CN103241909A - A treatment device for waste water from tobacco flake production - Google Patents

Abstract

The utility model provides a processing apparatus of tobacco sheet waste water, includes thick grid catch basin of machinery, rotatory grid machine, air supporting pond, one-level decalcification reaction tank, second grade decalcification reaction tank, coagulating basin, just sink pond, equalizing basin, hydrolysis-acidification tank, UASB anaerobism pond, electrolysis machine a, oxygen deficiency pond, good oxygen pond, well sink pond, electrolysis machine b, MBR system, electrolysis disinfection pond, sludge impoundment, sludge dewatering device, accident pond, gas collection device and marsh gas storage tank. The invention provides a treatment device based on the combination of a chemical decalcification technology, a biochemical technology, an electrochemical technology and an MBR technology, and the treatment device has the advantages of lower cost, higher efficiency and standard wastewater discharge.

Description

A treatment device for waste water from tobacco flake production

The present invention relates to a treatment device for tobacco sheet production wastewater, in particular to a treatment device for tobacco sheet production wastewater and tobacco production wastewater based on chemical decalcification technology, biochemical technology, electrochemical technology and MBR technology, which belongs to environmental engineering in the field of water pollution control. the

Background technique

During the production of tobacco leaves, the raw materials cannot be fully utilized. During the production process of tobacco from primary processing to cigarettes, there will be scraps accounting for about 1/3 of the total amount of raw tobacco materials. These tobacco scraps cannot be directly used as The raw material is again made into a cigarette product. In order to reduce the generation of waste and realize the comprehensive utilization of debris, tobacco sheet technology came into being. Tobacco sheet, also known as reconstituted tobacco (Reconstituted Tobacco), is a regenerated product made of tobacco materials such as tobacco dust, tobacco stems, and shredded tobacco pieces as raw materials, which are used as cigarette fillers to reduce tar in cigarettes content, reduce the health hazards of smoking to the human body. The use of tobacco sheets has many advantages such as improving the quality of shredded tobacco, reducing the cost of cigarettes, saving raw material consumption, and reusing resources. Rolling method, thick pulp method and papermaking method are the main production methods of tobacco sheet at present. Compared with roll-pressing and thick-pulp flakes, paper-making flakes have obvious advantages: reduced cigarette production costs, stable product quality, high filling value and filamentation rate, good mechanical processing resistance, improved cigarette burning speed and It reduces the amount of tar release, has high plasticity and is easier to process. It is an effective process for producing "healthy" cigarettes at present. It is precisely because the papermaking sheet has the incomparable advantages of the rolling method and the thick stock method, so it has been widely promoted at home and abroad.

The wastewater produced during the production of paper-making tobacco flakes has the common characteristics of papermaking wastewater such as a large amount of fiber, and tobacco wastewater has high color, poor biodegradability, and nicotine and calcium and magnesium content that are unfavorable to microbial growth. High 150 ~ 500mg/L and other characteristics, the main pollution indicators are as follows:

At the same time, the concentration of wastewater fluctuates greatly, CODcr is from 1500 to 25000mg/L, SS is from 1000 to 15000mg/L, nicotine and tar inhibit the growth of microorganisms, and the high content of calcium and magnesium leads to fouling of the reactor and cannot operate normally. waste water.

Chinese patent CN1683261A discloses a method for treating waste water from tobacco flake production by papermaking, namely coagulation air flotation + aerobic oxidation + mechanical filtration tobacco flake production wastewater.

Chinese patent CN102276093A discloses a method for treating waste water from the production of paper-making tobacco flakes. The process includes the following steps: passing the production waste water through a grid for coarse filtration, and flowing into the waste water regulating tank by gravity; lifting the waste water in the waste water regulating tank to the mixed Add Ca-diatomaceous earth composite coagulant to the condenser to react for 5-10min, then add polyferric sulfate and polyacrylamide separation agent into the static reaction tank for reaction, the reaction time is 50-60min; low-concentration organic wastewater After adjusting the pH to be acidic, it is pumped into the ultrasonic micro-electrolysis reactor, and through the joint reaction of ultrasonic and micro-electrolysis, the chemical oxygen-consuming substances in the wastewater are quickly digested, and the reaction time is 30-60min; then the wastewater is adsorbed by activated carbon and quartz Sand filtration; the sludge produced in the adjustment tank and static reaction tank section is used as solid fuel after dehydration of screw stack sludge.

Chinese patent CN10133045A discloses that the waste water from the production of tobacco flakes by the papermaking method is reused in the pulping section after one to three stages of filtration, and the reused water is regularly discharged to the sewage treatment station. affect the quality of the flakes.

Chinese patent CN1683261A discloses a method in which wastewater from papermaking tobacco sheet production is first coagulated and air flotation is used to remove suspended solids, and then sent to an aeration tank to remove most of the COD substances through aerobic microorganisms.

The above methods have a certain effect on the treatment of tobacco sheet production wastewater, but there are defects such as long process flow, large equipment investment, large floor space, and high operating costs. What is more serious is that the wastewater contains a large amount of calcium, which directly leads to biochemical The treatment system and the membrane separation system are massively fouled, and the system cannot operate normally. The discharged wastewater treated by the existing wastewater treatment technology cannot meet the discharge standard.

