CN101219847A - Integrated ultrafiltration membrane coagulation/bioreactor water purification treatment method and device - Google Patents

Abstract

The invention discloses an integrated ultrafiltration membrane coagulation/bioreactor water purification treatment method and a device thereof. The present invention completes coagulation and biological reaction in the same reaction tank. The raw water enters the ultrafiltration membrane coagulation/bioreactor, and the activated sludge microorganisms in the reactor biodegrade the ammonia nitrogen and small molecular weight organic matter in the influent; A coagulant is added to the reactor to remove large molecular weight organic matter and phosphorus; finally, the submerged ultrafiltration membrane module installed in the reactor performs solid-liquid separation, and high-quality drinking water is prepared. There is a perforated aeration pipe at the bottom of the reactor, connected to a sludge discharge pipe, and the remaining sludge in the reactor is regularly discharged. In order to ensure the membrane flux, the ultrafiltration membrane module is regularly backwashed by the membrane backwashing system. The present invention organically combines coagulation, biological action and physical interception of ultrafiltration, significantly reduces engineering cost and operating cost, and is a novel high-efficiency, energy-saving and easy-to-maintain and manage drinking water deep purification process.

Description

Integrated ultrafiltration membrane coagulation/bioreactor water purification treatment method and device

technical field

The invention belongs to water treatment technology, and in particular relates to a drinking water advanced purification technology, in particular to an ultrafiltration membrane coagulation/bioreactor integrated drinking water advanced treatment method and a device thereof.

Background technique

Since the protection of water sources has not received enough attention for a long time, drinking water sources are generally polluted by nitrogen, phosphorus and organic matter, and many types of trace organic pollutants that are toxic to human body have been found in drinking water, such as carcinogenic, teratogenic, Mutagenic substances, etc. and chlorinated disinfection by-products. This makes conventional drinking water treatment processes, such as coagulation, sedimentation, filtration, and disinfection treatment processes, face severe challenges, and it is increasingly difficult for the effluent to meet the requirements of drinking water quality standards. In this context, the research and development of new and efficient drinking water deep purification process has important practical significance. With the development of water quality testing technology, many new water quality problems have been discovered, such as Giardia and Cryptosporidium, Daphnia and red worms, water biological stability, high ammonia nitrogen content and so on. For this reason, countries all over the world, including my country, have formulated stricter water quality hygiene standards for drinking water. The ozone-granular activated carbon treatment process, which once played an important role in ensuring the quality of drinking water, can no longer achieve satisfactory treatment results for the above water quality problems. For example, "two insects", daphnia, and algae cannot be removed 100%, and for high ammonia nitrogen content, it is difficult to reduce the ammonia nitrogen content > 2 ~ 3mg/l to the water quality standard of 0.5mg/l, etc. In addition, ozone oxidation can generate bromate, formaldehyde and other by-products that have serious toxic effects on the human body, which makes the widespread use of ozone questionable; some studies have pointed out that the bacterial content in the effluent water of granular activated carbon increased significantly, and the bacteria's chlorine resistance Enhanced, the fine carbon particles flowing out with the water will have an adverse effect on the subsequent disinfection effect. In this context, it is necessary to develop a drinking water advanced treatment process that is safer and more effective than ozone-granular activated carbon.

At present, in the field of drinking water treatment, ultrafiltration technology has received great attention. Ultrafiltration can effectively remove particulate matter in the water, reduce the turbidity of the effluent to below 0.1NTU, and remove macromolecular organic pollutants, almost 100% intercepting microorganisms such as two insects, daphnia, red worms, algae, bacteria and even viruses. However, the ability of ultrafiltration alone to remove dissolved organic matter in water is very limited, especially for small molecular weight and easily biodegradable organic matter, which can hardly be removed by ultrafiltration. However, this part of small molecular weight organic matter will cause water biological stability problems, causing bacteria to multiply in the pipe network again, deteriorating water quality. At the same time, ultrafiltration cannot remove nitrogen and phosphorus.

Contents of the invention

The purpose of the present invention is to develop a drinking water advanced treatment process and device that is convenient for engineering application, low in operation cost, and can significantly improve water quality. That is, an integrated ultrafiltration membrane coagulation/bioreactor water purification treatment method and a device thereof.

