CN111410366A

CN111410366A - Wastewater treatment system and treatment process

Info

Publication number: CN111410366A
Application number: CN202010253018.8A
Authority: CN
Inventors: 汪坤鹏
Original assignee: Shunjingyuan Intelligent Equipment Technology Development Shenzhen Co ltd
Current assignee: Shunjingyuan Intelligent Equipment Technology Development Shenzhen Co ltd
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2020-07-14

Abstract

The invention relates to a wastewater treatment system and a treatment process, which comprises a regulating tank, physicochemical integrated treatment equipment, biochemical membrane treatment integrated treatment equipment and a clean water tank which are communicated in sequence; the physicochemical integrated treatment equipment comprises a demulsification coagulation reaction tank, a flocculation tank and an air floatation machine which are sequentially communicated, wherein a slag discharge port of the air floatation machine is connected with a filter press, an adjusting tank is communicated with the demulsification coagulation reaction tank, the biochemical membrane treatment integrated treatment equipment comprises a hydrolysis acidification tank, an anaerobic tank and a membrane biological reaction tank which are sequentially connected and communicated, an aeration device and an MBR membrane separation and filtration system are arranged in the membrane biological reaction tank, a reflux pump is also arranged in the membrane biological reaction tank, a reflux pipe is connected to the reflux pump, and the reflux pipe is communicated with the anaerobic tank; the hydrolysis acidification tank is communicated with a water outlet of the air floatation machine, and a water outlet of the MBR membrane separation and filtration system is communicated with a clean water tank. The advantages are that: the method can economically and efficiently purify the hardware workpiece cleaning wastewater.

Description

Wastewater treatment system and treatment process

Technical Field

The invention relates to the field of wastewater, in particular to a wastewater treatment system and a treatment process.

Background

The cleaning of hardware workpieces is to clean the metal surface by physical and/or chemical methods, such as dust removal, decontamination, renovation, polishing and other operations, and is widely applied in industry, but because the hardware workpieces contain various metal elements and attached dirt has various sources, the cleaning requirements are different, and the operation methods and the processes are different, so that the cleaning wastewater contains various metal ions, granular fixed suspended matters, organic matters in the cleaning agent and other pollutants, and the direct discharge of the hardware cleaning wastewater is bound to cause serious harm to the domestic water and living environment of people, so that the economic, efficient and applicable hardware workpiece cleaning wastewater treatment system and treatment process are not slow to find.

Disclosure of Invention

One of the objects of the present invention is to provide a wastewater treatment system, which has the advantages that: the method can economically and efficiently purify the hardware workpiece cleaning wastewater.

The invention also aims to provide a wastewater treatment process, which has the advantages that: the method can economically and efficiently purify the hardware workpiece cleaning wastewater.

The above object of the present invention is achieved by the following technical solutions: a wastewater treatment system comprises a regulating tank, a physicochemical integrated treatment device, a biochemical membrane treatment integrated treatment device and a clean water tank which are sequentially communicated; the physicochemical integrated treatment equipment comprises a demulsification and coagulation reaction tank, a flocculation tank and an air flotation machine which are sequentially communicated, wherein a slag discharge port of the air flotation machine is connected with a filter press, the adjusting tank is communicated with the demulsification and coagulation reaction tank, a first filling port is arranged on the demulsification and coagulation reaction tank, and a second filling port is arranged on the flocculation tank;

the integrated treatment equipment for the biochemical membrane treatment comprises a hydrolysis acidification tank, an anaerobic tank and a membrane biological reaction tank which are sequentially connected and communicated, wherein an aeration device and an MBR membrane separation and filtration system are arranged in the membrane biological reaction tank, a reflux pump is also arranged in the membrane biological reaction tank, the reflux pump is connected with a reflux pipe, and the reflux pipe is communicated with the anaerobic tank; the hydrolysis acidification tank is communicated with a water outlet of the air floatation machine, and a water outlet of the MBR membrane separation and filtration system is communicated with a clean water tank.

Through the technical scheme, the hardware workpiece cleaning wastewater can be economically and efficiently purified. Cleaning waste water, discharging into an adjusting tank for preliminary precipitation, then sending into a demulsification and coagulation reaction tank, adding a reagent A into the demulsification and coagulation reaction tank for demulsification and metal ion removal reaction to achieve oil stain resolution and metal ion concentration to form fine particles; then, the cleaning wastewater enters a flocculation tank, and a reagent B is added into the flocculation tank to form a feathery object from a solid suspension in the wastewater; then the cleaning wastewater enters an air flotation machine to realize the separation of water and suspended matters, the separated suspended matters and a small amount of water enter a filter press to be subjected to filter pressing, and the rest clear water enters a hydrolysis acidification tank; under the action of the hydrolysis acidification tank, macromolecule organic matters in the clear water are converted into micromolecule organic matters, and insoluble organic matters are converted into soluble organic matters; then clear water enters an anaerobic tank, denitrifying bacteria in the anaerobic tank reduce a large amount of NO 3-N and NO 2-N brought in the water into N2 by using organic matters in the sewage as a carbon source and release the N2 to the air, so that the BOD5 concentration in the water is continuously reduced, and the NOx-N concentration is greatly reduced; then clear water enters a membrane biological reaction tank, and organic matters are biochemically degraded by aerobic microorganisms; organic nitrogen is aminated and then nitrified to enable the concentration of NH 3-N to be remarkably reduced, but clear water is pumped into the anaerobic tank through a return pump in a recycling mode along with the increase of the concentration of NOx-N in the nitrification process, and the NOx-N is reduced into N2 by denitrifying bacteria and released to the air; in addition, the aeration device continuously supplies oxygen to the membrane biological reaction tank and performs aeration cleaning on an MBR membrane component in the MBR membrane separation and filtration system; and under the action of the MBR membrane separation and filtration system, the water reaching the standard is discharged to a clean water tank from a water outlet of the MBR membrane separation and filtration system.