Contents of the invention

The purpose of the present invention is to aim at the long process flow, large equipment investment, large floor area, high operating cost, and biochemical treatment system and membrane treatment system that cannot operate normally due to fouling in the existing tobacco production wastewater treatment method. The treated wastewater does not meet the standard and other defects, and provides a treatment based on the combination of chemical decalcification technology, biochemical technology, electrochemical technology and MBR technology, with low cost and high efficiency, so that it can meet the standard discharge of tobacco production wastewater device.

A treatment device for waste water from tobacco sheet production, including a mechanical coarse grid pool, a rotary grid machine, an air flotation tank, a primary decalcification reaction tank, a secondary decalcification reaction tank, a coagulation tank, a primary sedimentation tank, and a regulating tank , hydrolytic acidification tank, UASB anaerobic tank, electrolytic machine a, anoxic tank, aerobic tank, middle sedimentation tank, electrolytic machine b, MBR system, electrolytic disinfection tank, sludge tank, sludge dehydration device, accident tank, gas Collection devices and biogas storage tanks;

The inlet of the mechanical coarse grid sump is connected to the outlet of the tobacco waste water, the water outlet of the mechanical coarse grid sump is connected to the water inlet of the rotary grid machine, the water outlet of the rotary grid machine is connected to the water inlet of the air flotation tank, and the outlet of the air flotation tank is The water inlet is connected to the water inlet of the first-level decalcification reaction tank, the water outlet of the first-level decalcification reaction tank is connected to the water inlet of the second-level decalcification reaction tank, the water outlet of the second-level decalcification reaction tank is connected to the water inlet of the coagulation tank, and the coagulation tank The water outlet is connected to the water inlet of the primary sedimentation tank, the water outlet of the primary sedimentation tank is connected to the water inlet of the regulating tank, the water outlet of the regulating tank is connected to the water inlet of the hydrolytic acidification tank, the water outlet of the hydrolytic acidification tank is connected to the water inlet of the UASB anaerobic tank, and the UASB anaerobic tank is connected to the water outlet. The water outlet of the oxygen tank is connected with the water inlet of the electrolysis machine a, the water outlet of the electrolysis machine a is connected with the water inlet of the anoxic tank, the water outlet of the anoxic tank is connected with the water inlet of the aerobic tank, and the water outlet of the aerobic tank is connected with the water inlet of the intermediate sedimentation tank , the water outlet of the sinking tank is connected with the water inlet of the electrolysis machine b, the water outlet of the electrolysis machine b is connected with the water inlet of the MBR system, the water outlet of the MBR system is connected with the water inlet of the electrolytic disinfection tank, the water outlet of the electrolytic disinfection tank is connected with the drainage channel; the accident pool The water inlet of the UASB anaerobic tank is connected to the outlet of the tobacco flake production wastewater, the outlet of the accident pool is connected to the water inlet of the mechanical coarse grid sump; the gas outlet of the UASB anaerobic tank is connected to the inlet of the gas collection device, and the outlet of the gas collection device is connected to the secondary decalcification reaction The water inlet of the tank is connected, the gas outlet of the secondary decalcification reaction tank is connected with the inlet of the biogas storage tank; the sediment in the primary sedimentation tank, UASB anaerobic tank, anoxic tank, aerobic tank, intermediate sedimentation tank and MBR system ( That is, the outlet of the sludge) is connected to the inlet of the sludge tank, and the outlet of the sludge tank is connected to the inlet of the sludge dehydration device.

The air flotation tank is one of air distribution air flotation, electrical flotation, biological and chemical air flotation or dissolved air flotation.

The coagulation tank is equipped with a dispensing system and a dosing system.

Both the electrolyzer a and the electrolyzer b are equipped with a power supply and an electrolyzer; the electrode materials in the electrolyzer are graphite, titanium, iron, aluminum, zinc, copper, lead, nickel, molybdenum, chromium, alloys and nano-catalyzed One of the inert materials.

The surface layer of the nano-catalytic inert electrode is coated with a metal oxide inert catalytic coating with a grain size of 10-35nm, and the substrate of the nano-catalytic inert electrode is a titanium plate or a plastic plate.

The membrane components of the MBR system are selected from polyvinylidene fluoride hollow fiber membranes, polypropylene hollow fiber membranes, polysulfone hollow fiber membranes, polyethersulfone hollow fiber membranes, polyacrylonitrile hollow fiber membranes and polyvinyl chloride hollow fiber membranes kind of.

The membrane module of the MBR system has a membrane pore diameter of 0.10-0.2 μm, a working pressure of -1-50 kPa, and a working temperature of 5-45°C.

The technical scheme of the present invention is: waste water from tobacco flake production → slag removal → chemical decalcification → anaerobic treatment → electrolysis → A/O treatment → secondary electrolysis → MBR → electrolytic disinfection → standard discharge.

The effect of wastewater treatment above is shown in the table below:

Compared with the prior art, the present invention has the following outstanding advantages:

(1) After the false hardness (bicarbonate) is removed through the primary decalcification reaction of the chemical decalcification system, the carbonate radical reacts with calcium and magnesium ions to form carbonate precipitation through the secondary decalcification reaction pool, and then in In the coagulation tank, the carbonate precipitates and destabilizes, flocculates with coagulants such as FeSO ₄ and polyphenylene amide (PAM), and aggregates into coarse alum flower particles, which settle down in the primary sedimentation tank and finally effectively remove tobacco. The high-concentration calcium and magnesium ions in the wafer production wastewater have a removal rate of 50-90%, reduce the hardness of the water, make the Ca ²⁺ lower than 50 mg/L, prevent equipment scaling, and ensure the smooth subsequent biochemical treatment and electrolysis process. Stable operation.