The treatment method of the present invention is that the coagulation and the biological reaction are organically combined and completed in the same reaction pool. The raw water to be treated enters the ultrafiltration membrane coagulation/bioreactor through the constant level water tank, and the activated sludge microorganisms in the reactor biodegrade the ammonia nitrogen and small molecular weight organic matter in the influent; the hydraulic retention time in the reactor is 10 In the range of ~30min, the sludge residence time is generally in the range of 5d ~ 30d; at the same time, the coagulant dosing system is added to the ultrafiltration membrane coagulation/bioreactor to remove large molecular weight organic matter and phosphorus. The coagulant can be one of aluminum sulfate, polyaluminum chloride, ferric chloride, polyferric sulfate or other various coagulants that can be used for drinking water production, or the above coagulant and polyacrylamide, etc. The coagulant aid is added at the same time; the submerged ultrafiltration membrane module is installed in the reactor, and its material can be polyvinylidene fluoride or polyvinyl chloride or other ultrafiltration membranes. The module form can be hollow fiber type or flat plate type; the suction pressure of the ultrafiltration membrane is controlled by the suction pump in the range of 10kPa ~ 50kPa, and the membrane flux is in the range of 5L/m ² ·h ~ 50L/m ² ·h Inside; the bottom of the reactor is equipped with a perforated aeration tube, and the air pump outside the reactor is used to aerate the reactor to provide dissolved oxygen for the biological reaction, and to carry out stirring and mixing and cleaning of the membrane filaments. The air-water ratio is 5:1 ~20:1 range; there is a sludge discharge valve and a sludge discharge pipe at the bottom of the reactor, and the excess sludge is regularly discharged out of the reactor; in order to ensure the membrane flux, the ultrafiltration membrane module is regularly backwashed, and the ultrafiltration membrane is used to discharge water , completed by the backwash pump, and the backflush cycle depends on the suction pressure and membrane flux of the ultrafiltration membrane module; when the ultrafiltration membrane module is backwashed, the outlet valve of the ultrafiltration membrane is closed, and the valve of the ultrafiltration backwash is opened at the same time. The ultrafiltration membrane module is backwashed by the filter backwashing pipeline system.

The invention relates to an integrated ultrafiltration membrane coagulation/bioreactor water purification treatment device, which consists of a water inlet control system, a reaction tank, a coagulation and agent dosing system, an ultrafiltration membrane module, an outlet water control system, a blast exposure Gas system, mud discharge system, membrane backwashing system, characterized in that: the water inlet control system is composed of lift pump 1, high level water tank 2, constant level water tank 3 connected by pipelines, also in the case of gravity flow However, it is composed of pipelines directly connected to the constant-level water tank 3; the reaction tank is an integrated ultrafiltration membrane coagulation/biological reaction tank 4, and the raw water to be treated enters the integrated reaction tank 4 through the constant-level water tank 3, which can be integrated The bottom of the chemical reaction pool 4 can also enter through valves and pipelines at the bottom of the side of the integrated reaction pool 4; the reaction pool 4 of the integrated reaction pool 4 is equipped with a coagulant dosing system 15, and the coagulant The dosing system 15 adds the coagulant to the space between the middle and lower part of the mixed liquid in the integrated reaction tank 4 and the upper part of the blast aeration system, which can be continuous dosing or regular dosing in timed intervals every day; The filter membrane module 5 is installed on the upper part of the mixed liquid in the integrated reaction tank 4, and its water outlet is connected to the suction pump 8 through the ultrafiltration water outlet valve 7, and the suction pressure of the suction pump 8 is measured by a vacuum gauge 9; It is an activated sludge microorganism that can biodegrade ammonia nitrogen and small molecular weight organic matter in the influent and a mixed liquid with the coagulant added; the bottom or side of the reaction tank 4 is equipped with a sludge discharge tank connected to the sewage tank The valve 14 and the sludge discharge pipe form a sludge discharge system to regularly discharge excess sludge every day; one or more sets of perforated aeration pipes 13 are installed in the lower part of the mixed liquid in the reaction tank, and the air inlet end is connected to the air pump 11 through the gas flow meter 12 A blast aeration system is formed; the water outlet end of the ultrafiltration membrane module 5 is equipped with a vacuum gauge 6, and the ultrafiltration water outlet valve 7 is connected to the suction pump 8 to form a water inlet and outlet control system; the water outlet end of the ultrafiltration membrane module 5 is connected with an ultrafiltration reverse The backwash valve 9 and the ultrafiltration backwash pipeline 10 form a membrane backwash system with the backwash pump; the working relationship between the backwash system and the water outlet control system is that the backwash valve 9 and the backwash pump are closed when the ultrafiltration is performed normally. While the ultrafiltration water outlet valve 7 is opened, the suction pump 8 will extract the water after ultrafiltration; To flushing; Coagulant dosing system 15 adds coagulant and can be a kind of in aluminum sulfate, polyaluminum chloride, ferric chloride, polyferric sulfate or other various coagulants that can be used for drinking water production, It is also possible to add the above-mentioned coagulant and coagulant aids such as polyacrylamide at the same time.

