CN111704268A

CN111704268A - Novel medical wastewater treatment and recycling system and method

Info

Publication number: CN111704268A
Application number: CN202010571901.1A
Authority: CN
Inventors: 祝览铭; 封亚萍; 舒秀丽; 金敏
Original assignee: AFFILIATED HOSPITAL OF HANGZHOU NORMAL UNIVERSITY
Current assignee: AFFILIATED HOSPITAL OF HANGZHOU NORMAL UNIVERSITY
Priority date: 2020-06-22
Filing date: 2020-06-22
Publication date: 2020-09-25

Abstract

The invention provides a novel medical wastewater treatment and recycling system and a method, which comprises a primary wastewater treatment system or a secondary wastewater treatment system, wherein a sedimentation tank for placing wastewater to be disinfected and a disinfection tank for wastewater disinfection treatment are arranged in the system, a wastewater treatment and recycling system is arranged between the sedimentation tank and the disinfection tank, the system comprises a forward osmosis device and a reverse osmosis device which are connected with each other, and the reverse osmosis device is connected with the wastewater recycling tank. The invention carries out forward osmosis and reverse osmosis treatment on the effluent of the sedimentation tank through the forward osmosis device and the reverse osmosis device which are connected with each other, and concentrates the wastewater in the medical wastewater tank of the forward osmosis device, so that the disinfection water quantity can be reduced to about 25 percent of the original disinfection water quantity, and the disinfection cost is greatly reduced; and the chemical cleaning frequency and the cleaning wastewater discharge amount are reduced, the forward osmosis and reverse osmosis technology separation process is mature, the structure is simple, the operation is stable, and the method has a better application prospect in the field of medical wastewater treatment and recycling.

Description

Novel medical wastewater treatment and recycling system and method

Technical Field

The invention belongs to the field of medical wastewater treatment, and particularly relates to a novel medical wastewater treatment and recycling system and method.

Background

In recent years, with the rapid development of the medical industry of China, the discharge amount of medical wastewater is increasing day by day, the medical wastewater mainly comes from a diagnosis and treatment room, an operating room, a laboratory and the like, the components of the medical wastewater are relatively complex, the medical wastewater contains pathogenic microorganisms, chemical pollutants, radioactive pollutants and the like, and the medical wastewater has the characteristics of strong infectivity, disease induction and the like. The national environmental protection agency and the quality supervision, inspection and quarantine bureau release the discharge standard of water pollutants of medical institutions (GB18466-2005) to comprehensively control the discharge of medical wastewater in 7 months in 2005.

The current medical wastewater treatment generally comprises primary treatment and secondary treatment. In general, the typical process of primary treatment is primary precipitation plus disinfection treatment (as shown in fig. 1), and effluent is discharged into a municipal sewer and then treated by a sewage treatment plant in a unified way; the secondary treatment usually adopts activated sludge for further treatment, and comprises a grid well, a regulating tank, a hydrolysis acidification tank, a contact oxidation tank, a sedimentation tank and the like (as shown in figure 2), can comprehensively treat biological pollution, physicochemical pollution and toxic and harmful substances in the wastewater, and is suitable for the condition that the hospital wastewater is discharged into ground water areas.

Because the secondary treatment is carried out before reaching the standard and being discharged, the physical or chemical disinfection treatment is required, the physical disinfection is like ultraviolet disinfection, although the operation is simple and the secondary pollution is not generated, the energy is lower and has no continuity, the bacteria can not be effectively killed, and the application range is limited; chemical disinfection mainly utilizes the oxidizing property of chemical reagents to kill bacteria, such as chlorine dioxide has high-efficiency bactericidal capacity, does not generate carcinogenic substances, is a main stream medical wastewater treatment method, but has higher chemical disinfection cost.

