Xiong Yongtian 1, *, Mei Zhichuan B, Hong Aoye B, Shui Yue B Yi Hui,
Bangbin Yantian B, Kangming Maeda B
599-8570 Xueyuan Town, Osaka, Japan 1-2 Advanced Science and Technology of an Institute in osaka prefecture university.
School of Applied Materials Science and Engineering, Part B, osaka prefecture university, Xueyuan Town, Osaka 599-85301.
Received1July 26th, 999; The revised form 1999 summary was received on September 24th.
The ultrasonic degradation of 2-, 3- and 4- chlorophenol and pentachlorophenol in dilute solution was studied in air or argon atmosphere. degraded
In the following first-order kinetics, the initial state and interest rate are in the range of 4.5-6.6 mm min- 1, and the concentration of argon gas in 6.0-7.2 mMmin- 1 is100 mm.
Chlorophenol. The generation rate of OH radical is from underwater argon 19.8 mm min- 1 and underwater air 14.7 mMmin- 1 under the same conditions of sonication. Ultrasonic decomposition
Chlorophenol was effectively inhibited by adding tert-butanol, which was considered as an effective OH radical scavenger in aqueous solution. This shows that
The main degradation products of chlorophenol are via reaction and OH radical. Thermal reactions also occur from time to time, although its contribution is very small. In addition to the appropriate
Accelerated degradation of a large number of iron (Ⅱ) ions. This may be due to the regeneration of OH radical hydrogen peroxide, which will be the formation of recombination.
OH radicals, and may contribute to a little degradation.
The ability to inhibit bacterial reproduction, pentachlorophenol was irradiated with ultrasonic waves. ? 2000 Elsevier Science B.V. All rights reserved.
Keywords: chlorophenol, pentachlorophenol; ultrasonic degradation
1 。 introduce
Application of ultrasonic degradation
Recently, the chemical pollutants in water have been extensively studied. Example reports include degraded hydrogen sulfide [1] and chlorofluorocarbons.
[2-4], chlorinated hydrocarbons [5-8], polycyclic aromatic hydrocarbons [9], various phenols [65438+1October 65438+June 6]
Phosphine [17], oxytetracycline [18] and hydroxy acid.
(HBA card) [19]. Ultrasonic radiation is well known,
Provide various chemical and physical effects, such as
For general sonochemistry, see the references. [ 20-3 1 ] 。 Ultrasonic decomposition
A cavity formed by water and then folded can create a huge space.
As a result, the temperature and pressure of water rise.
Be decomposed into hydrogen atoms and hydroxyl groups.
[ 32,33 ] 。 Ultrasonic wave containing pollutants in aqueous solution will lead to its degradation.
Hydroxyl or hydrogen atom and/or high temperature;
Thus, ultrasonic irradiation appeared.
Is an effective method, degeneracy
Various organic pollutants.
In this paper, we report the results of ultrasound.
2-, 3- and 4- chlorophenols (2-, 3- and
4- directing agent) and pentachlorophenol (PeCP) are used in water.
High-power ultrasonic generator and the focus of our interest
Technical feasibility, ultrasonic damage
The environmental problems of these nonvolatile substances,
The basic program water is also discussed.
Acoustics
2 。 experiment
2. 1 。 material
2-, 3- and 4-CP and chlorobenzene (carbon black)
Reduce the atmospheric pressure from photochemical and distillation purification. reagent
PeCP grade (standard determination reagent
Other agricultural chemicals), methanol, dimethyl.
Isopropanol (tert-butanol), n-hexane, ammonium iron (II)
Sulfuric acid, sodium chloride and sodium sulfate
Cong Heguang Chemical Industry, Nutritional Broth (No.2) consists of
Protein potassium dihydrogen phosphate produced by Merck.
Monohydrogen of disodium phosphate shore field
Chenghua is used for further purification. argon
(purity 99.999%) purchased from Osaka Villa.
Water in pure water treatment system (millisecond -Q table).
2.2 。 Identify and determine raw materials.
And decomposition products
Identification confirmed 34 people.
Performance adopts Japan Shimadzu 6A high performance liquid crystal display.
The liquid chromatograph is equipped with a photoelectric detector.
