CN105668909A - Wastewater treatment method and system suitable for community hospitals - Google Patents

Abstract

The invention relates to a wastewater treatment method and system suitable for community hospitals. The method comprises the following steps: (1) medical waste water passes through the grid to remove large pieces of floating matter; (2) adjusts the water volume and uniform water quality; (3) directly adds magnetic additives to make the pollutants in the waste water form small magnetic nuclei; (4) adds flocculant to make Magnetic nucleation forms magnetic flocs; (5) Magnetic conveyor belts are used to separate solids and liquids using the principle of magnetic separation; (6) the supernatant is sterilized and discharged up to standard; (7) the magnetically attracted sludge is automatically scraped off with a scraper and disinfected After treatment, it will be shipped out together with medical waste for disposal. The method and the system formed therefrom are simple, convenient, and stable in effect, and are especially suitable for standard-reaching treatment of medical wastewater such as community hospitals.

Description

A wastewater treatment method and system suitable for community hospitals

technical field

The invention relates to a wastewater treatment method and system suitable for community hospitals, belonging to the technical field of wastewater treatment.

Background technique

Community health service is recognized by the world as an effective measure to transform the health service model. In order to solve the problem of difficult medical treatment for grassroots people, my country is exploring the system of first diagnosis, graded diagnosis and treatment and referral at the grassroots level, encouraging social capital to run hospitals, especially non-profit grassroots medical and health institutions, and allowing qualified doctors to open general practice in the community Doctor's office or private practice. Therefore, with the deepening of my country's medical reform, community hospitals have been greatly developed in recent years.

However, during the operation of the hospital, a certain amount of medical wastewater will be produced, which contains organic pollutants such as patient excreta, drugs, and diagnostic reagents, as well as a large number of pathogenic microorganisms, parasite eggs, and various viruses. The composition of these medical wastewater is complex and seriously pollutes the environment. Generally, large and medium-sized hospitals have built special wastewater treatment facilities for treatment and discharge. However, the process of these wastewater treatment stations is relatively complex, occupying a large area, and the cost of facility construction and operation is high, and most community hospitals do not have the corresponding implementation conditions. Therefore, there is still a lack of medical wastewater discharge treatment technology suitable for community hospitals.

The existing medical wastewater treatment technology usually adopts biochemical method and membrane method. For example, the invention patent CN201510669797.9 discloses a biochemical treatment system for medical wastewater treatment. The system consists of five functional areas: hydrolytic acidification pool, pre-anoxic pool, anaerobic pool, anoxic pool and aerobic pool. The requirements for the cultivation of biochemical strains are relatively high, and the structure of the treatment facilities is complex, which is not suitable for the actual conditions of community hospitals. Invention patent CN201510449482.3 discloses a membrane technology medical wastewater treatment method with ultraviolet disinfection. Using membrane technology to improve water quality, membrane modules have high requirements for daily maintenance, and are suitable for hospitals with reclaimed water reuse requirements. The three medical wastewater treatment invention patents CN201510377748.8, CN201510381161.4, and CN201510377052.5 of Anqing Wanqing Environmental Protection Technology Co., Ltd. are all based on biochemical methods and membrane technology. The process is complex, the facilities occupy a large area, and management is difficult. It does not meet the wastewater treatment conditions of community hospitals. Invention patent CN201210384918.1 discloses a treatment process for medical wastewater. The process steps include four stages: pretreatment, biochemical treatment, advanced treatment and chlorine dioxide disinfection treatment. The biochemical treatment includes anaerobic treatment, three-stage aerobic treatment, Secondary precipitation; the advanced treatment stage includes quartz sand filtration, activated carbon filtration, ultrafiltration, etc. The effluent of this process can meet the direct discharge standard of the medical industry, but the process is complicated and the control is difficult. It is suitable for the treatment of large-scale hospital wastewater located in environmentally sensitive areas.

Therefore, it is imperative to research and develop a treatment method and system suitable for community hospital wastewater with simple process, convenient operation and maintenance, and low construction and operation costs.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a wastewater treatment method and system suitable for community hospitals, realizes standard discharge of medical wastewater, has simple process, convenient operation and maintenance, and low cost.

