CN103214145A - Water pollution control method suitable for river inlets of northern areas - Google Patents

Abstract

The invention discloses a water pollution control method suitable for river inlets of northern areas, and belongs to the technical field of sewage. The adopted system comprises an anaerobic pool, a first aerobiotic pool and a second aerobiotic pool, wherein an independent aeration tube is arranged between the first aerobiotic pool and the second aerobiotic pool every 3.5-4.5 metres; dispersed suspension-type cascade ring fillers are poured in the anaerobic pool, the first aerobiotic pool and the second aerobiotic pool respectively, and the dosing rate is 30% of the volume of the pool; and an operation process can be divided into the four phases including a biofilm formation start-up period, a design flow water-inlet period, a low-temperature maintenance period and an impact load period. According to the water pollution control method disclosed by the invention, sewage at the river inlets of the rural-urban fringe zones of northern areas is mainly treated by a comprehensive-type bio-membrane reactor treatment process, and COD (chemical oxygen demand), BOD5 (five-day biochemical oxygen demand), NH4+-N, TN (total nitrogen) and SS (suspended solid) in the sewage can be removed with a good effect.

Description

Suitable northern area is gone into the river mouth water pollution control method

Technical field

The invention belongs to the combination area of city and country and go into water pollution control Technology of Sewage field, river mouth, relate to a kind of simple and easy effective biomembrance process treatment process.

Background technology

The composite type biofilm reactor is meant under current or air-flow effect and the constantly biofilm reactor of motion (stirring, expansion, fluidisation, turbulent fluctuation or circulation etc.) of biofilm carrier, and it belongs to a kind of sewage treatment process efficiently of fluid bed biological film reactor.It had both had the characteristics that traditional biological embrane method anti impulsion load, mud age is long, surplus sludge volume is few, had the high efficiency of activated sludge process and going slick property again.Compare with activated sludge process and other biomembrance process, the fluid bed biological film reactor is the process integration of active sludge and biomembrance process, gets the length of the two, keeps away the weak point of the two.Compare with fluid bed biological film technology: 1. aerobic biofilter can not make full use of the pond appearance; 2. the mechanical means problem often appears in blodisc; 3. the submerged biological filter is difficult to make load to be evenly distributed on the surface of carrier; 4. fluidized-bed instability.Compare with the biofilm reactor of majority, the fluid bed biological film reactor has overcome these shortcomings, has utilized whole pond to hold, and is the same with activated sludge reactor, compares with active sludge, and it refluxes without any need for mud, and is the same with the other biological membrane reactor.

Abroad, fluid bed biological film technology has entered operational phase in going into the river mouth water pollution control, flow into draining river, lake, natural pond treatment facility as Japanese M city, the purification facility of Chiba, Japan escape canal etc., and the fluid bed biological film technology of China also is in lab scale and pilot scale research stage basically, as the correlative study that summer cleaning politics, economics, organization, and ideology, Zhang Wenhu, Ma Jianyong, Wang Xuejiang etc. do, directly applying to into estuary improvement does not also have correlative study.

Adsorbing the very thin moisture film of one deck on the biomembranous surface, with respect to the current that movement outside, moisture film is an immobilized.Organism in the current can be by the microbial film oxidation.Because organic concentration low than in the mobile water layer in the moisture film, so the organism in the water layer that flows can enter in the moisture film by the turbulent fluctuation and the concentration difference diffusion of current, and further be diffused in the microbial film and go, constantly by microbial film absorption, absorption with degrade.Simultaneously, airborne oxygen constantly dissolves in the water, enters microbial film by flow water layer and moisture film, is used for oxidation of organic compounds and carry out metabolism itself by microorganism.Microorganism is in the process of decomposing organic matter, itself is propagation constantly, make the continuous thickening of microbial film, the oxygen that transmission is come in is very fast to be fallen by the top layer microbial consumption, biomembranous internal layer can not get the supply of oxygen, anaerobion is grown in a large number in the microbial film inboard, form anaerobic layer, and organic decomposition mainly relies on the effect of aerobic layer.Meta-bolites of microorganism such as water, carbonic acid gas, ammonia and other inorganic salt enter flow water layer or the air through moisture film from microbial film then in opposite direction.When biomembranous thickness is little, can keep equilibrium relationship between aerobic layer and the anaerobic layer, meta-bolites that anaerobic layer produces such as organic acid, alcohols, hydrogen sulfide etc. can further be degraded and be removed when being seen through aerobic layer, obtain satisfied effluent quality.But thicken gradually when anaerobic layer, the meta-bolites of anaerobic layer increases, and particularly gaseous product is constantly overflowed, and has weakened biomembranous pull-out capacity, and microbial film at this moment is called aged microbial film, is easy to split away off from carrier or filler.Simultaneously, the microbial film of growing again and making new advances in original position.Reach the purpose of disposing of sewage by this continuous circulation renewal.