Column 18 on ozone-depleting substances uses Na2HPO3, KH2PO3 and.
Sodium sulfate is used as eluent. Absorption spectrum CPS and
Determination and use of acoustic vibration reaction mixture
Shimadzu ultraviolet spectrophotometer 3 100. chlorion
Determine the use through 34 acoustic solutions.
Ion chromatograph (IC- 100, Yokogawa, North).
2.3 。 Ultrasonic irradiation
Addo ultrasonic generator (Kaijyo 402 1) and
Barium titanate oscillator 65 mm, diameter
Used for 200 khz ultrasonic irradiation and operation.
Input intensity and the solution of 200 samples in the United States
Acoustic vibration 65 ml is packed in a cylindrical glass container.
Oil-free bulb; Its total volume is150ml.
Ships with an inner diameter of 50 mm also have side effects.
The arm and silicone rubber are blistered or separated from each other.
The sample extracted from the sample was not exposed to air.
The bottom of the boat is flat and thin.
As far as possible (1mm), because the emitted ultrasonic waves.
The bottom decreases with the increase of thickness.
The ship is installed in a constant relative position.
Sound waves at the intersection of aircraft (3.75mm: 1/2)
From an oscillator). In order to solve the problem of stabilizing the reaction kettle
And the exact location, laboratory jack, pliers and
Bracket-all parts in the positioning system
Optical measurement-using. In the radiation, the ship was shut down. Rate OH radical formation
The estimate is 19.8 mm min- 1.
Argon and air below 14.7 mMmin- 1, and
The formation of hydrogen is estimated to be 20 mm min-1.
According to the ultrasonic decomposition of pure water in argon gas
This acoustic solution condition [19,34].
2.4 。 Ability to suppress decisions
bacterial reproduction
There are 98 directors of Salmonella typhimurium strains or directors 100.
Inoculated in nutrient broth medium, which is made up of 2.5g nutrient solution and 100ml water.
And autoclaved (ping HA24). Until/very
In bacterial inoculation and ultrasonic therapy
The solution of PeCP is to add incubation and shake hands at 37℃ for 30 h in the result test. clean
Substitutes (Japan Ikaki VST 1000) are used for these operations. Causes of turbidity at 650 nm in the test
Measure the appropriate culture time after bacterial reproduction. Ultrasonic treatment solution
Prepare as follows. Aqueous solution 100 mm
(1 in 26.7 million) PeCP is acoustic vibration until 95%.
PeCP is rotten. Adjust the pH value to
6.6. Add sodium hydroxide and irradiation solution.
Concentrated evaporation at 35℃ to obtain
The concentration of pentachlorobenzene in the test is equivalent to
Ultrasound treatment is 20 parts per million, if not.
Go on. In fact, at the test concentration,
About 1 ppm(5% of 1 ppm) and less.
Observation of bacterial reproduction
PeCP concentration after dilution.
3 。 Results and discussion
3. 1 。 Ultrasonic decomposition of chlorinated paraffin
Figure. 1 shows the time-dependent degradation.
2-, 3-, 4- chlorophenol and pentachlorophenol and free chloride.
Anions are carried out under ultrasound in argon or air atmosphere.
First-order attenuation begins at the initial stage of degradation. The degradation rate of argon is fast.
Compared with in the air, the first 34 people were 90- 100% degraded.
40 minutes, almost 1 hour 100%, under ultrasonic decomposition.
Argon, this is 70-80% and 80-90% for 40 minutes.
1 hour, acoustic decomposition in air. temperature
The folding cavity is defined as Tfin =
Tian [Pfin (C- 1)/product] where Tfin and Pfin are the final TEM.
Temperature and pressure, Sha Tin and pin initiation
Temperature and pressure chamber; ? The CP/ coefficient of = is
Constant pressure specific heat
Produce specific heat foam in a certain volume of gas.
The value of argon in C (1.67) is higher than that in air.
( 1.40 ) ; Therefore, the cavitation effect should be higher.
According to the ratio of argon to air. speed up
There seems to be little oxygen in the reaction. The decomposition speed of three kinds of protein is faster than that of 2-CP and 2-CP.