The wastewater treatment method applicable to community hospitals that the present invention relates to comprises the following steps:

(1) The medical wastewater passes through the grid to remove large floating objects, and the size of the suspended objects in the treated wastewater is ≤20mm;

⑵Adjust the water quantity and uniform water quality, the adjustment time (T1) is determined according to the working hours (T2) of the community hospital, T1≥(1/3)T2;

(3) Add magnetic additives and stir quickly to make the pollutants in the wastewater collide with the magnetic additives fully to form small magnetic nuclei;

(4) Add flocculant and stir slowly to make magnetic nuclei form magnetic flocs under the cross-linking action of flocculant;

⑸Magnetized conveyor belt is used, and the magnetic floc is magnetically attracted to its surface by the principle of magnetic separation to achieve solid-liquid separation. The separated supernatant requires SS≤20mm;

⑹ After the supernatant is added with disinfectant to remove pathogenic microorganisms, parasite eggs and various viruses, it is discharged through the unified discharge port to meet the standard;

⑺The magnetically attracted sludge on the magnetic conveyor belt is automatically scraped off with a scraper during operation, after being collected, disinfectant is added, and it is transported out together with medical waste for disposal in accordance with environmental protection regulations.

The grid of the present invention can be a mechanical grid or an artificial grid, and preferably, the grid pitch of the grid is ≤20mm.

The magnetic auxiliary agent described in the present invention is an auxiliary agent based on ferromagnetic powder granular material.

Preferably, the present invention uses iron powder with a particle size ≥ 100 mesh, a dosage of 200-500 mg/L, and a reaction stirring speed of ≥ 150 r/min.

The flocculant of the present invention refers to the conventional polymer flocculant in wastewater treatment. As a preference, the present invention adopts anionic PAM with a molecular weight of 10 million to 12 million and a dosage of 5 mg/L to 50 mg/L. The stirring speed is ≤50r/min.

Preferably, the conveying speed of the magnetically applied conveyor belt in the present invention is ≤0.5m/s, and the magnetic field strength is 0.1-0.5T.

Preferably, the disinfectant of the present invention is a chlorine-based disinfectant such as sodium hypochlorite, chlorine dioxide, etc., so as to achieve the continuation of the disinfection effect.

As a further preference, the present invention adopts sodium hypochlorite, the dosage is 30-50 mg/L (calculated as available chlorine), and the disinfection contact time is more than or equal to 1.0 h.

Correspondingly, based on the above treatment method, a wastewater treatment system for community hospitals has been formed, including grid wells, regulating tanks, reaction areas, solid-liquid separation areas, disinfection areas, mud collection areas, and automatic dosing devices; it is characterized in that , the hospital waste water enters the grid well by gravity, and the grid well is connected with the adjustment tank; the adjustment tank is connected with the reaction area through the lift pump; the reaction area is connected with the solid-liquid separation area, and the upper end of the solid-liquid separation area is connected with the sludge collection area. And it is connected with the disinfection area through the side pipe, and the waste water is discharged sequentially by gravity using the potential difference; the automatic dosing device is respectively connected with the reaction area and the disinfection area through the dosing pump.

The functions of the grid well and the regulating pool in the present invention are respectively to remove large pieces of floating matter, and regulate the water quantity and uniform water quality.

The reaction zone of the present invention is divided into two grids, and the magnetic auxiliary agent and flocculant are added in sequence. As a preference, the hydraulic retention time of the reaction zone is ≥0.5h.

The bottom layer of the solid-liquid separation area according to the present invention is arranged with a magnetic conveyor belt, and the magnetic conveyor belt is connected to the mud collection area. As a preference, the effective water depth of the solid-liquid separation area is ≤ 1.0m.

The upper end of the solid-liquid separation area according to the present invention is provided with an outlet weir, and its upper edge is lower than the lower edge of the opening of the partition between the solid-liquid separation area and the mud collection area. As a preference, the height difference is ≥ 10mm.

The mud collection area of the present invention is provided with a non-magnetic scraper, and preferably, a mud discharge port is provided at the lower end of the mud collection area.

A stirrer and a baffle are arranged in the disinfection zone of the present invention, so that the disinfectant and the waste water can be evenly mixed.

The automatic dosing device of the present invention includes three sets of equipment including a magnetic additive dosing device, a flocculant dosing device, and a disinfectant dosing device, wherein the magnetic auxiliary dosing device and the flocculant dosing device are connected to the reaction zone, The disinfectant dosing device is connected to the disinfection area, and the start switch of the dosing device is linked with the lifting pump switch of the regulating tank.

