CN111252996A

CN111252996A - Treatment method of betaine production wastewater

Info

Publication number: CN111252996A
Application number: CN201811458774.3A
Authority: CN
Inventors: 纪峰
Original assignee: Weifang Bohua Environmental Technology & Engineering Co ltd
Current assignee: Weifang Bohua Environmental Technology & Engineering Co ltd
Priority date: 2018-11-30
Filing date: 2018-11-30
Publication date: 2020-06-09

Abstract

The invention relates to a treatment process of betaine production wastewater, which comprises the following process steps: pretreating, namely collecting the mixed wastewater through a comprehensive adjusting tank, pumping the mixed wastewater into an ozone oxidation tank by a pump, performing ozone oxidation, then feeding the mixed wastewater into a hydrogen peroxide oxidation tank, adding hydrogen peroxide according to a proportion, oxidizing for 4 hours, adjusting the pH of the oxidized wastewater to 7 by a pH adjusting tank, controlling an alkali adding pump by a pH meter, performing aeration attenuation, removing redundant hydrogen peroxide in the wastewater, and feeding the wastewater into a biochemical system; and (2) biochemical treatment, namely, allowing the pretreated wastewater to enter a hydrolytic acidification tank, treating the wastewater by anaerobic microorganisms in the tank, allowing the wastewater to enter a contact oxidation tank, digesting and degrading organic matters in water by aerobic bacteria, performing sludge-water separation by a membrane in an MBR (membrane bioreactor) tank, and discharging the effluent on a discharge surface. The invention has the characteristics of convenient use, small occupied area, high treatment efficiency, low energy consumption, small sludge production amount and the like.

Description

Treatment method of betaine production wastewater

Technical Field

The invention relates to the technical field of wastewater treatment, in particular to a treatment process of betaine production wastewater.

Background

Betaine is an important organic chemical product and is widely used as a raw material for producing monosodium glutamate in feed additives, foods, cosmetic additives, detergents and food industries and a material for producing medical materials such as vitamins and tylosin. In the feed industry of China, betaine is widely used to replace methionine, so that the cultivation cost is reduced, and the defect that China seriously depends on import of methionine is overcome; the betaine is used for biological fermentation and can be used as a fermentation substrate of various medical raw materials such as monosodium glutamate, vitamin B2 and the like, and the application of the betaine can greatly change the state of the fermentation industry which takes grains as the fermentation substrate and reduce the grain pressure in China.

The market demand of China and even the world for betaine products is extremely large, the domestic production capacity at present can not meet the domestic demand far away, and the demand for betaine is gradually increased along with the expansion of the domestic breeding industry in this year. And the methionine market has become more and more a bottleneck restricting methionine using enterprises in China along with the fluctuation of international price at present, most of methionine in China depends on import, and if betaine is used for replacing methionine in industry in large scale, the import pressure of the China on methionine can be relieved.

With the rapid development of fish husbandry, the demand of animal feed additives is increased year by year, and because betaine has many physiological advantages beneficial to animals, can promote the growth of the animals after being used in the breeding industry, prevent and treat certain nutritional diseases of the animals, has good food calling performance for aquatic animals, can obviously reduce the feed cost and improve the economic benefit, the betaine is widely applied to various animal compound feeds as a multifunctional new vitex feed additive, is more and more important for people, and has a wider prospect in the breeding industry.

As the demand of the betaine is increased, the problem of wastewater pollution generated in the production process is increasingly becoming a restriction condition of the production process, so that the treatment of wastewater generated in the production process of the betaine is an important direction. The main sources of the wastewater can be known according to related data:

1. and discharging water from a vacuum pump of the stripping tower. The water has strong alkalinity (9.0-10.0), and comprises the following main components: free trimethylamine and water;

2. and (4) discharging water from the concentration vacuum water tank. The water content is relatively large and weak acid, and the main components are as follows: circulating water and a small amount of mother liquor possibly exist in the later stage of the system;

3. and (5) secondary condensation water of the concentration evaporator is discharged. The water is acidic (2.0-3.0), and the main components are as follows: hydrochloric acid gas, water and a small amount of mother liquor;