Compare with activated sludge process, biomembrance process has many advantages.Mainly show: (1) therefore has higher denitrogenation ability owing to there is the slow-paced nitrobacteria of many growth and breedings; (2) microorganism that exists in the microbial film is various and abundant, comprises aerobic bacteria, anerobe, fungi and algae etc., makes it show certain broad spectrum when removing pollutent; (3) a large amount of microorganism growth and the space that has occupied whole reactor, unit volume biomass specific activity mud method height, so the unit volume processing power is bigger; (4) the food chain specific activity mud method in the embrane method is long, and the mud of generation is mostly consumed by biology, so surplus sludge volume is few; (5) system operation is easy to maintenance, and energy consumption is low, need not mud and refluxes; (6) because of the little ecological complexity of system, strong to the ability to bear of waterpower and organic loading variation, operate stable.

Present domestic composite type biofilm reactor is applied to into the report of river mouth water pollution control few.This process application is gone into the river mouth water pollution control in the north cold area combination area of city and country does not also have relevant report at home.And the quality of biofilm reactor performance belongs in the reactor on the carrier microbic activity height in the microbial film to a great extent, and this environmental characteristic that depends primarily on the performance of carrier in the reactor and influence microorganism growth, so carrier property and environmental characteristic finally affect the effect of biofilm reactor.

In view of the four seasons difference variation of Chinese northern area is big, the water of combination area of city and country's rivers and canals pollutes heavy, goes into characteristics such as river mouth discharge is big, and is particularly important to the research of carrier property in the reactor and environmental characteristic thereof.This treatment process directly applies in the river mouth, has investigated the ability of its process for producing life combined sewage, and has determined that technology moves the optimal operating parameter in each period.

Summary of the invention

A kind of northern area that is applicable to is controlled into river mouth water pollution control technology and method, handle that the water yield is big, effluent quality good and stable, resist cold, capacity of resisting impact load is strong, cost is low.This composite type biofilm reactor treatment process can directly apply to the rivers and canals Pollution abatement of northern area, and removal effect is good.

The technical scheme that is adopted

The water quality characteristics of river mouth sewage: COD, BOD go in the combination area of city and country ₅, TP, TN and NH ₄ ⁺-N can be respectively 3～4,6～7,18～19,24～28,4～23 times of V class standard value.

1. be fit to northern area and go into the river mouth water pollution control method, it is characterized in that: the system of employing comprises anoxic pond, first Aerobic Pond, second Aerobic Pond, at first Aerobic Pond and second Aerobic Pond, every 3.5-4.5 rice independently aeration tube is set, adds dispersion suspension formula cascade ring filler in anoxic pond, first Aerobic Pond, second Aerobic Pond, dosing rate is 30% of a pool volume;

Can be divided in operational process: biofilm starting period, design discharge water inlet phase, low temperature are kept phase and impact load phase four-stage;

The biofilm starting period, per day water temperature T needs to be full of 1/2 of system volume at 12 ℃-20 ℃; In the meantime, psychrotroph is dropped into each reaction tank;

Operation divides three steps in the biofilm starting phase;

The first step is interrupted water inlet; In the tenth day of lunar month five days, every pond old water of part of regularly draining every day: promptly 1/5～1/3 of Total Water, and Xiang Chizhong replenishes fresh sewage; First Aerobic Pond and the suitable aeration of second Aerobic Pond, gas-water ratio is 2:1;