(2) After being treated by the UASB anaerobic treatment system, the COD, BOD and other indicators in the wastewater are greatly reduced, and the generated gas is collected by the gas collection device and then introduced into the secondary decalcification reaction tank in the chemical decalcification, so that the CO in the gas _2React with calcium and magnesium ions to form carbonate precipitation. On the one hand, CO ₂ in the gas is recovered, so that the gas _can be used effectively; The gas storage tank is collected and utilized or discharged at high altitude.

(3) After treatment by the slag removal and chemical decalcification system, the removal rate of SS in the wastewater is over 95%, and the SS in the regulating tank is greatly reduced, avoiding the deposition of sludge in the regulating tank, and reducing the workload of sludge cleaning in normal operation.

(4) The strong oxidizing free radicals generated by nano-catalytic electrolysis make the difficult-to-biochemical macromolecular compounds in wastewater open rings and break chains, turning them into biochemical small molecules, further increasing the B/C value and improving the conditions for subsequent biochemical treatment. And remove the chroma and odor in the wastewater, reduce ammonia nitrogen, COD and other indicators.

(5) Through the A/O biochemical pool, through the alternating action of anaerobic and aerobic, the sewage can be denitrified and dephosphorized.

(6) After being treated by the MBR system, the pollutants in the water will be further decomposed through the oxidative decomposition of microorganisms. At the same time, the high-efficiency interception effect of the membrane is used to effectively remove SS, chroma, pollutants and other indicators, and the effluent water quality is stable and discharges up to the standard .

the

Description of drawings

Fig. 1 is a schematic diagram of the structure and composition of an embodiment of a treatment device for waste water from tobacco sheet production according to the present invention.

Detailed ways

The specific embodiment of the present invention is described below with reference to accompanying drawing 1.

With reference to Fig. 1, a kind of treatment device of tobacco sheet production waste water, it comprises: mechanical coarse grid pool 1, rotary grid machine 2, air flotation tank 3, primary decalcification reaction tank 4, secondary decalcification reaction tank 5 , coagulation tank 6, primary sedimentation tank 7, regulating tank 8, hydrolytic acidification tank 9, UASB anaerobic tank 10, electrolysis machine a11, anoxic tank 12, aerobic tank 13, intermediate sedimentation tank 14, electrolysis machine b15, MBR System 16, electrolytic disinfection tank 17, discharge channel 18, accident tank 19, sludge tank 20, sludge filter press 21, lifting pump 22, lifting pump 23, lifting pump 24, lifting pump 25, pump 26, gas collection device 27 and biogas storage tank 28. The inlet of the mechanical coarse grid sump 1 is connected to the outlet of tobacco flake production waste water, the water outlet of the mechanical coarse grid sump 1 is connected to the water inlet of the rotary grid machine 2 through the lifting pump 20, and the water outlet of the rotary grid machine 2 is connected to the air The water inlet of the floating tank 3 is connected, the water outlet of the air flotation tank 3 is connected with the water inlet of the first decalcification reaction tank 4, the water outlet of the first decalcification reaction tank 4 is connected with the water inlet of the second decalcification reaction tank 5, and the second decalcification reaction tank Outlet 5 is connected to water inlet 6 of coagulation tank, outlet 6 of coagulation tank is connected to water inlet 7 of primary sedimentation tank, outlet 7 of primary sedimentation tank is connected to water inlet of regulating tank 8, and water outlet of regulating tank 8 is passed through lift pump 23 It is connected with the water inlet of the hydrolytic acidification tank 9, the water outlet of the hydrolytic acidification tank 9 is connected with the water inlet of the UASB anaerobic tank 10 through the lift pump 24, the water outlet of the UASB anaerobic tank 10 is connected with the water inlet of the electrolysis machine a11, and the water outlet of the electrolysis machine a11 is connected with the water inlet of the electrolysis machine a11. The water inlet of the anoxic pool 12 is connected, the water outlet of the anoxic pool 12 is connected with the water inlet of the aerobic pool 13, the water outlet of the aerobic pool 13 is connected with the water inlet of the intermediate sedimentation tank 14, the water outlet of the intermediate sedimentation tank 14 is connected with the water inlet of the electrolytic machine b15 Connection, the water outlet of the electrolytic machine b15 is connected with the water inlet of the MBR system 16, the water outlet of the MBR system 16 is connected with the water inlet of the electrolytic disinfection tank 17 through the lift pump 25, the water outlet of the electrolytic disinfection tank 17 is connected with the drainage channel 18, and the primary sedimentation tank 7 , UASB anaerobic tank 9, anoxic tank 12, aerobic tank 13, intermediate settling tank 14 and MBR system 16. The sludge outlet is connected to the sludge tank 20 inlet, and the sludge tank 20 outlet is connected to the sludge filter press 21 inlet Connection, the water inlet of the accident pool 19 is connected with the outlet of the tobacco sheet production wastewater, the water outlet of the accident pool 19 is connected with the water inlet of the mechanical coarse grid sump 1 through the pump 26; the gas outlet of the UASB anaerobic pool 10 is connected with the gas collection device 27 inlet Connection, the gas collection device 27 outlet is connected with the water inlet of the secondary decalcification reaction tank 5, and the gas outlet of the secondary decalcification reaction tank 5 is connected with the biogas storage tank 28 inlet; the primary sedimentation tank 7, the UASB anaerobic tank 10, the The outlets of the sediment (i.e. sludge) in the oxygen tank 12, the aerobic tank 13, the middle sedimentation tank 14 and the MBR system 16 are all connected to the inlet of the sludge tank 20, and the outlet of the sludge tank 20 is connected to the inlet of the sludge dewatering device 21.

