Coffee wastewater treatment device

Abstract

The utility model relates to a coffee wastewater treatment device, which belongs to the technical field of coffee processing wastewater treatment and comprises a sediment pool, an adjusting pool, a yeast reactor, a solid-liquid separator, a water distribution pool, an A / O biochemical pool and a secondary sedimentation tank. The yeast reactor is internally provided with an aeration device and is filled with microbe beads, the microbe beads are in a fluidized state, and candida mycoderma bacteria are adsorbed on the microbe beads; the sediment tank is communicated with the regulating tank through an overflow pipe; the adjusting tank is communicated with the yeast reactor through a lifting pump and a pipeline; a water inlet of the solid-liquid separator is communicated with a water outlet pipeline of the yeast reactor; two overflowing partition plates are arranged in the A / O biochemical pool to divide the A / O biochemical pool into a hydrolysis area, a denitrification area and a nitrification area; effective treatment of wastewater can be achieved without adding alkali, an anaerobic reactor which is low in starting speed, high in water inlet condition requirement and unstable in operation in a conventional process can be replaced, up-to-standard discharge of sewage is achieved, and in addition, the device is short in starting time, good in system stability and capable of adapting to changes of the quality and the quantity of the sewage.

Description

Technical Field

[0001] The utility model belongs to the technical field of coffee processing wastewater treatment, and specifically relates to a coffee wastewater treatment device. Background Art

[0002] The wastewater from the primary processing of fresh coffee fruit comes from the water used for washing, peeling and degumming, fermentation and secondary washing of fresh coffee fruit, and mainly contains peel, pulp, plant protein, sugar and a large amount of pectin. The concentration of organic pollutants in the wastewater is relatively high, COD cr The concentration is 10000-40000mg / L, BOD5 concentration is 2000-6000mg / L, ammonia nitrogen (NH3-N) concentration is 50-300mg / L, suspended solids (SS) concentration is 200-2000mg / L, total phosphorus (TP) concentration is 10-30mg / L, and the chromaticity of wastewater is as high as 2000. At the same time, coffee pulping and fermentation produce organic acids that make wastewater acidic, with a pH generally between 3-5, B / C=0.15-0.2, and pectin has high viscosity, is difficult to degrade, and has poor biodegradability. Direct discharge of coffee fruit primary processing wastewater will destroy the river ecosystem, eutrophicate the surrounding water bodies, seriously damage the self-purification capacity of the water body, and cause the receiving water body to become black and smelly, which has a great impact on environmental safety and human and animal safety.

[0003] At present, the primary processing wastewater of coffee mainly adopts the simple method of discharging after lime neutralization and precipitation or adopts the physicochemical and biochemical combined process of "water inlet → adding alkali to adjust pH value → pretreatment (solid-liquid separation method, such as coagulation sedimentation, flotation, filter press, etc.) → anaerobic (such as anaerobic reactors such as UASB, IC, EGSB) → anoxic-aerobic (such as A / O, A2 / O, etc.) → precipitation → effluent". The simple method has a large amount of lime addition, a large amount of slag production, poor treatment effect, pollution still exists, and it is impossible to achieve standard discharge. In the physicochemical and biochemical combined process, COD in sewage is mainly removed by anaerobic reaction. The anaerobic reaction needs to be carried out under neutral conditions, and high solid content will have a very adverse effect on the anaerobic reaction. Therefore, a large amount of alkali needs to be added before anaerobic treatment for neutralization and liquid-solid separation after neutralization. Not only will a large amount of neutralization slag be produced, but also because the primary processing wastewater of coffee contains a large amount of pectin, pectin is difficult to decompose, and solid-liquid separation is difficult. Not only is the treatment cost high, but the treatment effect is also poor. In addition, the anaerobic reaction conditions are harsh and the indicators are difficult to control stably, which also seriously affects the treatment effect of wastewater. After anaerobic treatment, it is still difficult to achieve standard discharge after A / O biochemical treatment and other treatments, and the treated wastewater still has a high COD content.

[0004] Yunnan plays an important role in China's coffee industry. Its coffee planting area and output account for more than 98% of the country's total. Coffee planting is one of the important sources of economic income for local people. The problem of wastewater treatment in the primary processing of coffee has seriously restricted the development of the industry.