Summary of the invention

In view of the above, the present invention provides a novel medical wastewater treatment and recycling system, which can effectively reduce the amount of water to be treated by chemical disinfection, thereby reducing the cost of medical wastewater treatment; and the effluent of the sedimentation tank is subjected to forward osmosis and reverse osmosis treatment, so that the effluent can be directly used for greening and toilet water.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the utility model provides a novel medical wastewater treatment recycling system, includes one-level wastewater treatment system or second grade wastewater treatment system, sets up in the system and is used for placing the sedimentation tank of treating the disinfection waste water and carries out the disinfection pond of waste water disinfection treatment, set up wastewater treatment recycling system between sedimentation tank and the disinfection pond, this system includes interconnect's positive osmotic engine and reverse osmosis unit, and reverse osmosis unit connects the waste water recycling pond.

Further, a forward osmosis membrane is fixedly arranged in the forward osmosis device, and divides the forward osmosis device into a medical wastewater tank and a liquid drawing tank; a reverse osmosis membrane is fixedly arranged in the reverse osmosis device and divides the reverse osmosis device into a feed liquid tank and a water production tank; the sedimentation tank is connected with the top of the medical wastewater tank through a water inlet pipeline, the disinfection tank is connected with the bottom of the medical wastewater tank through a water return pipeline, and the water production tank is connected with the wastewater reuse tank through a water outlet pipeline.

Further, the top of the liquid drawing groove is communicated with the top of the feeding groove through a first circulating pipe; the bottom of the liquid drawing tank is communicated with the bottom of the liquid feeding tank through a second circulating pipe, and a high-pressure pump is arranged on the second circulating pipe.

Furthermore, a booster pump and a filter are arranged on the water inlet pipeline, and the filter is used for removing particles in the liquid.

Furthermore, sodium chloride aqueous solution with the mass fraction of 0.1-1.0% is stored in the drawing liquid tank and the feeding liquid tank.

Further, 75% of water molecules in the effluent of the sedimentation tank are extracted into a drawing liquid of the forward osmosis device, bacteria or toxic and harmful substances in the medical wastewater are trapped on the surface of the forward osmosis membrane, and enter the disinfection tank along with the remaining 25% of the wastewater.

A novel medical wastewater treatment and reuse method comprises the following steps: and extracting part of water molecules in the effluent of the sedimentation tank into an extraction liquid of a forward osmosis device by a forward osmosis technology, and intercepting bacteria or toxic and harmful substances in the medical wastewater on the surface of the forward osmosis membrane and entering a disinfection tank along with the rest of the water molecules to perform subsequent disinfection treatment.

Further, the method also comprises the following steps: and extracting part of water molecules in the effluent of the sedimentation tank into an extraction liquid of a forward osmosis device, and separating the extraction liquid by using a reverse osmosis technology to obtain high-purity reuse water.

Further, 50% -75% of water molecules in the effluent of the sedimentation tank are extracted into a drawing liquid of the forward osmosis device, and the remaining 50% -25% of water molecules enter the disinfection tank.

Compared with the prior art, the novel medical wastewater treatment and recycling system has the following advantages:

(1) the invention carries out forward osmosis and reverse osmosis treatment on the effluent of the sedimentation tank through the forward osmosis device and the reverse osmosis device which are connected with each other, and can reduce the disinfection water amount to about 25 percent of the original disinfection water amount and greatly reduce the disinfection cost by concentrating the wastewater in the medical wastewater tank of the forward osmosis device;

(2) the non-pressure type forward osmosis technology is used for treating the wastewater with higher organic matter content, so that the deposition of organic matter pollutants on the surface of a membrane can be effectively avoided, the stable operation of a system is kept, and the chemical cleaning frequency and the cleaning wastewater discharge amount are reduced;

(3) the drawing liquid tank, the first circulating pipe, the feeding liquid tank and the second circulating pipe form a circulating loop through a high-pressure pump, so that the diluted forward osmosis drawing liquid is concentrated by a reverse osmosis system and then continues to be used as the drawing liquid to treat the effluent of the sedimentation tank;

(4) the effluent of the sedimentation tank is treated by forward osmosis and reverse osmosis, and the produced water of the reverse osmosis device is treated by two membrane materials of the forward osmosis membrane and the reverse osmosis membrane, so that the water can be directly used for greening, closestool water and the like, and can also be used as medical water after being qualified through inspection.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the invention without limitation. In the drawings:

FIG. 1 is a flow chart of a conventional primary treatment process for medical wastewater at present;

FIG. 2 is a flow chart of a conventional secondary treatment process for medical wastewater at present;

FIG. 3 is a schematic overall structure diagram of the inventive embodiment of the present invention;

fig. 4 is a schematic view of a connection structure of a forward osmosis device and a reverse osmosis device according to an embodiment of the present invention.

