over the course of 15 mins reaches this same threshold.

Therefore, after this of short duration operating mode, during test T0 and test T1, performance is totally different, it turned out that, The existence time difference of temperature curve: test T0 can reach the limit values 70 DEG C after 45 mins, and tests T1 Then can reach this limiting value after 120 minutes.Therefore, in general, according to the survey described in this invention The electric dehydration step lasts time of examination T1 is about 75 minutes, needed for required time relatively test T0 frequently Time to be grown；Test T0 can terminate after test starts about 45 minutes.

Additionally, the aridity recording on some point of the mud cake being obtained shows:

-for test T0, aridity mean value is 26 ± 5%；

-for test T1, aridity mean value is 38 ± 7%

Therefore, it can confirm on average, than only using polymer to process, to be applied in combination polymerization Thing and coagulating agent carry out place comprehend allow aridity promote 12 points.

Additionally, the energy consumption that each electric dehydration operation produces, can be according to the test described in this invention Record during T1 and reference test T0.

Energy consumption needed for the conventional electric dehydration operation of test T0 is 260kWh/tEE, and according to this invention Energy consumption needed for the electric dehydration operation that described test T1 is carried out is 140KWh/tEE, i.e. energy consumption almost subtracts Half.

Enforcement pattern described in this invention foregoing teachings or implement example only do citing use and non-exhaustive Enforcement pattern；These enforcement patterns in this invention content or enforcement example can be carried out by professional person Modification, or the various enforcement of other in the range of this invention pattern is taken in.

Additionally, the different characteristic of these enforcement patterns or enforcement example can be used alone, or combination Use.Be combined use in the case of, these features can as mentioned before or with described previously Content is different；The content of this invention is not limited only to the specific combination situation described in this report. Especially, as without opposing requests, the described feature related with enforcement pattern or enforcement example, Ke Yi Used in the case of similar to other enforcement patterns or enforcement example.

Claims

1. slurry dewatering technique, including the chemical treatment process (S1) of one mud to be drained off (10), In this operation, need to add flocculant (11b) and coagulation promoter (11a) in mud (10) to； And include one electric dehydration operation (S4).

2., according to the technique described in claim 1, the flocculant (11b) used in it is anion The polymer of type flocculant, cationic flocculant or flocculant in non-ion type.

3. according to the technique described in claim 1 or 2, wherein, in chemical treatment process (S1), In dry matter per ton, need to add to the quality of the flocculant in mud (11b) net products be 1 to 25kg。

4. according to one of them described technique of claims 1 to 3, coagulation promoter (11a) wherein used For mineral type.

5. according to one of them described technique of claims 1 to 3, coagulation promoter (11a) wherein used For organic type.

6. according to one of them described technique of claim 1 to 5, wherein, at chemical treatment process (S1) In, the net product quality adding the coagulation promoter (11a) in mud to is the 0.5% of dry quality of mud fluid To 20%.

7. according to one of them described technique of claim 1 to 6, wherein, electric dehydration operation (S4) Filter press (20) is carried out；This filter press includes at least two pallet (21a, 21b)；Each torr Dish (21a, 21b) is at least equipped with an electrode (23a, 23b)；And at least one pallet (21a) sets There is a filter (24)；Wherein, described filter press (20) is at electric dehydration operation (S4) In mud (10) is compressed.

8. according to one of them described technique of claim 1 to 7, wherein, electric dehydration operation (S4) At least originally should carry out under constant current strength, then, in the temperature closing on electrode (23a) region When reaching threshold temperature, abandon carrying out constant current regulation, with constant voltage regulative mode instead.

9. according to one of them described technique of claim 1 to 7, wherein, electric dehydration operation (S4) At least originally should carry out under constant current strength, then, when voltage reaches threshold value, abandon carrying out Constant current is regulated, with constant voltage regulative mode instead.

10. according to one of them described technique of claim 1 to 9, wherein, in electric dehydration operation (S4), in, electrode (23a, 23b) temperature near mud is less than limiting temperature, i.e. less than or etc. In 150 DEG C, preferably lower than or equal to 70 DEG C.

11., according to one of them described technique of claim 1 to 9, are additionally included in electric dehydration in addition One filter progress (S2) that operation (S4) was implemented in the past.

12., according to one of them described technique of claim 1 to 10, are additionally included in electric dehydration in addition One compression section (S3) that operation (S4) was implemented in the past.

13. according to one of them described technique of claim 1 to 11, wherein, need to be dehydrated mud (10) For the biological mud from sewage treatment plant.