WO2022083071A1

WO2022083071A1 - Deep purification device and process for non-degradable organic wastewater

Info

Publication number: WO2022083071A1
Application number: PCT/CN2021/084903
Authority: WO
Inventors: 冯晓荟; 钱媛媛; 张行
Original assignee: 麦王环境技术股份有限公司
Priority date: 2020-10-22
Filing date: 2021-04-01
Publication date: 2022-04-28

Abstract

A deep purification device for non-degradable organic wastewater. The purification device comprises COD pretreatment devices and COD deep treatment devices connected in series with the COD pretreatment devices. The devices are connected by pipelines and liquid pumps, and can effectively remove organic matter in the non-degradable organic wastewater. Further disclosed is a deep purification process for non-degradable organic wastewater.

Description

A deep purification device and process for refractory organic wastewater

technical field

The present application relates to the field of wastewater treatment, in particular to a deep purification device and process for refractory organic wastewater.

Background technique

The treatment of refractory organic wastewater is a recognized difficulty in the sewage and wastewater treatment industry at home and abroad. This kind of wastewater is more often found in coking wastewater, petroleum/petrochemical wastewater, chemical wastewater, pharmaceutical wastewater, textile/printing and dyeing wastewater and other industrial wastewater. The composition of COD in this type of wastewater is complex and highly toxic. Organics containing chromogenic groups, polycyclic aromatic hydrocarbons, heterocyclic organics, and cyanides lead to extremely poor biodegradability. Because this type of wastewater exists in the entire production process, the discharge is very large, and the harm to the environment and human health is immeasurable.

At present, most of the treatment of refractory organic wastewater (wastewater for short) follows the conventional treatment method, that is, the wastewater is pretreated and then subjected to biochemical treatment. However, after biochemical treatment, the effluent still contains a large amount of toxic pollutants. These pollutants are generally It exists in the form of suspended state, colloid and dissolved state, and cannot be directly discharged or the effluent cannot enter the back-end processing equipment.

Therefore, it is necessary to optimize and improve the treatment process for the existence of pollutants in the refractory wastewater.

SUMMARY OF THE INVENTION

In view of this, in view of the problems existing in the existing devices, the present application proposes a deep purification device and process for refractory organic waste water, which can strengthen the treatment of organic pollutants in the waste water through the combination of a pretreatment process and a deep purification process. The suspended matter in the effluent is almost zero. The deep purification device adopts an integrated device, which solves the problems of the traditional sedimentation tank with large footprint, slow settling time and high effluent suspended solids. The solid-liquid separation in this device adopts advanced membrane separation technology to make the effluent suspended solids almost zero. , improve the treatment effect of organic pollutants.

In order to achieve the above object, the application adopts the following scheme,

A deep purification process for refractory organic waste water, comprising:

The pretreatment section of S1.COD is mainly to remove suspended state and colloidal organic matter in the refractory wastewater, and the step S1 includes:

S11. Coagulation reaction of the refractory wastewater to be treated, that is, the refractory wastewater is sent to the first reaction tank, and the coagulation reaction is carried out based on a high-efficiency coagulation agent to remove suspended and colloidal organic pollutants, and the reaction mixture is transported To the first concentration tank, the reaction excess sludge is transported to the sludge dewatering device,

S12. Perform solid-liquid separation on the mixed liquid processed in step S11 based on the first solid-liquid separation device, and the obtained first effluent is transported to the intermediate water tank,

The advanced treatment section of S2.COD performs advanced treatment on the pretreated wastewater to remove dissolved and small molecular organic matter in the refractory wastewater;

The step S2 includes:

S21. Deep removal reaction of organic matter, that is, the first effluent after the treatment in S12 is transported to the second reaction tank, and the deep organic matter removal reaction is carried out based on the adsorption agent to remove dissolved organic matter and small molecules, and the mixed solution is transported to the second concentrated solution. tank, and the excess sludge is transported to the sludge dewatering device;