The electrical equipment such as the agitator and the lifting pump described in the present invention are all conventionally used equipment in the field of wastewater treatment, and their models can be normally selected according to industry standards.

Compared with the existing medical wastewater treatment methods and systems, the present invention has the following beneficial effects:

(1) The wastewater treatment method and system described in the present invention have the characteristics of high treatment efficiency, low construction and operation costs, small facility footprint, easy operation and management, etc., and are especially suitable for the actual situation of community hospitals;

(2) The wastewater treatment method and system described in this statement only involve physical and chemical reactions, and the running time can be adjusted according to the outpatient situation of the hospital, and can be started and shut down at any time, and there is no operation problem that the bacteria in the biochemical system need to be opened for a long time to survive;

(3) In the wastewater treatment method of the present invention, due to the external magnetic force, its sludge settling speed is nearly 10-15 times higher than the conventional coagulation sedimentation speed, and the treatment time is greatly shortened;

(4) The sludge produced by the method of the present invention has high compactness and low water content of about 40%-60%, which can meet the relevant requirements without additional dehydration mechanical facilities and save costs.

Description of drawings

Fig. 1 is a system structure diagram of the present invention

Fig. 2 is a method flowchart of the present invention

Among them: 1 means grid well; 2 means regulating tank; 3 means reaction area; 4 means solid-liquid separation area; 5 means mud collection area; 6 means disinfection area; Weir; 10 indicates magnetic transmission belt; 11 indicates magnetic additive dosing device; 12 indicates flocculant dosing device; 13 indicates disinfectant dosing device; 14 indicates lift pump; 15 indicates fast agitator; 16 indicates slow stirring Device; 17 represents a sterilizing mixer; 18 represents a baffle.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

Embodiment one

As shown in Figure 1, the medical wastewater treatment system suitable for community hospitals consists of a grid well 1, a regulating tank 2, a reaction zone 3, a solid-liquid separation zone 4, a disinfection zone 6, a mud collection zone 5, and an automatic dosing device. The automatic dosing device includes a magnetic additive dosing device 11, a flocculant dosing device 12 and a disinfectant dosing device 13, wherein the grid well 1 is connected to the regulating pool 2, and for the convenience of waste water collection, the grid well 1 The adjustment pool 2 is an underground structure, and the inlet elevation is lower than the bottom elevation of the sewage collection pipe; the reaction area 3 is divided into two grids, which are respectively connected with the magnetic additive dosing device 11 and the flocculant dosing device 12 dosing pipes, The two-grid reaction zone water window is located at the bottom of the partition to prolong the reaction contact time; the reaction zone 3 is connected to the solid-liquid separation zone 4, the effective water depth of the solid-liquid separation zone 4 is ≤ 1.0m, and the bottom layer is arranged with a magnetic conveyor belt 10; The conveyor belt 10 goes around the bottom of the solid-liquid separation area 4 to the mud collection area 5, and the sludge is discharged from the bottom mud discharge port 8 through the side non-magnetic scraper; the upper end of the solid-liquid separation area 4 is provided with a weir 9 to prevent the waste water from being poured back In the mud area 5, the upper edge of the outlet weir plate 9 is lower than the upper edge of the partition plate of the solid-liquid separation area 4 and the mud collection area 5 by more than 10 mm. The supernatant enters the disinfection area 6 through the water outlet weir 9 and the side pipe by gravity, and the disinfection area 6 is connected with the disinfectant dosing pipe of the disinfectant dosing device 13, with a built-in agitator 17 and a baffle plate 18 to make the disinfectant and waste water Mix evenly, and the sterilized waste water is discharged through the upper drain port 7.

According to the above system, combined with the treatment method shown in Figure 2, the wastewater treatment steps are as follows:

(1) After being collected by the sewage pipe, the hospital wastewater is first discharged into the grid well 1 with a grid pitch of less than 20mm to remove large impurities, and then flows into the regulating pool 2 by itself;

(2) The hydraulic retention time (T1) of the wastewater in the regulating tank 2 is not less than (1/3) the working time (T2) of the community hospital, so as to fully adjust the water quantity and uniform water quality, and facilitate subsequent treatment;

(3) The waste water in the regulating tank 2 is evenly pumped into the front compartment of the reaction zone 3 through the lifting pump 14, and the magnetic additive dosing device 11 is controlled according to the flow rate of the lifting pump 14 to add 200-500 mg/L of magnetic additives, and the magnetic additives are added at a rate greater than 150r/min Stir at a high speed for more than 20 minutes, so that the suspended particles and dissolved organic pollutants in the wastewater form magnetic nuclei with the additive, and then flow into the rear compartment of the reaction zone 3 by gravity;

⑷Add anion PAM5mg/L-50mg/L to the rear compartment of reaction zone 3, and stir at a slow speed of less than 50r/min for about 10min, so that the magnetic nuclei can form large block floc, the mixed liquid flows into the solid-liquid separation zone 4 by itself.