Description of reference numerals:

1-a sedimentation tank; 2, a booster pump; 3-a filter; 4-a water inlet pipeline; 5-a forward osmosis unit; 6-a first circulation pipe; 7-a reverse osmosis unit; 8-water outlet pipeline; 9-a wastewater reuse pool; 10-a high pressure pump; 11-a second circulation duct; 12-a water return pipeline; 13-a disinfection tank; 14-a medical wastewater tank; 15-forward osmosis membrane; 16-a draw solution tank; 17-a feed liquid tank; 18-a reverse osmosis membrane; 19-water production tank.

Detailed Description

It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings, which are merely for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be construed as limiting the invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the invention, the meaning of "a plurality" is two or more unless otherwise specified.

In the description of the invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted", "connected" and "connected" are to be construed broadly, e.g. as being fixed or detachable or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the creation of the present invention can be understood by those of ordinary skill in the art through specific situations.

The invention will be described in detail with reference to the following embodiments with reference to the attached drawings.

As shown in fig. 1 to 4, a novel medical wastewater treatment and recycling system comprises a primary wastewater treatment system or a secondary wastewater treatment system, and is characterized in that: the system is provided with a sedimentation tank 1 for placing wastewater to be disinfected and a disinfection tank 13 for disinfecting the wastewater, a wastewater treatment recycling system is arranged between the sedimentation tank 1 and the disinfection tank 13, the system comprises a forward osmosis device 5 and a reverse osmosis device 7 which are connected with each other, and the reverse osmosis device 7 is connected with a wastewater recycling tank 9.

FIG. 1 is a flow chart of a conventional primary treatment process for medical wastewater at present; the wastewater treatment and reuse system can be arranged between the sedimentation tank and the contact tank; FIG. 2 is a flow chart of a conventional secondary treatment process for medical wastewater at present; the contact oxidation pond can be used as a sedimentation pond, the sedimentation pond can also be independently arranged, and the wastewater treatment and recycling system can be arranged between the contact oxidation pond and the disinfection contact pond; the sedimentation tank 1 for holding wastewater to be disinfected and the disinfection tank 13 for performing wastewater disinfection treatment may be separately provided in the primary wastewater treatment system or the secondary wastewater treatment.

A forward osmosis membrane 15 is fixedly arranged in the forward osmosis device 5, and the forward osmosis membrane 15 divides the forward osmosis device into a medical wastewater tank 14 and a drawing liquid tank 16; a reverse osmosis membrane 18 is fixedly arranged in the reverse osmosis device 7, and the reverse osmosis membrane 18 divides the reverse osmosis device 7 into a feed liquid tank 17 and a water production tank 19; the sedimentation tank 1 is connected with the top of a medical wastewater tank 14 through a water inlet pipeline 4, the disinfection tank 13 is connected with the bottom of the medical wastewater tank 14 through a water return pipeline 12, and the water production tank 19 is connected with a wastewater reuse tank 9 through a water outlet pipeline 8.

The invention carries out forward osmosis treatment and reverse osmosis treatment on the effluent of the sedimentation tank 1 through the forward osmosis device 5 and the reverse osmosis device 7 which are connected with each other, and can reduce the disinfection water amount to about 25 percent of the original disinfection water amount and greatly reduce the disinfection cost by concentrating the wastewater in the medical wastewater tank 14 of the forward osmosis device 5; and through carrying out forward osmosis and reverse osmosis treatment to sedimentation tank 1 play water, sedimentation tank 1 goes out water and is handled through reverse osmosis membrane and reverse osmosis membrane twice membrane material, and the product water of reverse osmosis unit 7 is sent into waste water recycling pond 9, can directly be used for afforestation, closestool water etc. also can regard as medical water after the inspection is qualified, realizes medical wastewater recycling, the water economy resource.

