Sewage treatment device of denitrification biochemical carbon source

Abstract

The utility model belongs to the technical field of sewage treatment, and particularly relates to a sewage treatment device of a denitrification biochemical carbon source. Comprising a bioreactor which is connected with a secondary solid-liquid separator through a primary solid-liquid separator; the sewage treatment device further comprises a grillage machine, the grillage machine is connected with an adjusting tank through a primary sedimentation tank, the adjusting tank is connected with an aerobic tank through a sewage system, and the aerobic tank is connected with a disinfection tank through a separation system; kitchen waste / kitchen waste organic slurry enters a bioreactor, and municipal sewage enters a grillage machine; the secondary solid-liquid separator is also connected with a sewage system; the sewage system comprises an anaerobic tank and an anoxic tank; the separation system comprises at least one of a secondary sedimentation tank, a flocculation filter tank, a tubular ultrafiltration membrane and a hollow fiber membrane; the first-stage solid-liquid separator and the second-stage solid-liquid separator are used for solid-liquid separation of sewage. Sewage resources can be fully utilized, the cost is reduced, and the sewage treatment effect is good.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewage treatment, and in particular relates to a sewage treatment device for denitrification biochemical carbon source. Background Art

[0002] With the sustained and rapid development of my country's economy, the people's living standards are improving, the construction of new rural areas is increasing year by year, the urbanization transformation has been generally completed, more and more new rural and urban sewage is effectively collected, and the annual total sewage volume is increasing year by year. The existing domestic sewage treatment process is mainly based on low-cost biochemical treatment technology (see Table 1 below), but the imbalance of carbon-nitrogen ratio and insufficient carbon source in the sewage treatment process have led to the prominent contradiction of poor operation stability and high operation cost of the sewage system. At present, the mainstream process of sewage biochemical denitrification is biological denitrification. Ammonia nitrogen is converted into nitrate nitrogen by nitrifying bacteria, and then the nitrate nitrogen is converted into nitrogen gas by denitrifying bacteria, thereby realizing the removal of ammonia nitrogen in sewage. In an anaerobic environment, heterotrophic denitrifying bacteria use carbon sources (such as carbohydrates, alcohols, and organic acids) in sewage as electron donors to convert nitrite (NO2 - ) and nitrate (NO3 - ) acts as an electron acceptor to complete respiration to achieve the removal of ammonia nitrogen in sewage.

[0003] Table 1 Top 10 sewage treatment processes and their proportions

[0004]

[0005] At present, the water quality data analysis of the urban sewage treatment system of the Ministry of Housing and Urban-Rural Development shows that the BOD5 / TN ratio of the influent of about 70% of urban sewage treatment plants in my country is less than 4. According to the "Outdoor Drainage Design Code" (GB 50014-2016), the carbon-nitrogen ratio of sewage for biological denitrification is BOD5 / TKN>4. In order to achieve stable total nitrogen in the effluent, an external carbon source is required to increase the BOD5 / TKN ratio to 4 or even above 5. The conventional carbon sources (such as sodium acetate, glucose, and methanol) on the market are mainly derived from petrochemical enterprises and are relatively expensive. Therefore, the development of a new type of green biochemical carbon source with high efficiency and low cost will be a future trend.

[0006] After the organic slurry of the kitchen waste / restaurant waste treatment plant with a processing capacity of 5-100 tons / day undergoes anaerobic fermentation, the biogas slurry is discharged through the sewage treatment system in compliance with the standards. The biogas output of anaerobic fermentation is small, the methane content is low, the cost of configuring the generator set is high, and it is difficult to connect to the power grid. Most of them are treated by torch incineration. The biogas slurry treatment system requires large investment, high operating costs, and high energy consumption. Due to the above factors, it is difficult for small and medium-sized kitchen waste / restaurant waste treatment plants to achieve a break-even point, and many companies face the risk of suspension of operation.

[0007] The present application prepares biochemical carbon source from organic slurry of kitchen waste / restaurant garbage, and applies the biochemical carbon source to the municipal sewage treatment system, thereby promoting the development of kitchen waste / restaurant garbage treatment plants and reducing the operating costs of municipal sewage. The discharged sludge can be used for aerobic fermentation and composting, and the fertilizer can be used for garden cultivation or desert solidification, thus achieving waste treatment with waste and waste resource utilization. Utility Model Content

[0008] The utility model aims to provide a sewage treatment device with a denitrification biochemical carbon source, which can fully utilize sewage resources, reduce costs, and has a good sewage treatment effect.

[0009] In order to achieve the above purpose and other related purposes, the utility model provides the following technical solutions:

[0010] A wastewater treatment device for denitrification biochemical carbon source, comprising a bioreactor, wherein the bioreactor is connected to a secondary solid-liquid separator via a primary solid-liquid separator;

[0011] The sewage treatment device also includes a screen machine, the screen machine is connected to the regulating tank through the primary sedimentation tank, the regulating tank is connected to the aerobic tank through the sewage system, and the aerobic tank is connected to the disinfection tank through the separation system;

[0012] Among them, the organic slurry of kitchen waste / restaurant garbage enters the bioreactor, and the municipal sewage enters the screen machine; the secondary solid-liquid separator is also connected to the sewage system, and the sewage system includes an anaerobic tank and an anoxic tank; the separation system includes at least one of a secondary sedimentation tank, a flocculation filter, a tubular ultrafiltration membrane, and a hollow fiber membrane; the primary solid-liquid separator and the secondary solid-liquid separator are used for solid-liquid separation of sewage.