[0005] In addition, the coffee harvest season is mainly concentrated from November to March of the following year, with a processing time of about 5 months a year. There is no coffee primary processing wastewater in the other seven months. The existing physical, chemical and biochemical combined process, after a long period of shutdown, requires at least 2-3 months to start the anaerobic reaction, and the startup method is: retain the anaerobic wastewater of the previous year, and inoculate and domesticate anaerobic bacteria at least 2-3 months in advance of the coffee harvest season. The preparation time for anaerobic reaction is too long, the cost is high, and there is also the risk of poor anaerobic domestication effect. Not only that, the primary processing of fresh coffee fruits is usually concentrated in the daytime, and the water quality and water volume of the wastewater fluctuate greatly within a day. The existing physical, chemical and biochemical combined process is difficult to adapt to such fluctuations in water volume and water quality, which also seriously affects the treatment effect of the primary processing wastewater of fresh coffee fruits. Utility Model Content

[0006] In order to overcome the problems existing in the background technology, the utility model provides a coffee wastewater treatment device. By setting up a yeast reactor, the coffee fresh fruit processing wastewater can be treated without adding alkali, thereby reducing the amount of slag produced. The wastewater treatment effect is high and can adapt to changes in water quality and water volume. The treated wastewater can meet the discharge standards.

[0007] To achieve the above purpose, the utility model is implemented through the following technical solutions:

[0008] The coffee wastewater treatment device comprises a sedimentation tank, a regulating tank and a yeast reactor; the yeast reactor is a trough or tank structure, equipped with an aeration device and filled with microbial balls, on which Candida albicans is adsorbed; the sedimentation tank is connected to the regulating tank through an overflow pipe; the regulating tank and the yeast reactor are connected through a lifting pump and a pipeline.

[0009] Preferably, a cofferdam is provided on the upper part of the yeast reactor; and the water outlet of the yeast reactor is opened in the cofferdam area.

[0010] Preferably, the coffee wastewater treatment device also includes a solid-liquid separator, a water distribution tank, an A / O biochemical tank and a secondary sedimentation tank; the water inlet of the solid-liquid separator is connected to the water outlet pipeline of the yeast reactor; the A / O biochemical tank is provided with two flow baffles to divide it into a hydrolysis zone, a denitrification zone and a nitrification zone; the water distribution tank is connected to the hydrolysis zone through a pipeline; the nitrification zone is connected to the secondary sedimentation tank through a pipeline; the bottom of the secondary sedimentation tank is provided with a reflux pipe and a reflux pump A connected to the hydrolysis zone.

[0011] Preferably, the water distribution tank and the nitrification zone are both provided with aeration devices; the hydrolysis zone and the denitrification zone are respectively provided with stirring devices.

[0012] Preferably, a reflux pipe and a reflux pump B connected to the yeast reactor are provided at the bottom of the solid-liquid separator.

[0013] Preferably, the coffee wastewater treatment device further comprises a sludge collection tank, and the bottom of the secondary sedimentation tank is connected to the sludge collection tank through a pipeline.

[0014] Preferably, the secondary sedimentation tank is a tank structure, which is provided with a central tube and a stirring paddle; the stirring paddle is arranged in the central tube; a filtering filler layer is provided between the central tube and the outer tube, and a cofferdam is provided on the inner wall of the outer tube, and its clean water outlet is opened in the cofferdam area.

[0015] Preferably, the water inlet connection port between the nitrification zone and the secondary sedimentation tank is opened below the filter packing layer.

[0016] Preferably, the microbial pellets are distributed in a fluidized state in the yeast reactor.

[0017] Preferably, the microbial pellets are polyurethane porous pellets or PP plastic multi-faceted pellets.

[0018] Beneficial effects of the utility model:

[0019] The utility model provides a yeast reactor and arranges microbial balls adsorbed with Candida in the reactor, so that the coffee fruit wastewater can be effectively treated without adding alkali, and the yeast reaction does not require the assistance of other microorganisms. After the Candida reacts with the coffee fruit wastewater, the pH value of the wastewater increases, and the subsequent A / O biochemical reaction can be carried out without adding alkali or adding a small amount of alkali for fine adjustment, which greatly solves the problems of large alkali consumption and large slag production in the current coffee fruit wastewater treatment.