As shown in fig. 4, the top of the drawing liquid tank 16 is communicated with the top of the feeding liquid tank 17 through a first circulating pipe 6; the bottom of the liquid drawing tank 16 is communicated with the bottom of the liquid feeding tank 17 through a second circulating pipe 11, and the second circulating pipe 11 is provided with a high-pressure pump 10. The drawing liquid tank 16, the first circulating pipe 6, the feeding liquid tank 17 and the second circulating pipe 11 form a circulating loop through the high-pressure pump 10, so that the diluted forward osmosis drawing liquid is concentrated by the reverse osmosis system and then continues to be used as the drawing liquid to treat the effluent of the sedimentation tank.

And the water inlet pipeline 4 is provided with a booster pump 2 and a filter 3, and the filter 3 is used for removing particles in liquid. The wastewater to be disinfected after the primary or secondary treatment is in contact with a forward osmosis membrane 15 in a forward osmosis device 5 after impurities such as particles are removed by a filter 3.

Sodium chloride aqueous solution with the mass fraction of 0.1-1.0% is stored in the drawing liquid tank 16 and the feeding liquid tank 17. Further, 75% of water molecules in the effluent of the sedimentation tank 1 are extracted into the draw solution of the forward osmosis device 5, bacteria or toxic and harmful substances in the medical wastewater are trapped on the surface of the forward osmosis membrane 15, and enter the disinfection tank 13 along with the remaining 25% of the wastewater.

A novel medical wastewater treatment and reuse method comprises the following steps: part of water molecules in the effluent of the sedimentation tank 1 are extracted into the draw solution of the forward osmosis device 5 through a forward osmosis technology, bacteria or toxic and harmful substances in the medical wastewater are intercepted on the surface of the forward osmosis membrane 15, and enter the disinfection tank 13 along with the rest of the water molecules to carry out subsequent disinfection treatment.

Further, the method also comprises the following steps: and extracting part of water molecules in the effluent of the sedimentation tank 1 into a drawing liquid of a forward osmosis device 5, and separating the drawing liquid by using a reverse osmosis technology to obtain high-purity reuse water.

Further, 50% -75% of water molecules in the effluent of the sedimentation tank 1 are extracted into the draw solution of the forward osmosis device 5, and the remaining 50% -25% of water molecules enter the disinfection tank 13.

The working principle of the novel medical wastewater treatment and recycling system and the method is as follows: in the operation process, the wastewater to be disinfected after the first-stage or second-stage treatment is firstly contacted with a forward osmosis membrane 15 in a forward osmosis device 5 after impurities such as particles are removed by a filter 3, then under the action of high osmotic pressure of a drawing liquid, water molecules in the medical wastewater or the hemodialysis wastewater penetrate through the forward osmosis membrane 15 to enter the drawing liquid, and toxic and harmful substances such as bacteria, organic matters and the like in the wastewater to be disinfected are intercepted in a medical wastewater tank 14 by a separation membrane and enter a disinfection tank 13 for post-disinfection treatment; water molecules in the drawing liquid enter a reverse osmosis device 7, and are separated through a reverse osmosis membrane 18 under certain pressure to obtain high-purity produced water which is used as daily water for hospitals, such as greening water, toilet water and the like; and because the produced water is filtered by two membrane materials of forward osmosis and reverse osmosis (the pore diameter is less than 1 nm), harmful substances such as bacteria and the like are completely removed, and the produced water can be even used as medical water after being inspected to be qualified.

The preferred scheme adopts a forward osmosis technology to extract the medical wastewater subjected to secondary treatment, namely 75% of water molecules in the effluent of the sedimentation tank into forward osmosis drawing liquid, and toxic and harmful substances such as bacteria and the like in the wastewater are intercepted on the surface of the forward osmosis membrane 15 and enter a disinfection system along with the residual 25% of the wastewater; and the water molecules entering the forward osmosis drawing liquid further utilize a reverse osmosis technology to obtain high-purity reuse water. The forward osmosis technology and the reverse osmosis technology are mature separation technologies, the structure is simple, and the invention has better application prospect in the field of medical wastewater treatment and recycling.