Second step, water inlet continuously, continuous aeration; 40%, the first Aerobic Pond and the second Aerobic Pond gas-water ratio that flooding velocity is chosen as the design maximum flow are 6:1, and 12 ℃-20 ℃ of water temperatures guarantee that the waterpower total residence time is 6.5h; Move seven, water outlet COD clearance can reach 55-60%;

The 3rd step, the flooding quantity of raising technology, intaking is 60% of design flooding quantity, the Aerobic Pond gas-water ratio is reduced to 5:1 by 6:1; The anoxic pond aeration, the dissolved oxygen of using Chi Shui reaches more than the 3-4mg/L; The dissolved oxygen that two Aerobic Ponds go out Chi Shui reaches 8-l0mg/L and 5-7mg/L respectively, and total hydraulic detention time is 4.3h, 7 days time length;

At this moment, the total clearance 55-60% of water outlet COD; The highest clearance of water outlet ammonia nitrogen reaches 53-55%; When COD, ammonia-N removal rate all reach 50-55%, think that biofilm is successful;

The design discharge water inlet phase, this, water temperature needed at 10 ℃-20 ℃ in period, increased flooding quantity and was 80% of design flooding quantity; The gas-water ratio of first Aerobic Pond and second Aerobic Pond all drops to 3:1～4:1, and to go out the dissolved oxygen concentration of Chi Shui be 6～6.5mg/L to Aerobic Pond during this, the oxygen supply abundance; This moment, the waterpower total residence time was 2.9h; After 5 days, adjusting flooding quantity, is 100% promptly normal water inlet continuously, and gas-water ratio still is 3:1～4:1; At this moment to go out the dissolved oxygen concentration of Chi Shui be 5.8-6.2mg/L for first Aerobic Pond and second Aerobic Pond; At this moment anoxic pond adopts not aeration or few aeration method, guarantees that anoxic pond goes out the dissolved oxygen of Chi Shui less than 2.5-2.8mg/L; One week to 10 of steady running day, think normal water inlet continuously;

Low temperature is kept the phase, specific practice, and when 4～8 ℃ of water temperatures, flooding quantity is 2/3 of a designed water, and gas-water ratio is 3:1～4:1, and ammonia nitrogen index degradation rate reaches 45-50%, COD, BOD ₅Reach SS and all drop to below the 55-60%, COD goes out water concentration and is elevated to 65-70mg/L; When water temperature further is reduced to 0～4 ℃,, regulate aeration rate simultaneously again changing flooding quantity; Be flooding quantity be adjusted to the design flooding quantity 1/2, Aerobic Pond selects for use gas-water ratio to be transferred to 4:1～5:1; Hydraulic detention time need remain between 5.5～6h, at this moment COD and NH ₄ ⁺The clearance of-N can reach 65～76% and 57%～71% respectively;

The impact load phase, flooding quantity is 100% water inlet continuously of designed water, and gas-water ratio is controlled to be 3:1～4:1.

The present invention mainly adopts composite type biofilm reactor treatment process that river mouth sewage is gone into by the northern area combination area of city and country and handles, and can remove COD in the sewage, BOD ₅, NH ₄ ⁺-N, TN, SS, respond well.

Embodiment

Suitable northern area is gone into the river mouth water pollution control method, and its core is: anoxic pond, and first Aerobic Pond, second Aerobic Pond connects pulling flow type stage purification mode successively.The main easily materials such as COD of degraded of removing in second Aerobic Pond, then play the effect of denitrogenation and degraded rest COD in first Aerobic Pond.Aerobic stage secondary plug-flow method is divided in two Aerobic Ponds the nitrifier of removing the organism heterotrophic bacteria and removing ammonia nitrogen.Not only suppress in the denitrification process microorganism well and utilized easily that the degraded substrate repels the signs of degradation of microorganism to other substrates, improved nitrogen removal performance; Also further strengthened the COD removal effect.Gas circuit arrange to form the anaerobic-aerobic circulation: the same from biology angle microorganism just like the people, as 24 hours uninterrupted movable, just held incessantly less than several days, the time of movable and dormancy will be arranged equally.Microorganism is according to self seeking to be suitable for the place of own state, and they are to the less place of oxygen level when dormancy.