4. and (4) draining the steam condensate storage tank. The temperature is higher (more than or equal to 90 ℃): soft water;

5. and (5) draining water from the reaction tail gas absorption tower. The water is acidic (pH 3.0 or more), and is discharged according to the pH change of the absorption effect, and is discharged after being weakly acidic. The main components are as follows: hydrochloric acid, free trimethylamine, trimethylamine hydrochloride;

from the above sources of wastewater, the content of pollutants in the wastewater is complex, the water quality is complex, the wastewater contains pollutants such as free trimethylamine, trimethylglycine hydrochloride and hydrochloric acid, the fishy smell of the free trimethylamine is heavy, and the wastewater is acidic and has a high salt content. The comprehensive waste water belongs to the high-concentration chemical organic waste water which is difficult to treat

At present, a common sewage treatment plant cannot directly treat the wastewater, so that the search for a treatment process capable of effectively treating the wastewater generated in the betaine production is particularly important.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for treating the wastewater generated in the betaine production, which has a good wastewater treatment effect.

In order to solve the above problems, the technical scheme adopted by the invention is as follows: a treatment process of betaine production wastewater comprises the following process steps:

a) and (4) ozone oxidation, wherein the wastewater is pumped into an ozone oxidation tank by a pump after being collected by the comprehensive adjusting tank for ozone oxidation.

b) And (3) oxidizing the wastewater by using hydrogen peroxide, feeding the wastewater after the ozone oxidation into a hydrogen peroxide oxidation tank, and adding an oxidant hydrogen peroxide according to a proportion to perform oxidation treatment for 4 hours.

c) And (4) Ph is adjusted back to attenuate, the wastewater after the oxygen balance enters a Ph adjusting back tank, a Ph meter is used for controlling an alkali liquor dosing pump, the Ph is adjusted to 7, aeration attenuation is carried out, and redundant hydrogen peroxide in the water is removed.

d) Anaerobic biochemical treatment, wherein the pretreated wastewater automatically flows into a hydrolytic acidification tank, and macromolecular organic matters in the water are removed through degradation of anaerobic microorganisms in the tank.

e) Aerobic biochemical treatment, the biochemical property of the wastewater after anaerobic treatment is improved, and macromolecules and cyclic organic matters can be subjected to ring opening and decomposition. Entering a subsequent contact oxidation tank, and carrying out nitration reaction by aerobic microorganisms in the tank to degrade organic matters in water.

f) Performing membrane separation treatment, namely removing organic matters in the wastewater after aerobic treatment, performing sludge-water separation by using an MBR (membrane bioreactor) membrane, and discharging effluent which reaches the standard;

in the step a), an aeration device is arranged in the pool, and oxidation is carried out according to water aeration, wherein the ozone amount is 4g/t, and the oxidation time is 30 min;

in the step b), adding a hydrogen peroxide oxidant into the tank, adding the oxidant hydrogen peroxide according to the mass ratio of 1:1 of hydrogen peroxide to COD, operating a dosing pump and a water inlet pump in a linkage manner, and performing oxidation reaction on the hydrogen peroxide for 4 hours;

in the step c), a microporous aerator and a ph meter are arranged in the ph adjusting attenuation pool, the switch of a liquid caustic soda dosing pump is controlled according to the ph value of the wastewater, aeration attenuation is carried out after the ph is adjusted to 7, redundant hydrogen peroxide in water is removed, the concentration of the liquid caustic soda is 10%, and the dosing amount is controlled according to the ph meter.

By adopting the technical scheme, compared with the prior art, the invention has the following advantages:

1. ozone oxidation: oxidation reaction of ozone in aqueous solution. Since ozone is an unstable strong oxidant, O3 and its intermediate free radicals decomposed in water have strong oxidizing properties. Therefore, it can rapidly and widely oxidize some elements and organic compounds in the aqueous solution, even at a low concentration, and it can be accomplished instantaneously. The reaction speed is high and the oxidation performance is high.