The invention is further configured to: the device comprises at least two adjusting tanks, wherein the upper parts of the adjusting tanks are sequentially communicated, the depth of each adjusting tank is gradually reduced along the water flow direction, and the adjusting tank at the tail end is communicated with the demulsification and coagulation reaction tank.

By adopting the technical scheme, the precipitable substances in the cleaning wastewater are subjected to full precipitation and fractional precipitation; the depth of the adjusting tank is gradually reduced along the water flow direction, and precipitable substances with different particle sizes are precipitated into different adjusting tanks by utilizing the shallow tank theory.

The invention is further configured to: the demulsification and coagulation reaction tank, the flocculation tank, the air floatation machine and the biochemical membrane treatment integrated treatment equipment are all arranged on the supporting platform, and the water outlet of the air floatation machine is higher than the biochemical membrane treatment integrated treatment equipment; the footboard is installed to supporting platform one side, around the supporting platform with the footboard both sides all are equipped with the guardrail.

By adopting the technical scheme, the supporting platform supports the demulsification-coagulation reaction tank, the flocculation tank, the air floatation machine and the biochemical membrane treatment integrated treatment equipment, so that the demulsification-coagulation reaction tank, the flocculation tank, the air floatation machine and the biochemical membrane treatment integrated treatment equipment are prevented from being soaked by rainwater; the arrangement of the pedal is convenient for workers to climb on the supporting platform to overhaul the demulsification-coagulation reaction tank, the flocculation tank, the air flotation machine and the biochemical membrane treatment integrated treatment equipment; the setting of guardrail is used for protecting the staff, avoids the staff to be out of order to fall down from supporting platform or footboard.

The invention is further configured to: and the demulsification and coagulation reaction tank and the flocculation tank are both provided with stirring mechanisms.

Through above-mentioned technical scheme, make medicine and washing waste water mix more even to make medicine can react with the material in the washing waste water fast.

The invention is further configured to: the materialization integration treatment facility still includes that reagent A stores bucket and reagent B stores the bucket, reagent A stores and is connected and communicate between bucket and the first filling mouth and has first dosing pipe, reagent B stores and is connected and communicate between bucket and the second filling mouth and has second dosing pipe, install first dosing pump on the first dosing pipe, install the second on the second dosing pipe and add the medicine dosage pump.

Through the technical scheme, the agents can be added into the demulsification-coagulation reaction tank and the flocculation tank more accurately and more conveniently.

The invention is further configured to: the MBR membrane separation and filtration system comprises an MBR membrane assembly, and a water outlet mechanism and a back-washing mechanism which are connected to the MBR membrane assembly, wherein the water outlet mechanism is communicated with the clean water tank.

By adopting the technical scheme, under the action of the water outlet mechanism, water in the membrane biological reaction tank is filtered by the MBR membrane module and is discharged into the clean water tank; when the sludge accumulated on the MBR membrane module is too much, the backwashing mechanism can be opened to perform backwashing on the MBR membrane module, and the water performance of the MBR membrane module is recovered.

A wastewater treatment process adopts a wastewater treatment system to execute the following processes:

sending the cleaning wastewater in the equalizing basin into a demulsification coagulation reaction tank, adding a reagent A in the demulsification coagulation reaction tank to perform demulsification and metal ion removal reaction, achieving oil stain resolution and metal ion concentration, and forming fine particles, wherein the reagent A comprises: 72-79 parts of polyaluminum chloride, 17-22 parts of calcium chloride and 0.5-1 part of ferrous acetate;

then the washing waste water enters a flocculation tank, a reagent B is added into the flocculation tank, so that solid suspension in the waste water forms a feathery object, and the reagent B comprises: 35-45 parts of polyacrylamide, 25-35 parts of sodium chloride, 7-13 parts of sodium hydroxide and 15-20 parts of sodium silicate; the adding weight ratio of the reagent A to the reagent B is 1:10 to 10: 1; then the cleaning wastewater enters an air flotation machine to realize the separation of water and suspended matters, the separated suspended matters and a small amount of water enter a filter press to be subjected to filter pressing, and the rest clear water enters a hydrolysis acidification tank;

under the action of the hydrolysis acidification tank, macromolecule organic matters in the clear water are converted into micromolecule organic matters, and insoluble organic matters are converted into soluble organic matters;

then clear water enters an anaerobic tank, denitrifying bacteria in the anaerobic tank reduce a large amount of NO 3-N and NO 2-N brought in the water into N2 by using organic matters in the sewage as a carbon source and release the N2 to the air, so that the BOD5 concentration in the water is continuously reduced, and the NOx-N concentration is greatly reduced;

then clear water enters a membrane biological reaction tank, and organic matters are biochemically degraded by aerobic microorganisms; organic nitrogen is aminated and then nitrified to enable the concentration of NH 3-N to be remarkably reduced, but clear water is pumped into the anaerobic tank through a return pump in a recycling mode along with the increase of the concentration of NOx-N in the nitrification process, and the NOx-N is reduced into N2 by denitrifying bacteria and released to the air; in addition, the aeration device continuously supplies oxygen to the membrane biological reaction tank and performs aeration cleaning on an MBR membrane component in the MBR membrane separation and filtration system; and under the action of the MBR membrane separation and filtration system, the water reaching the standard is discharged to a clean water tank from a water outlet of the MBR membrane separation and filtration system.