S22. Perform solid-liquid separation on the mixed liquid processed in step S21 based on the second solid-liquid separation device, and the obtained water is transported to the water production tank. After this process, the suspended solids in the effluent are almost zero. After the first reaction tank, the coagulation agent uses polyferric sulfate to coagulate the suspended and colloidal organic matter in the refractory wastewater. The COD removal rate of this purification process is between 40% and 60%. In the second reaction tank, the adsorption agent selects sugar powder activated carbon, or coal powder activated carbon, or medicinal powder activated carbon, or powder activated coke to deeply purify the dissolved organic matter in the first effluent, and the COD removal rate of this process reaches 30% to 50%, so that the total removal rate of COD in the overall purification treatment process reaches more than 60%, which is much higher than the current treatment process.

In one embodiment, the pH value of the treated refractory wastewater ranges from 6 to 9, and the COD value ranges from 200 mg/L to 1000 mg/L.

In one embodiment, in step S11, the coagulation agent is selected from polymeric ferric sulfate.

In one embodiment, the COD removal rate in step S11 ranges from 40% to 60%.

In one embodiment, in this step S21, the adsorption agent is selected from at least one of sugar powder activated carbon, coal powder activated carbon, medicinal powder activated carbon or powder activated coke.

In one embodiment, the COD removal rate in step S21 reaches 30% to 50%.

In one embodiment, the first/second solid-liquid separation device adopts a roll-type microfiltration membrane, and the roll-type microfiltration membrane material is PVDF, and the recovery rate reaches 95% to 99%.

The embodiment of the present application provides a deep purification device for refractory organic waste water, which is characterized by comprising:

COD pretreatment device and COD deep purification device,

The COD pretreatment device includes:

The first reaction tank, the first concentration tank, the first solid-liquid separation device, the intermediate water tank, the sludge dewatering device and the first dosing device;

The first reaction tank has an inlet to flow into the wastewater to be treated,

a dosing hole, which is connected to the first dosing device via a pipeline and a dosing pump, and

a water outlet, which is connected to the water inlet of the first concentration tank through a pipeline and a pump;

The first concentration tank also has:

a water outlet, which is connected to the first solid-liquid separation device through a pipeline and a pump,

The mud outlet is connected with the sludge dewatering device through the pipeline and the sludge pump,

The first solid-liquid separation device has:

a water production port, the water production port is connected with the water inlet of the intermediate pool through a pipeline,

a concentrated water outlet, the concentrated water outlet is connected with the first concentration tank through a pipeline;

The intermediate pool has a water outlet, and the water outlet is connected to the COD deep purification device through a pipeline and a lifting pump of the intermediate pool. The deep purification device adopts an integrated device during implementation. The above-mentioned first reaction tank, first concentration tank, first solid-liquid separation device, intermediate water tank, sludge dewatering device and first dosing device are configured to be integrated into a large In this way, the deep purification device has a small footprint, stable operation and high processing efficiency.

In one embodiment, the COD deep purification device includes: a second reaction tank, a second concentration tank, a second solid-liquid separation device, a water production tank and a second dosing device,

The second reaction tank has:

a water inlet, the water inlet is connected to the water outlet of the intermediate pool,

The dosing hole is connected to the second dosing device through the pipeline and the dosing pump,

a water outlet, the water outlet is connected with the water inlet of the second concentration tank through a pipeline and a pump,

The second concentration tank also has:

The water outlet is connected with the water inlet of the second solid-liquid separation device through the pipeline and the pump,

The second solid-liquid separation device has,

a water production port, the water production port is connected with the water inlet of the water production tank through a pipeline,

The concentrated water port is connected with the second concentration tank through a pipeline.

In one embodiment, a stirring device is arranged in the first/second reaction tank, respectively, and based on the stirring device, the added medicament and the sewage are fully mixed.

In one embodiment, the stirring device has a single-layer or double-layer stirring blade.

In one embodiment, the first solid-liquid separation device and the second solid-liquid separation device respectively have roll-type microfiltration membranes made of PVDF material.

beneficial effect

Compared with the prior art, the embodiments of the present application have the following advantages:

The deep purification device proposed in this application adopts an integrated device, which is simple in operation, small in floor space, short in hydraulic retention time, universally applicable to deep purification of wastewater in different industries, stable in operation, convenient in management, and high in treatment efficiency. Value.