2. Hydrogen peroxide oxidation: the organic trimethylamine contained in the wastewater can react violently with the oxidant to decompose the free trimethylamine in the wastewater, and experiments show that after the wastewater reacts with hydrogen peroxide, the concentration of the trimethylamine in the wastewater is reduced from 2700ppm to 1492ppm, the degradation rate is 44.5 percent, the COD in the wastewater is reduced from 4000mg/L to 1480mg/L, and the COD degradation rate is up to 63 percent), and meanwhile, the B/C ratio of the wastewater is improved, and conditions are created for subsequent biodegradation. And the amount of sludge generated by hydrogen peroxide oxidation is small. High oxidation performance and small sludge production.

3. The anaerobic section is set in a contact anaerobic mode, and elastic filler is distributed in the tank, so that the microbial biomass higher than that of the common fluidized bed type anaerobic tank can be maintained. As an anaerobic system, the anaerobic bacteria can degrade organic substances in the wastewater, so that the subsequent aerobic load is reduced, the aerobic treatment time is shortened, the investment is reduced, and in addition, a certain amount of organic substances are degraded by the anaerobic bacteria with less energy consumption, so that the energy consumption is relatively saved; and the second system is used as a more stable uniform system for the flow state in the pool, has a good uniform effect and can buffer the instantaneous impact load. And moreover, due to the existence of anaerobic sludge in the tank, SS in the adsorbable trapped wastewater is enhanced and degraded, so that the sludge is treated.

1) At least 45% of the suspension can be hydrolyzed to a dissolved state by anaerobic digestion. Therefore, the simultaneous treatment of the sludge and the wastewater can be realized, and the sludge yield is reduced.

2) Has strong adaptability to water quality and water temperature change.

3) The macromolecule reducing substances of the anaerobic bacteria are decomposed into micromolecule substances or directly degraded, so that the biodegradability of the wastewater is improved, and favorable conditions are provided for the subsequent aerobic biological treatment.

High efficiency, low energy consumption, small mud production amount and strong adaptability.

4. The contact oxidation method is an aerobic biomembrane process, and microorganisms grow in water in a biomembrane form and a suspended state, so that the contact oxidation method has the characteristics of both activated sludge and a biological filter. The tank is internally provided with a combined filler and an aeration pipeline system, and a microporous aerator is arranged on the aeration pipeline system. The filler is made of napped PP strand silk and twisted ropes, is in a round hairbrush shape, has large specific surface area, and can be attached with a large number of microorganisms (biological membranes). The filler is fast in film hanging and easy in film stripping, and the strand silk can play a good cutting role on air bubbles during operation, so that the air bubbles are cut into small bubbles, the gas-liquid contact area can be increased, the oxygen transfer is promoted, and the treatment effect is improved. The microporous aerator has high strength, is not easy to damage, has even gas distribution, small resistance loss and corrosion resistance, has the oxygen utilization rate of more than 15 percent, and can achieve greater energy-saving effect when being matched with combined fillers. Because the specific surface area of the filler is large, the utilization rate of oxygen in the pool is high, the volume load is high, and the impact resistance is realized; the biological contact oxidation tank does not need a sludge backflow system, so that the sludge bulking problem does not exist, and the operation and management are convenient; the biological contact oxidation pond has a large amount of biological solids, and the F/M can be kept at a certain level when the organic volume load is high. Organic carbohydrates are finally decomposed into CO2 and H2O in the biological contact oxidation pond.

In the method, oxygen required by microorganisms is supplied by blast aeration, after a biological film grows to a certain thickness, the microorganisms on the wall of the filler can carry out anaerobic metabolism due to oxygen deficiency, the generated gas and the scouring action formed by aeration can cause the falling of the biological film and promote the growth of a new biological film, and at the moment, the fallen biological film flows out of the pool along with effluent.

The method has the characteristics of both an activated sludge method and a biological filter, so the method has the advantages of high biomass and high organic pollutant removal rate, and has the main characteristics of:

1) the specific surface area of the filler is large, the oxygenation condition in the tank is good, and the biosolids per unit volume in the tank is high, so that the biological contact oxidation tank has high volume load;

2) because the biological contact oxidation pond has a large amount of biological solids and water flow is completely mixed, the biological contact oxidation pond has good adaptability to sudden changes of water quality and water quantity;

3) because a plurality of microorganisms are attached to and grow on the surface of the filler, the loss rate is low, so that the sludge backflow is not needed, the sludge bulking phenomenon can be avoided, and the operation management is more convenient.