It can be seen from Figure 1 that the separation slag produced by the mechanical coarse grid sump 1 and the rotary grid machine 2 is packed and shipped out.

The present invention is the design of the waste water treatment device for tobacco flake production completed after an in-depth and systematic comparative study of the components, properties and existing treatment schemes of the existing tobacco flake production wastewater. It uses chemical decalcification, biochemistry, electrolysis, MBR The combined use of methods such as these forms a treatment device especially suitable for tobacco sheet production wastewater.

A specific embodiment of a tobacco sheet production wastewater treatment device is given below in conjunction with FIG. 1 .

Example 1

2000 tons/day tobacco sheet production wastewater treatment method.

The water quality indicators of the tobacco flake production wastewater are shown in Table 1 after determination.

Table 1 Water quality indicators of wastewater from tobacco flake production

serial number project unit measured value serial number project unit measured value 1 BOD ₅ mg/L 5800 5 Chroma times 15000 2 COD _Cr mg/L 25000 6 Ca ²⁺ mg/L 200 3 SS mg/L 15000 7 water temperature ℃ 50 4 pH value the 6.2 the the the the

(1) Slag removal

Wastewater from tobacco flake production is collected by pipelines and then discharged into mechanical coarse grid pool 1. Coarse grids are set in the pool to isolate and remove medium and coarse floating objects in the sewage to prevent subsequent processing equipment from clogging, and then through the lifting pump 22, Elevate the waste water from tobacco flake production to the rotary mechanical grill machine 2, further remove most of the insoluble suspended solids in the water through the filtration of the filter screen, pack the generated slag and transport it abroad, and the waste water passes through the air flotation tank 3 to treat the waste water Medium and large particle fibers and other suspended solids are separated, which greatly reduces the processing load of subsequent processes.

(2) Chemical decalcification

The effluent from the air flotation tank 3 flows into the first-level decalcification reaction tank 4 through the pipeline, and firstly adds an appropriate amount of lime saturated clear solution to adjust the pH value to 8.5 through the dosing device under stirring, and then flows into the second-level after removing the false hardness (bicarbonate) The decalcification reaction tank 5 is passed into the gas generated by the UASB anaerobic tank 10 in the anaerobic treatment of step (3), so that CO ₂ in the gas reacts with calcium and magnesium ions to form carbonate precipitation, and the effluent flows into the coagulation tank 6 and then stirred Under the conditions, first add 6mg/L FeSO ₄ , then add Na ₂ CO ₃ to adjust the pH value to 8, and finally add 2mg/L polyphenylene amide (PAM), after the reaction is complete, enter the primary sedimentation tank 7 for precipitation and separation, so that Remove calcium and magnesium ions in tobacco treatment wastewater with a removal rate of 75%, reduce water hardness, make the Ca ²⁺ concentration 50 mg/L, and prevent follow-up equipment and facilities from scaling due to excessive Ca ²⁺ ; primary precipitation The sediment (that is, sludge) in the pool 7 is sent to the sludge pool 20 through pumps and pipelines, and finally filtered and separated in the sludge filter press 21, and calcium carbonate is recovered, and the water from the primary sedimentation pool 7 enters the regulating pool 8.

(3) Anaerobic treatment

The effluent from the adjustment tank 8 is lifted to the hydrolytic acidification tank 9 by the lifting pump 23, and stays in the hydrolytic acidification tank 9 for a certain period of time, and the macromolecular organic matter in the wastewater is hydrolyzed and acidified into small molecular organic acids by acid-producing bacteria under the action of the acid-producing bacteria. Then enter the UASB anaerobic pool 10 through the lifting pump 24, through the adsorption of anaerobic bacteria and facultative bacteria in the UASB anaerobic pool 10, fermentation, and under the joint action of methanogenesis, the organic acid will be decomposed into methane and carbon dioxide, and the anaerobic treatment will improve The B/C value of the wastewater improves the biodegradability of the wastewater; the generated methane and carbon dioxide are collected by the gas collection device 27 and then introduced into the secondary decalcification reaction tank 5 in the chemical decalcification step (2) to remove carbon dioxide and carbon dioxide in the biogas. Hydrogen sulfide and mercaptan compound impurities are purified and recovered to biogas in the gas storage tank 28; waste water enters step (4).

(4) Electrolysis

The effluent from the UASB anaerobic tank 10 enters the electrolysis machine a11 for electrolysis to remove chromaticity and odor. At the same time, the difficult-to-biochemical macromolecular compounds in the wastewater are opened and broken to become biochemical small molecules, and part of the ammonia nitrogen and COD are removed. Further increase the B/C value and improve the conditions of subsequent biochemical treatment; the voltage between two adjacent electrodes of the electrolysis machine is 3V, and the current density is 300mA/cm ² .