The deep purification device can effectively remove the organic matter in the refractory organic wastewater when it is running, and use the roll-type microfiltration membrane to separate it to improve the removal rate of the organic matter.

Description of drawings

Other features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features and aspects of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1, Fig. 2 are the schematic flow charts of the processing technology of the embodiment of the application;

FIG. 3 is a schematic structural diagram of a deep purification device according to an embodiment of the present application.

In the figure: the first reaction tank 101, the first concentration tank 102, the first roll-type microfiltration membrane solid-liquid separation device 103, the intermediate water tank 104, the sludge dewatering device 106, the first dosing device 105, the first concentration tank inlet pump 107. The first solid-liquid separation device inlet pump 108, the first dosing pump 109, the intermediate tank lift pump 110, the second reaction tank 201, the second concentration tank 202, the second roll-type microfiltration membrane solid-liquid separation device 203, production The water tank 204 , the second dosing device 205 , the second concentration tank inlet pump 206 , the second volume microfiltration membrane solid-liquid separation device inlet pump 207 , the second dosing pump 208 , and the sludge transfer pump 209 .

Detailed ways

Various exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numbers in the figures denote elements that have the same or similar functions. While various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated. Terminology explanation, TDS (total dissolved solids) will be mentioned in this embodiment, which refers to total dissolved solids, also known as total salt content, including the content of both inorganic and organic substances. COD (Chemical Oxygen Demand) refers to chemical oxygen demand is a chemical method to measure the amount of reducing substances that need to be oxidized in a water sample.

The embodiments of the present application propose a deep purification device and process for refractory organic wastewater (wastewater for short). The purification device includes: a first reaction pool, a first dosing device, a first concentration pool, a first roll-type microfiltration membrane device, an intermediate water pool, a second reaction pool, a second dosing device, a second concentration pool, a second Roll-type microfiltration membrane equipment, water production tank, sludge dewatering device, and each device is connected by pipeline and liquid pump. When the purification device is in operation, it effectively solves the problems of low efficiency in removing organic matter from refractory wastewater and the water quality of the produced water does not meet the influent indicators of the subsequent process. At the same time, the entire process flow is deviceized, and the traditional large tank sedimentation, filtration and separation are abandoned, and the roll-type microfiltration membrane is used for separation. , deep purification, improve the removal rate of organic matter, compared with the conventional coagulation sedimentation, degrading organic matter treatment process, the purification device of the embodiment of the present application has the advantages of simple equipment operation, small footprint, short hydraulic retention time, and the depth of wastewater from different industries. The purification has universal applicability, stable operation, convenient management, high processing efficiency, and has important application value.

As shown in FIG. 1, the deep purification process of the refractory wastewater according to the embodiment of the application, which includes:

The pretreatment section of S1.COD removes suspended and colloidal organic matter in refractory wastewater,

The S1, COD preprocessing section includes:

S11. Coagulation reaction of the refractory wastewater to be treated, that is, the refractory wastewater is sent to the first reaction tank, and the coagulation reaction is carried out to remove suspended state and colloidal organic pollutants, and the reaction mixture is sent to the first concentration tank , the reaction sludge is transported to the sludge dewatering device;

S12. Perform solid-liquid separation on the mixed liquid processed in step S11 based on the first solid-liquid separation device, and the obtained first effluent is sent to the intermediate water tank.

The advanced treatment section of S2.COD performs advanced treatment on the pretreated wastewater to remove dissolved and small molecular organic matter in the degraded wastewater.

This step S2 includes:

S21. Deep organic matter removal reaction, that is, the first effluent treated in S12 is transported to the second reaction tank, and the deep organic matter removal reaction is carried out to remove dissolved organic matter and small molecules, and the mixed solution is transported to the second concentrated pool. The reaction The sludge is transported to the sludge dewatering device;

S22. Perform solid-liquid separation on the mixed liquid processed in step S21 based on the second solid-liquid separation device, and the obtained water is transported to the water production tank. In this step, the mixed solution processed in step S21 is transported to the second solid-liquid separation device for solid-liquid separation.