This technology is arranged in gas circuit, at first Aerobic Pond and second Aerobic Pond, every 3.5-4.5 rice independently aeration tube is set, like this at the dissolved oxygen content height on aeration tube top, the middle portion dissolved oxygen oxygen level of two aeration tubes is relatively low, make current form a plurality of anaerobic-aerobic circulating biological environment in the plug-flow process, this stage purification mode has improved the effect of sewage disposal greatly.In anoxic pond, first Aerobic Pond, second Aerobic Pond, add dispersion suspension formula cascade ring filler (the new environmental protection equipment of Guangzhou iron of fine quality company limited, model 65 * ￠ 50mm), its best dosing rate is 30% of a pool volume, this filler aperture is big, hole is big, do not stop up at the processing big yield, suit into the river mouth sewage disposal.The material that filler uses and shape (there are bioaffinity, weak shearing force, good mass-transfer performance in the residence) had both guaranteed fluidized state good in the reactor this moment.Because the filler shift in position, oxygen enters less than filler inside during level, forms the anoxic space, and when being in vertical position, the dissolved oxygen state that reaches capacity forms anaerobic-aerobic circulating biological environment.One of two directions formation has a plurality of nutrition complex systems such as bacterium, fungi algae, protozoon, metazoan in length and breadth in reactor, has promoted the biochemical degradation reaction to carry out.

Composite type biofilm reactor treatment process can be divided in operational process: biofilm starting period, design discharge water inlet phase, low temperature are kept phase and impact load phase four main processes.

The biofilm starting period is characterized in that per day water temperature T needs at 12 ℃-20 ℃, and generally the higher period water inlet of water temperature at noon is full of 1/2 of system volume, and suitable aeration.In the meantime, with psychrotroph (day a skin grind vibrio hollisae(vibrios body) 1706B) drop into each reaction tank.Operation divides three steps in the biofilm starting phase.The first step is interrupted water inlet.In the tenth day of lunar month five days, every pond old water of part of regularly draining every day: promptly 1/5～1/3 of Total Water, and Xiang Chizhong replenishes fresh sewage.First Aerobic Pond and the suitable aeration of second Aerobic Pond, gas-water ratio is the 2:1(gas-water ratio: the ratio of gas volume hourly and sewage quantity, the scene is more easy to control), aeration intensity is difficult for to hang over microbial film on the filler in order to avoid wash away oneself too big.Carry out instantaneous aeration in the anoxic pond and only play stirring action.After continuous like this 15 days, the internal surface that can be observed filler adheres to the filemot microbial film of the one deck of having grown, and feel thickness and matter are thin.Second step, water inlet continuously, continuous aeration.The living environment of stable supplying nutrition and oxygen is provided to microorganism.40%, the first Aerobic Pond and the second Aerobic Pond gas-water ratio that flooding velocity is chosen as the design maximum flow are 6:1, and 12 ℃-20 ℃ of water temperatures guarantee that waterpower total residence time (enter treating pond and go out treating pond again) is 6.5h.Move seven, water outlet COD clearance can reach 55-60%.Biofilm development is very fast in the pond at this moment, and filling surface is own covered with skim brown membranoid substance, and hand touches the surface the thickness sense.The treatment effect of technology obviously improves.The 3rd step, the flooding quantity of raising technology.Water inlet is 60% of the design flooding quantity, and the Aerobic Pond gas-water ratio is reduced to 5:1 by 6:1.The anoxic pond aeration, the dissolved oxygen of using Chi Shui reaches more than the 3-4mg/L.

The dissolved oxygen that two Aerobic Ponds go out Chi Shui reaches 8-l0mg/L and 5-7mg/L respectively, and total hydraulic detention time is 4.3h, 7 days time length.At this moment, the total clearance 55-60% of water outlet COD.Dioxy pond nitration treatment effect is also fine, and the highest clearance of water outlet ammonia nitrogen can reach 53-55%.When COD, ammonia-N removal rate all reach 50-55%, can think that biofilm is successful.