(5) A/O processing

The effluent from the electrolysis enters the anoxic tank 12, the aerobic tank 13, and the intermediate sedimentation tank 14 in sequence, and part of the sludge in the intermediate sedimentation tank 14 is returned to the anoxic tank through the return pump, and can be carried out under the alternating action of anoxic and aerobic microorganisms. Nitrogen and phosphorus are removed, and organic matter in wastewater is further oxidized and decomposed through aerobic treatment, and COD and BOD are deeply removed; aerobic pool 13 is evenly filled with a large number of biological suspension fillers to provide habitat, growth and reproduction places for aerobic microorganisms, In order for microorganisms to form a biofilm on the surface of the filler. An aeration and oxygenation mixing system is installed at the bottom of the aerobic pool 13 to oxygenate the sewage so that the dissolved oxygen in the water is maintained at 2-4 mg/L. More adequate contact, in addition, through the agitation of gas and water backwashing, it can effectively wash away the aging biofilm growing on the surface of the filler, promote the replacement of the biofilm, and maintain a high activity of the biofilm.

(6) Secondary electrolysis

The effluent from the middle sedimentation tank 14 enters the electrolysis machine b15 again for electrolysis, so that the macromolecular organic matter that is difficult to biochemically undergoes electrolysis to undergo ring-opening and chain breaking, and is converted into small molecular organic matter that is easy to biochemically, increasing the B/C; during electrolysis, two adjacent The voltage between the electrodes was 6V, and the current density was 20mA/cm ² .

(7) MBR processing

The effluent from the secondary electrolysis enters the MBR system 16, which performs biochemical and membrane separation on the wastewater, degrades the remaining organic pollutants and removes suspended solids.

(8) Disinfection

After the wastewater is treated by the MBR system 16, the effluent is then sterilized by the electrolytic disinfection tank 17 to further remove chroma, sterilize the wastewater, and finally discharge it up to the standard.

(9) Sludge treatment

UASB anaerobic tank 10 in step (3) anaerobic treatment, anoxic tank 12, aerobic tank 13 and intermediate sedimentation tank 14 in step (5) A/O treatment, and sludge generated in step (7) MBR system 16 All enter the sludge tank 20 through the pipeline, and then the dehydration of the sludge filter press 21 reduces the volume of the sludge. After dehydration, the mud cake is incinerated, and the filtrate is returned to the regulating tank 8 in step (2) chemical decalcification .

The quality indicators of the effluent water were determined and shown in Table 2.

Table 2 Water quality indicators of effluent

serial number project unit measured value serial number project unit measured value 1 BOD ₅ mg/L 20 5 Chroma times 20 2 COD _Cr mg/L 60 6 Ca ²⁺ mg/L 40 3 SS mg/L 60 7 water temperature ℃ twenty three 4 pH value the 6.8 the the the the

Example 2

5000 tons/day tobacco sheet production wastewater treatment method.

The water quality indicators of the tobacco flake production wastewater are shown in Table 3 after determination.

Table 3 Water quality indicators of tobacco sheet production wastewater

serial number project unit measured value serial number project unit measured value 1 BOD ₅ mg/L 2000 5 Chroma times 25000 2 COD _Cr mg/L 8000 6 Ca ²⁺ mg/L 300 3 SS mg/L 6200 7 water temperature ℃ 55 4 pH value the 6 the the the the

(1) Slag removal

Wastewater from tobacco flake production is collected by pipelines and then discharged into mechanical coarse grid pool 1. Coarse grids are set in the pool to isolate and remove medium and coarse floating objects in the sewage to prevent subsequent processing equipment from clogging, and then through the lifting pump 22, Elevate the waste water from tobacco flake production to the rotary mechanical grill machine 2, further remove most of the insoluble suspended solids in the water through the filtration of the filter screen, pack the generated slag and transport it abroad, and the waste water passes through the air flotation tank 3 to treat the waste water Medium and large particle fibers and other suspended solids are separated, which greatly reduces the processing load of subsequent processes.

(2) Chemical decalcification

The effluent from the air flotation tank 3 flows into the first-level decalcification reaction tank 4 through the pipeline, and firstly adds an appropriate amount of lime saturated clarified solution to adjust the pH value to 9.5 through the dosing device under stirring. After removing the false hardness (bicarbonate), it flows into the second-level Decalcification reaction tank 5, add 400mg/L Na ₂ CO ₃ , make carbonate radical react with calcium and magnesium ions to form carbonate precipitate, make CO ₂ in the gas react with calcium and magnesium ion to form carbonate precipitate, and the effluent flows into coagulation After pool 6, add 10mg/L FeSO ₄ under stirring conditions, then add Na ₂ CO ₃ to adjust the pH value to 8.5, and finally add 2.5mg/L polyphenylene amide (PAM), and enter the primary sedimentation tank after the reaction is complete 7 Carry out precipitation and separation to remove calcium and magnesium ions in tobacco treatment wastewater, with a removal rate of 84%, reduce the hardness of water, and make the Ca ²⁺ concentration 48mg/L, preventing subsequent equipment and facilities from being caused by excessive Ca ²⁺ Scaling; the sediment (i.e. sludge) in the primary sedimentation tank 7 is sent into the sludge tank 20 through pumps and pipelines, and finally filtered and separated in the sludge filter press 21, and calcium carbonate is recovered. The primary sedimentation tank 7 Outlet water then enters regulating pond 8.

