CN106830441A - Solid-liquid separation system - Google Patents

Abstract

The invention discloses a solid-liquid separation system, which comprises a sedimentation reaction tank, a concentrated membrane device, a sedimentation tank and a collection tank connected in sequence; the concentrated water port of the concentrated membrane device is connected with the sedimentation tank, and the sewage The mud outlet is connected with a centrifuge or a filter press, the clear water outlet of the concentration membrane device and the water outlet of the sedimentation tank are all connected with the collection tank, and the sludge outlet of the centrifuge or filter press is connected with a solid waste Recycling unit. The solid-liquid separation system of the present invention has a good treatment effect, not only the solid waste and clear water obtained through separation can be recycled, and zero pollutant discharge is realized, but also the cost and load of sludge treatment are effectively reduced, and the problem of waste of resources is solved, and Greatly reduce the production cost of the enterprise.

Description

Solid-liquid separation system

technical field

The invention relates to the technical field of wastewater treatment, in particular to a solid-liquid separation system.

Background technique

Currently, for heavy metal ions (Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Ag ⁺ , Pd ²⁺ , Pb ²⁺ , Au ²⁺ , Cr ³⁺ , Fe ³⁺ , Al ³⁺ , Ca ²⁺ , Ba ²⁺ ) wastewater for solid-liquid separation process, most of them use chemical method to add drugs or adjust the pH value of wastewater by adding NaOH to form heavy metal hydroxide precipitation, and then add PAC, PAM Such as flocculant, increase the precipitation particles, and then slowly pass through the inclined plate sedimentation tank for solid-liquid separation, but this method not only wastes a lot of materials such as PAC and PAM, but also contains a large amount of organic impurities in the heavy metal hydroxide precipitate generated. At the same time, the water content is high, which increases the cost of recycling. Even in some cases, it cannot be recycled and can only be treated as sludge. It is necessary to entrust a qualified hazardous waste treatment organization to conduct sludge harmless treatment at a high price.

As for other methods, such as ultrafiltration membrane, microfiltration membrane, nanofiltration membrane and other equipment for solid-liquid separation of heavy metal wastewater, due to large equipment investment and high maintenance costs, it is rarely used on a large scale.

Contents of the invention

In view of this, a solid-liquid separation system provided by the present invention better overcomes the problems and defects of the above-mentioned prior art, not only the solid waste and clear water obtained through separation can be recycled, and zero pollutant discharge is realized, but also It effectively reduces the cost and load of sludge treatment, solves the problem of waste of resources, and greatly reduces the production cost of enterprises.

A solid-liquid separation system, comprising a sedimentation reaction tank, a concentrated membrane device, a sedimentation tank, and a collection tank connected in sequence; the concentrated water port of the concentrated membrane device is communicated with the sedimentation tank, and the sludge outlet of the sedimentation tank is communicated with a A centrifuge or a filter press, the clear water outlet of the concentration membrane device and the water outlet of the sedimentation tank are both connected to the collection tank, and the sludge outlet of the centrifuge or filter press is connected to a solid waste recovery treatment device.

Further, the Gute separation system also includes a wastewater storage tank, which communicates with the sedimentation reaction tank through a pump.

Further, the Gute separation system also includes a reduction reaction tank communicated with the precipitation reaction tank.

Further, the Gute separation system also includes a first dosing device and a second dosing device communicated with the reduction reaction tank, the first dosing device is used to add acidic substances to the reduction reaction tank , the second dosing device is used to add reducing agent to the reduction reaction tank.

Further, the reduction reaction tank is provided with a first pH monitoring device and a potential controller, the first pH monitoring device is connected to the first dosing device, and the potential controller is connected to the second dosing device connect.

Further, the Gute separation system also includes a third dosing device communicated with the precipitation reaction tank, and the third dosing device is used to add alkaline substances to the precipitation reaction tank.

Further, the precipitation reaction tank is provided with a second pH monitoring device, and the second pH monitoring device is connected to the third dosing device.

Further, it also includes a fourth dosing device communicated with the precipitation reaction tank, and the fourth dosing device is used for dosing reaction substances into the precipitation reaction tank.

Further, the Gute separation system also includes a combined nanofiltration-microfiltration device connected to the collection tank, the water outlet of the combined nanofiltration-microfiltration device is connected to a clear water pool, and the nanofiltration-microfiltration The sludge outlet of the combination device communicates with the sedimentation tank.