[0013] In one embodiment of the present invention, the secondary solid-liquid separator is further connected to a desludging system, and the desludging system includes a horizontal centrifuge.

[0014] In one embodiment of the utility model, the secondary solid-liquid separator is connected to the horizontal centrifuge via a separator sludge pump, the horizontal centrifuge is also connected to a sludge transport device, and the disinfection tank is an ultraviolet disinfection tank.

[0015] In one embodiment of the utility model, municipal sludge and the kitchen waste / restaurant garbage organic slurry both enter the bioreactor through a kitchen waste / restaurant garbage slurry feed pump; the bioreactor is connected to the primary solid-liquid separator through a carbon source reactor discharge pump; the municipal sewage enters the screen machine through a sewage feed pump, and the screen machine is connected to the sewage system through a regulating tank lift pump; the sewage system is connected to the separation system through a secondary sedimentation tank feed pump, and the separation system is connected to the disinfection tank through a filter tank outlet pump, and the disinfection tank discharges qualified clean water through a clean water pump.

[0016] In one embodiment of the utility model, the bioreactor includes a stirrer, which is a central stirrer; the bioreactor also includes an alkali addition tube and an enhancer addition tube, the alkali solution enters the bioreactor through the alkali addition tube, and the enhancer enters the bioreactor through the enhancer addition tube.

[0017] In one embodiment of the utility model, the alkali solution contains at least one of sodium carbonate, sodium bicarbonate, sodium hydroxide solution, and potassium hydroxide, the strengthener is magnetic powder, the particle size of the magnetic powder is 300~900 mesh, and the added amount of the strengthener is 2~3% of the feed amount of the kitchen waste / food waste organic slurry.

[0018] In one embodiment of the utility model, the online detection instrument includes a probe placed inside the bioreactor, and the probe is used to detect dissolved oxygen and pH in the bioreactor; the bioreactor also includes a microporous aeration tube connected to a blower; the bioreactor can directional fermentation and biochemically treat carbon sources;

[0019] The dissolved oxygen in the bioreactor is maintained at 0.3-1.0 mg / L, and the pH in the bioreactor is maintained at 5.8-6.5; the temperature of the kitchen waste / food garbage organic slurry in the bioreactor is controlled at 52-55° C., and the concentration of the suspended matter remaining after the reaction in the bioreactor is controlled at 16-20 g / L; a biochemical carbon source can also be added to the sewage system, and the ratio of the biochemical carbon source addition amount to the sewage treatment amount is 600-800:1.

[0020] In one embodiment of the utility model, the first-stage solid-liquid separator includes a screen or grid with a pore size of 0.55~1.0mm, the second-stage solid-liquid separator includes an inclined plate with an inclination angle of 65~80 degrees and a sludge hopper; the primary sedimentation tank includes a grit hopper.

[0021] In one embodiment of the present invention, the aerobic tank includes an aeration pipe, and the aeration pipe is connected to an aeration fan.

[0022] In one embodiment of the utility model, the sewage treatment device also includes a reflux system, the reflux system includes a nitrification liquid reflux pipe, a sludge reflux pipe, and a sludge discharge pipe. The secondary sedimentation tank feed pump is connected to the anoxic tank through the nitrification liquid reflux pipe, the secondary sedimentation tank sludge pump is connected to the anaerobic tank through the sludge reflux pipe, and the secondary sedimentation tank is connected to the desludging system through the sludge discharge pipe; the desludging system is also connected to the primary sedimentation tank; the reflux of the secondary sedimentation tank includes sludge reflux and nitrification liquid reflux, the sludge reflux flow rate is 20%~50% of the inlet flow rate, and the nitrification liquid reflux flow rate is 100%~400% of the inlet flow rate.

[0023] The beneficial effects of the utility model are:

[0024] This application can solve multiple technical problems, specifically:

[0025] (1) Question 1: In order to achieve the total nitrogen standard in municipal sewage, the addition of carbon sources leads to high operating costs.

[0026] The C / N ratio of existing urban sewage is lower than 4. In order to achieve the standard of total nitrogen in effluent, a large amount of industrial carbon source needs to be added to increase the C / N ratio by 6~8, resulting in high sewage operation costs. The present application achieves the standard of total nitrogen in effluent by adding a biochemical carbon source prepared by organic slurry of kitchen waste / restaurant garbage. Organic slurry is a low-value, high-concentration wastewater. After aerobic biochemical fermentation, the high-concentration complex organic matter is converted into small-molecule organic matter. Small-molecule organic matter can be absorbed and utilized by aerobic microorganisms, and aerobic microorganisms use their energy to remove and degrade other pollutants. The prepared biochemical carbon source raw material is inexpensive, the preparation process is simple, the investment cost is low, the land occupation is small, and the operation cost of the biochemical carbon source preparation process is low, so the operation cost of municipal sewage can be reduced.