[0020] The yeast reactor of the utility model is equipped with microbial balls, which are distributed in a fluidized state in the yeast reactor. The microbial balls adsorb pollutants, and Candida attaches and grows on the microbial balls, thereby increasing the volume load of the yeast reactor. The utility model can replace the anaerobic reactor in the conventional process, which has a slow start-up speed, high requirements on water inlet conditions, and unstable operation, by arranging the yeast reactor, so as to achieve sewage discharge meeting the standards.

[0021] The yeast reaction startup time of the utility model can usually be completed within 7 days. Compared with the anaerobic startup time of at least 3 months in the existing coffee fresh fruit processing process, the utility model greatly shortens the startup time of coffee fresh fruit wastewater processing, has a high startup success rate, and saves the cost of coffee fresh fruit wastewater treatment.

[0022] The coffee fruit wastewater treatment process of the utility model can adapt to the fluctuation of the water volume and water quality of the coffee wastewater, and can further adapt to the day and night difference and seasonal difference of the coffee fruit added. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a schematic diagram of the overall structure of the utility model;

[0024] In the figure, 1 is a sedimentation tank, 2 is a regulating tank, 3 is a lifting pump, 4 is a yeast reactor, 5 is a microbial ball, 6 is an aeration device, 7 is a solid-liquid separator, 8 is a reflux pump A, 9 is a water distribution tank, 10 is a cofferdam, 11 is a stirring device, 12 is an A / O biochemical tank, 13 is a secondary sedimentation tank, 14 is a sludge collection tank, 15 is a flow baffle, 16 is a reflux pump B, 17 is a central tube, 18 is a stirring paddle, 19 is a filter packing layer, and 20 is a clean water outlet. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings to facilitate understanding by technicians.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "provided with" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention will be understood according to specific circumstances.

[0027] like Figure 1 As shown, the coffee wastewater treatment device includes a sedimentation tank 1, a regulating tank 2, a yeast reactor 4, a solid-liquid separator 7, a water distribution tank 9, an A / O biochemical tank 12, a secondary sedimentation tank 13 and a sludge collection tank 14. The sedimentation tank 1 is connected to the regulating tank 2 through an overflow pipe; the regulating tank 2 and the yeast reactor 4 are connected through a lift pump 3 and a pipeline, and the yeast reactor 4 and the solid-liquid separator 7 are connected through a pipeline. Two flow baffles 15 are provided in the A / O biochemical tank 12, which divide the A / O biochemical tank 12 into a hydrolysis zone, a denitrification zone and a nitrification zone; the water distribution tank 9 is connected to the hydrolysis zone through a pipeline; the water distribution tank 9 is connected to the hydrolysis zone through a pipeline, and the nitrification zone and the secondary sedimentation tank 13 are connected through a pipeline; the bottom of the secondary sedimentation tank 13 is provided with a reflux pipe connected to the hydrolysis zone and a reflux pump A8.

[0028] The coffee fruit processing wastewater is settled in the sedimentation tank 1, where a small amount of peel, pulp and insoluble inorganic particles are removed, and then enters the regulating tank 2. According to the water quality in the regulating tank 2, it is determined whether nitrogen and phosphorus need to be added to meet the subsequent yeast reaction requirements. The water in the regulating tank 2 is sent to the yeast reactor 4 through the lifting pump 3 for yeast reaction.

[0029] The yeast reactor 4 is a tank or tank structure, with an aeration device 6 installed inside and filled with microbial pellets 5. The microbial pellets 5 are distributed in the tank in a fluidized state and adsorbed with Candida. The microbial pellets 5 are porous pellets made of polyurethane with a diameter of 20 mm or multi-faceted pellets made of PP plastic. In the yeast reactor of the utility model, Candida liquid is added to the wastewater, and Candida is adsorbed on the microbial pellets 5, so that the volume load is greatly improved. The aeration device 6 provides oxygen for the yeast reaction. A circle of cofferdams 10 is provided on the upper part of the yeast reactor 4, and the water outlet of the yeast reactor 4 is opened in the cofferdam area. The cofferdam 10 serves to block the solid phase and the microbial pellets 1. The wastewater after the yeast reaction is discharged from the water outlet over the cofferdam 10 and enters the solid-liquid separator 7.