Further, the sedimentation tank is communicated with the centrifuge or filter press through a sludge storage tank; the water outlet of the centrifuge or filter press is communicated with the concentration membrane device.

Compared with prior art, the beneficial effect of solid-liquid separation system of the present invention is:

(1), the solid-liquid separation system of the present invention makes heavy metal ions (Cu ²⁺ , Ni ^{2 +} , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Ag ⁺ , Pd ²⁺ , One or more anions such as Pb ²⁺ , Au ²⁺ , Cr ³⁺ , Fe ³⁺ , Al ³⁺ , Ca ²⁺ , Ba ²⁺ ) or F ^- , PO ₄ ^2- , SO ₄ ^2- The reactant undergoes a precipitation reaction to form a precipitate, which is then concentrated by a concentration membrane device, so that the precipitate particles are concentrated and aggregated, thickened and enlarged, and the precipitation is accelerated. The obtained solid waste does not contain organic impurities such as PAC and PAM, and has a low water content. It can not only be recycled and reused, but also achieve zero pollutant discharge, which effectively reduces the cost of sludge treatment and load, and solve the problem of resource waste, and greatly reduce the production cost of enterprises, with great social and economic benefits.

(2) Further, the solid-liquid separation system of the present invention monitors the pH value in the reaction tank in real time by setting a pH monitoring device to the precipitation reaction tank, and controls the automatic dosing of the dosing device according to the corresponding pH value, so that the degree of automation of the system is improved. High, safe and stable operation, simple operation, convenient management and better processing effect.

(3), further, the solid-liquid separation system of the present invention can more thoroughly remove the trace fine suspended solids in the clear water collected in the collection tank by setting the nanofiltration-microfiltration combination device through the double filtration of microfiltration and nanofiltration The filtered sediment is discharged into the sedimentation tank in batches for further treatment, and the filtered water is discharged into the clean water tank for recycling.

In order to make the above-mentioned objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is the first structural representation of the solid-liquid separation system of the present invention;

Fig. 2 is the second structural representation of the solid-liquid separation system of the present invention;

Fig. 3 is a third structural schematic diagram of the solid-liquid separation system of the present invention.

Explanation of reference numbers:

101 Waste water storage tank

102 Suction pump

103 reduction reaction pool

1031 First pH monitoring device

1032 The first dosing device

1033 Second dosing device

1034 Potential Controller

104 sedimentation reaction tank

1041 Second pH monitoring device

1042 The third dosing device

1043 The fourth dosing device

105 concentrated membrane device

106 sedimentation tank

107 collection pool

108 Sludge Storage Tank

109 Centrifuges or filter presses

110 Solid waste recovery and treatment device

111 Nanofiltration-microfiltration combination device

112 clear water pool

detailed description

In order to facilitate the understanding of the present invention, the solid-liquid separation system will be described more fully below with reference to the relevant drawings. A preferred embodiment of the solid-liquid separation system is shown in the accompanying drawings. However, the solid-liquid separation system can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the solid-liquid separation system more thorough and comprehensive.

In describing the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", The orientations or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and It is not to indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, or operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "communication" should be understood in a broad sense, for example, it can be mechanical communication or electrical communication, or both The internal communication of each element may be directly connected or indirectly connected through an intermediary. Those skilled in the art can understand the specific meanings of the above terms according to specific situations.

Referring to Fig. 1, a kind of solid-liquid separation system 1 comprises the sedimentation reaction tank 104, concentration film device 105, sedimentation tank 106, collection tank 107 that are connected successively; The sludge outlet of the settling tank 106 is connected with a centrifuge or a filter press 109, and the clear water port of the concentrated membrane device 105 and the water outlet of the settling tank 106 are all connected with the collection tank 107, and the centrifuge Or the sludge outlet of the filter press 109 is connected with a solid waste recovery treatment device 110 .