[0027] (2) Problem 2: The investment and operating costs of small-scale restaurant kitchen waste slurry treatment are high.

[0028] After the existing small-scale restaurant kitchen / kitchen waste organic slurry is pre-treated to extract oil, the biogas slurry adopts the "hydrolysis + anaerobic digestion + biogas residue dehydration + flotation machine + secondary A / O system + ultrafiltration + nanofiltration + desludging sewage" process to achieve effluent discharge standards. Due to the small processing volume and the small total amount of biogas produced by the anaerobic system, it is not suitable for biogas power generation technology, and the biogas is burned in the torch. The organic slurry treatment process is long, the investment and construction cost is high, the operating cost is high, the whole project has low benefits, and it is difficult to achieve a profit and loss balance.

[0029] In this application, the organic slurry of kitchen waste / restaurant garbage is subjected to aerobic biochemical fermentation + secondary solid-liquid separation, the biochemical carbon source is used for sewage denitrification, and the separated carbon source sludge is used as an inoculant and conditioner for the preparation of aerobic compost for municipal sludge. The treatment process is short, the investment cost is low, the operating cost is low, and the product has high added value.

[0030] (3) Question 3: The hydrolysis and fermentation of organic slurry of kitchen waste / restaurant garbage produces low organic acid content, low SCOD content, and poor sludge sedimentation effect.

[0031] The organic slurry contains a large amount of complex macromolecular organic matter. After hydrolysis and fermentation, a large amount of CO2 and volatile organic acids (VFA) will be produced, which will increase the acid value of the mixed solution. When the system pH value is lower than 5, it is not conducive to the acid protease degradation bacteria to produce ammonia nitrogen by protein degradation, which will lead to insufficient alkali production in the system. The most suitable pH value for acid protease degradation bacteria is between 5.5 and 6.5, and the most suitable pH value for other acid-producing fermentation bacteria is 5.5 to 7.0. In a conventional fermentation system, the concentration of volatile organic acids is between 6000 and 10000 mg / L.

[0032] To further increase the concentration of organic acids produced in the system, increase soluble COD, and increase the dissolution rate of particulate matter. This application aerates the system to maintain a micro-oxygen environment, form an aerobic fermentation environment, blow off CO2 in the sewage, and promote the conversion of organic matter into VFA. Through the automatic alkali addition system, the pH value in the system is maintained at 5.5~7.0, and the acid-producing fermentation bacteria are maintained in the optimal pH range. By controlling the temperature in the reaction at 52~55℃, the SCOD concentration value will be increased by 10%~20%; to further improve the conversion of organic matter, by adding magnetic powder, the transfer of electrons in the hydrolysis process is promoted, and the dissolution rate of particulate matter is promoted. In order to increase the residence time of granular sludge, the sludge from the secondary solid-liquid separator is returned to the system, and the residence time of the carbon source sludge is increased from 5~7 days to 25~35d. After deep directional aerobic fermentation, the sludge has good sedimentation performance.

[0033] (4) Question 4: After conventional aerobic fermentation (stirring and natural fermentation in a fermentation tank), the mixed liquid of kitchen waste / restaurant garbage has a high suspended concentration and low organic acid. The discharge material also needs to be added with coagulants and flocculants, and horizontal centrifugal solid-liquid separation. The operating cost of solid-liquid separation is high, and it will also introduce problems such as flocculants.

[0034] The deep directional fermentation adopted in this application produces high organic acid and good sludge precipitation effect. 99% of the suspended solids not less than the filter aperture are removed by the first-stage solid-liquid separation, and the filtrate passes through the second-stage solid-liquid device to remove sediments and floating materials, and the clean water is directly used in the municipal sewage denitrification system. The equipment of the two-stage filtration occupies a small area, has an installed power of 4~6kw, low operating power consumption, and no need to add chemicals. The first-stage solid-liquid separator includes a screen or grid with an aperture of 0.55~1.0mm, and the clear liquid can be filtered by the second-stage solid-liquid separator for automatic flushing. The second-stage solid-liquid separator includes an inclined plate and a sludge hopper with an inclination angle of 65~80 degrees, and adopts an upper row of suspended solids, an inclined plate sedimentation plate in the middle, and a scraper plate at the bottom. The advantages of the large specific gravity of the suspended solids in the mixed liquid and the good precipitation effect are used to perform solid-liquid separation. Finally, the effluent SS is 500~1000mg / L.

[0035] (5) Question 5: When the organic slurry of kitchen waste / restaurant garbage is directly applied to the sewage treatment system, the sludge settling performance of the sewage biochemical system will be affected and the effluent COD will exceed the standard.

[0036] The SCOD content of kitchen waste / restaurant garbage organic slurry is between 50,000 and 80,000 mg / L, of which the concentration of volatile straight fatty acids is between 3,000 and 6,000 mg / L, so the proportion of organic matter that is easily degradable by microorganisms is 5% to 10%. If the above organic slurry is directly applied to the sewage treatment process, the sewage biochemical system will have a high utilization rate of easily degradable organic matter, and other slowly degradable and difficultly degradable organic matter will remain in the sewage system, resulting in excessive effluent COD.