The examples of the present invention further include: the forward osmosis technique refers to the flow of water from a higher water chemical potential (or lower osmotic pressure) side region through the permselective membrane to a lower water chemical potential (or higher osmotic pressure) -side region. Two solutions with different osmotic pressures are respectively placed on two sides of the membrane with selective permeability, one is raw material solution (Feed solution) with lower osmotic pressure, and the other is driving solution or draw solution (Drawsolution) with higher osmotic pressure, and forward osmosis uses the osmotic pressure difference of the solutions on two sides of the membrane as driving force to make water spontaneously permeate through the membrane from one side of the raw material solution to the driving solution-side. The reverse osmosis technique is also known as reverse osmosis, a membrane separation operation that separates a solvent from a solution using a pressure difference as a driving force. The feed solution on one side of the membrane is pressurized and when the pressure exceeds its osmotic pressure, the solvent will reverse osmosis against the direction of natural osmosis.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the invention, so that any modifications, equivalents, improvements and the like, which are within the spirit and principle of the present invention, should be included in the scope of the present invention.

Claims

1. The utility model provides a novel medical wastewater treatment recycling system, includes one-level wastewater treatment system or second grade wastewater treatment system, sets up in the system and is used for placing sedimentation tank (1) of treating disinfection waste water and disinfection pond (13) that carry out waste water disinfection and handle, its characterized in that: a wastewater treatment and recycling system is arranged between the sedimentation tank (1) and the disinfection tank (13), the system comprises a forward osmosis device (5) and a reverse osmosis device (7) which are connected with each other, and the reverse osmosis device (7) is connected with a wastewater recycling tank (9).

2. The novel medical wastewater treatment and recycling system according to claim 1, wherein: a forward osmosis membrane (15) is fixedly arranged in the forward osmosis device (5), and the forward osmosis membrane (15) divides the forward osmosis device into a medical wastewater tank (14) and a drawing liquid tank (16); a reverse osmosis membrane (18) is fixedly arranged in the reverse osmosis device (7), and the reverse osmosis membrane (18) divides the reverse osmosis device (7) into a feed liquid tank (17) and a water production tank (19); the sedimentation tank (1) is connected with the top of the medical wastewater tank (14) through a water inlet pipeline (4), the disinfection tank (13) is connected with the bottom of the medical wastewater tank (14) through a water return pipeline (12), and the water production tank (19) is connected with the wastewater reuse tank (9) through a water outlet pipeline (8).

3. The novel medical wastewater treatment and recycling system according to claim 2, wherein: the top of the liquid drawing tank (16) is communicated with the top of the feeding liquid tank (17) through a first circulating pipe (6); the bottom of the liquid drawing tank (16) is communicated with the bottom of the liquid feeding tank (17) through a second circulating pipe (11), and the second circulating pipe (11) is provided with a high-pressure pump (10).

4. The novel medical wastewater treatment and recycling system according to claim 1, wherein: set up booster pump (2) and filter (3) on inlet channel (4), filter (3) are arranged in getting rid of the particulate matter in the liquid.

5. The novel medical wastewater treatment and recycling system according to claim 2, wherein: sodium chloride aqueous solution with the mass fraction of 0.1-1.0% is stored in the drawing liquid tank (16) and the feeding liquid tank (17).

6. A novel medical wastewater treatment and recycling method is characterized by comprising the following steps: and extracting part of water molecules in the effluent of the sedimentation tank (1) into the draw solution of the forward osmosis device (5) by a forward osmosis technology, and intercepting bacteria or toxic and harmful substances in the medical wastewater on the surface of the forward osmosis membrane (15) and entering a disinfection tank (13) along with the rest part of water molecules for subsequent disinfection treatment.

7. The novel medical wastewater treatment and recycling method according to claim 6, characterized in that: further comprising the steps of: and extracting part of water molecules in the effluent of the sedimentation tank (1) into a drawing liquid of a forward osmosis device (5), and separating the drawing liquid by using a reverse osmosis technology to obtain high-purity reuse water.

8. The novel medical wastewater treatment and recycling method according to claim 6, characterized in that: extracting 50% -75% of water molecules in the effluent of the sedimentation tank (1) into a drawing liquid of the forward osmosis device (5), and enabling the remaining 50% -25% of water molecules to enter a disinfection tank (13).