As a first example, when the wastewater to be treated contains metal ions (Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Ag ⁺ , Pd ²⁺ , Pb ²⁺ , Au ²⁺ , Cr ³⁺ , Fe ³⁺ , Al ³⁺ , Ca ²⁺ or Ba ²⁺ , etc.) wastewater, the pH value of the wastewater is adjusted to a certain range by adding sodium hydroxide in the precipitation reaction tank 104 , using sodium hydroxide and metal ions (Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Ag ⁺ , Pd ²⁺ , Pb ²⁺ , Au ²⁺ , Cr ^{3 +} , Fe ³⁺ , Al ³⁺ , Ca ²⁺ or Ba ²⁺ , etc.) undergo precipitation reactions to form hydroxide precipitates (such as Cu(OH) ₂ , Ni(OH) ₂ , Zn(OH) ₂ , Fe(OH) ) ₂ , Co(OH) ₂ , Pd(OH) ₂ , Pb(OH) ₂ , Fe(OH) ₃ , Al(OH) ₃ , etc.); the specific reaction formula can be listed as follows:

Cr ³⁺ +2OH ^- ＝Cr(OH) ₃ ↓;

Cu ²⁺ +2OH ^- ＝Cu(OH) ₂ ↓;

Ni ²⁺ +2OH ⁻ =Ni(OH) ₂ ↓.

As a second exemplary illustration, when the wastewater to be treated is wastewater containing one or more anions such as F ^- , PO ₄ ^2- , SO ₄ ^2- , etc., the precipitation reaction tank 104 is filled with calcium hydroxide , adjust the pH value of the wastewater to a certain range, and at the same time use calcium hydroxide to react with one or more anions such as F ^- , PO ₄ ^2- , SO ₄ ^2- in the wastewater to form precipitates (such as CaF ₂ , CaPO ₄ or CaSO ₄ etc.), concrete reaction formula can be listed as follows:

2F ^- +Ca ²⁺ =CaF ₂ ↓;

PO ₄ ^2- +Ca ²⁺ =CaPO ₄ ↓;

SO ₄ ^2- +Ca ^2+- =CaSO ₄ ↓.

As a third example, when the wastewater to be treated contains metal ions (Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Pd ²⁺ , Pb ²⁺ , Au ²⁺ , Sr ²⁺ , Ca ²⁺ or Ba ²⁺ , etc.) wastewater, the precipitation reaction tank 104 can be added carbonate (such as Na ₂ CO ₃ , K ₂ CO ₃ or (NH4) ₂ CO ₃ etc.) , adjust the pH value of the wastewater to a certain range, and at the same time use carbonate and metal ions (Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Pd ²⁺ , Pb ^{2 +} , Au ²⁺ , Sr ²⁺ , Ca ²⁺ or Ba ²⁺ , etc.) undergo precipitation reactions to generate carbonate or basic carbonate precipitation (such as CuCO ₃ , NiCO ₃ , ZnCO ₃ , CdCO ₃ , FeCO ₃ , CoCO ₃ , MnCO ₃ , BaCO ₃ , SrCO ₃ or PbCO ₃ , etc.), the specific reaction formula can be listed as follows:

Cu ²⁺ +CO ₃ ^2- ＝CuCO ₃ ↓;

Ba ²⁺ +CO ₃ ^2- ＝BaCO ₃ ↓;

Co ²⁺ +CO ₃ ²⁻ =CoCO ₃ ↓.

As a fourth example, when the wastewater to be treated contains metal ions (Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Pd ²⁺ , Pb ²⁺ or Ag ⁺ , etc.) In the case of waste water, the pH value of the waste water can be adjusted to a certain range by adding alkaline substances such as sodium hydroxide in the precipitation reaction tank 104, and then add soluble salts containing S ^2- (such as Na ₂ S , K ₂ S, (NH ₄ ) ₂ S, MgS, CaS, BaS or SrS, etc.) and metal ions (Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Pd ^{2 +} , Pb ²⁺ or Ag ⁺ , etc.) undergoes a precipitation reaction to generate sulfide precipitates (such as CuS, NiS, ZnS, CdCO ₃ , FeS, CoS, PdS or PbS, etc.), and the specific reaction formula can be listed as follows:

Cu ²⁺ +S ^2- ＝CuS↓;

Ni ²⁺ +S ^2- ＝Ni S↓;

Co ²⁺ +S ^2- =CoS↓.

