Aquaculture sewage treatment process

Abstract

The invention discloses an aquaculture sewage treatment process. The aquaculture sewage treatment process specifically comprises the following steps: S1, collecting and filtering treatment; s2, air floatation treatment: introducing the sewage separated in the step S1 into a first regulating tank, regulating the water quantity and water quality through the first regulating tank, and then introducing the sewage into air floatation equipment for air floatation treatment to remove suspended matter impurities and odor of the sewage, S3, primary aerobic treatment, S4, anaerobic treatment, S5, secondary aerobic treatment, S6, decoloration and disinfection treatment, and S5, secondary aerobic treatment. The invention relates to the technical field of aquaculture sewage treatment. According to the aquaculture sewage treatment process, sewage can be treated in batches, and more efficient treatment is carried out through coordinated work of anaerobic treatment and aerobic treatment, so that the treatment efficiency is greatly improved, and the purpose of improving the sewage treatment efficiency through cooperative intermittent use of anaerobic treatment and aerobic treatment is well achieved; the condition that the aerobic treatment equipment is in an idle state for a long time is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture wastewater treatment, and in particular to an aquaculture wastewater treatment process. Background Art

[0002] Aquaculture wastewater is mainly composed of the excrement and food residues of aquaculture animals. It has high organic matter concentration, high suspended matter, high ammonia nitrogen and phosphorus content. All indicators have exceeded the national emission standards by several times or even dozens of times. It is very easy to breed harmful bacteria. Due to the large amount and high concentration of aquaculture wastewater, it is difficult to treat and constantly causes pollution incidents. Aquaculture wastewater has become a greater source of pollution than industrial wastewater and domestic sewage. Therefore, it needs to be treated to meet the standards before it can be discharged normally.

[0003] Referring to a kind of aquaculture wastewater treatment process with Chinese patent publication number CN106277650B, it can effectively reduce the concentration of suspended solids, ammonia nitrogen and organic pollutants in the wastewater to the standard level. The whole treatment process is fully biodegradable without secondary pollution. The removal effect of suspended solids in the filtration link is good, which reduces the difficulty of subsequent wastewater treatment. The filtered sludge dries naturally and does not require sludge dewatering equipment for dehydration, so the treatment cost is low.

[0004] Referring to a farm sewage treatment system and process with Chinese patent publication number CN117023893A, the organic matter, suspended solids, colored matter, phosphorus and total nitrogen content in the aquaculture sewage are reduced in stages. The sewage is thoroughly purified, thereby effectively achieving true standard discharge, with good purification effect, high treatment efficiency and low operating cost; the whole process is intelligently controlled to ensure refined management, effectively save labor costs and reduce labor intensity.

[0005] A comprehensive analysis of the above reference patents reveals the following defects:

[0006] The existing aquaculture wastewater treatment process does not completely remove organic matter from the wastewater after anaerobic biological treatment during the anaerobic and aerobic treatment of wastewater. Therefore, anaerobic treatment must generally be used in combination with aerobic treatment. However, due to the long generation period of anaerobic microorganisms, low growth rate, and slow sludge growth, the startup time of the anaerobic reactor is relatively long, generally up to 1-2 months, or even longer. Therefore, after the long anaerobic treatment is completed, it is transported to the aerobic treatment equipment for treatment, which causes the aerobic treatment equipment to be idle for a long time, resulting in the entire sewage treatment equipment. The utilization rate is greatly reduced, and the sewage treatment efficiency is also low. It is impossible to achieve more efficient treatment by treating the sewage in batches and coordinating anaerobic treatment and aerobic treatment. For example, reference patents CN106277650B, an aquaculture sewage treatment process, and CN117023893A, a farm sewage treatment system and process, although both use anaerobic and aerobic treatment methods, have low treatment efficiency and cannot achieve the purpose of improving sewage treatment efficiency by combining anaerobic treatment and aerobic treatment intermittently, thereby bringing great inconvenience to the efficient treatment of sewage. Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] In view of the deficiencies in the prior art, the present invention provides an aquaculture wastewater treatment process, which solves the problem that in the prior aquaculture wastewater treatment process, the generation period of anaerobic microorganisms is long, the growth rate is low, and the sludge grows slowly during the anaerobic and aerobic treatment of wastewater. Therefore, the startup time of the anaerobic reactor is long. Therefore, after the long-term anaerobic treatment is completed, it is transported to the aerobic treatment equipment for treatment, which causes the aerobic treatment equipment to be idle for a long time, thereby greatly reducing the utilization rate of the entire sewage treatment equipment, and the sewage treatment efficiency is also low. It is impossible to achieve more efficient treatment by batch processing of sewage and coordinating the anaerobic treatment and aerobic treatment, and it is impossible to achieve the purpose of improving the sewage treatment efficiency by using anaerobic treatment and aerobic treatment intermittently.