[0037] In this application, the SCOD content of the organic slurry of kitchen waste / restaurant garbage is between 60,000 and 90,000 mg / L, of which the concentration of volatile straight fatty acids is between 28,000 and 31,000 mg / L, and the proportion of organic acids is more than 5 times higher than that of the denitrification stage of municipal sewage by adding biochemical carbon sources with directional deep fermentation, so as to achieve effluent standards.

[0038] In summary, this application prepares biochemical carbon source from organic slurry of kitchen waste / restaurant garbage, and applies the biochemical carbon source to the municipal sewage treatment system, which drives the development of kitchen waste / restaurant garbage treatment plants and reduces the operating costs of municipal sewage. The discharged sludge can be used for aerobic fermentation and composting, and the fertilizer can be used for garden cultivation or desert solidification, thus achieving waste treatment and waste resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0041] Figure 2 It is a process flow diagram of the utility model;

[0042] The following are marked in the figure: 101. Food waste / kitchen waste slurry feed pump; 102. Bioreactor; 103. Alkali adding pipe; 104. Enhancer adding pipe; 105. Central agitator; 106. Online detection instrument; 107. Blower; 108. Carbon source reactor discharge pump; 109. Primary solid-liquid separator; 110. Secondary solid-liquid separator; 111. Separator mud pump; 112. Horizontal centrifuge; 201. Sewage feed pump; 202. Screen machine; 203. Primary sedimentation tank; 204. Regulating tank; 205. Regulating tank lifting pump; 206. Anaerobic tank; 207. Anoxic tank; 208. 8. Aerobic tank; 209. Aeration pipe; 210. Aeration fan; 211. Second sedimentation tank feed pump; 212. Second sedimentation tank; 213. Second sedimentation tank sludge pump; 214. Flocculation filter; 215. Filter outlet pump; 216. Ultraviolet disinfection tank; 217. Clean water pump; 218. Primary sedimentation tank sludge pump; 301. Biochemical carbon source addition pipe; 302. Primary sedimentation tank sludge pipe; 303. Nitration liquid return pipe; 304. Sludge return pipe; 305. Sludge discharge pipe; 401. Kitchen waste / restaurant garbage organic slurry; 402. Sludge transport device; 403. Municipal sewage; 404. Clean water meets discharge standards. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. Unless otherwise specified, the equipment and materials used in the embodiments can be easily obtained from commercial companies.

[0044] In the field of sewage treatment, the English abbreviations used in this application are well known, among which: SS: suspended solids, suspended solids in water.

[0045] The kitchen waste / restaurant garbage slurry feed pump 101, the carbon source reactor discharge pump 108, the separator sludge pump 111, the sewage feed pump 201, the regulating tank lift pump 205, the secondary sedimentation tank feed pump 211, the secondary sedimentation tank sludge pump 213, the filter tank outlet pump 215, the clean water pump 217, and the primary sedimentation tank sludge pump 218 are all pumps.

[0046] Example 1

[0047] like Figure 1 to Figure 2 As shown, a wastewater treatment device for denitrification and biochemical carbon source includes three routes.

[0048] First route:

[0049] Reference Figure 1 The kitchen waste / food waste slurry feed pump 101 is connected to the bioreactor 102 by pipeline. The bioreactor 102 has the functions of directional fermentation and biochemical treatment of carbon sources. The kitchen waste / food waste slurry feed pump 101 is used to pump the kitchen waste / food waste organic slurry 401 into the bioreactor 102. The center of the bioreactor 102 is provided with a stirrer, which is a central stirrer 105. The top of the bioreactor 102 is also provided with an alkali adding pipe 103 and an enhancer adding pipe 104, and the bioreactor 102 is also connected to an online detection instrument 106. The online detection instrument 106 has a dissolved oxygen probe and a pH probe, which are both inserted into the bioreactor 102 and are used to detect the dissolved oxygen and pH in the bioreactor 102, respectively. A microporous aeration pipe is also provided at the bottom of the bioreactor 102, and the microporous aeration pipe is connected to a blower 107 by pipeline. The blower 107 can be located outside the bioreactor 102.

[0050] The bioreactor 102 is connected to the primary solid-liquid separator 109 through the carbon source reactor discharge pump 108. The aforementioned connection is a pipeline connection. The primary solid-liquid separator 109 has a screen or grid with a pore size of 0.55~1.0mm. The primary solid-liquid separator 109 is a solid-liquid separator. This is a well-known principle and will not be elaborated on.

[0051] The primary solid-liquid separator 109 is connected to the secondary solid-liquid separator 110 by pipeline. An inclined plate for sedimentation is arranged in the secondary solid-liquid separator 110. The angle of the inclined plate is 65 to 80 degrees. A scraper plate may also be arranged in the secondary solid-liquid separator 110. A sludge hopper is arranged at the bottom of the secondary solid-liquid separator 110. The outlet of the sludge hopper is connected to the separator sludge pump 111 by pipeline. The separator sludge pump 111 is connected to the desludge system by pipeline. The desludge system includes a horizontal centrifuge 112. The horizontal centrifuge 112 is also connected to the sludge transport device 402. The sludge transport device 402 is used to transport the collected sludge.