The concentrated membrane device 105 can be exemplified as a high-pressure reverse osmosis coiled membrane, a high-pressure reverse osmosis disc membrane, a vibrating membrane, or a forward osmosis membrane. The concentration membrane device 105 can also be exemplified as a nanofiltration membrane, an ultrafiltration membrane, a microfiltration membrane, or a general filter element. In the concentration membrane device 105, through membrane separation, the precipitated hydroxide particles are further concentrated, aggregated, thickened and enlarged.

The solid waste recovery treatment device 110 is used to process and recycle the solid waste obtained after being dehydrated by the centrifuge or the filter press 109 . The solid waste recovery and treatment device 110 can be enumerated as a calciner. When the main component of the solid waste residue is metal hydroxide, the metal oxide with high purity can be obtained by calcining through the calciner; or hydrogen gas can be further introduced into the calciner and nitrogen to continue to reduce metal oxides into metal elements with higher purity, and the obtained metal elements or metal oxides can be continuously recycled.

Preferably, the solid-liquid separation system 1 of the embodiment of the present invention also includes a waste water storage tank 101, and the waste water storage tank 101 communicates with the sedimentation reaction tank 104 through a pump 102, that is, the waste water in the waste water storage tank 101 is pumped by the pump 102 is pumped into the precipitation reaction tank 104 for reaction.

Preferably, as shown in FIG. 2 , the solid-liquid separation system 1 of the embodiment of the present invention further includes a reduction reaction tank 103 communicated with the precipitation reaction tank 104 .

Preferably, in the embodiment of the present invention, the reduction reaction pool 103 is communicated with a first dosing device 1032 and a second dosing device 1033, and the first dosing device 1032 is used for dosing to the reduction reaction pool 103 For acidic substances, the second dosing device 1033 is used to add reducing agent to the reduction reaction tank 103 .

Preferably, the reduction reaction tank 103 is provided with a first pH monitoring device 1031 and a potential controller 1034, the first pH monitoring device 1031 is connected to the first dosing device 1032, and the potential controller 1034 is connected to the The second dosing device 1033 is connected.

In the above-mentioned reduction reaction pool 103, the addition of a reducing agent is used to reduce the highly oxidative high-valent metal ions (such as Cr ⁶⁺ , Mn ⁶⁺ , etc.) in the wastewater to reduce the low-valent metal ions, which is beneficial to the subsequent precipitation reaction in the precipitation reaction pool 104. A precipitate was obtained.

As an illustration, when the highly oxidizing high-valent metal ion in the wastewater is Cr ⁶⁺ , the reducing agent can be sodium sulfite, sodium metabisulfite or sodium bisulfite. For example, when the reducing agent is sodium sulfite, the specific reduction reaction is:

4Cr ⁶⁺ +3S ₂ O ₅ ^2- +9H ₂ O = 4Cr ³⁺ +6SO ₄ ^2- +18H ⁺ , the amount of reducing agent used in this example is slightly larger than the theoretical amount of the reaction, which facilitates sufficient reaction.

Furthermore, in order to ensure that the reduction reaction in the reduction reaction pool 103 achieves the best effect, that is, to completely reduce Cr ⁶⁺ in the wastewater to Cr ³⁺ , the pH value in the reaction pool must reach 2.5-3.0. Therefore, in the embodiment of the present invention, the first pH monitoring device 1031 is used to monitor the pH value of the wastewater in the reduction reaction tank 103 in real time. When the monitored pH value is greater than 3.0, the first pH monitoring device 1031 automatically controls The first dosing device 1032 adds acidic substances to the reduction reaction tank 103; when the monitored pH value is lower than 2.5, the first pH monitoring device 1031 automatically controls the first dosing device 1032 to reduce the reaction tank 103 Addition of acidic substances was stopped in the pool 103. The acidic substance can be exemplified by sulfuric acid, hydrochloric acid and the like.

It should be noted that, in order to ensure that the reduction reaction in the reduction reaction tank 103 achieves the best effect, that is to completely reduce the Cr ⁶⁺ in the wastewater to Cr ³⁺ , the potential in the reaction tank must be controlled at 220-270mV. Therefore, in the embodiment of the present invention, the potential controller 1034 (ORP meter) is used to monitor the potential of the wastewater in the reduction reaction tank 103 in real time. When the monitored potential is higher than 270mV, the potential controller 1034 (ORP meter) ) automatically controls the second dosing device 1033 to add reducing agent to the reduction reaction tank 103; when the monitored pH value is lower than 220mV, the potential controller 1034 (ORP meter) automatically controls the second dosing The device 1033 stops adding the reducing agent to the reduction reaction tank 103 .