The present invention is also characterized in that the ultrafiltration membrane module 5 can be polyvinylidene fluoride or polyvinyl chloride or other ultrafiltration membranes; the module form can be a hollow fiber type or a flat plate type.

The present invention is also characterized in that the membrane pore diameter of the ultrafiltration membrane module 5 should be in the range of 0.01 μm to 0.1 μm;

The present invention is also characterized in that the ultrafiltration membrane module 5 is a submerged external pressure ultrafiltration membrane module.

The present invention has the following advantages:

Aiming at the situation that drinking water sources are generally polluted by nitrogen, phosphorus and organic matter, the present invention organically combines the coagulation unit in the conventional drinking water treatment process with the bioreactor unit in the membrane bioreactor, and combines coagulation and biological reaction placed in the same reactor. The invention uses coagulation to remove large molecular weight organic pollutants and soluble phosphate, uses biodegradation to remove small molecular weight organic pollutants and ammonia nitrogen, and finally uses ultrafiltration membranes to efficiently intercept particulate matter and microorganisms in the reactor to achieve advanced treatment Source water for the purpose of preparing high-quality drinking water.

The present invention puts the coagulation, biological reaction and ultrafiltration in the same reactor to complete, on the one hand, it significantly improves the quality of drinking water, on the other hand, it significantly reduces the project cost and operating cost, and greatly reduces the occupied area. It is a new type of high-efficiency, energy-saving and easy-to-maintain and manage drinking water deep purification process, which is convenient for popularization and application.

The present invention organically combines coagulation and biological action to make up for the defects that coagulation cannot remove ammonia nitrogen and small molecular weight organic matter, and biological action cannot remove large molecular weight organic matter and phosphate, and uses different methods to remove different types of pollutants , can not only greatly improve the treatment effect, but also make the treatment effect stable and not easily affected by the impact load.

The invention adopts an ultrafiltration membrane with a pore size in the range of 0.0 μm to 0.1 μm, which can effectively control and remove particulate matter, macromolecular organic pollutants, two insects, daphnia, red worms, algae, bacterial viruses and other microorganisms in the ultrafiltration. Efficient solid-liquid separation in membrane coagulation/bioreactors to produce high-quality drinking water.

The invention adopts the submerged external pressure ultrafiltration membrane, and compared with the internal pressure ultrafiltration membrane, the energy consumption is significantly reduced.

The invention adopts lower membrane suction pressure and membrane flux, which further reduces energy consumption, effectively delays membrane fouling, reduces the number of membrane physical cleaning and chemical cleaning, prolongs the service life of the membrane, and reduces the maintenance and operation of the process cost.

Description of drawings

Fig. 1 is the system diagram of device of the present invention;

Fig. 2 is the water purification effect table of the present invention.

Detailed ways

The specific process is: the raw water to be treated, including river water after preliminary clarification treatment or lake and reservoir water with low turbidity, enters the integrated ultrafiltration membrane coagulation/bioreactor through the constant level water tank; The activated sludge microorganisms biodegrade the ammonia nitrogen and small molecular weight organic matter in the influent; the coagulant added to the reactor through the coagulant dosing system mixes with the large molecular weight organic matter and phosphate in the influent At the same time, the coagulation agent remaining in the reactor will also absorb the organic pollutants and phosphate in the influent; finally, the water treated by biological action and coagulation is drawn from the ultrafiltration membrane module by the suction pump. When the ultrafiltration membrane is pulled out, the powerful role of the ultrafiltration membrane in removing particulate matter in water, removing macromolecular organic pollutants, and intercepting microorganisms such as two insects, daphnia, red worms, algae, bacteria and even viruses is fully exerted. Safe and hygienic quality drinking water is prepared.

In order to effectively control and remove microorganisms such as particulate matter, macromolecular organic pollutants, two insects, daphnia, red worms, algae, bacteria and viruses in water, the pore size of the ultrafiltration membrane is generally in the range of 0.0 μm to 0.1 μm. In order to effectively control membrane fouling, reduce the number of physical cleaning and chemical cleaning of the membrane, and prolong the service life of the membrane, the ultrafiltration membrane adopts lower suction pressure and membrane flux. The membrane suction pressure is generally in the range of 10kPa to 50kPa; The amount is generally in the range of 5L/m ² ·h to 50L/m ² ·h.