[0009] (II) Technical solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions: a process for treating aquaculture wastewater, specifically comprising the following steps:

[0011] S1. Collection, filtration and treatment: The farm sewage is concentrated into the sewage collection pool, and then passed into the solid-liquid separation equipment, and the excrement is filtered out by the solid-liquid separation equipment. After separation, the excrement is concentrated and then aired or dried before being returned to the field for use;

[0012] S2, flotation treatment: the sewage separated in step S1 is passed into the first regulating tank, and after the water quantity and water quality are adjusted in the first regulating tank, it is passed into the flotation equipment for flotation treatment to remove suspended impurities and odor in the sewage;

[0013] S3, first aerobic treatment: the sewage after flotation treatment in step S2 is first introduced into the second regulating tank, and the water quantity and water quality are adjusted in the second regulating tank in the second aerobic treatment equipment, and the sewage to be treated is divided into two sewage of equal volume, and respectively introduced into the first aerobic treatment equipment and the second aerobic treatment equipment for aerobic treatment, and the aerobic microorganisms in the aerobic tanks of the first aerobic treatment equipment and the second aerobic treatment equipment are used for aerobic treatment to fully biodegrade the organic matter in the wastewater, and most of the organic matter in the wastewater is decomposed and removed by the biological activity of the microorganisms under the condition of oxygenation, and the cycle is set to 6-8h;

[0014] S4, anaerobic treatment: the sewage after aerobic treatment in step S3 is passed into the anaerobic reactor, one of the aerobic treatment equipments continues to pass new sewage to be aerobic treated from the second regulating tank, and the aerobic activated sludge in the other aerobic treatment equipment is replaced and the sewage to be treated is stopped, the anaerobic reactor is started, the reaction temperature is controlled to be 15-25°C, the organic load is 10-12kg / m·d, the hydraulic retention time of the hydrolysis and acidification stage is 8-11h, and the hydraulic retention time of the anaerobic reactor is 4-6 days. The anaerobic action of the anaerobic reactor removes most of the difficult-to-degrade organic matter, thereby improving the biodegradability of the sewage;

[0015] S5, second aerobic treatment: the sewage after the anaerobic treatment in step S4 is passed into the aerobic treatment equipment where the aerobic activated sludge is replaced and the sewage to be treated is stopped, so that the organic small molecules are rapidly oxidized, and the dissolved oxygen in the reactor is controlled at 2-3 mg / L water. After water intake, aeration, sedimentation and static operation, the operation cycle is set to 3-5 hours. At this time, the new sewage treated in step S4 is passed into the anaerobic reactor for circulation treatment;

[0016] S6, decolorization and disinfection treatment: the solution after the second aerobic treatment in step S5 is discharged to the photocatalytic sewage treatment equipment for sewage decolorization treatment, and then passed through the disinfection tank for ozone disinfection treatment, that is, it is reused or discharged after meeting the discharge standard conditions.

[0017] Preferably, the regulating tank in step S2 adopts one of in-line regulation or off-line regulation. In-line regulation is to use the incoming water relying on the wastewater's own gravity and the outgoing water being lifted by a pump. Off-line regulation is to place the regulating tank on a bypass. When the wastewater flow is too high, excess wastewater is pumped into the regulating tank. When the flow is lower than the design flow, it flows from the regulating tank to the collection well and is sent for subsequent treatment.

[0018] Preferably, the flotation treatment in step S3 specifically includes the following steps:

[0019] T1. Pass the sewage to be treated into the flotation tank, control the height of the sewage in the flotation tank to be 80-120 cm, then add flotation agent to the flotation tank at an amount of 0.5-1.3 g per liter, and then mix and stir for 5-10 minutes through a mixing device to fully mix the flotation agent and the sewage;

[0020] T2. During the mixing process in step T1, the heating component in the flotation tank is started to heat the sewage to 37-42°C, and then the temperature is kept constant. After the stirring is completed, the aeration structure in the flotation tank is started to introduce air into the sewage for flotation treatment for 2-4 hours, and the bubble diameter in the flotation tank is controlled to be 10-30μm, and the bubble rising speed is 10-20mm / s;

[0021] T3. The bubbles carry the suspended matter and odor in the sewage upwards. The odor is extracted by the vacuum pump for centralized treatment, while the suspended matter and grease floating on the liquid surface are scraped from the liquid surface into the collection box through the scooping structure for centralized collection.

[0022] Preferably, the flotation agent in step T1 is one of polyaluminium chloride coagulant, SP type demulsifier or AR type demulsifier.

[0023] Preferably, the method for the first aerobic treatment in step S3 specifically comprises the following steps:

[0024] E1. Start the aeration mechanism in the first aerobic treatment equipment and the second aerobic treatment equipment to aerate the sewage so that the sewage is fully in contact with the activated sludge at the bottom of the aerobic tank, thereby ensuring that the aerobic bacteria in the activated sludge can fully contact with the sewage. The organic load of this aerobic treatment is 1-8 kg / m·d;

[0025] E2, making the aeration hydraulic retention time of the aerobic treatment in step E1 greater than 4 hours, the sludge age greater than 1 day, and the sludge concentration 2-4 g / L;

[0026] E3. After the oxidation is completed, the effluent enters the electrolytic cell, and the disturbance structure is started to disturb the sewage in the electrolytic cell. The sewage is subjected to electrocoagulation treatment for 1-1.5 hours through the electrodes in the electrolytic cell, and then allowed to stand for 1-1.5 hours to remove colloidal particles and other suspended matter.

[0027] Preferably, in step E2, during the aeration process, banded bacterial flocs grow in suspension, with a geometric size of 1-2 cm and a sedimentation rate in water of at least 20 cm / min.

[0028] Preferably, in step E3, water is introduced into the bottom of the electrolytic cell body, and the aeration mechanism is turned on at the same time, the air-water volume flow ratio is 0.8:1-3:1, the operating voltage working range is 50-100V, and after the electric flocculation is completed, the sewage is allowed to flow out from the upper part of the electrolytic cell body.