In the embodiment of the present application, during solid-liquid separation, the maximum water inlet pressure flowing into the first/second solid-liquid separation device is 0.8Mpa, the maximum pressure drop is 0.12Mpa, and the operating pH value ranges from 2 to 10. After the purification process proposed in this application, it is suitable for the pH value of the refractory wastewater to be between 6 and 9, and the COD in the wastewater to be between 200 mg/L and 1000 mg/L. In the first reaction tank, the coagulation agent (using polymeric ferric sulfate) is used to coagulate the suspended and colloidal organic matter in the refractory wastewater. The COD removal rate of this purification process is between 40% and 60%. In the second reaction tank, the dissolved organic matter in the first effluent is deeply purified by using the adsorption agent. The adsorption agent is selected from sugar powder activated carbon, or coal powder activated carbon, or medicinal powder activated carbon, or powder activated coke. In this process, the COD removal rate reaches 30% to 50%, so that the overall removal rate of COD in the overall purification process reach 60% to 75%.

The mixed liquid after COD pretreatment and deep purification process of the refractory wastewater are respectively subjected to solid-liquid separation to obtain the first effluent and product water. The first solid-liquid separation device adopts a roll-type microfiltration membrane, and the roll-type microfiltration membrane material is: PVDF, the recovery rate is 95% to 99%, and the solid content of concentrated water is 1% to 5%. in,

As shown in FIG. 2, the deep purification process of the refractory wastewater according to the embodiment of the present application includes: a COD pretreatment section S100, a COD deep purification section S200,

Wherein, the COD preprocessing section S100 includes:

The organic waste water to be treated flows into the first reaction tank through the pipeline, and the first dosing equipment is used to add chemicals to the first reaction tank for coagulation reaction to remove suspended and colloidal organic pollutants, and the mixed solution is transported to the first concentration tank. ,

The reaction sludge reacted in the first concentration tank is transported to the sludge dewatering device,

The mixed liquid reacted in the first concentration tank is sent to the first solid-liquid separation device for solid-liquid separation, and the obtained first effluent is sent to the intermediate water tank.

COD deep purification section, including:

Based on the second dosing equipment, the agent is added into the second reaction tank, the agent in the second reaction tank is mixed with the inflowing first effluent, and the mixed liquid is transported to the second concentration tank,

The sludge produced by the reaction in the second concentration tank is transported to the sludge dewatering device, the resulting mixed liquid is transported to the second solid-liquid separation device for solid-liquid separation, and the obtained water is transported to the water production tank.

FIG. 3 is a schematic structural diagram of a deep purification device for refractory wastewater according to an embodiment of the present application. The device includes a COD pretreatment device and a COD deep purification device.

in,

The COD pretreatment device includes: a first reaction tank 101, a first concentration tank 102, a first solid-liquid separation device 103, an intermediate water tank 104, a sludge dewatering device 106, a first dosing device 105, and a first concentration tank inlet pump 107. The first solid-liquid separation device inlet pump 108, the first dosing pump 109, and the intermediate pool lift pump 110;

The refractory waste water enters the first reaction tank 101 through the inlet 101a of the first reaction tank 101. The first dosing device 105 is connected to the dosing hole 101b of the first reaction tank 101 through the pipeline and the dosing pump 109, and the first reaction The water outlet 101c of the pool 101 is connected to the water inlet of the first concentration pool 102 through a pipeline and a pump 107, the water outlet of the first concentration pool 102 is connected to the first solid-liquid separation device 103 through a pipeline and a pump 108, and the mud outlet of the first concentration pool 102 It is connected to the sludge dewatering device 106 through the pipeline and the sludge pump 209, the water production port of the first solid-liquid separation device 103 is connected to the water inlet of the intermediate tank 104 through the pipeline, and the concentrated water port 103a is connected to the first concentration tank 102 through the pipeline. The water outlet 104 is connected to the water inlet 201a of the second reaction tank 201 through the pipeline and the intermediate tank lift pump 110 .