(5) Because the density of the flocs in the solid-liquid separation zone 4 is higher than that of water, they sink by their own weight, and at the same time, the magnetic conveyor belt 10 set at the bottom of the separation zone 4 applies a certain magnetic field to quickly absorb the ferromagnetic flocs on it. On the surface, it not only speeds up the solid-liquid separation rate, but also makes the solid-liquid separation more thorough. The SS and COD concentrations in the supernatant are reduced by nearly 20% compared with conventional coagulation methods.

(6) The supernatant liquid flows into the disinfection area 6 by itself, and the disinfectant dosing device 13 is used to control the dosage of the disinfectant to 30-50 mg/L (calculated as available chlorine) according to the flow rate of the lift pump 14, and the disinfection contact time is not less than 1.0 h. To remove pathogenic microorganisms, parasite eggs and various viruses, and finally discharge them into the urban sewage pipe network through a unified discharge outlet;

⑺Magnetized conveyor belt 10 circulates at an average speed of no more than 0.5m/s. When the magnetically attracted sludge reaches the sludge collection area 5, it is automatically scraped off by the non-magnetic scraper set on the side, and after sludge discharge Disinfectants are added after being discharged from port 8 and collected, and shipped out for disposal together with medical waste in accordance with the requirements of environmental protection regulations.

Embodiment two

A community hospital has an 8-hour outpatient service and produces 20 tons of medical wastewater per day, with an average wastewater COD of 350mg/L, an average SS of 500mg/L, an average ammonia nitrogen of 45mg/L, and an average of no less than 1.0× ¹⁰⁶ fecal coliform bacteria.

Using the method and system in Embodiment 1, the relevant design parameters are as follows:

(1) Both the grid well and the adjustment pool adopt the buried brick-concrete structure, the grid pitch of the grid is 15mm, the effective pool capacity of the adjustment pool is 10m ³ , and the adjustment time is 4 hours. The flow rate of the lifting pump is 2.5m ³ /h, and the head is 8.0m;

⑵Effective tank capacity of the reaction zone is 1.5m ³ , and the reaction contact time is 0.6 hours. The surface load of the solid-liquid separation area is 1.7m ³ /m ² ·h, and the effective water depth is 1.0m. The transmission speed of the magnetic conveyor belt is 0.5m/s;

(3) The effective pool volume in the disinfection area is 3m ³ , and the disinfection contact time is 1.2 hours;

The wastewater treatment process is as follows:

The wastewater from the community hospital passes through the grid to remove large debris, and then flows into the regulating pool to adjust the water volume and uniform water quality; the wastewater from the regulating pool is pumped into the pre-reaction area by a lift pump, and 350mg/L of ferromagnetic additives are added, and it is stirred rapidly at a speed of 180r/min , and add 15 mg/L anionic PAM with a molecular weight of 10 million in the post-reaction area, and stir slowly at a speed of 40 r/min; after the waste water after the dosing reaction passes through the solid-liquid separation area, the supernatant flows into the disinfection area by itself, and is put into the disinfection area. Add 45mg/L sodium hypochlorite solution (calculated by available chlorine content), and the effluent is brought into the urban sewage pipe network; the bottom conveyor belt in the solid-liquid separation area brings the mud into the mud collection area, and after being collected and disinfected, it will be disposed of together with the rest of the hospital's medical solid waste .

The wastewater treatment effect is as follows:

The test results show that the treated wastewater can meet the discharge requirements in the "Water Pollutant Discharge Standard for Medical Institutions" (GB18466-2005). The moisture content of the treated sludge is about 45% on average, and it can meet the environmental protection related disposal requirements without using subsequent dehydration equipment.

The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that for those skilled in the art, several equivalent substitutions or changes can be made without departing from the concept of the present invention, and these should be covered within the protection scope of the present invention.