[0029] Preferably, in step S3, control valves are provided in the connecting pipes between the second regulating tank and the first aerobic treatment equipment and the second aerobic treatment equipment respectively. By controlling the opening and closing of the two control valves, it is possible to control the sewage in the second regulating tank to flow into the first aerobic treatment equipment and the second aerobic treatment equipment normally or not.

[0030] Preferably, the biochemical reaction process of aerobic treatment in steps S3 and S5 is:

[0031] H2S+2O2→H2SO4+energy;

[0032] The biological nitrification reaction process is:

[0033] NH4 + +2O2→NO3 - +2H + +H2O+energy.

[0034] Preferably, the biochemical reaction process of aerobic decomposition in steps S3 and S5 is:

[0035] C6H 12 O6+6O2→6CO2+6H2O+2817.3KJ;

[0036] C 11 H 29 O7N+14O2+H + →11CO2+13H2O+NH4 + +Energy.

[0037] (III) Beneficial effects

[0038] The present invention provides a process for treating aquaculture wastewater. Compared with the prior art, it has the following beneficial effects:

[0039] (1) The aquaculture wastewater treatment process specifically includes the following steps: S1, collection and filtration treatment; S2, flotation treatment: the wastewater separated in step S1 is passed into a first regulating tank, and after the water volume and water quality are adjusted in the first regulating tank, it is passed into a flotation device for flotation treatment to remove suspended impurities and odors in the wastewater; S3, first aerobic treatment; S4, anaerobic treatment; S5, second aerobic treatment; S6, decolorization and disinfection treatment. The wastewater can be treated in batches and more efficiently treated by coordinating the anaerobic treatment and the aerobic treatment, which greatly improves the treatment efficiency and achieves the goal of achieving ... Aerobic treatment is used in conjunction with intermittent use to improve the sewage treatment efficiency, and solves the problem of long start-up time of anaerobic reactors due to the long generation period of anaerobic microorganisms, low growth rate and slow sludge growth. The present invention improves the utilization rate of each equipment in the entire sewage treatment process by using two aerobic treatment equipment and one anaerobic treatment equipment in good coordination and cooperation, avoiding the situation where the aerobic treatment equipment is idle for a long time after the long-term anaerobic treatment is completed and then transported to the aerobic treatment equipment for treatment, thereby greatly improving the sewage treatment efficiency, thereby greatly facilitating the efficient treatment of sewage.

[0040] (2) The aquaculture wastewater treatment process adopts the method of electric flocculation to carry out rapid flocculation treatment during aerobic treatment, replacing the existing drug flocculation method, which can greatly shorten the flocculation time and make the flocculation more thorough. The disturbance structure can make the wastewater in the electrolytic cell flow, so that the wastewater can fully contact the electrode, thereby greatly improving the flocculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a process flow chart of the present invention;

[0042] Figure 2 It is a process diagram of aquaculture wastewater treatment of the present invention;

[0043] Figure 3 This is a graph showing the relationship between the electrocoagulation time and the suspended matter content in an application example of the present invention. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] See also Figure 1-3The embodiment of the present invention provides three technical solutions: an aquaculture wastewater treatment process, specifically including the following embodiments:

[0046] Embodiment 1: A process for treating aquaculture wastewater, comprising the following steps:

[0047] S1. Collection, filtration and treatment: The farm sewage is concentrated into the sewage collection pool, and then passed into the solid-liquid separation equipment, and the excrement is filtered out by the solid-liquid separation equipment. After separation, the excrement is concentrated and then aired or dried before being returned to the field for use;

[0048] S2, flotation treatment: the sewage separated in step S1 is passed into the first regulating tank, and after the water quantity and water quality are adjusted in the first regulating tank, it is passed into the flotation equipment for flotation treatment to remove suspended impurities and odors in the sewage. The regulating tank adopts in-line regulation, which means that the inlet water relies on the wastewater's own gravity and the outlet water is lifted by a pump;

[0049] S3, first aerobic treatment: the sewage after flotation treatment in step S2 is first introduced into the second regulating tank, and the second aerobic treatment equipment is adjusted in water quantity and water quality through the second regulating tank, and the sewage to be treated is divided into two sewage of equal volume, respectively introduced into the first aerobic treatment equipment and the second aerobic treatment equipment for aerobic treatment, and aerobic treatment is performed by aerobic microorganisms in the aerobic tanks of the first aerobic treatment equipment and the second aerobic treatment equipment, and the organic matter in the wastewater is fully biodegraded. Under the condition of oxygenation, most of the organic matter in the wastewater is decomposed and removed by the biological activity of microorganisms. The cycle is set to 6-8h. The second regulating tank is respectively provided with a control valve in the connecting pipe between the first aerobic treatment equipment and the second aerobic treatment equipment. By controlling the opening and closing of the two control valves, it is possible to control the sewage in the second regulating tank to normally enter or not enter the first aerobic treatment equipment and the second aerobic treatment equipment;

[0050] S4, anaerobic treatment: the sewage after aerobic treatment in step S3 is passed into the anaerobic reactor, one of the aerobic treatment equipments continues to pass new sewage to be aerobic treated from the second regulating tank, and the aerobic activated sludge in the other aerobic treatment equipment is replaced and the sewage to be treated is stopped, the anaerobic reactor is started, the reaction temperature is controlled to be 20°C, the organic load is 11kg / m·d, the hydraulic retention time of the hydrolysis and acidification stage is 10h, and the hydraulic retention time of the anaerobic reactor is 5 days. Most of the refractory organic matter is removed by the anaerobic action of the anaerobic reactor, and the biodegradability of the sewage is improved;