The COD deep purification device includes: a second reaction tank 201, a second concentration tank 202, a second solid-liquid separation device 203, a water production tank 204, a second dosing device 205, a second concentration tank inlet pump 206, a second roll-type micrometer Membrane solid-liquid separation device inlet pump 207, second dosing pump 208, sludge delivery pump 209,

The second dosing device 205 is connected to the dosing hole 201b of the second reaction tank 201 through the pipeline and the dosing pump 208, the water outlet 201c of the second reaction tank 201 is connected to the water inlet 202a of the second concentration tank 202 through the pipeline and the pump 206, and the first The water outlet 202b of the second concentration tank 202 is connected to the water inlet of the second solid-liquid separation device 203 through a pipeline and a pump 207, and the mud outlet of the second concentration tank 202 is connected to the sludge dewatering device 106 through a pipeline and a sludge pump 209. The water production port of the liquid separation device 203 is connected to the water inlet of the water production tank 204 through a pipeline, and the concentrated water outlet 203a is connected to the second concentration tank 202 through a pipeline. The sludge is discharged through the outlet 106a of the sludge dewatering device 106 .

In this embodiment, a stirring device 101d/201d is respectively configured in the first/second reaction tank, which is electrically connected to the driving motor M respectively, and the stirring device is driven to rotate based on the driving of the driving motor M so that the added medicament is fully mixed with the sewage. Preferably, the stirring device has single-layer or double-layer stirring blades. The first dosing device is used for adding coagulation agent, and the coagulation agent is selected from polymeric ferric sulfate. The second dosing device is used for adding adsorption agent, and the adsorption agent is selected from at least one of sugar powder activated carbon, coal powder activated carbon, medicinal powder activated carbon or powder activated coke. The first solid-liquid separation device 103 and the second solid-liquid separation device 203 are respectively provided with roll-type microfiltration membranes. The roll-type microfiltration membrane material is PVDF, the recovery rate is 95%-99%, and the solid content of concentrated water is 1%-5%. The roll-type microfiltration membrane has a high shear flow rate on the membrane surface, excellent membrane flux and retention performance, and high anti-fouling performance. The COD pretreatment device is connected in series with the COD deep purification device. Preferably, the COD deep purification device has a water inlet, and the water inlet is connected to the outlet of the intermediate water tank of the COD pretreatment device through a pipeline and a pump. This enhances the COD removal effect. In this embodiment, the deep purification device is implemented using an integrated device, that is, the above-mentioned first reaction tank, first concentration tank, first solid-liquid separation device, intermediate water tank, sludge dewatering device, and first dosing device, etc. The device is arranged in a large box, so that the deep purification device occupies a small area and has high processing efficiency. Filtration separation adopts roll-type microfiltration membrane separation to improve the removal rate of organic matter.

The effects of the present application will be described below with reference to specific embodiments.

Example 1

Taking the effluent of the secondary sedimentation tank after biochemical treatment of a typical coking wastewater treatment project as an example, the coking wastewater has a pH=7.8 and a COD of 178 mg/L. After the two parts) treatment, COD < 46mg/L, the water quality of the produced water meets the requirements of the water inflow index of the subsequent process.

Example 2

In this example, the biochemical effluent of a typical zero-discharge project in the petrochemical industry is taken as an example. The pH of the wastewater is 7.3 and the COD is 320 mg/L. ) treatment, COD<80mg/L, and the water quality of the produced water meets the requirements of the water inflow index of the subsequent process.

The above-mentioned embodiments are only intended to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly, and cannot limit the protection scope of the present invention. All modifications made according to the spirit and essence of the main technical solutions of the present invention should be covered within the protection scope of the present invention.

Claims

A deep purification process for refractory organic waste water, comprising:

The pretreatment section of S1.COD is mainly to remove suspended and colloidal organic matter in refractory wastewater.