Claims (10)

1. a kind of wastewater treatment method applicable to community hospital is characterized in that described wastewater treatment method applicable to community hospital comprises the steps: (1) The medical wastewater passes through the grid to remove large floating objects, and the size of the suspended objects in the treated wastewater is ≤20mm; ⑵Adjust the water quantity and uniform water quality, the adjustment time (T1) is determined according to the working hours (T2) of the community hospital, T1≥(1/3)T2; (3) Add magnetic additives and stir quickly to make the pollutants in the wastewater collide with the magnetic additives fully to form small magnetic nuclei; (4) Add flocculant and stir slowly to make magnetic nuclei form magnetic flocs under the cross-linking action of flocculant; ⑸Magnetized conveyor belt is used, and the magnetic floc is magnetically attracted to its surface by the principle of magnetic separation to achieve solid-liquid separation. The separated supernatant requires SS≤20mm; ⑹ After the supernatant is added with disinfectant to remove pathogenic microorganisms, parasite eggs and various viruses, it is discharged through the unified discharge port to meet the standard; ⑺The magnetically attracted sludge on the magnetic conveyor belt is automatically scraped off with a scraper during operation, after being collected, disinfectant is added, and it is transported out together with medical waste for disposal in accordance with environmental protection regulations. 2. A wastewater treatment method suitable for community hospitals according to claim 1, characterized in that said grid is a mechanical grid or an artificial grid, and the grid pitch of the grid is ≤20mm; said magnetization The conveying speed of the conveyor belt is ≤0.5m/s, and the magnetic field strength is 0.1-0.5T. 3. A kind of waste water treatment method suitable for community hospitals according to claim 1, characterized in that the magnetic additive is an additive based on ferromagnetic powder granular material, particle size ≥ 100 mesh, and The dosage is 200-500mg/L, and the reaction stirring speed is ≥150r/min. 4. A wastewater treatment method suitable for community hospitals according to claim 1, characterized in that the flocculant is anionic PAM with a molecular weight of 10 million to 12 million and a dosage of 5 mg/L to 50 mg /L, the reaction stirring speed is ≤50r/min. 5. a kind of waste water treatment method that is applicable to community hospital according to claim 1 is characterized in that described disinfectant adopts chlorine series disinfectant, and dosage is 30-50mg/L (in available chlorine), Disinfection contact time ≥ 1.0h. 6. A wastewater treatment system suitable for community hospitals, said wastewater treatment system suitable for community hospitals comprising grid wells, regulating tanks, reaction zones, solid-liquid separation zones, disinfection zones, mud collection zones, automatic dosing The device is characterized in that the hospital waste water enters the grid well by gravity, and the grid well is connected with the adjustment tank; the adjustment tank is connected with the reaction area through the lifting pump; The mud area is connected, and connected with the disinfection area through the side pipe, and the waste water is discharged sequentially by gravity using the potential difference; the automatic dosing device is respectively connected with the reaction area and the disinfection area through the dosing pump. 7. A wastewater treatment system suitable for community hospitals according to claim 6, characterized in that the reaction zone is divided into two grids, and magnetic additives and flocculants are added in sequence, and the hydraulic retention time in the reaction zone is ≥ 0.5h . 8. A wastewater treatment system suitable for community hospitals according to claim 6, characterized in that the bottom layer of the solid-liquid separation area is arranged with a magnetic conveyor belt, and the magnetic conveyor belt is connected with the mud collection area to separate solid-liquid The effective water depth of the area is ≤1.0m; the upper end of the solid-liquid separation area is provided with an outlet weir, and its upper edge is lower than the lower edge of the opening of the partition between the solid-liquid separation area and the mud collection area, and the height difference is ≥10mm. 9. A kind of waste water treatment system applicable to community hospitals according to claim 6, characterized in that a non-magnetic scraper is provided in the described mud collection area, and a mud discharge outlet is provided at the lower end of the mud collection area; the disinfection Agitators and baffles are set in the zone. 10. A wastewater treatment system suitable for community hospitals according to claim 6, characterized in that the automatic dosing device includes three sets of magnetic additive dosing device, flocculant dosing device, and disinfectant dosing device Equipment, in which the magnetic additive dosing device, the flocculant dosing device are connected to the reaction area, the disinfectant dosing device is connected to the disinfection area, and the start switch of the dosing device is linked with the lifting pump switch of the regulating tank.