CN104386887B - A kind of bean curd factory effluent minitype direct exhaust type biological treatment and equipment - Google Patents

Abstract

The invention relates to a small-scale direct-discharge biological treatment process and equipment for tofu production wastewater, which belongs to the field of wastewater treatment. In order to overcome the difficulties existing in the existing methods for treating tofu production wastewater for small enterprises, the equipment includes a controller, a grille The regulating pool, the SBR pool, the first solenoid valve, the air pump communicated with the inside of the SBR pool through the air intake pipe, the porous packing and the water level sensor set inside the SBR pool, the cushion layer set at the bottom of the SBR pool, the water level sensor set at the bottom of the SBR pool Drain, the second electromagnetic valve controlling the switch of the drain of the SBR pool, and the cushion layer at the bottom of the SBR pool are made of rough materials. The equipment in the present invention is easy to operate, the process is simple and easy to implement, the cost is low, and the effect is good. It has double benefits of the environment and society. It is very suitable for small-volume tofu production wastewater, can be used by small enterprises, and can also be applied to other high-concentration wastewater The treatment has a good application prospect.

Description

A small-scale direct discharge biological treatment process and equipment for tofu production wastewater

technical field

The invention belongs to the field of wastewater treatment, and in particular relates to a small-scale direct-discharge biological treatment process and equipment for wastewater from tofu production.

Background technique

Tofu is a daily food for people, but a large amount of waste water will be generated in the production process. It is generally believed that the ratio of unit mass of tofu finished product and discharged waste water is more than 1:10, that is, the production of 1 kg of tofu produces at least 10 L of waste water. Since more than 50% of the tofu in the market is produced by the waste water of tofu workshops distributed in the suburbs of the city, the amount of waste water is small and scattered, but the degree of pollution is high, and the discharge method is mostly direct discharge. The first consequence is to increase the load on the municipal sewage pipe network Second, it is easy to produce odor, breed mosquitoes and flies and affect the surrounding environment and human health. The waste water produced in the tofu production process is mainly soaked bean water, yellow slurry water and workshop flushing water. Tofu production wastewater contains a large amount of protein, fat, starch and other nutrients. From the perspective of sewage treatment, the range of water quality indicators for the discharged tofu production wastewater is: CODcr (dichromate index) content is 2000-20000mg/L, The content of BOD5 (consumed dissolved oxygen) is 800-12000mg/L, which is a kind of high-concentration organic wastewater, but it is non-toxic and harmless, and is suitable for biological treatment.

At present, biological methods are mainly used to treat tofu production wastewater at home and abroad, mainly including anaerobic biological treatment method, aerobic treatment method and sequencing batch bioreactor (SBR), because sequencing batch bioreactor (SBR) has intermittent operation , aerobic and anaerobic alternation, nitrogen and phosphorus removal, etc., are very suitable for the discharge characteristics of tofu wastewater. The above method has been adopted in large-scale soybean product production enterprises, and some useful substances such as soybean protein have also been recovered if possible. Since sewage treatment is a systematic project, the amount of wastewater treated is large, and it is more common in large-scale enterprises, but at the same time, the equipment The requirements for personnel and personnel are high, and these process equipment are directly used for small-scale tofu production wastewater. Because it is difficult to realize the centralized collection of small-scale wastewater, the efficacy of the equipment cannot be fully utilized. For small enterprises (displacement ≤ 1 ton/day), due to lack of capital and technology, the introduction of complete sets of equipment increases the cost, let alone recycling. At the same time, the amount of waste water produced by small enterprises is small, but it cannot be directly discharged into the sewer, otherwise It is easy to cause corruption and fermentation and even sewer blockage to affect the surrounding environment.

Contents of the invention

In order to overcome the difficulties existing in small enterprises in the existing methods for treating wastewater from tofu production, the invention provides a small-scale direct discharge biological treatment process and equipment for wastewater from tofu production.

The technical solution of the present invention is: a small-scale direct discharge type biological treatment process equipment for tofu production wastewater, which includes a regulating tank with a grid, an SBR tank, a first electromagnetic tank connecting the water outlet of the regulating tank and the water inlet of the SBR tank. Valve, the air pump connected to the inside of the SBR pool through the intake pipe, the water level sensor set inside the SBR pool, the cushion layer set at the bottom of the SBR pool, the drain port set at the bottom of the SBR pool, and the first switch for controlling the drain switch of the SBR pool Two solenoid valves, a controller connected to the water level sensor and controlling the first solenoid valve and the second solenoid valve, and the cushion layer at the bottom of the SBR pool are made of rough materials.