The design discharge water inlet phase, this, water temperature needed at 10 ℃-20 ℃ in period, increased flooding quantity and was 80% of design flooding quantity.The gas-water ratio of first Aerobic Pond and second Aerobic Pond all drops to 3:1～4:1, and to go out the dissolved oxygen concentration of Chi Shui be 6～6.5mg/L to Aerobic Pond during this, the oxygen supply abundance.This moment, the waterpower total residence time was 2.9h: anoxic pond 1.3h, and first Aerobic Pond is 0.84h, and second Aerobic Pond is 0.76h.The technology overall operation is in good condition.Stable (flooding quantity, total hrt, gas-water ratio are certain) adjusted flooding quantity after 5 days, was 100% promptly normal water inlet continuously, and gas-water ratio still is 3:1～4:1.At this moment to go out the dissolved oxygen concentration of Chi Shui be 5.8-6.2mg/L for first Aerobic Pond and second Aerobic Pond.When anoxic pond goes out the dissolved oxygen concentration 3-4mg/L of Chi Shui, can influence the technique denitrification ability, at this moment anoxic pond adopts not aeration or few aeration method, guarantees that anoxic pond goes out the dissolved oxygen of Chi Shui less than 2.5-2.8mg/L.

In a word, in the dissolved oxygen concentration of this stage dissolved oxygen in anoxic tank concentration, first Aerobic Pond and second Aerobic Pond scope shown in last the time, the art breading best results.Stablize week to 10 day, can think normal water inlet continuously.

Low temperature is kept the phase, and northern China is after the winter that enters, and per day water temperature can drop to below 8 ℃, and water temperature is generally at 0～8 ℃.At this moment, the clearance of systemic contamination index all can descend to some extent.Water temperature returns to more than 8 ℃, and no longer falls the low temperature phase of keeping after rise and finish.Should take to reduce the flooding quantity method in the low temperature phase of keeping, reach the nitrated residence time that prolongs first Aerobic Pond, second Aerobic Pond.Specific practice, when 4～8 ℃ of water temperatures, flooding quantity is 2/3 of a designed water, and gas-water ratio is 3:1～4:1, and ammonia nitrogen index degradation rate reaches 45-50%, COD, BOD ₅Reach SS and all drop to below the 55-60%, COD goes out water concentration and is elevated to 65-70mg/L.When water temperature further is reduced to 0～4 ℃, specific practice:, regulate aeration rate simultaneously again changing flooding quantity.Be flooding quantity be adjusted to the design flooding quantity 1/2, Aerobic Pond selects for use gas-water ratio to be transferred to 4:1～5:1, this moment clearance can reach 50%, treatment effect is not subjected to the influence of temperature.

Hydraulic detention time need remain between 5.5～6h, at this moment COD and NH ₄ ⁺The clearance of-N can reach 65～76% and 57%～71% respectively.

It is ending by the end of February since December to the second year that Beijing area low temperature is kept it.

The impact load phase, low load stage, 100% normal water inlet continuously is when gas-water ratio is 3:1～4:1.Water inlet COD is 100～150mg/L, goes out water concentration all below 60mg/L, and the COD clearance reaches 76%, obtains good effect of removing.Influent concentration is when this range, and the constant substantially maintenance of clearance is stable.The high loading stage, 100% normal water inlet continuously, when gas-water ratio was 3:1～4:1,160～300mg/L when water inlet COD fluctuation of concentration is big caused effluent COD concentration to be higher than 60mg/L, and clearance drops to 65%.But move after for some time 3-5 days, the COD clearance gos up again to some extent, reaches about 78%.This explanation composite type biofilm reactor has the impact load of adaptation ability.It is generally acknowledged that the microbial film processing power that low organic loading is tamed out is relatively poor, higher relatively organic loading makes biomembranous biomass with the influent concentration adjustment, and the COD clearance recovers normal again and processing rate also improves.In a word, the processing power of this biofilm reactor strengthens with the raising of water inlet COD concentration.

After the composite type biofilm reactor is handled, the biodegradability BOD of water outlet ₅/ COD value drops to below 0.30 by being about 0.45～0.65, and water outlet does not almost have color, illustrates that the composite type biofilm reactor has to handle the waste water ability efficiently.