4) The biomass in the pool is large, when the organic load is high, the F/M can be kept at a certain level, and the sludge yield is low. The sludge bulking problem does not exist, and the operation management is simple and convenient.

5) The microorganism concentration is high, the treatment efficiency is high: because microorganisms mainly adhere to and grow on the surface of the filler in the biofilm method, the microorganisms are easier to adhere than the sludge which is suspended and grown by a main carrier of a strain in the specific sludge method, the microorganisms are not easy to flow out along with water flow, and the long retention time can be ensured, so that the high biological concentration can be maintained, which is very important for relieving the toxic influence of long-chain or medium-chain fatty acids on the microorganisms in the wastewater. Due to the higher amount of microorganisms, the reactor can be maintained to operate at a higher efficiency.

6) The problems of sludge floating and loss are avoided: the filler is attached to grow and mainly exists in a form of a biological film, so that the problems of sludge floating and loss are avoided. The suspended growth of the sludge by the activated sludge method is easily influenced by the oil-coated film, and the risk of sludge bulking is high.

7) The impact load resistance and the recovery capability after impact load are strong: since the biofilm grows on the surface of the filler, microorganisms outside the biofilm and in the suspended sludge are affected while organisms inside the biofilm are preserved when the impact load is borne. After the impact load is over, the outer dead biological film is stripped, and the preserved inner biological film can immediately take the important role of recovering the microbial quantity and activity in the reactor. The thalli of the activated sludge grown in suspension are all and directly affected during impact, the whole treatment system is paralyzed when the thalli are serious, and then new strains need to be inoculated again.

5. MBR membrane: mainly utilizes membrane separation equipment immersed in a biological tank to trap activated sludge and solid substances after biological treatment in a tank. Therefore, the concentration of activated sludge (MLSS) and the sludge age (SRT) in the system can be improved by more than 2-5 times, the relative Hydraulic Retention Time (HRT) can be greatly reduced, and large particles which are difficult to degrade can be continuously reacted and degraded in the treatment tank, so that the biological reaction function of the membrane bioreactor can be strengthened to the maximum extent through a membrane separation technology. MBR membrane bioreactor systems have been developed for nearly a decade in China, and have become a mature technology and attract attention of the world in the continuing advancement of membrane manufacturing technology and long-term application experience of the company. Some experts refer to the development of membrane technology as the "third industrial revolution".

Compared with the prior art, the membrane bioreactor occupies equal area to 1/3 of the prior art, reduces operation cost by 1/3, has strong system shock resistance, wide application range, high automation degree, no need of special management, stable and reliable operation, and stable effluent quality superior to national regulated reuse water standard, and is an upgraded substitute product of the prior sewage treatment process.

Treatment efficiency: the removal rate of BOD and COD is more than 95%, the removal rate of SS is more than 99%, and the removal rate of ammonia nitrogen is more than 90%.

The MBR process has the following characteristics:

the effluent quality is good and stable under the filtration of the high MLSS and the microfiltration membrane. High volume load, short residence time and small occupied area. The sedimentation tank and the filtering unit are replaced, and the problem of sludge settleability is avoided. Strong load impact resistance and high efficiency of treating organic wastewater. The suspended matter and turbidity are close to zero, and the method is suitable for recycling reclaimed water. Can effectively remove ammonia nitrogen. Can eliminate most pathogenic bacteria and reduce the dosage of disinfectant. Low operation cost, low energy consumption and automatic control. The sludge discharge period is long, and the sludge amount is less under the condition of biological self-decomposition.

The present invention will be described in detail below with reference to the accompanying drawings and examples.

Drawings

FIG. 1 is a flow chart of a method for treating betaine production wastewater in the embodiment of the invention.

Detailed Description

Examples for the purpose of facilitating understanding of those skilled in the art, the present invention will be further described with reference to examples using betaine production wastewater from Shandong Xiangweis Biotech Ltd as a sample.