The step S1 includes:

S11. Coagulation reaction of the refractory wastewater to be treated, that is, the refractory wastewater is sent to the first reaction tank, and the coagulation reaction is carried out based on a high-efficiency coagulation agent to remove suspended and colloidal organic pollutants, and the reaction mixture is transported To the first concentration tank, the reaction excess sludge is transported to the sludge dewatering device,

S12. Perform solid-liquid separation on the mixed liquid processed in step S11 based on the first solid-liquid separation device, and the obtained first effluent is transported to the intermediate water tank,

The advanced treatment section of S2.COD performs advanced treatment on the pretreated wastewater to remove dissolved and small molecular organic matter in the refractory wastewater;

The step S2 includes:

S21. Deep removal reaction of organic matter, that is, the first effluent after the treatment in S12 is transported to the second reaction tank, and the deep organic matter removal reaction is carried out based on the adsorption agent to remove dissolved organic matter and small molecules, and the mixed solution is transported to the second concentrated solution. tank, and the excess sludge is transported to the sludge dewatering device;

S22. Perform solid-liquid separation on the mixed liquid processed in step S21 based on the second solid-liquid separation device, and the obtained water is transported to the water production tank.
The deep purification process according to claim 1, wherein the pH value of the refractory wastewater to be treated is between 6 and 9, and the COD value is between 200 mg/L and 1000 mg/L.
The deep purification process according to claim 1, wherein, in the step S11, the coagulation agent is selected from polymeric ferric sulfate.
The deep purification process according to claim 3, wherein the COD removal rate in the step S11 is between 40% and 60%.
The deep purification process according to claim 1, wherein in the step S21, the adsorbent is selected from at least one of sugar powder activated carbon, coal powder activated carbon, medicinal powder activated carbon or powder activated coke .
The deep purification process according to claim 1, wherein the COD removal rate in the step S21 reaches 30% to 50%.
The deep purification process according to claim 1, wherein the first/second solid-liquid separation device adopts a roll-type microfiltration membrane, the roll-type microfiltration membrane material is PVDF, and the recovery rate is 95% to 99%. %.
A deep purification device for refractory organic waste water is characterized in that, comprising:

COD pretreatment device and COD deep purification device,

The COD pretreatment device includes:

The first reaction tank, the first concentration tank, the first solid-liquid separation device, the intermediate water tank, the sludge dewatering device and the first dosing device;

The first reaction tank has an inlet to flow into the wastewater to be treated,

a dosing hole, which is connected to the first dosing device via a pipeline and a dosing pump, and

a water outlet, which is connected to the water inlet of the first concentration tank through a pipeline and a pump;

The first concentration tank also has:

a water outlet, which is connected to the first solid-liquid separation device through a pipeline and a pump,

The mud outlet is connected with the sludge dewatering device through the pipeline and the sludge pump,

The first solid-liquid separation device has:

a water production port, the water production port is connected with the water inlet of the intermediate pool through a pipeline,

a concentrated water outlet, the concentrated water outlet is connected with the first concentration tank through a pipeline;

The intermediate pool has a water outlet, and the water outlet is connected with the COD deep purification device through a pipeline and an intermediate pool lift pump.
The deep purification device for refractory organic wastewater according to claim 8, wherein the COD deep purification device comprises: a second reaction tank, a second concentration tank, a second solid-liquid separation device, a water production tank and a second Two dosing devices,

The second reaction tank has:

a water inlet, the water inlet is connected to the water outlet of the intermediate pool,

The dosing hole is connected to the second dosing device through the pipeline and the dosing pump,

a water outlet, the water outlet is connected with the water inlet of the second concentration tank through a pipeline and a pump,

The second concentration tank also has:

The water outlet is connected with the water inlet of the second solid-liquid separation device through the pipeline and the pump,

The mud outlet is connected with the sludge dewatering device through the pipeline and the sludge pump,

The second solid-liquid separation device has,

a water production port, the water production port is connected with the water inlet of the water production tank through a pipeline,

The concentrated water port is connected with the second concentration tank through a pipeline.
The deep purification device for refractory organic waste water according to claim 9, characterized in that, a stirring device is arranged in the first and second reaction tanks respectively, and based on the stirring device, the added medicament is fully mixed with the sewage.