[0052] The secondary solid-liquid separator 110 is also connected to the sewage system via the biochemical carbon source addition pipe 301 , and the sewage system includes an anaerobic tank 206 and an anoxic tank 207 .

[0053] Second route:

[0054] Reference Figure 1, the sewage feed pump 201 is connected to the screen machine 202 by pipeline. The principle of the screen machine is well known and will not be elaborated on. The sewage feed pump 201 is used to pump the municipal sewage 403 into the screen machine 202. The screen machine 202 is connected to the primary sedimentation tank 203 by pipeline. The principle of the primary sedimentation tank is well known and will not be elaborated on. The primary sedimentation tank 203 is connected to the regulating tank 204 by pipeline. The principle of the regulating tank is well known and will not be elaborated on. The regulating tank 204 is connected to the regulating tank lifting pump 205 by pipeline. The regulating tank lifting pump 205 is connected to the anaerobic tank 206 by pipeline. The anaerobic tank 206 is connected to the anoxic tank 207 by pipeline. The anoxic tank 207 is connected to the aerobic tank 208 by pipeline. The aeration pipe 209 is connected to the aeration fan 210 at the bottom of the aerobic tank 208. The aeration pipe 209 is connected to the aeration fan 210. The aeration fan 210 can be arranged outside the aerobic tank 208.

[0055] The aerobic tank 208 is connected to the secondary sedimentation tank feed pump 211 by pipeline, and the secondary sedimentation tank feed pump 211 is connected to the secondary sedimentation tank 212 by pipeline. The principle of the secondary sedimentation tank is well known and will not be described in detail. The secondary sedimentation tank 212 is connected to the flocculation filter 214 by pipeline, and the flocculation filter 214 is a micro flocculation filter or a flocculation tank.

[0056] The flocculation filter 214 is connected to the filter outlet pump 215 by pipeline, and the filter outlet pump 215 is connected to the ultraviolet disinfection tank 216 by pipeline, and the ultraviolet disinfection tank 216 is connected to the clean water pump 217 by pipeline. The ultraviolet disinfection tank 216 is a disinfection tank using ultraviolet disinfection method.

[0057] The third route:

[0058] Reference Figure 1 The bottom of the primary sedimentation tank 203 is connected to a sand settling bucket, and the sand settling bucket is connected to the primary sedimentation tank sludge pump 218 by pipeline. The primary sedimentation tank sludge pump 218 is connected to the horizontal centrifuge 112 through the primary sedimentation tank sludge pipe 302.

[0059] The secondary sedimentation tank feed pump 211 is also connected to the anoxic tank 207 through the nitrification liquid return pipe 303; the secondary sedimentation tank sludge pump 213 is also connected to the anaerobic tank 206 through the sludge return pipe 304; the secondary sedimentation tank sludge pump 213 is also connected to the desludge system through the sludge discharge pipe 305.

[0060] refer to Figure 1 and Figure 2 The operation steps of the sewage treatment device for denitrification biochemical carbon source proposed in this application are as follows:

[0061] S1: Inoculation and activation with municipal sludge. A 3% SS mixed concentrate is prepared with municipal sludge, and then the mixed concentrate is transported to the bioreactor 102 by the kitchen waste / food waste slurry feed pump 101. The amount of the inoculated mixed concentrate is 1 / 3 of the effective volume of the bioreactor 102, and the mixture is continuously exposed for 3 days.

[0062] S2: The kitchen waste / kitchen waste organic slurry 401 is pumped into the bioreactor 102 by the kitchen waste / kitchen waste slurry feed pump 101, and at the same time, alkali solution is added into the bioreactor 102 through the alkali adding pipe 103 to adjust the pH to 5.8-6.5, and the enhancer is added into the bioreactor 102 through the enhancer adding pipe 104, and the central agitator 105 is started to achieve uniform mixing of the materials and maintain a suspended state. The temperature of the kitchen waste / kitchen waste organic slurry 401 is controlled at 52-55°C to promote the conversion of suspended matter into easily degradable soluble organic matter.

[0063] Intelligent control of dissolved oxygen: The dissolved oxygen in the bioreactor 102 is detected by the dissolved oxygen probe in the online detection instrument 106, and the dissolved oxygen is maintained between 0.3 and 1.0 mg / L. When the dissolved oxygen in the bioreactor 102 is lower than the lower limit (0.3 mg / L), the central intelligent controller gives a signal instruction to stop the operation of the central agitator 105 and start the blower 107 to aerate and oxygenate through the microporous aeration pipe at the bottom of the bioreactor 102; when the dissolved oxygen in the bioreactor 102 is higher than the upper limit (1.0 mg / L), the central intelligent controller gives a signal instruction to stop the blower 107 and start the central agitator 105.