[0051] S5, second aerobic treatment: the sewage after the anaerobic treatment in step S4 is passed into the aerobic treatment equipment where the aerobic activated sludge is replaced and the sewage to be treated is stopped, so that the organic small molecules are rapidly oxidized, and the dissolved oxygen in the reactor is controlled at 2.5 mg / L water. After water intake, aeration, sedimentation and static operation, the operation cycle is set to 4 hours. At this time, the new sewage treated in step S4 is passed into the anaerobic reactor for circulation treatment;

[0052] S6, decolorization and disinfection treatment: the solution after the second aerobic treatment in step S5 is discharged to the photocatalytic sewage treatment equipment for sewage decolorization treatment, and then passed through the disinfection tank for ozone disinfection treatment, that is, it is reused or discharged after meeting the discharge standard conditions.

[0053] The flotation treatment in step S3 of the embodiment of the present invention specifically includes the following steps:

[0054] T1. Pass the sewage to be treated into the flotation tank, control the height of the sewage in the flotation tank to be 100 cm, then add a flotation agent to the flotation tank, add the flotation agent at an amount of 0.9 g per liter, and then mix and stir for 8 minutes through a mixing device to fully mix the flotation agent and the sewage. The flotation agent is a polyaluminium chloride coagulant;

[0055] T2. During the mixing process in step T1, the heating component in the flotation tank is started to heat the sewage to 40°C, and then the temperature is kept constant. After the stirring is completed, the aeration structure in the flotation tank is started to introduce air into the sewage for flotation treatment for 3 hours. The bubble diameter in the flotation tank is controlled to be 20μm, and the bubble rising speed is 15mm / s;

[0056] T3. The bubbles carry the suspended matter and odor in the sewage upwards. The odor is extracted by the vacuum pump for centralized treatment, while the suspended matter and grease floating on the liquid surface are scraped from the liquid surface into the collection box through the scooping structure for centralized collection.

[0057] The method for the first aerobic treatment in step S3 of the embodiment of the present invention specifically includes the following steps:

[0058] E1. Start the aeration mechanism in the first aerobic treatment equipment and the second aerobic treatment equipment to aerate the sewage so that the sewage is fully in contact with the activated sludge at the bottom of the aerobic tank, thereby ensuring that the aerobic bacteria in the activated sludge can fully contact with the sewage. The organic load of this aerobic treatment is 5kg / m·d;

[0059] E2, the aeration hydraulic retention time of the aerobic treatment in step E1 is 5 hours, the sludge age is 2 days, the sludge concentration is 3g / L, and during the aeration process, there is suspended growth of ribbon-like bacterial flocs with a geometric size of 1.5cm and a sedimentation velocity in water of 30cm / min;

[0060] E3. After the oxidation is completed, the effluent enters the electrolytic cell, and the disturbance structure is started to disturb the sewage in the electrolytic cell. The electro-flocculation treatment is carried out through the electrodes in the electrolytic cell for 1.25 hours. The colloid particles and other suspended matter are removed after standing for 1.25 hours. Water is introduced into the bottom of the electrolytic cell, and the aeration mechanism is started at the same time. The air-water volume flow ratio is 1.6:1, and the operating voltage working range is 80V. After the electro-flocculation is completed, the sewage is allowed to flow out from the upper part of the electrolytic cell.

[0061] The biochemical reaction process of aerobic treatment in steps S3 and S5 of the embodiment of the present invention is:

[0062] H2S+2O2→H2SO4+energy;

[0063] The biological nitrification reaction process is:

[0064] NH4 + +2O2→NO3 - +2H + +H2O+energy.

[0065] The biochemical reaction process of aerobic decomposition metabolism in steps S3 and S5 of the embodiment of the present invention is:

[0066] C6H 12 O6+6O2→6CO2+6H2O+2817.3KJ

[0067] C 11 H 29 O7N+14O2+H + →11CO2+13H2O+NH4 + +Energy.

[0068] Embodiment 2: A process for treating aquaculture wastewater, comprising the following steps:

[0069] S1. Collection, filtration and treatment: The farm sewage is concentrated into the sewage collection pool, and then passed into the solid-liquid separation equipment, and the excrement is filtered out by the solid-liquid separation equipment. After separation, the excrement is concentrated and then aired or dried before being returned to the field for use;

[0070] S2, flotation treatment: the sewage separated in step S1 is passed into the first regulating tank, and after the water quantity and water quality are adjusted in the first regulating tank, it is passed into the flotation equipment for flotation treatment to remove suspended impurities and odors in the sewage. The regulating tank adopts off-line regulation. Specifically, the off-line regulation is to set the regulating tank on the bypass. When the wastewater flow is too high, the excess wastewater is pumped into the regulating tank. When the flow is lower than the design flow, it flows from the regulating tank to the water collection well and is sent for subsequent treatment;

[0071] S3, first aerobic treatment: the sewage after flotation treatment in step S2 is first introduced into the second regulating tank, and the second aerobic treatment equipment is adjusted in water quantity and water quality through the second regulating tank, and the sewage to be treated is divided into two sewage of equal volume, respectively introduced into the first aerobic treatment equipment and the second aerobic treatment equipment for aerobic treatment, and aerobic treatment is performed by aerobic microorganisms in the aerobic tanks of the first aerobic treatment equipment and the second aerobic treatment equipment, and the organic matter in the wastewater is fully biodegraded. Under the condition of oxygenation, most of the organic matter in the wastewater is decomposed and removed by the biological activity of microorganisms. The cycle is set to 6-8h. The second regulating tank is respectively provided with a control valve in the connecting pipe between the first aerobic treatment equipment and the second aerobic treatment equipment. By controlling the opening and closing of the two control valves, it is possible to control the sewage in the second regulating tank to normally enter or not enter the first aerobic treatment equipment and the second aerobic treatment equipment;