[0030] The pH value of coffee fruit processing wastewater is low. By adding alkali to adjust the pH value, not only the alkali consumption is large, but also the acid-base neutralization will produce a large amount of slag, increase the salinity, and thus affect the efficiency of subsequent biochemical reactions. Acid-base neutralization will also produce a large amount of suspended matter, but these substances will not be removed with the acid-base neutralization, and need to be removed by coagulation and precipitation. The coagulation reaction requires the addition of a large amount of PAC and PAM agents, and the agent consumption is huge, resulting in high treatment costs. The utility model treats coffee fruit wastewater by setting a yeast reactor, and there is no need to adjust the pH value of the inlet water. Not only can the biochemical reaction be directly carried out under acidic conditions, but the pH value of the wastewater will increase after the reaction, so there is no need to add a large amount of alkali to adjust the pH value, and the viscous pectin dissolved in the wastewater will be decomposed, the organic pollutants in the water will be degraded, and the viscosity of the water will be reduced, which greatly reduces the difficulty of subsequent solid-liquid separation of the wastewater. The yeast reaction will not only decompose and consume pectin, but also has a good removal effect on COD, BOD, NH3-N, and TP.

[0031] Candida has good adaptability and tolerance to the high organic matter concentration and acidity of coffee fruit processing wastewater. No other microorganisms need to be added during the yeast reaction process, and Candida has good growth, reproduction, metabolism and fermentation during the reaction process. The utility model adds bacterial liquid when the yeast reactor is started and debugged, and no bacterial liquid needs to be added after the reaction is continuously and stably operated. The pH of the coffee fruit wastewater treated by the present invention is about 3-5, and the pH value increases to 5-7 after the yeast reaction.

[0032] Through extensive research, the inventors found that Candida has good tolerance to fresh coffee fruit processing wastewater, and has good growth, reproduction, metabolism and fermentation during the reaction process. It can adapt well to changes in the water quality and quantity of wastewater, and can further adapt to changes in water quality and quantity by adjusting the amount of sludge returned to the yeast reaction to meet the yeast reaction treatment effect under changes in water quality and quantity. If the wastewater inlet volume increases, the reflux volume of the reflux pump B16 is increased.

[0033] The solid-liquid separator 7 can be an inclined tube sedimentation tank. The wastewater is precipitated in the solid-liquid separator 7, and the bottom sludge returns to the yeast reactor 4 through the reflux pipe and the reflux pump B16. The upper clear liquid enters the water distribution tank 9 through the pipeline. The water distribution tank 9 and the nitrification zone are both provided with an aeration device 6, and the hydrolysis zone and the denitrification zone are respectively provided with a stirring device 11. The wastewater enters the hydrolysis zone through the water distribution tank 9, and enters the secondary sedimentation tank 13 through the nitrification zone.

[0034] Hydrolysis and acidification can improve the biodegradability of wastewater. After the wastewater is treated by the yeast reactor, the bioavailable pollutants are reduced, and the biodegradability is reduced. In order to improve the efficiency of the subsequent anaerobic reaction, a hydrolysis reaction is set up. The hydrolysis reaction is a process in which the insoluble organic matter in the water is hydrolyzed into soluble organic matter by hydrolyzing bacteria and acidifying bacteria under the condition of containing a large number of hydrolytic bacteria and acidifying bacteria, and the macromolecular substances that are difficult to biodegrade are converted into small molecules that are easily biodegradable, thereby improving the biodegradability of wastewater and providing a good water quality environment for subsequent biochemical treatment. Hydrolysis refers to the biochemical reaction that takes place outside the cell before organic matter enters the microbial cell. Microorganisms complete the biocatalytic reaction by releasing extracellular free enzymes or fixed enzymes attached to the outer wall of the cell. Create conditions for improving the efficiency of subsequent anaerobic reactions. In the A / O biochemical reaction process, the remaining organic pollutants and nitrogen and phosphorus are removed by the growth and reproduction of activated sludge, and denitrification is performed by nitrification and denitrification.