Through the technical scheme, the hardware workpiece cleaning wastewater can be economically and efficiently purified.

The reagent A has the functions of breaking emulsification, changing the surface potential of dispersed solid suspended matters and destroying the electrical balance of metal ions, so that oil stains in the wastewater are resolved, the solid suspended matters are gradually gathered, coulomb repulsion among the metal ions is reduced, and the oil stains, the solid suspended matters and the metal ions are mixed together to form a large amount of aggregates. The reagent B has the function of further fusing and growing the aggregation body which envelops and nets a large amount of solid suspended matters, metal ions and the like in the wastewater, and further fully adsorbing and entrapping the residual pollutants in the water in the period, so that a large amount of colloidal-feather-shaped flocs are generated and can be separated by precipitation, centrifugation or other physical methods, and the content of various metal ions, solution solid suspended matters and other pollutants in the wastewater can be greatly reduced.

In the reagent A of the present invention, polyaluminum chloride is used as a main component. Polyaluminum chloride (PAC) is a water-soluble inorganic high molecular polymer, is a yellow or light yellow, dark brown and dark gray resin-like solid, and can generate physicochemical processes such as charge neutralization, adsorption bridging, net trapping, rolling sweeping and the like in wastewater through the bridging action of hydroxide ions and the aggregation action of polyvalent anions to aggregate solid suspended matters and metal ions. In the present invention, when the content of polyaluminum chloride in the agent a is less than 72 parts by weight, it will be difficult to sufficiently exert the effect of aggregating solid suspensions and metal ions of polyaluminum chloride; when the content of the polyaluminum chloride in the agent a is more than 79 parts by weight, the content of other components is too small to exert an auxiliary effect, and the application effect of the agent a is rather lowered.

The reagent A also contains calcium chloride which can be matched with polyaluminium chloride, so that the ionic strength in water is increased, the precipitation and aggregation of non-polar substances are promoted, the charge neutralization is promoted, and the aggregation of metal ions is accelerated. In the present invention, when the content of polyaluminum chloride in the agent a is less than 17 parts by weight, it is not sufficient to effectively increase the ionic strength in water; on the other hand, when the content of the polyaluminum chloride in the agent A is more than 22 parts by weight, an excessive amount of calcium ions remain in the water, adversely affecting the effect of the final water treatment.

In addition, the reagent A also comprises ferrous acetate, which can obviously improve the effect of aggregating solid suspended matters and metal ions of the polyaluminium chloride, and the reason is that the ferrous acetate can greatly improve the dispersibility of the polyaluminium chloride in wastewater, increase the contact area with the solid suspended matters and the metal ions, enable the generated aggregate to show a colloidal form, and greatly improve the adsorption performance of the polyaluminium chloride and the stability of the product. In the invention, when the content of ferrous acetate in the reagent A is less than 0.5 part by weight, the aim of improving the dispersibility of the polyaluminium chloride in the wastewater to increase the adsorption area is difficult to realize; when the content of the ferrous acetate in the reagent A is more than 1 part by weight, the bridging effect of hydroxide ions in the polyaluminium chloride is destroyed, and the water treatment effect is reduced.

In the reagent B of the present invention, polyacrylamide contains a large amount of amide groups in its structural unit, so that it has very good water solubility, and is easily hydrogen-bonded in water, and also forms a network structure by mechanical entanglement between hydrogen bonds and molecular chains, thereby capturing a large amount of aggregates produced by treatment with the reagent a in the net-like wastewater and producing a large amount of colloidal flocs. Further, the polyacrylamide is preferably anionic. In the present invention, when the content of polyacrylamide in the reagent B is less than 35 parts by weight, it is insufficient to completely separate out the above-mentioned aggregate; when the content of polyacrylamide in the agent B is more than 45 parts by weight, the polyacrylamide itself is excessively entangled, and the aggregate is prevented from entering into the molecular pores to be captured, so that it is difficult to exert the maximum effect of polyacrylamide.

The present invention also includes sodium chloride and sodium hydroxide in reagent B, and preferably, the weight ratio of sodium chloride to sodium hydroxide may be 2:1 to 3: 1. By adopting the sodium chloride and the sodium hydroxide in the content and the proportion, the reagent B can effectively adjust the degree of hydrogen bonds and mechanical entanglement among molecular chains in the polyacrylamide, so that the polyacrylamide is in a semi-dispersed state of mutual connection, and the mutual connection cannot be easily formed into floccules due to too few formed hydrogen bonds and entanglement, and cannot be easily netted by self-collapsing due to too much formed hydrogen bonds and entanglement.