The diameter of the holes on the grid is less than 1mm.

The volume of the regulating pool is greater than 1 cubic meter.

The inside of the SBR pool is also provided with porous fillers, which are hollow spherical fillers and are fixedly arranged around the drain outlet.

The drain port is set at the center of the bottom of the SBR pool, and the opening position of the drain port is raised.

The bottom of the SBR pool is raised with a slope of 2% from the center to the four walls.

A small-scale direct-discharge biological treatment process for tofu production wastewater. The treatment process of this process is divided into two processes: pretreatment and SBR tank main treatment in sequence. Among them, the main process of SBR tank main treatment includes: water intake, aeration , sedimentation, drainage and idle.

The specific flow of the process is as follows: step 1, the first solenoid valve is closed, step 2, the waste water produced by tofu production flows into the regulating tank through the grid that blocks the large particles and large-diameter impurities in the waste water, and step 3, the waste water is in the regulating tank Carry out the pretreatment of impurity precipitation, step 4, after the pretreatment is completed, the controller controls the first solenoid valve to open, the waste water enters the SBR pool through the outlet of the regulating pool, step 5, the water level sensor in the SBR pool senses that the waste water in the SBR pool reaches the set level After the water level is fixed, the controller controls the first electromagnetic valve to close, and at the same time the controller controls the air pump to open to aerate the wastewater in the SBR tank. Step 6. After the aeration treatment, the controller controls the air pump to stop running, and the water in the SBR tank The waste water enters the sedimentation time, step 7, after sedimentation, the controller controls the second electromagnetic valve to open, and starts to drain, step 8, after the drainage is completed, the controller controls the second electromagnetic valve to close, and returns to step 2.

The time of the aeration treatment is 2 hours.

The precipitation time is 1 hour.

The beneficial effects of the present invention are: the equipment in the present invention is easy to operate, the process is simple and easy, the cost is low, the effect is good, and there are double benefits of the environment and society, and it is very suitable for the tofu production wastewater with a small amount of water (<1 ton), and can be processed by It is used by small enterprises and can also be applied to the treatment of other high-concentration wastewater, which has a good application prospect.

Description of drawings

Fig. 1 is the structural representation of the tofu production waste water small-scale straight discharge type biological treatment equipment of the specific embodiment of the present invention;

In the figure, 1 is the grille, 2 is the regulating pool, 3 is the first solenoid valve, 4 is the SBR pool, 5 is the air pump, 6 is the hollow spherical packing, 7 is the drainage port, 8 is the cushion, 9 is the second The electromagnetic valve.

detailed description

Referring to the accompanying drawings, through the description of the embodiments, the specific embodiments of the present invention include the shape, structure, mutual position and connection relationship of each part, the function and working principle of each part, and the manufacturing process of the various components involved. And the method of operation and use, etc., are described in further detail to help those skilled in the art have a more complete, accurate and in-depth understanding of the inventive concepts and technical solutions of the present invention.

As shown in Fig. 1, a kind of equipment of tofu production wastewater small-scale in-line biological treatment process, this equipment comprises the adjusting pool 2 with grid 1, SBR (sequencing batch bioreactor method) pool 4, connecting adjusting pool 2 The first solenoid valve 3 of the water outlet and the water inlet of the SBR pool 4, the air pump 5 communicating with the interior of the SBR pool 4 through the intake pipe, the hollow spherical packing 6 and the water level sensor arranged inside the SBR pool 4, and the water level sensor arranged in the SBR pool 4 The cushion layer 8 at the bottom, the drain outlet 7 arranged at the bottom of the SBR pool 4, the second solenoid valve 9 that controls the switch of the drain outlet 7 of the SBR pool 4, is connected with the water level sensor and controls the first solenoid valve 3 and the second solenoid valve 9 controller. In order to intercept large particles and large-diameter impurities in the waste water, the diameter of the holes on the grid 1 is less than 1 mm. Since small-scale tofu factories generally produce more concentrated waste water, in order to accommodate the waste water, the volume of the regulating pool 2 must ensure that it can accommodate the daily waste water volume of the small tofu factory, and the discharge of the small tofu factory is ≤ 1 ton per day, so the volume of the regulating pool 2 The volume must be greater than 1 cubic meter. In order to strengthen the adsorption of microorganisms and slow down the water flow rate during drainage, the material of the cushion layer 8 at the bottom of the SBR pool 4 is rough material. When draining, the cushion layer 8 made of rough material will also make the sludge difficult to be taken away by the water flow. , At the same time, part of the sludge was initially discharged and played a role in microbial renewal. In order to increase the attachment effect of microorganisms, perform secondary buffering and adsorption on the water flow, and further reduce the sludge loss, the hollow spherical packing 6 is fixedly arranged around the outlet 7, and the outlet 7 is arranged at the center of the SBR pool 4, in order to further slow down the sludge loss. The water flow drives the adverse effect of microorganisms at the bottom of the pool, and the opening position of the drain outlet 7 is raised, so that the bottom of the SBR pool 4 has a certain elevation slope from the center to the four walls, and the slope is 2%.