In order to ensure that the activated sludge microorganisms in the integrated ultrafiltration membrane coagulation/bioreactor have sufficient dissolved oxygen, ensure that the activated sludge and coagulant in the reactor are evenly mixed, and wash and clean the surface of the ultrafiltration membrane, The lower part of the ultrafiltration membrane module is provided with a perforated aeration pipe, which provides aeration into the reactor through an air pump outside the reactor, and the air-water ratio is generally in the range of 5:1 to 20:1. In order to avoid excessive accumulation of sludge in the reactor, affecting the treatment effect or causing membrane fouling, a sludge discharge pipe is installed at the bottom of the coagulation/bioreactor to regularly discharge the remaining sludge to the outside of the reactor, and the sludge residence time is generally controlled at 5 days ~30d range.

Example

The integrated ultrafiltration membrane coagulation/bioreactor water purification treatment device shown in Figure 1 is used to treat a certain slightly polluted source water. The raw water to be treated is first lifted by the lift pump 1 to the high-level water tank 2, and then enters the ultrafiltration membrane coagulation/bioreactor 4 through the constant-level water tank 3, and the hydraulic retention time in the reactor is 30 minutes. At the same time, the coagulant is added to the ultrafiltration membrane coagulation/bioreactor 4 by the coagulant dosing system 15, the coagulant is polyaluminum chloride, and the dosage is 10mg/L; the sludge in the reactor The residence time is 20d. The ultrafiltration membrane module 5 adopts the submerged hollow fiber ultrafiltration membrane provided by Hainan Lisheng Water Purification Technology Co., Ltd., the membrane pore size is 0.01 μm, and the membrane material is polyvinyl chloride. The water flux of the ultrafiltration membrane is 10L/m ² ·h, and the outlet water of the ultrafiltration membrane is sucked out by the suction pump 8 through the ultrafiltration outlet valve 7, and the ultrafiltration backwash valve 9 is closed at this time. The suction pressure of the suction pump 8 is measured by the vacuum gauge 6 within the range of 15kPa～30kPa. The ultrafiltration membrane coagulation/bioreactor 4 is aerated into the reactor by an external air pump 11 through a perforated aeration pipe 13 located at the bottom of the reactor. The gas-water ratio is 20:1, and is controlled by a gas flow meter 12 . The sludge residence time in the ultrafiltration membrane coagulation/bioreactor 4 is 20 days, and the excess sludge is discharged out of the reactor through the sludge discharge valve 14 . When the ultrafiltration membrane module 5 is backwashed, the ultrafiltration membrane water outlet valve 7 is closed, the ultrafiltration backwash valve 9 is opened, and the ultrafiltration membrane module 5 is backwashed by the ultrafiltration backwashing pipeline system 10 . The specific treatment effect of the ultrafiltration membrane coagulation/bioreactor integrated drinking water advanced treatment process is shown in Table 1.

Claims (5)

1. integrated ultrafiltration membrane coagulation/bio-reactor water purification processing method with coagulation and organically combination of biological respinse, places in the one reaction pool and finishes; Pending former water enters ultra-filtration membrane coagulation/bio-reactor by permanent position water tank, and the active sludge microorganism in the reactor is handled ammonia nitrogen in the water inlet and small molecular weight organism biodegrade; In the interior hydraulic detention time 10～30min scope of this reactor; Simultaneously, by the coagulant dosage system in ultra-filtration membrane coagulation/bio-reactor dosing coagulant to remove macromolecule organism and phosphorus, can to be that Tai-Ace S 150, polymerize aluminum chloride, iron(ic) chloride, bodied ferric sulfate or other are various can be used for a kind of in the coagulating agent that tap water produces with coagulating agent, adds when also can be coagulant aids such as above-mentioned coagulating agent and polyacrylamide; The submerged ultrafiltration assembly is installed in the reactor, but its material polyvinylidene difluoride (PVDF) or polyvinyl chloride or other ultra-filtration membrane, membrane pore size should be in 0.01 μ m～0.1 mu m range, and kit form can be the tubular fibre formula, also can be flat; In 10kPa～50kPa scope, membrane flux is at 5L/m by suction pump control ultra-filtration membrane swabbing pressure ²H～50L/m ²In the h scope; Reactor bottom is provided with boring aeration pipe, and the pneumatic pump outer by reactor carries out aeration in reactor, for biological respinse provides dissolved oxygen, and mixes and the film silk cleans, and gas-water ratio is in 5: 1～20: 1 scopes; Reactor bottom is provided with mud valve and shore pipe, regularly discharges excess sludge outside reactor, and the control sludge retention time is in 5d～30d scope; For guaranteeing that membrane flux regularly carries out back flushing to hyperfiltration membrane assembly, adopt the ultra-filtration membrane water outlet, to finish by backwashing pump, the recoil cycle decides on the swabbing pressure and the membrane flux of hyperfiltration membrane assembly; Close the ultra-filtration membrane flowing water Valve during hyperfiltration membrane assembly back flushing, open the ultrafiltration back flush valves simultaneously, system carries out back flushing to hyperfiltration membrane assembly by the ultrafiltration counter-flushing pipeline.