Preferably, in the embodiment of the present invention, the precipitation reaction tank 104 is also connected with a third dosing device 1042 , and the third dosing device 1042 is used for dosing alkaline substances into the precipitation reaction tank 104 .

Preferably, the precipitation reaction tank 104 is provided with a second pH monitoring device 1041 , and the second pH monitoring device 1041 is connected to the third dosing device 1042 .

The working principle of the second pH monitoring device 1041 is the same as that of the above-mentioned first pH monitoring device 1031, that is, it is used for real-time monitoring of the pH value in the precipitation reaction tank 104, and controls the third dosing device 1042 to start or Stop adding alkaline substances.

Preferably, as shown in Figure 3, the precipitation reaction tank 104 is also communicated with a fourth dosing device 1043, and the fourth dosing device 1043 is used to add reaction substances to the precipitation reaction tank 104 such as containing ^{S2 -} Soluble salts (such as Na ₂ S, K ₂ S, (NH ₄ ) ₂ S, MgS, CaS, BaS or SrS, etc.).

Preferably, the solid-liquid separation system 1 of the embodiment of the present invention further includes a combined nanofiltration-microfiltration device 111 communicated with the collection tank 107, and the water outlet of the combined nanofiltration-microfiltration device 111 is connected with a clear water pool 112 , the sludge outlet of the combined nanofiltration-microfiltration device 111 communicates with the sedimentation tank 106 .

It should be noted that the solid-liquid separation system 1 of the present invention can more thoroughly remove traces of fine solids in the clear water collected in the collection tank 107 by setting the nanofiltration-microfiltration combined device 111 through the double filtration of microfiltration and nanofiltration Suspended matter and sediment obtained by filtration are discharged into the sedimentation tank 106 in batches for reprocessing, and the filtered water is discharged into the clear water tank 112 for recycling.

Preferably, the sedimentation tank 106 communicates with the centrifuge or filter press 109 through a sludge storage tank 108 ; the water outlet of the centrifuge or filter press 109 communicates with the concentration membrane device 105 .

It should be understood that the sludge storage tank 108 is used to store the sludge discharged from the sludge outlet of the sedimentation tank 106, and after accumulating to a certain amount, it is transported to the centrifuge or filter press 109 for pressure filtration, so as to avoid the sludge in the sedimentation tank. 106 intermittently provides sludge to the centrifuge or the filter press 109, affecting the service life of the centrifuge or the filter press 109.

The solid-liquid separation system 1 of the present invention recycles the waste water obtained after being dehydrated and separated by the centrifuge or the filter press 109 to the concentration membrane device 105, so as to realize secondary recycling, treatment and utilization of the waste water, and reduce discharge pollution.

The concrete technological process of this solid-liquid separation system 1 is:

Take the waste water to be treated that contains Ni ²⁺ as an example, as shown in Figure 1, the waste water containing Ni ²⁺ is pumped in the sedimentation reaction tank 104 by water pump 102, drops into sodium hydroxide by the 3rd dosing device 1042, Adjust the pH value of the wastewater to 10.5-11, and at the same time react with Ni ²⁺ in the wastewater to form Ni(OH) ₂ precipitates, which are then concentrated by the concentration membrane device 105, so that the Ni(OH) ₂ precipitate particles are concentrated, aggregated, thickened and enlarged Then enter in the sedimentation tank 106 and carry out solid-liquid separation, and the supernatant that obtains is discharged in the collection tank 107 by the sedimentation tank 106 outlet; When the amount of sludge in the sludge storage tank 108 reaches a certain amount, the sludge pump (not shown in the figure) is pumped to the centrifuge or filter press 109 for dehydration and separation, and the waste water obtained is recycled to the concentration membrane device 105 to continue for two years. Secondary treatment, the obtained solid Ni(OH) ₂ is transported to the solid waste recovery treatment device 110 for simple treatment and recycling. Finally, the supernatant collected in the collection tank 107 is further removed from the supernatant collected in the collection tank 107 through the nanofiltration-microfiltration combination device 111, and the trace fine suspended matter in the supernatant collected in the collection tank 107, and the sediment obtained by filtering is discharged in batches. Secondary treatment is continued in the sedimentation tank 106, and the filtered water is discharged into the clear water tank 112 for recycling.