After the above measures, it has been proved by experiments that under the condition of small flow of water outlet, only in the initial 10 minutes or so, the outlet water of the outlet 7 will carry part of the sludge and be lost, and the concentration of suspended solids (MLSS) in the discharged water is greater than 3g/L. But after 10 minutes, the effluent was relatively clear, and the MLSS of the discharged water was 0.75g/L. With the increase of drainage time, the MLSS of the effluent finally remained at a value less than 0.3g/L, thus realizing direct drainage.

A small-scale direct-discharge biological treatment process for tofu production wastewater. The treatment method of the process is that the two processes of pretreatment and SBR tank main treatment are connected in series. The main process includes: water intake, aeration, sedimentation, drainage and idle. The specific process is as follows: step 1, the first solenoid valve 3 is closed, step 2, the waste water produced by tofu production flows into the regulating pool 2 through the grid 1 that blocks the large particles and large-diameter impurities in the waste water, and step 3, the waste water is in the regulating pool 2 to perform pretreatment, pretreatment is to carry out impurity precipitation on the wastewater entering the regulating tank 2, which is conducive to the homogenization of wastewater and effectively reduces the initial concentration of organic pollution. Step 4, after the pretreatment is completed, the controller controls the first electromagnetic The valve 3 is opened, and the waste water enters the SBR pool 4 through the outlet of the regulating pool 2. Step 5, after the water level sensor in the SBR pool 4 senses that the waste water in the SBR pool 4 reaches the set water level, the controller controls the first solenoid valve 3 to close, At the same time, the controller controls the air pump 5 to open, and the wastewater in the SBR pool 4 is aerated. In step 6, after 2 hours of aeration, the controller controls the air pump 5 to stop running, and the wastewater in the SBR pool 4 enters the settling time. Step 7, after settling for 1 hour, the controller controls the second solenoid valve 9 to open, and starts to drain water. Step 8, after the drainage is completed, the controller controls the second solenoid valve 9 to close, and returns to step 2.

When the size of the SBR pool 4 is set to 40cm×40cm×80cm, a batch of wastewater (100L) is taken as the research object, and the mixed wastewater in the regulating tank 2 is sampled (n=5) for analysis and measurement at the initial moment CODcr (Chemical Oxygen Demand), and then analyze and measure the waste water in the SBR pool 4 in different aeration periods (0.5h, 1h, 2h, 3h, 4h, 5h) of the aeration process n=5 after settling for 1 hour CODcr, the measurement results are shown in Table 1. The results show that with the increase of aeration time, the CODcr after precipitation is gradually decreasing. After 0.5 hours of treatment, the removal rate has reached nearly 40%. After 2 hours , The effluent index meets the third-level standard of the national comprehensive sewage discharge standard. As a small tofu factory, this standard has improved a lot compared to most of the current direct discharge into the sewer.

Table 1 COD index of influent and effluent water from tofu production wastewater at different aeration times (sampling at 5 cm from the water surface and sedimentation for 1 h)

When the size of the SBR pool 4 is set to 40cm x 40cm x 80cm, a batch of wastewater (100L) is taken as the research object, and the mixed wastewater in the regulating pool 2 is sampled n=3 at the initial moment for analysis and determination of SS( concentration of suspended solids), and then sample (n=3) the effluent from the outlet 7 in different aeration periods (0.5h, 1h, 2h, 3h, 4h, 5h) of the aeration process to analyze and measure SS, and the measurement results are shown in Table 2 As shown, the results show that: with the increase of aeration time, the concentration of suspended solids (SS) at the outlet is gradually decreasing. After 0.5 hours of treatment, the removal rate has exceeded 30%. After 1 hour, the effluent basically meets the national sewage comprehensive The three-level standard of the discharge standard, after 3 hours, the effluent is basically clear to the naked eye, and the effluent index of the subsequent treatment remains low, and the treatment effect is stable and slows down.