[0072] S4, anaerobic treatment: the sewage after aerobic treatment in step S3 is passed into the anaerobic reactor, one of the aerobic treatment equipments continues to pass new sewage to be aerobic treated from the second regulating tank, and the aerobic activated sludge in the other aerobic treatment equipment is replaced and the sewage to be treated is stopped, the anaerobic reactor is started, the reaction temperature is controlled to be 15°C, the organic load is 10kg / m·d, the hydraulic retention time of the hydrolysis and acidification stage is 8h, and the hydraulic retention time of the anaerobic reactor is 4 days. Most of the refractory organic matter is removed by the anaerobic action of the anaerobic reactor, and the biodegradability of the sewage is improved;

[0073] S5, second aerobic treatment: the sewage after the anaerobic treatment in step S4 is passed into the aerobic treatment equipment where the aerobic activated sludge is replaced and the sewage to be treated is stopped, so that the organic small molecules are rapidly oxidized, and the dissolved oxygen in the reactor is controlled at 2 mg / L water. After water intake, aeration, sedimentation and static operation, the operation cycle is set to 3 hours. At this time, the new sewage treated in step S4 is passed into the anaerobic reactor for circulation treatment;

[0074] S6, decolorization and disinfection treatment: the solution after the second aerobic treatment in step S5 is discharged to the photocatalytic sewage treatment equipment for sewage decolorization treatment, and then passed through the disinfection tank for ozone disinfection treatment, that is, it is reused or discharged after meeting the discharge standard conditions.

[0075] The flotation treatment in step S3 of the embodiment of the present invention specifically includes the following steps:

[0076] T1. Pass the sewage to be treated into the flotation tank, control the height of the sewage in the flotation tank to be 80 cm, then add a flotation agent to the flotation tank, add the flotation agent at an amount of 0.5 g per liter, and then mix and stir for 5 minutes through a mixing device to fully mix the flotation agent and the sewage. The flotation agent is an SP type demulsifier;

[0077] T2. During the mixing process in step T1, the heating component in the flotation tank is started to heat the sewage to 37°C, and then the temperature is kept constant. After the stirring is completed, the aeration structure in the flotation tank is started to introduce air into the sewage for flotation treatment for 2 hours. The bubble diameter in the flotation tank is controlled to be 10μm, and the bubble rising speed is 10mm / s;

[0078] T3. The bubbles carry the suspended matter and odor in the sewage upwards. The odor is extracted by the vacuum pump for centralized treatment, while the suspended matter and grease floating on the liquid surface are scraped from the liquid surface into the collection box through the scooping structure for centralized collection.

[0079] The method for the first aerobic treatment in step S3 of the embodiment of the present invention specifically includes the following steps:

[0080] E1. Start the aeration mechanism in the first aerobic treatment equipment and the second aerobic treatment equipment to aerate the sewage so that the sewage is fully in contact with the activated sludge at the bottom of the aerobic tank, thereby ensuring that the aerobic bacteria in the activated sludge can fully contact with the sewage. The organic load of this aerobic treatment is 1 kg / m·d;

[0081] E2, the aeration hydraulic retention time of the aerobic treatment in step E1 is 4 hours, the sludge age is 1 day, the sludge concentration is 2 g / L, and during the aeration process, there is suspended growth of ribbon-like bacterial flocs with a geometric size of 1 cm and a sedimentation rate in water of 20 cm / min;

[0082] E3. After the oxidation is completed, the effluent enters the electrolytic cell, and the disturbance structure is started to disturb the sewage in the electrolytic cell. The electro-flocculation treatment is carried out through the electrodes in the electrolytic cell for 1 hour. The colloid particles and other suspended matter are removed after standing for 1 hour. Water is introduced into the bottom of the electrolytic cell, and the aeration mechanism is started at the same time. The air-water volume flow ratio is 0.8:1, and the operating voltage working range is 50V. After the electro-flocculation is completed, the sewage is allowed to flow out from the upper part of the electrolytic cell.

[0083] The biochemical reaction process of aerobic treatment in steps S3 and S5 of the embodiment of the present invention is:

[0084] H2S+2O2→H2SO4+energy;

[0085] The biological nitrification reaction process is:

[0086] NH4 + +2O2→NO3 - +2H + +H2O+energy.

[0087] The biochemical reaction process of aerobic decomposition in steps S3 and S5 of the embodiment of the present invention is:

[0088] C6H 12O6+6O2→6CO2+6H2O+2817.3KJ

[0089] C 11 H 29 O7N+14O2+H + →11CO2+13H2O+NH4 + +Energy.