Take the wastewater to be treated containing Cr6 ⁺ as an example, as shown in Figure 2, the wastewater containing ZnS is drawn into the reduction reaction tank 103 by the water pump 102, and sulfuric acid is added by the first dosing device 1032 to make the reduction reaction tank When the pH value in 103 is adjusted to 2.5-3.0, a reducing agent is added to reduce Cr ⁶⁺ in the wastewater to Cr ³⁺ , and then the wastewater is transported to the sedimentation reaction tank 104; Sodium hydroxide is put into the pool 104 to adjust the pH value of the wastewater to 6-6.5. At the same time, it reacts with Cr ³⁺ in the wastewater to form a Cr(OH) ₃ precipitate, which is then concentrated by the concentration membrane device 105 to precipitate the Cr(OH) ₃ The particles are concentrated and aggregated and thickened; then enter the sedimentation tank 106 for solid-liquid separation, and the obtained supernatant is discharged into the collection tank 107 through the outlet of the sedimentation tank 106; the sediment is discharged to the sewage through the sludge outlet of the sedimentation tank 106 In the mud storage tank 108, when the amount of sludge in the sludge storage tank 108 reaches a certain amount, the sludge pump (not shown in the figure) is pumped to the centrifuge or filter press 109 for dehydration and separation, and the obtained waste water is recycled to The secondary treatment is continued in the concentration membrane device 105, and the obtained solid Cr(OH) ₃ is transported to the solid waste recovery treatment device 110 for simple treatment and recycling. Finally, the supernatant collected in the collection tank 107 is further removed from the supernatant collected in the collection tank 107 through the nanofiltration-microfiltration combination device 111, and the trace fine suspended matter in the supernatant collected in the collection tank 107, and the sediment obtained by filtering is discharged in batches. Secondary treatment is continued in the sedimentation tank 106, and the filtered water is discharged into the clear water tank 112 for recycling.

Take the wastewater to be treated containing Zn ²⁺ as an example, as shown in Figure 3, the wastewater containing Zn ²⁺ is sucked in the sedimentation reaction tank 104 by the water pump 102, first by the 3rd dosing device 1042 to the sedimentation reaction tank 104 puts in sodium hydroxide, adjusts the pH value of the waste water to 7-9, then puts Na ₂ S into the precipitation reaction tank 104 through the fourth dosing device 1043, reacts with Zn ²⁺ in the waste water to form ZnS precipitate, and then concentrates Membrane device 105 concentrates, so that the ZnS precipitated particles are concentrated, aggregated, thickened and enlarged; then enter the sedimentation tank 106 for solid-liquid separation, and the obtained supernatant is discharged into the collection tank 107 through the outlet of the sedimentation tank 106; the sediment passes through the sedimentation tank The sludge outlet of 106 is discharged in the sludge storage tank 108, and when the amount of sludge in the sludge storage tank 108 reaches a certain amount, it is pumped into a centrifuge or a filter press 109 through a sludge pump (not shown) for further processing. Dehydration and separation, the obtained waste water is recycled to the concentration membrane device 105 for further secondary treatment, and the obtained solid ZnS is sent to the solid waste recovery treatment device 110 for simple treatment and recycling. Finally, the supernatant collected in the collection tank 107 is further removed from the supernatant collected in the collection tank 107 through the nanofiltration-microfiltration combination device 111, and the trace fine suspended matter in the supernatant collected in the collection tank 107, and the sediment obtained by filtering is discharged in batches. Secondary treatment is continued in the sedimentation tank 106, and the filtered water is discharged into the clear water tank 112 for recycling.