The invention also comprises sodium silicate in the reagent B. Sodium silicates can be represented by the formula Na2O · nSiO2, where n represents the modulus, the larger the number, the greater the Si content, the less soluble the corresponding sodium silicate is in water and the greater the viscosity. In the present invention, the modulus is preferably 1, i.e., the sodium silicate is preferably Na2O · SiO2, which may also be expressed as Na2SiO 3. Sodium silicate can play the synergism to polyacrylamide, perfects and richens the network structure of its formation for the floccule volume that finally forms is great, and stability is higher, separates with the water easily, and can also further promote adsorption and the parcel of polyacrylamide to pollutants such as the remaining solid suspended solid in water, metal ion and hold in the palm, improves the effect of water treatment.

Preferably, the reagent a comprises: 75 parts of polyaluminium chloride, 20 parts of calcium chloride and 0.8 part of ferrous acetate. At the above preferred weight parts, the agent a can more effectively exert the action of promoting the aggregation of solid suspended matter and metal ions in wastewater.

The reagent A of the present invention further contains 0.2 to 0.5 parts by weight of aluminum acetate, preferably 0.3 to 0.4 parts by weight, and more preferably 0.4 parts by weight. The aluminum acetate (Al (CH3COO) (OH)2) improves the aggregation effect of the reagent A on pollutants, particularly on solid suspended matters and metal ions on the whole, greatly improves the stability of the reagent A, and effectively avoids the backward movement of the aggregated solid suspended matters and metal ions to water.

Preferably, the reagent B comprises: 39 parts of polyacrylamide, 28 parts of sodium chloride, 10 parts of sodium hydroxide and 18 parts of sodium silicate. At the above preferred weight parts, the reagent B can effectively net the aggregates to form flocs and further remove the pollutants such as solid suspended matters and metal ions remaining in the water.

In conclusion, the beneficial technical effects of the invention are as follows:

1. the method can economically and efficiently purify the hardware workpiece cleaning wastewater;

2. the reagent A and the reagent B can effectively flocculate and purify hardware workpiece cleaning wastewater, have high flocculating and precipitating speed on pollutants, wide pH application range and excellent water purifying effect, and can greatly reduce the content of various metal ions and solution solid suspended matters contained in the wastewater.

Drawings

FIG. 1 is a schematic structural diagram of the first embodiment;

FIG. 2 is a schematic diagram of the second embodiment.

In the figure, 1, a regulating reservoir; 21. a demulsification and coagulation reaction tank; 22. a flocculation tank; 23. an air flotation machine; 24. a liquid inlet pipe; 241. a liquid inlet pump; 25. a first connecting pipe; 251. a first transfer pump; 26. a second connecting pipe; 261. a second transfer pump; 27. a reagent A storage barrel; 271. a first dosing tube; 272. a first dosing metering pump; 28. a reagent B storage barrel; 281. a second dosing tube; 282. a second dosing metering pump; 29. a stirring mechanism; 3. a filter press; 41. a hydrolysis acidification pool; 411. a third connecting pipe; 42. an anaerobic tank; 43. a membrane biological reaction tank; 44. a reflux pump; 45. a return pipe; 46. an aeration device; 471. an MBR membrane module; 472. a water outlet pipe; 473. a self-priming pump; 474. a drain pipe; 475. a backwash pipe; 476. a three-way valve; 477. a backwash pump; 478. back flushing the water inlet pipe; 5. a clean water tank; 6. a sludge tank; 61. a blow-off pipe; 62. a sewage pump; 7. a support platform; 8. a pedal; 9. a guardrail; 10. rain-proof canopy.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Sources of materials

Polyaluminum chloride, the Al2O3 content is more than or equal to 29 percent, the basicity is 40.0 percent, and the polyaluminum chloride is purchased from Henan fountain water treatment limited company;

calcium chloride (CaCl2) with content of 96% or more, and is purchased from Guangjiang environmental protection science and technology Limited in Henan;

ferrous acetate (Fe (CH3COO)2) with purity of 99% and purchased from Hubei Xinkang pharmaceutical chemical Co., Ltd;

aluminum acetate (Al (CH3COO) (OH)2) with purity of 98% is purchased from Hubei Qifei pharmaceutical chemical Co., Ltd;

polyacrylamide with solid content more than or equal to 90% and purchased from Henan China spring Water treatment Co., Ltd;

sodium chloride (NaCl), 99% pure, purchased from tokyo chemical reagents gmbh;

sodium hydroxide (NaOH), 90% pure, purchased from Tianjin Tonglida chemical Co., Ltd;

sodium silicate (Na2SiO3) with a purity of 99% was purchased from Suzhou Yiheng fine chemical Co., Ltd.

Example 1:

referring to fig. 1, the wastewater treatment system disclosed by the invention comprises an adjusting tank 1, a physicochemical integrated treatment device, a filter press 3, a biochemical membrane treatment integrated treatment device and a clean water tank 5. Equalizing basin 1 mainly used deposits and deposits temporarily washing waste water, and equalizing basin 1 sets up two at least, and equalizing basin 1 is provided with threely in this embodiment, and 1 upper portions of equalizing basin communicate in proper order, and the degree of depth of each equalizing basin 1 reduces along the rivers direction gradually to utilize shallow pond theory to make the precipitable thing of different particle diameters deposit to in the equalizing basin 1 of difference.