[0090] Embodiment 3: A process for treating aquaculture wastewater, comprising the following steps:

[0091] S1. Collection, filtration and treatment: The farm sewage is concentrated into the sewage collection pool, and then passed into the solid-liquid separation equipment, and the excrement is filtered out by the solid-liquid separation equipment. After separation, the excrement is concentrated and then aired or dried before being returned to the field for use;

[0092] S2, flotation treatment: the sewage separated in step S1 is passed into the first regulating tank, and after the water quantity and water quality are adjusted in the first regulating tank, it is passed into the flotation equipment for flotation treatment to remove suspended impurities and odors in the sewage. The regulating tank adopts in-line regulation, which means that the inlet water relies on the wastewater's own gravity and the outlet water is lifted by a pump;

[0093] S3, first aerobic treatment: the sewage after flotation treatment in step S2 is first introduced into the second regulating tank, and the second aerobic treatment equipment is adjusted in water quantity and water quality through the second regulating tank, and the sewage to be treated is divided into two sewage of equal volume, respectively introduced into the first aerobic treatment equipment and the second aerobic treatment equipment for aerobic treatment, and aerobic treatment is performed by aerobic microorganisms in the aerobic tanks of the first aerobic treatment equipment and the second aerobic treatment equipment, and the organic matter in the wastewater is fully biodegraded. Under the condition of oxygenation, most of the organic matter in the wastewater is decomposed and removed by the biological activity of microorganisms. The cycle is set to 6-8h. The second regulating tank is respectively provided with a control valve in the connecting pipe between the first aerobic treatment equipment and the second aerobic treatment equipment. By controlling the opening and closing of the two control valves, it is possible to control the sewage in the second regulating tank to normally enter or not enter the first aerobic treatment equipment and the second aerobic treatment equipment;

[0094] S4, anaerobic treatment: the sewage after aerobic treatment in step S3 is passed into the anaerobic reactor, one of the aerobic treatment equipments continues to pass new sewage to be aerobic treated from the second regulating tank, and the aerobic activated sludge in the other aerobic treatment equipment is replaced and the sewage to be treated is stopped, the anaerobic reactor is started, the reaction temperature is controlled to be 25°C, the organic load is 12kg / m·d, the hydraulic retention time of the hydrolysis and acidification stage is 11h, and the hydraulic retention time of the anaerobic reactor is 6 days. Most of the refractory organic matter is removed by the anaerobic action of the anaerobic reactor, and the biodegradability of the sewage is improved;

[0095] S5, second aerobic treatment: the sewage after the anaerobic treatment in step S4 is passed into the aerobic treatment equipment where the aerobic activated sludge is replaced and the sewage to be treated is stopped, so that the organic small molecules are rapidly oxidized, and the dissolved oxygen in the reactor is controlled at 3 mg / L water. After water intake, aeration, sedimentation and static operation, the operation cycle is set to 5 hours. At this time, the new sewage treated in step S4 is passed into the anaerobic reactor for circulation treatment;

[0096] S6, decolorization and disinfection treatment: the solution after the second aerobic treatment in step S5 is discharged to the photocatalytic sewage treatment equipment for sewage decolorization treatment, and then passed through the disinfection tank for ozone disinfection treatment, that is, it is reused or discharged after meeting the discharge standard conditions.

[0097] The flotation treatment in step S3 of the embodiment of the present invention specifically includes the following steps:

[0098] T1. Pass the sewage to be treated into the flotation tank, control the height of the sewage in the flotation tank to be 120 cm, then add a flotation agent to the flotation tank at an amount of 1.3 g per liter, and then mix and stir for 10 minutes through a mixing device to fully mix the flotation agent and the sewage. The flotation agent is an AR type demulsifier;

[0099] T2. During the mixing process in step T1, the heating component in the flotation tank is started to heat the sewage to 42°C, and then the temperature is kept constant. After the stirring is completed, the aeration structure in the flotation tank is started to introduce air into the sewage for flotation treatment for 4 hours. The bubble diameter in the flotation tank is controlled to be 30μm, and the bubble rising speed is 20mm / s;

[0100] T3. The bubbles carry the suspended matter and odor in the sewage upwards. The odor is extracted by the vacuum pump for centralized treatment, while the suspended matter and grease floating on the liquid surface are scraped from the liquid surface into the collection box through the scooping structure for centralized collection.

[0101] The method for the first aerobic treatment in step S3 of the embodiment of the present invention specifically includes the following steps:

[0102] E1. Start the aeration mechanism in the first aerobic treatment equipment and the second aerobic treatment equipment to aerate the sewage so that the sewage is fully in contact with the activated sludge at the bottom of the aerobic tank, thereby ensuring that the aerobic bacteria in the activated sludge can fully contact with the sewage. The organic load of this aerobic treatment is 8kg / m·d;

[0103] E2, the aeration hydraulic retention time of the aerobic treatment in step E1 is 6 hours, the sludge age is 3 days, the sludge concentration is 4g / L, and during the aeration process, there is suspended growth of ribbon-like bacterial flocs with a geometric size of 2cm and a sedimentation velocity in water of 40cm / min;

[0104] E3. After the oxidation is completed, the effluent enters the electrolytic cell, and the disturbance structure is started to disturb the sewage in the electrolytic cell. The electro-flocculation treatment is carried out through the electrodes in the electrolytic cell for 1.5 hours. The colloid particles and other suspended matter are removed after standing for 1.5 hours. Water is introduced into the bottom of the electrolytic cell, and the aeration mechanism is started at the same time. The air-water volume flow ratio is 3:1, and the operating voltage working range is 100V. After the electro-flocculation is completed, the sewage is allowed to flow out from the upper part of the electrolytic cell.

[0105] The biochemical reaction process of aerobic treatment in steps S3 and S5 of the embodiment of the present invention is:

[0106] H2S+2O2→H2SO4+energy;

[0107] The biological nitrification reaction process is:

[0108] NH4 + +2O2→NO3 - +2H + +H2O+energy.