(3) Anaerobic treatment

The effluent from the adjustment tank 8 is lifted to the hydrolytic acidification tank 9 by the lifting pump 23, and stays in the hydrolytic acidification tank 9 for a certain period of time, and the macromolecular organic matter in the wastewater is hydrolyzed and acidified into small molecular organic acids by acid-producing bacteria under the action of the acid-producing bacteria. Then enter the UASB anaerobic pool 10 through the lifting pump 24, through the adsorption of anaerobic bacteria and facultative bacteria in the UASB anaerobic pool 10, fermentation, and under the joint action of methanogenesis, the organic acid will be decomposed into methane and carbon dioxide, and the anaerobic treatment will improve The B/C value of the wastewater improves the biodegradability of the wastewater; the generated methane and carbon dioxide are collected by the gas collection device 27 and then introduced into the secondary decalcification reaction tank 5 in the chemical decalcification step (2) to remove carbon dioxide, carbon dioxide, and Hydrogen sulfide and mercaptan compound impurities are purified and recovered to biogas in the gas storage tank 28; waste water enters step (4).

(4) Electrolysis

The effluent from the UASB anaerobic tank 10 enters the electrolysis machine a11 for electrolysis to remove chromaticity and odor. At the same time, the difficult-to-biochemical macromolecular compounds in the wastewater are opened and broken to become biochemical small molecules, and part of the ammonia nitrogen and COD are removed. Further increase the B/C value and improve the conditions for subsequent biochemical treatment; the voltage between two adjacent electrodes of the electrolysis machine is 8V, and the current density is 150mA/cm ² .

(5) A/O processing

The effluent from the electrolysis enters the anoxic tank 12, the aerobic tank 13, and the intermediate sedimentation tank 14 in sequence, and part of the sludge in the intermediate sedimentation tank 14 is returned to the anoxic tank through the return pump, and can be carried out under the alternating action of anoxic and aerobic microorganisms. Nitrogen and phosphorus are removed, and organic matter in wastewater is further oxidized and decomposed through aerobic treatment, and COD and BOD are deeply removed; aerobic pool 13 is evenly filled with a large number of biological suspension fillers to provide habitat, growth and reproduction places for aerobic microorganisms, In order for microorganisms to form a biofilm on the surface of the filler. An aeration and oxygenation mixing system is installed at the bottom of the aerobic pool 13 to oxygenate the sewage to maintain the dissolved oxygen in the water at 2-4 mg/L. More adequate contact, in addition, through the agitation of gas and water backwashing, it can effectively wash away the aging biofilm growing on the surface of the filler, promote the replacement of the biofilm, and maintain a high activity of the biofilm.

(6) Secondary electrolysis

The effluent from the middle sedimentation tank 14 enters the electrolysis machine b15 again for electrolysis, so that the macromolecular organic matter that is difficult to biochemically undergoes electrolysis to undergo ring-opening and chain breaking, and is converted into small molecular organic matter that is easy to biochemically, increasing the B/C; during electrolysis, two adjacent The voltage between the electrodes was 4 V, and the current density was 100 mA/cm ² .

(7) MBR processing

The effluent from the secondary electrolysis enters the MBR system 16, which performs biochemical and membrane separation on the wastewater, degrades the remaining organic pollutants and removes suspended solids.

(8) Disinfection

After the wastewater is treated by the MBR system 16, the effluent is then sterilized by the electrolytic disinfection tank 17 to further remove chroma, sterilize the wastewater, and finally discharge it up to the standard.

(9) Sludge treatment

UASB anaerobic tank 10 in step (3) anaerobic treatment, anoxic tank 12, aerobic tank 13 and intermediate sedimentation tank 14 in step (5) A/O treatment, and sludge generated in step (7) MBR system 16 All enter the sludge tank 20 through the pipeline, and then the dehydration of the sludge filter press 21 reduces the volume of the sludge. After dehydration, the mud cake is incinerated, and the filtrate is returned to the regulating tank 8 in step (2) chemical decalcification .

The quality indicators of the effluent water were determined and shown in Table 4.

Table 4 Water quality indicators of effluent

serial number project unit measured value serial number project unit measured value 1 BOD ₅ mg/L 15 5 Chroma times 20 2 COD _Cr mg/L 60 6 Ca ²⁺ mg/L 35 3 SS mg/L 40 7 water temperature ℃ 25 4 pH value the 6.5 the the the the

Example 3

8000 tons/day tobacco sheet production waste water recycling method.

The water quality indicators of the tobacco sheet production wastewater were determined and shown in Table 5.

Table 5 Water quality indicators of tobacco sheet production wastewater

serial number project unit measured value serial number project unit measured value 1 BOD ₅ mg/L 600 5 Chroma times 20000 2 COD _Cr mg/L 2000 6 Ca ²⁺ mg/L 400 3 SS mg/L 1000 7 water temperature ℃ 50 4 pH value the 6.5 the the the the

(1) Slag removal

Wastewater from tobacco flake production is collected by pipelines and then discharged into mechanical coarse grid pool 1. Coarse grids are set in the pool to isolate and remove medium and coarse floating objects in the sewage to prevent subsequent processing equipment from clogging, and then through the lifting pump 22, Elevate the waste water from tobacco flake production to the rotary mechanical grill machine 2, further remove most of the insoluble suspended solids in the water through the filtration of the filter screen, pack the generated slag and transport it abroad, and the waste water passes through the air flotation tank 3 to treat the waste water Medium and large particle fibers and other suspended solids are separated, which greatly reduces the processing load of subsequent processes.