Referring to fig. 1, the atomization integrated treatment equipment comprises a demulsification and coagulation reaction tank 21, a flocculation tank 22 and an air flotation machine 23, wherein a liquid inlet pipe 24 is connected and communicated between the upper part of a regulating tank 1 at the tail end and the demulsification and coagulation reaction tank 21, a liquid inlet pump 241 is installed on the liquid inlet pipe 24, and the cleaning waste liquid in the regulating tank 1 can be pumped into the demulsification and coagulation reaction tank 21 through the liquid inlet pump 241. A first connecting pipe 25 is connected and communicated between the demulsification and coagulation reaction tank 21 and the flocculation tank 22, a first transfer pump 251 is arranged on the first connecting pipe 25, and the cleaning waste liquid in the demulsification and coagulation reaction tank 21 can be pumped into the flocculation tank 22 through the first transfer pump 251. A second connecting pipe 26 is connected and communicated between the flocculation tank 22 and the air flotation machine 23, a second transfer pump 261 is installed on the second connecting pipe 26, and the cleaning waste liquid in the flocculation tank 22 can be pumped into the air flotation machine 23 through the second transfer pump 261.

The physicochemical integrated treatment equipment further comprises a reagent A storage barrel 27 and a reagent B storage barrel 28, wherein a first filling port is arranged on the reagent A storage barrel 27, and a second filling port is arranged on the reagent B storage barrel 28. A first dosing pipe 271 is connected and communicated between the reagent A storage barrel 27 and the first filling port, a second dosing pipe 281 is connected and communicated between the reagent B storage barrel 28 and the second filling port, a first dosing pump 272 is installed on the first dosing pipe 271, and a second dosing pump is installed on the second dosing pipe 281. The reagent A in the reagent A storage barrel 27 can be pumped into the emulsion breaking coagulation reaction tank 21 by starting the first dosing metering pump 272, and the reagent B in the reagent B storage barrel 28 can be pumped into the flocculation tank 22 by starting the second dosing pump. Stirring mechanisms 29 are respectively arranged in the demulsification and coagulation reaction tank 21 and the flocculation tank 22 so as to stir the cleaning waste liquid when adding the chemicals and promote the reaction and the sufficient mixing of the chemicals and the cleaning waste liquid.

Referring to fig. 1, a sludge discharge port of the air flotation machine 23 is communicated with a sludge tank 6, a discharge pipe 61 is connected between the sludge tank 6 and the filter press 3, and a discharge pump 62 is installed on the discharge pipe 61; the sludge discharged from the air flotation machine 23 first flows into the sludge tank 6, and then the sludge enters the filter press machine 3 for sludge-water separation under the action of the sewage pump 62.

Referring to fig. 1, the integrated treatment equipment for biochemical membrane treatment comprises a hydrolysis acidification tank 41, an anaerobic tank 42 and a membrane biological reaction tank 43 which are arranged in parallel, wherein the upper part of the hydrolysis acidification tank 41 is communicated with the water outlet of the air floatation machine 23 through a third connecting pipe 411, the hydrolysis acidification tank 41, the anaerobic tank 42 and the membrane biological reaction tank 43 are communicated in sequence, and during work, water flows through the hydrolysis acidification tank 41, the anaerobic tank 42 and the membrane biological reaction tank 43 in sequence.

The membrane biological reaction tank 43 is provided with a reflux pump 44, an aeration device 46 and an MBR membrane separation and filtration system. A return pipe 45 is connected to the return pump 44, one end of the return pipe 45, which is far away from the return pump 44, extends into the anaerobic tank 42, and when the return pump 44 works, water in the membrane biological reaction tank 43 returns to the anaerobic tank 42 through the return pipe 45 under the action of the return pump 44.

Referring to fig. 1, the MBR membrane separation and filtration system comprises an MBR membrane module 471 arranged in a membrane bioreactor 43, and a water outlet mechanism and a back flush mechanism connected to the MBR membrane module 471, wherein the water outlet mechanism comprises a water outlet pipe 472 connected to a water outlet of the MBR membrane module 471, a self-priming pump 473 installed at one end of the water outlet pipe 472 far away from the MBR membrane module 471, and a water outlet pipe 474 connected between a water outlet of the self-priming pump 473 and a clean water tank 5, a large number of hollow fiber membranes are arranged in the MBR membrane module 471, the membrane aperture is 0.1-0.2 μm and smaller than the diameter of bacteria, the MBR membrane belongs to the grade of a micro/ultra-filtration membrane, bacteria in water can be effectively intercepted and removed, and the amount of subsequently added disinfectant is reduced.

The backwashing mechanism includes a backwashing pipe 475 connected to the water outlet pipe 472 by a three-way valve 476, a backwashing pump 477 installed at an end of the backwashing pipe 475 remote from the three-way valve 476, and a backwashing water inlet pipe 478 connected between a water inlet of the backwashing pump 477 and the clean water tank 5. When the self-priming pump 473 works, the backwashing pipe 475 is not communicated with the water outlet pipe 472, and water in the membrane biological reaction tank 43 is filtered by the MBR membrane module 471 and then sequentially enters the clean water tank 5 through the water outlet pipe 472, the self-priming pump 473 and the water outlet pipe 474; when the sludge adhered to the MBR membrane module 471 is excessive, the backwashing pump 477 is opened, the three-way valve 476 is adjusted to enable the backwashing pipe 475 to be communicated with the water outlet pipe 472, and the water in the clean water tank 5 enters the MBR membrane module 471 through the backwashing water inlet pipe 478, the backwashing pump 477, the backwashing pipe 475 and the water outlet pipe 472 to perform backwashing on the MBR membrane module 471 so as to recover the water passing performance of the MBR membrane module 471.