[0109] The biochemical reaction process of aerobic decomposition in steps S3 and S5 of the embodiment of the present invention is:

[0110] C6H 12 O6+6O2→6CO2+6H2O+2817.3KJ

[0111] C 11 H 29 O7N+14O2+H + →11CO2+13H2O+NH4 + +Energy.

[0112] In the embodiment of the present invention, the task of water quality regulation is to mix wastewater from different times or different sources to make the outflow water quality more uniform. The regulating tank is also called a homogenizing tank or a homogenizing tank. Water quality regulation uses the differential flow method to make wastewater from different times and different concentrations self-hydraulic mixing.

[0113] Application example: Taking a specific breeding farm as an example, the average daily sewage discharge of the breeding farm is 120.5-168.1m 3, centralized and uninterrupted sewage treatment is required to meet the standards before it can be discharged. The farm previously used the existing aquaculture sewage treatment process of centralized anaerobic treatment followed by aerobic treatment for treatment. The specific treatment cycle is shown in Table 1. Due to the low treatment efficiency, it cannot meet the daily discharge demand. It is necessary to build a larger sewage pre-storage tank for centralized storage first, and then slowly treat it after the previous treatment cycle. If the farm conducts large-scale breeding, it is necessary to build another set of sewage treatment process lines to meet the demand, which greatly increases the cost. Therefore, the farm develops an efficient aquaculture sewage treatment process. According to the aquaculture sewage treatment process of the present invention, another set of sewage treatment lines is constructed in the farm. Three experiments are carried out according to the treatment steps and parameters of Examples 1-3 of the present invention, and the specific time period used to reach the same discharge standard is statistically analyzed. The specific experimental data are shown in Table 1.

[0114] Table 1 Application example data table

[0115]

[0116] It can be seen from Table 1 that the aerobic treatment time within a treatment cycle, the anaerobic treatment time within a treatment cycle, and the total time of a treatment cycle in the sewage treatment processes of Examples 1-3 of the present invention are all significantly shorter than those of the existing sewage treatment processes. Therefore, the sewage treatment process of the present invention greatly shortens the treatment cycle compared to the existing sewage treatment process.

[0117] At the same time, the changes of suspended matter content in sewage in the aerobic treatment steps of Examples 1-3 of the present invention with the time of electro-flocculation were detected, counted and analyzed, and compared with the changes of suspended matter content in sewage in the flocculation process using the existing flocculant. The specific detection data are as follows: Figure 3 As shown, through Figure 3 It can be seen that the speed of treating suspended solids in sewage by the electro-flocculation methods of Examples 1-3 of the present invention is faster and more complete than that of removing suspended solids by existing flocculants, and the electro-flocculation treatment effect of Example 1 of the present invention is the best.

[0118] The effluent from sewage treatment in this application example should comply with the relevant provisions of the current national standard "Pollutant Discharge Standard for Urban Sewage Treatment Plants" (GB18918-2002).

[0119] In summary, the present invention can achieve more efficient treatment by batch processing of sewage and by coordinating anaerobic treatment and aerobic treatment, which greatly improves the treatment efficiency, and well achieves the purpose of improving sewage treatment efficiency by using anaerobic treatment and aerobic treatment intermittently, and solves the problem that the start-up time of anaerobic reactor is long due to the long generation period of anaerobic microorganisms, low growth rate and slow sludge growth. The present invention improves the utilization rate of each equipment in the entire sewage treatment process by using two aerobic treatment equipment and one anaerobic treatment equipment for good coordination and use, and avoids the situation that the aerobic treatment equipment is idle for a long time after the long anaerobic treatment is completed and then transported to the aerobic treatment equipment for treatment, thereby greatly improving the sewage treatment efficiency, thereby greatly facilitating the efficient treatment of sewage, and at the same time, by using the electric flocculation method to perform rapid flocculation treatment in the aerobic treatment process, replacing the existing drug flocculation means, it can achieve greatly shortened flocculation time, more thorough flocculation, and can make the sewage in the electrolytic cell flow by coordinating the disturbance structure, so that the sewage can fully contact with the electrode, thereby greatly improving the flocculation efficiency.