[0064] Intelligent pH control: The pH in the bioreactor 102 is detected by the pH probe in the online detection instrument 106, and the pH is maintained between 5.8 and 6.5. When the pH value in the bioreactor 102 is lower than the lower limit (5.8), the central intelligent controller gives a signal instruction to add alkali solution into the bioreactor 102 through the alkali addition pipe 103; when the pH value in the bioreactor 102 is higher than 6.5, the central intelligent controller gives a signal instruction to stop adding alkali solution into the bioreactor 102 through the alkali addition pipe 103.

[0065] The alkali solution contains at least one of sodium carbonate, sodium bicarbonate, sodium hydroxide solution and potassium hydroxide.

[0066] The enhancer is made of raw magnetite crushed into magnetic powder by a grinder. The particle size of the magnetic powder is 800 meshes. The addition ratio is 2% to 3% of the feed amount of the kitchen waste / restaurant garbage organic slurry 401. The working principle is that the magnetic powder promotes the direct or indirect electron transfer process of the kitchen waste / restaurant garbage organic slurry 401 through iron reduction hydrolysis acidification bacteria, strengthens the decomposition of complex organic matter such as protein, and increases the NH4 + The concentration value promotes the conversion to easily degradable organic matter and its accumulation, and promotes the stability of the system pH value.

[0067] After the kitchen waste / restaurant garbage organic slurry 401 is separated by hydrolysis and acidification bacteria in the bioreactor 102, the concentration of the suspended matter remaining in the mixed liquid is 16-20 g / L, and the suspended matter is discharged from the system in the form of carbon source sludge.

[0068] S3: The slurry that has completed directional fermentation and acid production in the bioreactor 102 is pumped to the primary solid-liquid separator 109 through the carbon source reactor discharge pump 108. After solid-liquid separation, coarse particles in the mixed liquid are removed, and a screen or grid with a pore size of 0.55~1.0mm is selected for solid-liquid separation to remove suspended and fibrous materials.

[0069] S4: The material after solid-liquid separation in the primary solid-liquid separator 109 enters the secondary solid-liquid separator 110 for gravity separation. The sludge hopper outlet is connected to the separator sludge pump 111. 1 / 4~1 / 3 of the sludge is transported to the desludging system through the separator sludge pump 111, and the remaining sludge is returned to the bioreactor 102 to further decompose the complex organic matter into easily degradable organic matter, thereby increasing the SCOD concentration value of the discharge material.

[0070] S5: The organic slurry after solid-liquid separation in the secondary solid-liquid separator 110 is added (it can be pumped in, the pump is not shown, or other conveying methods can be used) to the anaerobic tank 206 and the anoxic tank 207 of the sewage system, and a biochemical carbon source is added at the same time. In this application, the organic slurry can be directly used as a biochemical carbon source, and a commercial carbon source can also be added. The ratio of the amount of biochemical carbon source added to the amount of sewage treated is 600~800:1. By adding a biochemical carbon source, the C / N ratio of the influent is increased to 5~7, meeting the microbial energy consumption requirements of denitrification and phosphorus removal.

[0071] S6: Municipal sewage is transported to the screen machine 202 through the sewage feed pump 201 to remove suspended matter, and the suspended matter is transported out for disposal. The effluent from the screen machine 202 enters the primary sedimentation tank 203, and relies on gravity to separate the particles with a large specific gravity in the mixed liquid. The liquid phase of the primary sedimentation tank 203 flows to the regulating tank 204 by gravity, and the precipitated particles enter the grit hopper. The grit hopper is connected to the primary sedimentation tank sludge pump 218. The primary sedimentation tank sludge pump 218 is used to regularly transport the sludge to the horizontal centrifuge 112 for solid-liquid separation. After the sewage passes through the regulating tank 204, the regulating tank lift pump 205 transports the sewage to the anaerobic tank 206. The sewage is treated in turn through the anaerobic tank 206, the anoxic tank 207, and the aerobic tank 208. When entering the aerobic tank 208, the external aeration fan 210 can be turned on to aerate and oxygenate the aerobic tank 208 through the aeration pipe 209. The sewage treated in the aerobic tank 208 is pumped into the secondary sedimentation tank 212 by the secondary sedimentation tank feed pump 211.

[0072] S7: The sludge at the bottom of the secondary sedimentation tank 212 is returned to the anaerobic tank 206 through the secondary sedimentation tank sludge pump 213. The polyphosphate-accumulating bacteria in the returned sludge metabolize in the anaerobic tank 206 using the energy of the original sewage and the biochemical carbon source to release total phosphorus, and the activity is restored by the denitrifying bacteria. Then the mixed liquid of the anaerobic tank 206 overflows into the anoxic tank 207. The denitrifying bacteria that have been restored in the anoxic tank 207 use the easily degradable organic matter remaining in the original sewage and the external biochemical carbon source to degrade the NO x —N is denitrified and converted into N2; the effluent from the anoxic pool 207 overflows into the aerobic pool 208, where the autotrophic nitrifying bacteria in the aerobic pool 208 use the oxygen in the sewage to convert NH4 + -N is converted to NO x —N, heterotrophic bacteria adsorb and metabolize organic matter in sewage. After being treated in aerobic tank 208, sewage enters secondary sedimentation tank 212 again for solid-liquid separation.