Table 2 The SS index of the influent and effluent water of tofu production wastewater at different aeration times (outlet sampling)

Therefore, the time of aeration treatment in the present invention is selected as 2 hours.

The present invention has been exemplarily described above in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods, as long as various insubstantial improvements are adopted in the method concept and technical solutions of the present invention, or there is no improvement Directly applying the concept and technical solutions of the present invention to other occasions is within the protection scope of the present invention.

Claims (8)

1. A kind of equipment of tofu production wastewater small-scale direct discharge type biological treatment process, it is characterized in that: this equipment comprises the adjusting pool (2) with grid (1), SBR pool (4), connecting adjusting pool (2) The first electromagnetic valve (3) of the water outlet and the water inlet of the SBR pool (4), the air pump (5) connected to the inside of the SBR pool (4) through the intake pipe, the water level sensor arranged inside the SBR pool (4), and the setting The cushion layer (8) at the bottom of the SBR pool (4), the drain port (7) arranged at the bottom of the SBR pool (4), the second solenoid valve (9) controlling the switch of the drain port (7) of the SBR pool (4) , be connected with the water level sensor and control the controller of the first solenoid valve (3) and the second solenoid valve (9), the making material of the pad (8) at the bottom of the SBR pool (4) is a rough material, and the grid ( 1) The diameter of the upper opening is less than 1 mm, and the volume of the regulating pool (2) is greater than 1 cubic meter. 2. the equipment of the small-scale in-line biological treatment process of bean curd production waste water according to claim 1, is characterized in that: described SBR pool (4) inside also is provided with porous packing, and porous packing is hollow spherical packing (6), It is fixedly arranged around the drain port (7). 3. the equipment of the small-scale straight discharge type biological treatment process of bean curd production waste water according to claim 1, it is characterized in that: described outfall (7) is arranged on the central position of SBR pool (4), and outfall (7) is in The position of the inlet opening in the SBR tank (4) is elevated. 4. The equipment for the small-scale direct discharge biological treatment process of tofu production wastewater according to claim 3, characterized in that: the bottom of the SBR pool (4) has a slope of 2% from the center to the four walls. 5. According to the equipment of the small-scale in-line biological treatment process of tofu production waste water described in any one of claims 1-4, it is characterized in that: the treatment process of the technique of the biological treatment equipment is divided into pretreatment and SBR in sequence The main process of the pool is two processes, among which, the main process of the main process of the SBR pool includes: water intake, aeration, sedimentation, drainage and idle. 6. According to the equipment of the small-scale direct discharge biological treatment process of tofu production wastewater according to claim 5, it is characterized in that: the specific flow of the process is as follows: step 1, the first electromagnetic valve (3) is closed, step 2, tofu production The generated wastewater flows into the regulating tank (2) through the grid (1) that blocks large particles and large-diameter impurities in the wastewater. Step 3, the wastewater is pretreated for impurity precipitation in the regulating tank (2). Step 4, pre-treatment After the treatment is completed, the controller controls the first electromagnetic valve (3) to open, and the waste water enters the SBR pool (4) through the water outlet of the regulating pool (2). In step 5, the water level sensor in the SBR pool (4) senses the SBR pool (4) ) reaches the set water level, the controller controls the first electromagnetic valve (3) to close, and at the same time the controller controls the air pump (5) to open to aerate the wastewater in the SBR pool (4), step 6, After the aeration treatment, the controller controls the air pump (5) to stop running, and the wastewater in the SBR tank (4) enters the settling time, step 7, after settling, the controller controls the second solenoid valve (9) to open and start draining, the step 8. After the drainage is completed, the controller controls the second solenoid valve (9) to close, and returns to step 2. 7. The equipment for the small-scale direct discharge biological treatment process of tofu production wastewater according to claim 6, characterized in that: the time of the aeration treatment is 2 hours. 8. The equipment for the small-scale direct discharge biological treatment process of tofu production wastewater according to claim 6, characterized in that: the settling time is 1 hour.