Claims (1)

1. be fit to northern area and go into the river mouth water pollution control method, it is characterized in that: the system of employing comprises anoxic pond, first Aerobic Pond, second Aerobic Pond, at first Aerobic Pond and second Aerobic Pond, every 3.5-4.5 rice independently aeration tube is set, adds dispersion suspension formula cascade ring filler in anoxic pond, first Aerobic Pond, second Aerobic Pond, dosing rate is 30% of a pool volume;

Can be divided in operational process: biofilm starting period, design discharge water inlet phase, low temperature are kept phase and impact load phase four-stage;

The biofilm starting period, per day water temperature T needs to be full of 1/2 of system volume at 12 ℃-20 ℃; In the meantime, psychrotroph is dropped into each reaction tank;

Operation divides three steps in the biofilm starting phase;

The first step is interrupted water inlet; In the tenth day of lunar month five days, every pond old water of part of regularly draining every day: promptly 1/5～1/3 of Total Water, and Xiang Chizhong replenishes fresh sewage; First Aerobic Pond and the suitable aeration of second Aerobic Pond, gas-water ratio is 2:1;

Second step, water inlet continuously, continuous aeration; 40%, the first Aerobic Pond and the second Aerobic Pond gas-water ratio that flooding velocity is chosen as the design maximum flow are 6:1, and 12 ℃-20 ℃ of water temperatures guarantee that the waterpower total residence time is 6.5h; Move seven, water outlet COD clearance can reach 55-60%;

The 3rd step, the flooding quantity of raising technology, intaking is 60% of design flooding quantity, the Aerobic Pond gas-water ratio is reduced to 5:1 by 6:1; The anoxic pond aeration, the dissolved oxygen of using Chi Shui reaches more than the 3-4mg/L; The dissolved oxygen that two Aerobic Ponds go out Chi Shui reaches 8-l0mg/L and 5-7mg/L respectively, and total hydraulic detention time is 4.3h, 7 days time length;

At this moment, the total clearance 55-60% of water outlet COD; The highest clearance of water outlet ammonia nitrogen reaches 53-55%; When COD, ammonia-N removal rate all reach 50-55%, think that biofilm is successful;

The design discharge water inlet phase, this, water temperature needed at 10 ℃-20 ℃ in period, increased flooding quantity and was 80% of design flooding quantity; The gas-water ratio of first Aerobic Pond and second Aerobic Pond all drops to 3:1～4:1, and to go out the dissolved oxygen concentration of Chi Shui be 6～6.5mg/L to Aerobic Pond during this, the oxygen supply abundance; This moment, the waterpower total residence time was 2.9h; After 5 days, adjusting flooding quantity, is 100% promptly normal water inlet continuously, and gas-water ratio still is 3:1～4:1; At this moment to go out the dissolved oxygen concentration of Chi Shui be 5.8-6.2mg/L for first Aerobic Pond and second Aerobic Pond; At this moment anoxic pond adopts not aeration or few aeration method, guarantees that anoxic pond goes out the dissolved oxygen of Chi Shui less than 2.5-2.8mg/L; One week to 10 of steady running day, think normal water inlet continuously;

Low temperature is kept the phase, specific practice, and when 4～8 ℃ of water temperatures, flooding quantity is 2/3 of a designed water, and gas-water ratio is 3:1～4:1, and ammonia nitrogen index degradation rate reaches 45-50%, COD, BOD ₅Reach SS and all drop to below the 55-60%, COD goes out water concentration and is elevated to 65-70mg/L; When water temperature further is reduced to 0～4 ℃,, regulate aeration rate simultaneously again changing flooding quantity; Be flooding quantity be adjusted to the design flooding quantity 1/2, Aerobic Pond selects for use gas-water ratio to be transferred to 4:1～5:1; Hydraulic detention time need remain between 5.5～6h, at this moment COD and NH ₄ ⁺The clearance of-N can reach 65～76% and 57%～71% respectively;

The impact load phase, flooding quantity is 100% water inlet continuously of designed water, and gas-water ratio is controlled to be 3:1～4:1.