[0073] The flow rate of sludge return from the secondary sedimentation tank 212 is 20% to 50% of the inlet flow rate. Part of the sludge is discharged to the horizontal centrifuge 112 for solid-liquid separation. The clear liquid of solid-liquid separation is returned to the anaerobic tank 206. The return rate of nitrification liquid from the secondary sedimentation tank 212 is 100% to 400% of the inlet flow rate. The clear liquid overflowing from the secondary sedimentation tank 212 enters the flocculation filter 214. The effluent of the flocculation filter 214 is pumped to the ultraviolet disinfection tank 216 through the filter effluent pump 215. After disinfection, it meets the discharge standards, that is, the clear water meets the discharge standards 404.

[0074] S8: The sludge from the secondary solid-liquid separator 110, the sludge from the primary sedimentation tank 203, and the sludge from the secondary sedimentation tank 212 enter the horizontal centrifuge 112 for solid-liquid separation. The solid phase with a water content of 80% after separation is used for aerobic fermentation to prepare organic fertilizer.

[0075] The sludge discharged from the secondary solid-liquid separator 110 contains a large amount of magnetic powder, hydrolytic acidifying bacteria, protein, and cellulose. The microorganisms in the municipal sludge are decomposed by hydrolytic acidifying bacteria, and the magnetic powder indirectly or directly promotes the efficiency of electron transfer, and strengthens the wall-breaking and dissolving effect of hydrolytic acidifying bacteria on the microbial bacteria in the sludge of the secondary sedimentation tank 212. The maturation time of sludge to prepare organic fertilizer is shortened by 3 to 5 days. The hydrolytic acidified sludge of the biochemical carbon source contains a large amount of protein and cellulose, which provides nitrogen fertilizer for sludge composting; the cellulose is distributed in the compost, maintaining appropriate gaps in the compost, which is conducive to aeration and fermentation.

[0076] Example 2

[0077] In this embodiment, a tubular ultrafiltration membrane or a hollow fiber membrane is used to replace the secondary sedimentation tank 212 for solid-liquid separation. The clear liquid after membrane solid-liquid separation can enter the disinfection tank, and the effluent meets the discharge standards. Compared with the sludge separation in the secondary sedimentation tank 212, the use of a tubular ultrafiltration membrane or a hollow fiber membrane can achieve a high sludge concentration in the biochemical system, and the sludge concentration can reach 10-20g / L, with a small area occupation, low one-time investment cost, and effluent SS meeting the standards.

[0078] Example 3

[0079] In this embodiment, data is used to characterize the processing effect of the device of the present application, as follows:

[0080] At present, the influent BOD5 / TN ratio of urban sewage treatment plants in my country is less than 4. In order to achieve that the municipal sewage effluent meets the first level requirement of Table 1 of the Pollutant Discharge Standard for Urban Sewage Treatment Plants GB18918-2002 for effluent total nitrogen <20 (Table 1 here is Table 1 in the standard), it is necessary to add a large amount of easily degradable organic matter (i.e., external carbon source) to control the influent BOD5 / TN between 5 and 6, which increases the sewage operation cost.

[0081] Conventional carbon sources on the market (such as sodium acetate, glucose, methanol, etc.) are mainly derived from petrochemical enterprises and are relatively expensive. In order to reduce operating costs, this application increases the BOD5 / TN of the influent to 5~6 by adding a biochemical carbon source prepared by fermentation of kitchen waste / dining kitchen organic slurry, and the effluent water quality meets the standard. The operating cost comparison of different added carbon sources is shown in Table 2 below. Except for the explosive methanol carbon source, the operating cost of adding a biochemical carbon source reduces the cost of the reagent by 40%~70%.

[0082] Table 2 Operating costs of different added carbon sources

[0083]

[0084] The treatment effect of municipal sewage is that the effluent water quality meets the Class B standard in Table 1 of the Pollutant Discharge Standard for Urban Sewage Treatment Plants GB18918-2002. After adding the biochemical carbon source in the denitrification stage, the effluent index is shown in Table 3 below.

[0085] Table 3 Water quality before and after adding biochemical carbon source

[0086]

[0087] Compared with the prior art, the device of the present application also has the technical effects shown in Table 4 below. Conventional hydrolysis and fermentation are the prior art, and deep directional fermentation is the present application.

[0088] Table 4 Hydrolysis and fermentation discharge index table

[0089]

[0090] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A sewage treatment device for denitrification biochemical carbon source, characterized in that: It comprises a bioreactor (102), wherein the bioreactor (102) is connected to a secondary solid-liquid separator (110) via a primary solid-liquid separator (109); The sewage treatment device further comprises a screen machine (202), the screen machine (202) is connected to a regulating tank (204) via a primary sedimentation tank (203), the regulating tank (204) is connected to an aerobic tank (208) via a sewage system, and the aerobic tank (208) is connected to a disinfection tank via a separation system; The kitchen waste / restaurant garbage organic slurry (401) enters the bioreactor (102), and the municipal sewage (403) enters the screen machine (202); the secondary solid-liquid separator (110) is also connected to the sewage system, and the sewage system includes an anaerobic tank (206) and an anoxic tank (207); the separation system includes at least one of a secondary sedimentation tank (212), a flocculation filter (214), a tubular ultrafiltration membrane, and a hollow fiber membrane; the primary solid-liquid separator (109) and the secondary solid-liquid separator (110) are used for solid-liquid separation of sewage.