In summary, the beneficial effects of the solid-liquid separation system of the present invention are:

(1), the solid-liquid separation system of the present invention makes heavy metal ions (such as Cu ²⁺ , Ni ²⁺ , Zn ²⁺ , Fe ²⁺ , Co ²⁺ , Ag ⁺ , Pd ²⁺ , Pb ²⁺ , Au ²⁺ , Cr ³⁺ , Fe ³⁺ , Al ³⁺ , Ca ²⁺ or Ba ²⁺ , etc.) or one or more anions such as F ^- , PO ₄ ^2- , SO ₄ ^2- Precipitation reaction occurs with the external reactant to form a precipitate, and then concentrated by the concentration membrane device, so that the precipitate particles are concentrated and aggregated to thicken and increase, and the precipitation is accelerated, and then the solid-liquid separation is carried out in the sedimentation tank, and the sediment in the sedimentation tank is passed through the centrifuge Or filter press for dehydration, the obtained solid waste residue does not contain PAC, PAM and other organic impurities, but only simple heavy metal hydroxides, etc., and the water content is also low. After simple treatment, it can not only be recycled, but also achieve zero pollution. The discharge of pollutants effectively reduces the cost and load of sludge treatment, solves the problem of waste of resources, and greatly reduces the production cost of enterprises, which has great social and economic benefits.

(2) Further, the solid-liquid separation system of the present invention monitors the pH value in the reaction tank in real time by setting a pH monitoring device to the precipitation reaction tank, and controls the automatic dosing of the dosing device according to the corresponding pH value, so that the degree of automation of the system is improved. High, safe and stable operation, simple operation, convenient management and better processing effect.

(3) Further, the solid-liquid separation system of the present invention can more thoroughly remove traces of fine solids in the clear water collected in the collection tank by setting the nanofiltration-microfiltration combined device, after double filtration by microfiltration and nanofiltration Suspended solids, the filtered sediments are discharged into the sedimentation tank in batches for further treatment, and the filtered water is discharged into the clear water tank for recycling.

Although terminologies representing structures are frequently used above, such as "precipitation reaction tank", "concentrating membrane device", "first pH monitoring device", etc., the possibility of using other terms is not excluded. These terms are used only for the purpose of describing and explaining the essence of the present invention more conveniently; interpreting them as any kind of additional limitation is against the spirit of the present invention.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention.

Claims (10)

1. A solid-liquid separation system, characterized in that: comprise a settling reaction tank, a concentrated membrane device, a sedimentation tank, and a collection tank connected successively; the concentrated water port of the concentrated membrane device is communicated with the settling tank, and the settling tank The sludge outlet of the centrifuge or filter press is connected with a centrifuge or a filter press, and the clear water outlet of the concentrated membrane device and the water outlet of the sedimentation tank are all connected with the collection tank, and the sludge outlet of the centrifuge or filter press is connected with a Solid waste recycling and processing device. 2 . The solid-liquid separation system according to claim 1 , further comprising a waste water storage tank, and the waste water storage tank is communicated with the sedimentation reaction tank through a water pump. 3. The solid-liquid separation system according to claim 1, further comprising a reduction reaction tank communicated with the precipitation reaction tank. 4. The solid-liquid separation system according to claim 3, characterized in that: it also includes a first dosing device and a second dosing device communicated with the reduction reaction tank, the first dosing device is used to Acidic substances are added to the reduction reaction tank, and the second dosing device is used to add a reducing agent to the reduction reaction tank. 5. The solid-liquid separation system according to claim 4, characterized in that: the reduction reaction tank is provided with a first pH monitoring device and a potential controller, and the first pH monitoring device and the first dosing device connected, the potential controller is connected with the second dosing device. 6. The solid-liquid separation system according to claim 1, characterized in that: it also includes a third dosing device communicated with the sedimentation reaction tank, and the third dosing device is used to throw into the sedimentation reaction tank Add alkaline substances. 7. The solid-liquid separation system according to claim 6, characterized in that: the precipitation reaction tank is provided with a second pH monitoring device, and the second pH monitoring device is connected to the third dosing device. 8. The solid-liquid separation system according to claim 6, characterized in that: it also includes a fourth dosing device communicated with the sedimentation reaction tank, and the fourth dosing device is used to throw into the sedimentation reaction tank Add reactant. 9. The solid-liquid separation system according to claim 1, characterized in that: it also includes a combined nanofiltration-microfiltration device communicated with the collection tank, and the water outlet of the combined nanofiltration-microfiltration device is connected with clear water pool, and the sludge outlet of the nanofiltration-microfiltration combined device communicates with the sedimentation tank. 10. The solid-liquid separation system according to claim 1, characterized in that: the settling tank is communicated with the centrifuge or filter press through a sludge storage tank; the water outlet of the centrifuge or filter press is connected to the The concentrating membrane device communicates.