[0035] The treated wastewater is separated into clean water and bottom mud in the secondary sedimentation tank 13. The clean water after separation is reused or discharged in compliance with the standards, and the bottom mud can be processed into fertilizer.

[0036] The secondary sedimentation tank 13 is provided with a central tube 17 and a stirring paddle 18; the stirring paddle 18 is arranged in the central tube 17; a filter packing layer 19 is arranged between the central tube 17 and the outer tube, and a cofferdam 10 is arranged on the inner wall of the outer tube, and its clean water outlet 20 is opened in the cofferdam area. The wastewater from the nitrification area enters below the filter packing layer 19 of the secondary sedimentation tank 13, and after the sediment is precipitated, it is sent to the sludge collection tank 14 from the bottom of the tank, and the clear liquid is discharged from the clean water outlet 20, and the clear liquid is reused or discharged in compliance with the standards. Flocculants can be added to the secondary sedimentation tank 13 to accelerate the separation of sediment and clean water. The central tube 17 provides a stirring interval, and the flocculated wastewater is filtered through the filter packing layer 19 and then discharged from the clean water outlet 20 over the cofferdam 10.

[0037] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the utility model.

Claims

1. A coffee wastewater treatment device, characterized in that: The invention comprises a sedimentation tank (1), a regulating tank (2) and a yeast reactor (4); the yeast reactor (4) is a tank or a tank structure, is provided with an aeration device (6) and is filled with microbial pellets (5), and the microbial pellets (5) are adsorbed with Candida; the sedimentation tank (1) and the regulating tank (2) are connected via an overflow pipe; the regulating tank (2) and the yeast reactor (4) are connected via a lift pump (3) and a pipeline.

2. The coffee wastewater treatment device according to claim 1, characterized in that: A cofferdam (10) is provided on the upper part of the yeast reactor (4); and a water outlet of the yeast reactor (4) is opened in the cofferdam area.

3. The coffee wastewater treatment device according to claim 2, characterized in that: It also includes a solid-liquid separator (7), a water distribution tank (9), an A / O biochemical tank (12) and a secondary sedimentation tank (13); the water inlet of the solid-liquid separator (7) is connected to the water outlet pipe of the yeast reactor (4); two flow partitions (15) are provided in the A / O biochemical tank (12) to divide it into a hydrolysis zone, a denitrification zone and a nitrification zone; the water distribution tank (9) is connected to the hydrolysis zone through a pipe; the nitrification zone and the secondary sedimentation tank (13) are connected through a pipe; and a reflux pipe and a reflux pump A (8) connected to the hydrolysis zone are provided at the bottom of the secondary sedimentation tank (13).

4. The coffee wastewater treatment device according to claim 3, characterized in that: The water distribution tank (9) and the nitrification zone are both provided with an aeration device (6); the hydrolysis zone and the denitrification zone are respectively provided with a stirring device (11).

5. The coffee wastewater treatment device according to claim 3, characterized in that: The bottom of the solid-liquid separator (7) is provided with a reflux pipe and a reflux pump B (16) which are connected to the yeast reactor (4).

6. The coffee wastewater treatment device according to claim 5, characterized in that: It also comprises a sludge collection tank (14), and the bottom of the secondary sedimentation tank (13) is connected to the sludge collection tank (14) through a pipeline.

7. The coffee wastewater treatment device according to any one of claims 3 to 6, characterized in that: The secondary sedimentation tank (13) is a tank structure, in which a central cylinder (17) and a stirring paddle (18) are arranged; the stirring paddle (18) is arranged in the central cylinder (17); a filtering filler layer (19) is arranged between the central cylinder (17) and the outer cylinder; a cofferdam (10) is arranged on the inner wall of the outer cylinder, and a clean water outlet (20) is opened in the cofferdam area.

8. The coffee wastewater treatment device according to claim 7, characterized in that: The water inlet connection port between the nitrification zone and the secondary sedimentation tank (13) is opened below the filter packing layer (19).

9. The coffee wastewater treatment device according to claim 1, characterized in that: The microbial pellets (5) are distributed in a fluidized state in the yeast reactor.

10. The coffee wastewater treatment device according to claim 8, characterized in that: The microbial balls (5) are polyurethane porous balls or PP plastic multi-faceted balls.

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