(2) Chemical decalcification

The effluent from the air flotation tank 3 flows into the first-level decalcification reaction tank 4 through the pipeline, and first adds an appropriate amount of lime saturated clear solution to adjust the pH value to 9.0 through the dosing device under stirring. After removing the false hardness (bicarbonate), it flows into the second-level Decalcification reaction tank 5, add 100mg/L Na ₂ CO ₃ , make carbonate radical react with calcium and magnesium ions to form carbonate precipitate, make CO ₂ in the gas react with calcium and magnesium ion to form carbonate precipitate, and the effluent flows into coagulation After pool 6, add 50mg/L FeSO ₄ under stirring conditions, then add Na ₂ CO ₃ to adjust the pH value to 9.0, and finally add 3mg/L polyphenylene amide (PAM), and enter the primary sedimentation tank 7 after the reaction is complete Precipitation and separation are carried out to remove calcium and magnesium ions in tobacco treatment wastewater, with a removal rate of 87.5%, reducing the hardness of water, making the Ca ²⁺ concentration 50mg/L, and preventing subsequent equipment and facilities from being caused by excessive Ca ²⁺ formation. Scale; the sediment (i.e. sludge) in the primary sedimentation tank 7 is sent into the sludge tank 20 through pumps and pipelines, and finally filtered and separated in the sludge filter press 21, and calcium carbonate is recovered, and the water from the primary sedimentation tank 7 Then enter the adjustment pool 8.

(3) Anaerobic treatment

The effluent from the adjustment tank 8 is lifted to the hydrolytic acidification tank 9 by the lifting pump 23, and stays in the hydrolytic acidification tank 9 for a certain period of time, and the macromolecular organic matter in the wastewater is hydrolyzed and acidified into small molecular organic acids by acid-producing bacteria under the action of the acid-producing bacteria. Then enter the UASB anaerobic pool 10 through the lifting pump 24, through the adsorption of anaerobic bacteria and facultative bacteria in the UASB anaerobic pool 10, fermentation, and under the joint action of methanogenesis, the organic acid will be decomposed into methane and carbon dioxide, and the anaerobic treatment will improve The B/C value of the wastewater improves the biodegradability of the wastewater; the generated methane and carbon dioxide are collected by the gas collection device 27 and then introduced into the secondary decalcification reaction tank 5 in the chemical decalcification step (2) to remove carbon dioxide, carbon dioxide, and Hydrogen sulfide and mercaptan compound impurities are purified and recovered to biogas in the gas storage tank 28; waste water enters step (4).

(4) Electrolysis

The effluent from the UASB anaerobic tank 10 enters the electrolysis machine a11 for electrolysis to remove chromaticity and odor. At the same time, the difficult-to-biochemical macromolecular compounds in the wastewater are opened and broken to become biochemical small molecules, and part of the ammonia nitrogen and COD are removed. Further increase the B/C value and improve the conditions of subsequent biochemical treatment; the voltage between two adjacent electrodes of the electrolysis machine is 12V, and the current density is 50mA/cm ² .

(5) A/O processing

The effluent from the electrolysis enters the anoxic tank 12, the aerobic tank 13, and the intermediate sedimentation tank 14 in sequence, and part of the sludge in the intermediate sedimentation tank 14 is returned to the anoxic tank through the return pump, and can be carried out under the alternating action of anoxic and aerobic microorganisms. Nitrogen and phosphorus are removed, and organic matter in wastewater is further oxidized and decomposed through aerobic treatment, and COD and BOD are deeply removed; aerobic pool 13 is evenly filled with a large number of biological suspension fillers to provide habitat, growth and reproduction places for aerobic microorganisms, In order for microorganisms to form a biofilm on the surface of the filler. An aeration and oxygenation mixing system is installed at the bottom of the aerobic pool 13 to oxygenate the sewage to maintain the dissolved oxygen in the water at 2-4 mg/L. More adequate contact, in addition, through the agitation of gas and water backwashing, it can effectively wash away the aging biofilm growing on the surface of the filler, promote the replacement of the biofilm, and maintain a high activity of the biofilm.

(6) Secondary electrolysis

The effluent from the middle sedimentation tank 14 enters the electrolysis machine b15 again for electrolysis, so that the macromolecular organic matter that is difficult to biochemically undergoes electrolysis to undergo ring-opening and chain breaking, and is converted into small molecular organic matter that is easy to biochemically, increasing the B/C; during electrolysis, two adjacent The voltage between the electrodes was 2 V, and the current density was 200 mA/cm ² .

(7) MBR processing

The effluent from the secondary electrolysis enters the MBR system 16, which performs biochemical and membrane separation on the wastewater, degrades the remaining organic pollutants and removes suspended solids.

(8) Disinfection

After the wastewater is treated by the MBR system 16, the effluent is then sterilized by the electrolytic disinfection tank 17 to further remove chroma, sterilize the wastewater, and finally discharge it up to the standard.