2. integrated ultrafiltration membrane coagulation/bio-reactor high-efficiency water purifying treatment device, by water inflow control system, reaction tank, coagulation dosing system, hyperfiltration membrane assembly, go out water control system, blast aeration system, sludge drainage system, film back-purge system and form, it is characterized in that: described water inflow control system is connected and composed by pipeline by lift pump (1), elevated tank (2), permanent position water tank (3), also directly connects permanent position water tank (3) by pipeline and constitute under the situation of run by gravity; Described reaction tank is integrated ultrafiltration membrane coagulation/biological reaction tank (4), pending former water enters integrated reacting pond (4) by permanent position water tank (3), can also can in the sidepiece of integrated reacting pond (4), enter by valve and pipeline the below in the bottom of integrated reacting pond (4); The supporting coagulant dosage system (15) that is equipped with in integrated reacting pond (4), coagulant dosage system (15) to the middle and lower part of the interior mixing liquid in integrated reacting pond (4) and the space between the blast aeration system top, can be to add continuously or regularly add at times coagulant dosage; Hyperfiltration membrane assembly (5) is installed on the interior mixing liquid internal upper part in integrated reacting pond (4), and its water side connects suction pump (8) through ultrafiltration flowing water Valve (7), and the swabbing pressure of suction pump (8) is by vacuum meter (9) metering; Be can be in the reaction tank (4) to the active sludge microorganism of ammonia nitrogen and small molecular weight organism biodegrade processing in the water inlet and the mixing liquid of institute's dosing coagulant; Mud valve (14) and the shore pipe that is connected to pollution discharge pond is equipped with in the bottom of reaction tank (4) or sidepiece below, forms sludge drainage system, every day the regular discharge excess sludge; One or more groups boring aeration pipe (13) is installed on mixing liquid bottom in the reaction tank, and its inlet end connects pneumatic pump (11) through gas meter (12) and forms blast aeration system; Vacuum meter (6) is equipped with in hyperfiltration membrane assembly (5) water side, connects suction pump (8) through ultrafiltration flowing water Valve (7) and forms the Inlet and outlet water Controlling System; Hyperfiltration membrane assembly (5) water side also is connected to ultrafiltration back flush valves (9) and ultrafiltration counter-flushing pipeline (10), with backwashing pump component film back-purge system; Back-purge system and the work relationship that goes out water control system be, back flush valves (9) and backwashing pump are closed when ultrafiltration is normally carried out, and ultrafiltration flowing water Valve (7) is opened, and suction pump (8) is with water extraction after the ultrafiltration; Back flush valves when back flushing (9) is opened and ultrafiltration flowing water Valve (7) and suction pump (8) are closed, and backwashing pump carries out counterflush to ultra-filtration membrane; Can to be that Tai-Ace S 150, polymerize aluminum chloride, iron(ic) chloride, bodied ferric sulfate or other are various can be used for a kind of in the coagulating agent that tap water produces to coagulant dosage system (15) dosing coagulant, adds when also can be coagulant aids such as above-mentioned coagulating agent and polyacrylamide.

3. integrated ultrafiltration membrane coagulation as claimed in claim 2/bio-reactor high-efficiency water purifying treatment device is characterized in that described hyperfiltration membrane assembly (5) can be polyvinylidene difluoride (PVDF) or polyvinyl chloride or other ultra-filtration membrane; Kit form can be the tubular fibre formula, also can be flat.

4. integrated ultrafiltration membrane coagulation as claimed in claim 3/bio-reactor high-efficiency water purifying treatment device is characterized in that, the membrane pore size of hyperfiltration membrane assembly (5) should be in 0.01 μ m～0.1 mu m range in the described reactor.

5. integrated ultrafiltration membrane coagulation as claimed in claim 2/bio-reactor high-efficiency water purifying treatment device is characterized in that described hyperfiltration membrane assembly (5) is an immersion external pressure hyperfiltration membrane assembly.

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