2. The sewage treatment device for denitrification biochemical carbon source according to claim 1, characterized in that: The secondary solid-liquid separator (110) is also connected to a desludging system, which includes a horizontal centrifuge (112); the sewage system is connected to the separation system via a secondary sedimentation tank feed pump (211).

3. The sewage treatment device for denitrification biochemical carbon source according to claim 2, characterized in that: The secondary solid-liquid separator (110) is connected to the horizontal centrifuge (112) via a separator sludge pump (111); the horizontal centrifuge (112) is also connected to a sludge transport device (402); and the disinfection tank is an ultraviolet disinfection tank (216).

4. The wastewater treatment device for denitrification biochemical carbon source according to claim 1, characterized in that: Municipal sludge and the kitchen waste / food waste organic slurry (401) both enter the bioreactor (102) through a kitchen waste / food waste slurry feed pump (101); the bioreactor (102) is connected to the primary solid-liquid separator (109) through a carbon source reactor discharge pump (108); the municipal sewage (403) enters the screen machine (202) through a sewage feed pump (201), and the screen machine (202) is connected to the sewage system through a regulating tank lift pump (205); the separation system is connected to the disinfection tank through a filter tank outlet pump (215), and the disinfection tank discharges qualified clean water through a clean water pump (217).

5. The sewage treatment device of denitrification biochemical carbon source according to claim 1, characterized in that: The bioreactor (102) comprises a stirrer, wherein the stirrer is a central stirrer (105); The bioreactor (102) further comprises an alkali addition pipe (103) and a fortifier addition pipe (104), wherein the alkali solution enters the bioreactor (102) through the alkali addition pipe (103), and the fortifier enters the bioreactor (102) through the fortifier addition pipe (104).

6. The sewage treatment device for denitrification biochemical carbon source according to claim 5, characterized in that: The alkaline solution comprises at least one of sodium carbonate, sodium bicarbonate, sodium hydroxide solution and potassium hydroxide. The strengthening agent is magnetic powder, the particle size of the magnetic powder is 300-900 meshes, and the added amount of the strengthening agent is 2-3% of the feed amount of the kitchen waste / food waste organic slurry (401).

7. The sewage treatment device of denitrification biochemical carbon source according to claim 1, characterized in that: The online detection instrument (106) comprises a probe placed inside the bioreactor (102), and the probe is used to detect dissolved oxygen and pH in the bioreactor (102); the bioreactor (102) further comprises a microporous aeration tube connected to a blower (107); the bioreactor (102) is capable of directional fermentation and biochemical treatment of carbon sources; The dissolved oxygen in the bioreactor (102) is maintained at 0.3-1.0 mg / L, and the pH in the bioreactor (102) is maintained at 5.8-6.5; the temperature of the kitchen waste / food waste organic slurry (401) in the bioreactor (102) is controlled at 52-55° C., and the concentration of the suspended matter remaining after the reaction in the bioreactor (102) is controlled at 16-20 g / L; the secondary solid-liquid separator (110) can also add a biochemical carbon source to the sewage system, and the ratio of the amount of the biochemical carbon source added to the amount of sewage treated is 600-800:

1.

8. The sewage treatment device of denitrification biochemical carbon source according to claim 1, characterized in that: The first-stage solid-liquid separator (109) comprises a screen or grid bars with a pore size of 0.55 to 1.0 mm, the second-stage solid-liquid separator (110) comprises an inclined plate with an inclination angle of 65 to 80 degrees and a sludge hopper; and the primary sedimentation tank (203) comprises a grit hopper.

9. The sewage treatment device for denitrification biochemical carbon source according to claim 1, characterized in that: The aerobic pool (208) comprises an aeration pipe (209), and the aeration pipe (209) is connected to an aeration fan (210).

10. The wastewater treatment device for denitrification biochemical carbon source according to claim 2, characterized in that: The sewage treatment device further comprises a reflux system, the reflux system comprising a nitrification liquid reflux pipe (303), a sludge reflux pipe (304), and a sludge discharge pipe (305); the secondary sedimentation tank feed pump (211) is connected to the anoxic tank (207) via the nitrification liquid reflux pipe (303); the anaerobic tank (206) is connected to the secondary sedimentation tank sludge pump (213) via the sludge reflux pipe (304); the secondary sedimentation tank (212) is connected to the desludging system via the sludge discharge pipe (305); the desludging system is also connected to the primary sedimentation tank (203); the reflux of the secondary sedimentation tank (212) comprises sludge reflux and nitrification liquid reflux; the sludge reflux flow rate is 20% to 50% of the influent flow rate, and the nitrification liquid reflux flow rate is 100% to 400% of the influent flow rate.

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