(9) Sludge treatment

UASB anaerobic tank 10 in step (3) anaerobic treatment, anoxic tank 12, aerobic tank 13 and intermediate sedimentation tank 14 in step (5) A/O treatment, and sludge generated in step (7) MBR system 16 All enter the sludge tank 20 through the pipeline, and then the dehydration of the sludge filter press 21 reduces the volume of the sludge. After dehydration, the mud cake is incinerated, and the filtrate is returned to the regulating tank 8 in step (2) chemical decalcification .

The water quality indicators of the effluent were determined and are shown in Table 6.

Table 6 Water quality indicators of effluent

serial number project unit measured value serial number project unit measured value 1 BOD ₅ mg/L 15 5 Chroma times 20 2 COD _Cr mg/L 60 6 Ca ²⁺ mg/L 40 3 SS mg/L 50 7 water temperature ℃ 25 4 pH value the 6 the the the the

Claims (7)

1. the treatment unit of a tobacco sheet factory effluent is characterized in that: comprise mechanical coarse rack water collecting basin, rotation grid maker, air flotation pool, one-level decalcification reaction tank, secondary decalcification reaction tank, coagulation basin, preliminary sedimentation tank, equalizing tank, hydrolysis acidification pool, UASB anaerobic pond, electrolysis machine a, anoxic pond, Aerobic Pond, medium sediment pool, electrolysis machine b, MBR system, electrosterilization pond, sludge sump, sludge dehydration device, accident pool, gas collector and biogas gas holder;

The import of described mechanical coarse rack water collecting basin connects with the outlet of tobacco wastewater, machinery coarse rack water collecting basin water outlet connects with rotation grid maker water-in, rotation grid maker water outlet connects with the air flotation pool water-in, the air flotation pool water outlet connects with one-level decalcification reaction tank water-in, one-level decalcification reaction tank water outlet connects with secondary decalcification reaction tank water-in, secondary decalcification reaction tank water outlet connects with the coagulation basin water-in, the coagulation basin water outlet connects with the preliminary sedimentation tank water-in, the preliminary sedimentation tank water outlet connects with the equalizing tank water-in, the equalizing tank water outlet connects with the hydrolysis acidification pool water-in, the hydrolysis acidification pool water outlet connects with UASB anaerobic pond water-in, UASB anaerobic pond water outlet connects with electrolysis machine a water-in, electrolysis machine a water outlet connects with the anoxic pond water-in, the anoxic pond water outlet connects with the Aerobic Pond water-in, the Aerobic Pond water outlet connects with the medium sediment pool water-in, the medium sediment pool water outlet connects with electrolysis machine b water-in, electrolysis machine b water outlet connects with MBR system water-in, MBR system water outlet connects with electrosterilization pond water-in, and electrosterilization pond water outlet connects with discharge channel; The water-in of accident pool connects with the outlet of tobacco sheet factory effluent, and the accident pool water outlet connects with mechanical coarse rack water collecting basin water-in; UASB anaerobic pond pneumatic outlet connects with the gas collector import, and the gas collector outlet connects with secondary decalcification reaction tank water-in, and the pneumatic outlet of secondary decalcification reaction tank connects with the import of biogas gas holder; Throw out in preliminary sedimentation tank, UASB anaerobic pond, anoxic pond, Aerobic Pond, medium sediment pool and the MBR system (being mud) outlet all connects with the sludge sump import, and the sludge sump outlet connects with the sludge dehydration device import.

2. the treatment unit of a kind of tobacco sheet factory effluent as claimed in claim 1 is characterized in that: described air flotation pool is a kind of in gas distribution air supporting, electric floating, biological and chemical air supporting or the air-dissolving air-float.

3. the treatment unit of tobacco sheet factory effluent as claimed in claim 1, it is characterized in that: described coagulation basin has dispensing system and medicine system.

4. the treatment unit of a kind of tobacco sheet factory effluent as claimed in claim 1, it is characterized in that: described electrolysis machine a and electrolysis machine b are equipped with power supply and electrolyzer; Electrode materials in the described electrolyzer is a kind of in graphite, titanium, iron, aluminium, zinc, copper, lead, nickel, molybdenum, chromium, alloy and the nano-catalytic inert material.

5. as the treatment unit of claim 1 or 4 described a kind of tobacco sheet factory effluents, it is characterized in that: the top layer of described nano-catalytic noble electrode is coated with the metal oxide inertia catalyst coatings that crystal grain is 10～35nm, and the substrate of described nano-catalytic noble electrode is titanium plate or plastic plate.

6. the treatment unit of a kind of tobacco sheet factory effluent as claimed in claim 1 is characterized in that: the membrane module of described MBR system is selected from a kind of in polyvinylidene difluoride (PVDF) hollow-fibre membrane, polypropylene hollow fiber membrane, ps hollow fiber uf membrane, polyethersulfone hollow-fibre membrane, polyacrylonitrile hollow-fibre membrane and the PVC hollow fiber membrane.

7. as the treatment unit of claim 1 or 6 described a kind of tobacco sheet factory effluents, it is characterized in that: the membrane pore size of the membrane module of described MBR system is 0.10～0.2 μ m, operating pressure is-1～-50kPa, working temperature is 5～45 ℃.

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