[0120] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0121] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0122] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for treating aquaculture wastewater, characterized in that: The specific steps include: S1. Collection, filtration and treatment: The farm sewage is concentrated into the sewage collection pool, and then passed into the solid-liquid separation equipment, and the excrement is filtered out by the solid-liquid separation equipment. After separation, the excrement is concentrated and then aired or dried before being returned to the field for use; S2, flotation treatment: the sewage separated in step S1 is passed into the first regulating tank, and after the water quantity and water quality are adjusted in the first regulating tank, it is passed into the flotation equipment for flotation treatment to remove suspended impurities and odor in the sewage; S3, first aerobic treatment: the sewage after flotation treatment in step S2 is first introduced into the second regulating tank, and the water quantity and water quality are adjusted in the second regulating tank in the second aerobic treatment equipment, and the sewage to be treated is divided into two sewage of equal volume, and respectively introduced into the first aerobic treatment equipment and the second aerobic treatment equipment for aerobic treatment, and the aerobic microorganisms in the aerobic tanks of the first aerobic treatment equipment and the second aerobic treatment equipment are used for aerobic treatment to fully biodegrade the organic matter in the wastewater, and most of the organic matter in the wastewater is decomposed and removed by the biological activity of the microorganisms under the condition of oxygenation, and the cycle is set to 6-8h; S4, anaerobic treatment: the sewage after aerobic treatment in step S3 is passed into the anaerobic reactor, one of the aerobic treatment equipments continues to pass new sewage to be aerobic treated from the second regulating tank, and the aerobic activated sludge in the other aerobic treatment equipment is replaced and the sewage to be treated is stopped, the anaerobic reactor is started, the reaction temperature is controlled to be 15-25°C, the organic load is 10-12kg / m·d, the hydraulic retention time of the hydrolysis and acidification stage is 8-11h, and the hydraulic retention time of the anaerobic reactor is 4-6 days, and most of the difficult-to-degrade organic matter is removed by the anaerobic action of the anaerobic reactor; S5, second aerobic treatment: the sewage after the anaerobic treatment in step S4 is passed into the aerobic treatment equipment where the aerobic activated sludge is replaced and the sewage to be treated is stopped, so that the organic small molecules are rapidly oxidized, and the dissolved oxygen in the reactor is controlled at 2-3 mg / L water. After water intake, aeration, sedimentation and static operation, the operation cycle is set to 3-5 hours. At this time, the new sewage treated in step S4 is passed into the anaerobic reactor for circulation treatment; S6, decolorization and disinfection treatment: the solution after the second aerobic treatment in step S5 is discharged to the photocatalytic sewage treatment equipment for sewage decolorization treatment, and then passed through the disinfection tank for ozone disinfection treatment, that is, it is reused or discharged after meeting the discharge standard conditions.

2. The aquaculture wastewater treatment process according to claim 1, characterized in that: In step S2, the regulating tank adopts one of in-line regulation or out-line regulation.

3. The aquaculture wastewater treatment process according to claim 1, characterized in that: The flotation treatment in step S3 specifically includes the following steps: T1. Pass the sewage to be treated into the flotation tank, control the height of the sewage in the flotation tank to be 80-120 cm, then add flotation agent to the flotation tank at an amount of 0.5-1.3 g per liter, and then mix and stir for 5-10 minutes through a mixing device to fully mix the flotation agent and the sewage; T2. During the mixing process in step T1, the heating component in the flotation tank is started to heat the sewage to 37-42°C, and then the temperature is kept constant. After the stirring is completed, the aeration structure in the flotation tank is started to introduce air into the sewage for flotation treatment for 2-4 hours, and the bubble diameter in the flotation tank is controlled to be 10-30μm, and the bubble rising speed is 10-20mm / s; T3. The bubbles carry the suspended matter and odor in the sewage upwards. The odor is extracted by the vacuum pump for centralized treatment, while the suspended matter and grease floating on the liquid surface are scraped from the liquid surface into the collection box through the scooping structure for centralized collection.

4. The aquaculture wastewater treatment process according to claim 3, characterized in that: In the step T1, the flotation agent is one of polyaluminium chloride coagulant, SP type demulsifier or AR type demulsifier.

5. The aquaculture wastewater treatment process according to claim 1, characterized in that: The method for the first aerobic treatment in step S3 specifically comprises the following steps: E1. Start the aeration mechanism in the first aerobic treatment equipment and the second aerobic treatment equipment to aerate the sewage so that the sewage is fully in contact with the activated sludge at the bottom of the aerobic tank, thereby ensuring that the aerobic bacteria in the activated sludge can fully contact with the sewage. The organic load of this aerobic treatment is 1-8 kg / m·d; E2, making the aeration hydraulic retention time of the aerobic treatment in step E1 greater than 4 hours, the sludge age greater than 1 day, and the sludge concentration 2-4 g / L; E3. After the oxidation is completed, the effluent enters the electrolytic cell, and the disturbance structure is started to disturb the sewage in the electrolytic cell. The sewage is subjected to electrocoagulation treatment for 1-1.5 hours through the electrodes in the electrolytic cell, and then allowed to stand for 1-1.5 hours to remove colloidal particles and other suspended matter.

6. The aquaculture wastewater treatment process according to claim 5, characterized in that: In the step E2, during the aeration process, banded bacterial flocs grow in suspension, with a geometric size of 1-2 cm and a sedimentation rate in water of at least 20 cm / min.

7. The aquaculture wastewater treatment process according to claim 5, characterized in that: In step E3, water is introduced into the bottom of the electrolytic cell body, and the aeration mechanism is turned on at the same time. The air-water volume flow ratio is 0.8:1-3:1, and the operating voltage working range is 50-100V. After the electric flocculation is completed, the sewage is made to flow out from the upper part of the electrolytic cell body.

8. The aquaculture wastewater treatment process according to claim 1, characterized in that: In step S3, control valves are provided in the connecting pipes between the second regulating tank and the first aerobic treatment equipment and the second aerobic treatment equipment respectively. By controlling the opening and closing of the two control valves, it is possible to control the sewage in the second regulating tank to flow into the first aerobic treatment equipment and the second aerobic treatment equipment normally or not.

9. The aquaculture wastewater treatment process according to claim 1, characterized in that: The biochemical reaction process of aerobic treatment in steps S3 and S5 is: H2S+2O2→H2SO4+energy; The biological nitrification reaction process is: NH4 + +2O2→NO3 - +2H + +H2O+energy.

10. The aquaculture wastewater treatment process according to claim 1, characterized in that: The biochemical reaction process of aerobic decomposition in steps S3 and S5 is: <h2 style=";text-align:left;direction:ltr">C6H<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> O6+6O2→6CO2+6H2O+2817.3KJ; C 11 H 29 O7N+14O2+H + →11CO2+13H2O+NH4 + +Energy.

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