Example 2:

referring to fig. 2, the present embodiment is different from embodiment 1 in that: the wastewater treatment system also comprises a supporting platform 7, wherein the demulsification coagulation reaction tank 21, the flocculation tank 22, the air flotation machine 23, the reagent storage barrel A, the reagent storage barrel B and the biochemical membrane treatment integrated treatment equipment are arranged on the supporting platform 7, and the water outlet of the air flotation machine 23 is higher than the biochemical membrane treatment integrated treatment equipment; a pedal 8 is arranged on one side of the supporting platform 7, and guardrails 9 are arranged around the supporting platform 7 and on two sides of the pedal 8. A rain-proof shed 10 is also arranged on the supporting platform 7 to prevent the medicament from solarization and failure, and electric elements from short circuit and metal aging.

Example 3:

a wastewater treatment process using the wastewater treatment system disclosed in example 1 to perform the following processes: the method comprises the steps of cleaning waste water, discharging the cleaned waste water into an adjusting tank 1 for preliminary precipitation, pumping the waste water into a demulsification and coagulation reaction tank 21 through a liquid inlet pump 241, adding a reagent A into the demulsification and coagulation reaction tank 21, and stirring the waste water by a stirring mechanism 29 at the speed of 50-70 rpm for 7-10 min. The emulsification effect is broken, the surface potential of the dispersed solid suspended matters is changed, and the electrical balance of the metal ions is destroyed, so that the oil stains in the wastewater are resolved, the solid suspended matters are gradually gathered, the coulomb repulsion among the metal ions is reduced, and the oil stains, the solid suspended matters and the metal ions are mixed together to form a large amount of aggregates. In this example, reagent A included: 75 parts of polyaluminium chloride, 20 parts of calcium chloride and 0.8 part of ferrous acetate.

Then the cleaning waste water enters the flocculation tank 22 under the action of the first transfer pump 251, a reagent B is added into the flocculation tank 22, and the stirring mechanism 29 is used for stirring for 20-25 min at the speed of 0-50 rpm to accelerate the reaction, so that the preliminarily gathered aggregates in the waste water further fuse and grow up and cover a large amount of aggregates of suspended solids, metal ions and the like, and further fully adsorb and wrap the pollutants remained in the water in the process, thereby generating a large amount of glue feather-like flocs, wherein the reagent B comprises 39 parts by weight of polyacrylamide, 28 parts by weight of sodium chloride, 10 parts by weight of sodium hydroxide and 18 parts by weight of sodium silicate, the weight ratio of the reagent A to the reagent B can be 1:10 to 10:1, preferably 1:3 to 3:1, more preferably 1:1, in the embodiment, the dosage of the reagent A and the reagent B are both 0.02-0.5 g/L.

Then the cleaning wastewater enters the air floating machine 23 under the action of the second transfer pump 261, the water and the suspended matters are separated under the action of the air floating machine 23, the separated suspended matters and a small amount of water enter the filter press 3 for filter pressing, and the rest clear water enters the hydrolysis acidification tank 41;

macromolecule organic matters in the clear water are converted into micromolecule organic matters under the action of the hydrolysis acidification tank 41, and insoluble organic matters are converted into soluble organic matters; then clear water enters the anaerobic tank 42, denitrifying bacteria in the anaerobic tank 42 reduce a large amount of NO 3-N and NO 2-N brought in the water into N2 by using organic matters in the sewage as a carbon source and release the N2 to the air, so that the BOD5 concentration in the water is continuously reduced, and the NOx-N concentration is greatly reduced; then clear water enters the membrane biological reaction tank 43, and organic matters are biochemically degraded by aerobic microorganisms; the organic nitrogen is ammoniated and then nitrified, so that the concentration of NH 3-N is obviously reduced, but as the concentration of NOx-N is increased in the nitrification process, clear water is pumped into the anaerobic tank 42 through the reflux pump 44 in a recycling mode, and the NOx-N is reduced into N2 by denitrifying bacteria and released to the air; in addition, the aeration device 46 continuously supplies oxygen to the membrane biological reaction tank 43 and performs aeration cleaning on an MBR membrane module 471 in the MBR membrane separation and filtration system; and under the action of the MBR membrane separation and filtration system, the water reaching the standard is discharged to a clean water tank 5 from a water outlet of the MBR membrane separation and filtration system.

Example 4

The present embodiment is different from embodiment 3 in that:

the reagent A comprises: 74 parts of polyaluminum chloride, 20 parts of calcium chloride, 0.7 part of ferrous acetate, and

the reagent B comprises: 41 parts of polyacrylamide, 27 parts of sodium chloride, 11 parts of sodium hydroxide and 17 parts of sodium silicate.