With the attached drawing, the process for treating the betaine production wastewater comprises the following process steps:

f) And (4) performing membrane separation treatment, namely removing organic matters in the wastewater after the aerobic treatment, performing sludge-water separation by using an MBR (membrane bioreactor) membrane, and discharging the effluent which reaches the standard.

The front section of the treatment process is provided with the regulating tank for regulating the water quality and the water quantity, and the impact load caused by the strong acid and the strong base and high-concentration organic matters which have large water quality and water quantity fluctuation and are often generated in the production wastewater can be buffered.

Because the wastewater contains organic matters which are difficult to be biologically degraded and is not suitable for direct biochemical treatment, the method of ozone oxidation and hydrogen peroxide oxidation is adopted as pretreatment, and the oxidized wastewater can reduce macromolecular organic matters in water, improve the biochemical property of the wastewater and prepare for subsequent biochemical treatment.

The ozone oxidation and the hydrogen peroxide oxidation are adopted, so that the oxidation is strong, a large amount of sludge is not generated, a sedimentation tank is not required, and the occupied area is saved.

In the step a), an aeration device is arranged in the pool, and oxidation is carried out according to water aeration, wherein the ozone amount is 4g/t, and the oxidation time is 30 min.

In the step b), a hydrogen peroxide oxidant is added into the tank, the dosage of the oxidant hydrogen peroxide is added according to the mass ratio of the hydrogen peroxide to the COD of 1:1, a dosing pump and a water inlet pump are operated in a linkage mode, and the oxidation reaction time of the hydrogen peroxide is 4 hours.

In the step d), the elastic filler is arranged in the hydrolysis acidification tank, and the anaerobic microorganisms attached to the filler degrade the polluted organic matters in the water.

In the step e), a micropore aerator is arranged at the bottom of the contact oxidation tank for supplying oxygen, a combined filler is arranged in the tank, and the attached aerobic microorganisms grow to nitrify and degrade the organic matters in the water.

In the step f), a microporous aerator is arranged in the MBR membrane tank, a membrane component is arranged in the MBR membrane tank for sludge-water separation, and the effluent after membrane filtration reaches the standard and is discharged.

And f), discharging the sludge separated in the step f) into a sludge pool, performing filter pressing through a sludge filter press, treating the sewage in a comprehensive adjusting tank, and transporting the sludge cakes to qualified units for treatment.

The treatment effects of the examples are as follows:

as can be seen from the above table, the detection result of the effluent after the treatment in the example can meet the requirement of the standard of the make-up water of the open circulating cooling water system in the Water quality control Standard for reclaimed water as cooling water (GB/T19923-2005).

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The method for treating the wastewater generated in the betaine production is characterized by comprising the following process steps:

a) an ozone oxidation step: after being collected by the comprehensive adjusting tank, the wastewater is pumped into an ozone oxidation tank by a pump for ozone oxidation;

b) hydrogen peroxide oxidation step: the wastewater after ozone oxidation enters a hydrogen peroxide oxidation tank, and an oxidant hydrogen peroxide is added for oxidation treatment for 4 hours;

c) ph callback attenuation step: the wastewater after the oxygen balance enters a ph adjusting tank, a ph meter is used for controlling an alkali liquor dosing pump, the ph is adjusted to 7, aeration attenuation is carried out, and redundant hydrogen peroxide in the water is removed;

d) anaerobic biochemical treatment: the pretreated wastewater automatically flows into a hydrolytic acidification tank, and macromolecular organic matters in the water are removed through degradation of anaerobic microorganisms in the tank;

e) aerobic biochemical treatment: the biochemical property of the wastewater after anaerobic treatment is improved, and macromolecules and cyclic organic matters can be subjected to ring opening and decomposition;

entering a subsequent contact oxidation tank, and carrying out nitration reaction on organic matters in the water through aerobic microorganisms in the tank to degrade the organic matters;

f) membrane separation treatment: after organic matters in the wastewater subjected to aerobic treatment are removed, performing sludge-water separation by using an MBR (membrane bioreactor) membrane, and discharging the effluent after reaching the standard;