Example 5

The present embodiment is different from embodiment 3 in that:

the reagent A comprises: 76 parts of polyaluminum chloride, 19 parts of calcium chloride, 0.9 part of ferrous acetate, and

the reagent B comprises: 38 parts of polyacrylamide, 29 parts of sodium chloride, 10 parts of sodium hydroxide and 19 parts of sodium silicate.

Example 6

The present embodiment is different from embodiment 3 in that:

the reagent A comprises: 72 parts by weight of polyaluminum chloride, 22 parts by weight of calcium chloride, 0.5 part by weight of ferrous acetate, and

the reagent B comprises: 45 parts of polyacrylamide, 25 parts of sodium chloride, 12 parts of sodium hydroxide and 15 parts of sodium silicate.

Example 7

The present embodiment is different from embodiment 3 in that:

the reagent A comprises: 79 parts by weight of polyaluminum chloride, 17 parts by weight of calcium chloride, 1 part by weight of ferrous acetate, and

the reagent B comprises: 35 parts of polyacrylamide, 35 parts of sodium chloride, 13 parts of sodium hydroxide and 20 parts of sodium silicate.

Example 8

The present embodiment is different from embodiment 3 in that:

the reagent A comprises: 75 parts by weight of polyaluminum chloride, 20 parts by weight of calcium chloride, 0.8 part by weight of ferrous acetate, 0.4 part by weight of aluminum acetate, and

the reagent B comprises: 39 parts of polyacrylamide, 28 parts of sodium chloride, 10 parts of sodium hydroxide and 18 parts of sodium silicate.

Example 9

The present embodiment is different from embodiment 3 in that:

Comparative example 1

The present embodiment is different from embodiment 3 in that:

the reagent A comprises: 65 parts by weight of polyaluminum chloride, 27 parts by weight of calcium chloride, 0.2 part by weight of ferrous acetate, and

the reagent B comprises: 50 parts of polyacrylamide, 18 parts of sodium chloride, 18 parts of sodium hydroxide and 10 parts of sodium silicate.

Comparative example 2

The present embodiment is different from embodiment 3 in that:

the reagent A comprises: 85 parts by weight of polyaluminum chloride, 12 parts by weight of calcium chloride, 1.5 parts by weight of ferrous acetate, and

the reagent B comprises: 30 parts of polyacrylamide, 40 parts of sodium chloride, 5 parts of sodium hydroxide and 25 parts of sodium silicate.

Comparative example 3

The present embodiment is different from embodiment 3 in that: and the weight ratio of the reagent A to the reagent B is 15:1, wherein the compositions of the reagent A and the reagent B are the same as those of the reagent 3.

Comparative example 4

The present embodiment is different from embodiment 3 in that: the weight ratio of the reagent A to the reagent B is 1:15, wherein the compositions of the reagent A and the reagent B are the same as those of the example 3.

Test examples

The wastewater from cleaning of hardware was sampled and treated with 0.1 g/L of wastewater with the reagents A and B of examples 3 to 9 and comparative examples 1 to 4, respectively, by adding reagent A to the wastewater to be cleaned and stirring at 60rpm for 10min, then adding reagent B and stirring at 40rpm for 25min, and finally, allowing to stand and settle for 10min, and the supernatant was taken to test the content of metal ions (μ g/L) and the content of suspended solid (mg/L), and the results are shown in Table 1 below.

ND: not detected out

In the above table 1, metal ions such as total chromium, total cadmium, total manganese, total lead, total copper, and total zinc in wastewater were detected by HJ700-2014 inductively coupled plasma mass spectrometry for determination of 65 elements in water, total mercury was detected by HJ694-2014 atomic fluorescence method for determination of mercury, arsenic, selenium, bismuth, and antimony in water, and suspended matter was detected by GB/T11901-. Referring to table 1, it can be seen that the use of the reagents a and B according to examples 3 to 9 of the present invention can effectively reduce metal ions and solid suspensions in wastewater, and particularly, the purification effect can be further improved by adding aluminum acetate to the reagent a. In contrast, it has been difficult to obtain excellent water treatment effects when the contents of the respective components in the agent a and the agent B of comparative examples 1 and 2 are outside the range defined in the present invention, and the removal effects of the present invention on contaminants are not achieved when the proportions of the agent a and the agent B of comparative examples 3 and 4 are outside the range defined in the present invention.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims

1. A wastewater treatment system is characterized in that: comprises a regulating tank (1), a physicochemical integrated treatment device, a biochemical membrane treatment integrated treatment device and a clean water tank (5) which are communicated in sequence;

the physicochemical integrated treatment equipment comprises a demulsification and coagulation reaction tank (21), a flocculation tank (22) and an air flotation machine (23) which are sequentially communicated, wherein a slag discharge port of the air flotation machine (23) is connected with a filter press (3), the adjusting tank (1) is communicated with the demulsification and coagulation reaction tank (21), a first filling port is arranged on the demulsification and coagulation reaction tank (21), and a second filling port is arranged on the flocculation tank (22);

the integrated treatment equipment for the biochemical membrane treatment comprises a hydrolysis acidification tank (41), an anaerobic tank (42) and a membrane biological reaction tank (43) which are sequentially connected and communicated, wherein an aeration device (46) and an MBR membrane separation and filtration system are arranged in the membrane biological reaction tank (43), a reflux pump (44) is further arranged in the membrane biological reaction tank (43), a reflux pipe (45) is connected to the reflux pump (44), and the reflux pipe (45) is communicated with the anaerobic tank (42); the hydrolysis acidification tank (41) is communicated with a water outlet of the air floatation machine (23), and a water outlet of the MBR membrane separation and filtration system is communicated with the clean water tank (5).

2. A wastewater treatment system according to claim 1, characterized in that: the device is characterized in that at least two regulating ponds (1) are arranged, the upper parts of the regulating ponds (1) are sequentially communicated, the depth of each regulating pond (1) is gradually reduced along the water flow direction, and the regulating pond (1) at the tail end is communicated with the demulsification and coagulation reaction pond (21).

3. A wastewater treatment system according to claim 1, characterized in that: the device is characterized by also comprising a supporting platform (7), wherein the demulsification-coagulation reaction tank (21), the flocculation tank (22), the air floatation machine (23) and the biochemical membrane treatment integrated treatment equipment are all arranged on the supporting platform (7), and the water outlet of the air floatation machine (23) is higher than the biochemical membrane treatment integrated treatment equipment; footboard (8) are installed to supporting platform (7) one side, supporting platform (7) around with footboard (8) both sides all are equipped with guardrail (9).

4. A wastewater treatment system according to claim 1, characterized in that: and the demulsification and coagulation reaction tank (21) and the flocculation tank (22) are both provided with stirring mechanisms (29).

5. A wastewater treatment system according to claim 1, characterized in that: materialization integration treatment facility still includes that reagent A stores bucket (27) and reagent B stores bucket (28), reagent A stores and is connected and communicate between bucket (27) and the first filling mouth and has first medicine pipe (271), reagent B stores and is connected and communicate between bucket (28) and the second filling mouth and has second medicine pipe (281), install first medicine dosing pump (272) on first medicine pipe (271), install the second on second medicine dosing pipe (281) and add the medicine dosage pump.

6. A wastewater treatment system according to claim 1, characterized in that: the MBR membrane separation and filtration system comprises an MBR membrane assembly (471) and a water outlet mechanism and a back flush mechanism which are connected to the MBR membrane assembly (471), wherein the water outlet mechanism is communicated with the clean water tank (5).

7. A wastewater treatment process is characterized in that: performing the following process using the wastewater treatment system of any of claims 1-6:

send into emulsion breaking coagulation reaction pond (21) with the washing waste water in equalizing basin (1) to add reagent A in emulsion breaking coagulation reaction pond (21) and break the emulsion and remove metal ion reaction, reach the oil stain and resolve and metal ion and concentrate, form tiny particle, reagent A includes: 72-79 parts of polyaluminum chloride, 17-22 parts of calcium chloride and 0.5-1 part of ferrous acetate;

then the washing waste water enters a flocculation tank (22), and a reagent B is added into the flocculation tank (22) to enable solid suspension in the waste water to form a feathery object, wherein the reagent B comprises: 35-45 parts of polyacrylamide, 25-35 parts of sodium chloride, 7-13 parts of sodium hydroxide and 15-20 parts of sodium silicate; the adding weight ratio of the reagent A to the reagent B is 1:10 to 10: 1;

then the cleaning wastewater enters an air flotation machine (23) to realize the separation of water and suspended matters, the separated suspended matters and a small amount of water enter a filter press (3) to be subjected to filter pressing, and the rest clear water enters a hydrolysis acidification tank (41);

macromolecule organic matters in the clear water are converted into micromolecule organic matters under the action of a hydrolysis acidification pool (41), and insoluble organic matters are converted into soluble organic matters;

then clear water enters an anaerobic tank (42), denitrifying bacteria in the anaerobic tank (42) utilize organic matters in sewage as a carbon source to reduce a large amount of NO 3-N and NO 2-N brought in the water into N2 and release the N2 to the air, so that the BOD5 concentration in the water continues to be reduced, and the NOx-N concentration is greatly reduced;

then clear water enters a membrane biological reaction tank (43), and organic matters are biochemically degraded by aerobic microorganisms; the organic nitrogen is ammoniated and then nitrified, so that the concentration of NH 3-N is reduced remarkably, but as the concentration of NOx-N is increased in the nitrification process, clear water is recycled and pumped into the anaerobic tank (42) through the return pump (44), and the denitrifying bacteria reduce the NOx-N into N2 again and release the N2 to the air; in addition, the aeration device (46) continuously supplies oxygen to the membrane biological reaction tank (43) and performs aeration cleaning on an MBR membrane component (471) in the MBR membrane separation and filtration system; and under the action of the MBR membrane separation and filtration system, the water reaching the standard is discharged to a clean water tank (5) from a water outlet of the MBR membrane separation and filtration system.

8. The process for treating wastewater according to claim 7, wherein: the reagent A comprises: 75 parts of polyaluminium chloride, 20 parts of calcium chloride and 0.8 part of ferrous acetate.

9. The process for treating wastewater according to claim 7, wherein: the reagent A further comprises 0.2-0.5 weight part of aluminum acetate.

10. The process for treating wastewater according to claim 7, wherein: the reagent B comprises: 39 parts of polyacrylamide, 28 parts of sodium chloride, 10 parts of sodium hydroxide and 18 parts of sodium silicate.