4 protein. Due to that electrical characteristic of Ohio
Free radicals, oh, free radicals attacking websites are expected to
Chloride ions and OH groups are adjacent to and in the direction of chain segments.
Generally speaking, compounds in parents.
OH radicals other than aromatic compounds. In fact,
This is the HBA card for observing the sound solution [19].
In three kinds of protein, three points are adjacent at the same time.
First, it faces chloride ions and OH groups in Ohio.
Free radicals will appear most easily, and three kinds of protein are.
As the most fragile addition reaction.
Oh, radical. Reaction between agreements.
Experimental results and reasoning show that,
Contribution of OH radical reaction to 34 sonolysis.
Very important.
3.2 。 Ultrasonic decomposition affects the ability to inhibit bacteria.
Multiplication uses PeCP
According to reports, PeCP inhibition ability
Breeding green algae subspecies reticulata
Irradiate with ultrasonic wave [1 1]. Work in this field
PeCP's ability to suppress influence.
Effect of ultrasonic irradiation on the reproduction of typhoid bacillus. Figure. 2 shows (1) 98 and strain director which inhibit bacterial reproduction.
(2) Emergency Response Officer 100 Pentachlorobenzene and its sonicated products.
The ability of ultrasound drops, but drops.
Slightly lower than the degradation of pentachlorobenzene; this is
Indicative formation inhibition of other materials
PeCP is in acoustic solution, although the quantity
Will be insignificant. Long irradiation time
It is more complicated than complete destruction, and then it must be completely deleted.
Inhibition of ability.
3.3 。 Decomposition mechanism and reaction website
At all 34 intensities, two ultraviolet rays are absorbed.
Band in 2 15-225 and 270-280 nm (250 and
PeCP at 320 nm), all of which are distributed on the aromatic ring,
Reduce exposure, although it is different.
The band is acoustically decomposed in air at a shorter wavelength.
It's a little unclear. The results show that, on the whole,
CPS and PeCP, aromatic ring cracking.
Ultrasonic parallel irradiation and degradation
Starting compound. Figure. 3 changes in display
Take the ultraviolet spectra of three kinds of protein as an example. A similar trend
Observation and others 34.
Figure. 4 shows the scavenging effect of tert-butanol
Sonolyssis4 protein. Degenerative effectiveness
Quench the extra tert-butyl alcohol, but not completely,
Even with a molar concentration of 100 times.
Tert-butanol to 3 protein. According to reports, tert-butyl alcohol is
An Effective Scavenger for Hydroxyl Radicals —— Sonolysis in Water
19,35], and the degradation was completely inhibited.
(HBA card) at this concentration.
More detailed survey reply
Mechanism and reaction of website sonolysis CB
More disordered and hydrophobic than 34
Show.
Figure. Fig. 5 shows the sonochemically degraded CB,
Formation and function of chloride ion in tert-butyl alcohol
Except for the ultrasonic decomposition of carbon black. Rate degradation
Faster than CPS and HBA cards.
Higher conversion rate and chloride ion
Tert-butanol has a low scavenging effect.
Table 1 shows the decrease of initial rate.
Check 34 jobs and compare them.
Those HBA cards and CB degenerate and OH radicals.
Formed by ultrasonic decomposition of water.
The degraded sonolytic HBA card will start.
Through the special reaction with a large number of OH radicals
Solution and empty foam in thermal reaction.
Or the interface area can be excluded, because
Nonvolatile hydrophilic HBA card.
However, turbulent and hydrophobic carbon black will
Always consider the cavitation phenomenon of foam and its main reasons
The degradation pathway may be pyrolysis at high temperature.
In the bubble, it is the most thorough and rapid.
Degeneration will interfere.
In fact, the degradation rate of tert-butyl alcohol is very high.
The concentration far exceeds the formation of OH radicals.
Support pyrolysis pathway.
A reaction between CB and HBA card is in the middle.
Observe chlorinated paraffin (though a little brief)
Close to the HBA card). With HBA card, more.
At present, hydrophobic chlorinated paraffins in various countries and regions may concentrate on an interface to react with OH radicals or in thermal reactions.
Rich. Estimate from the diagram. 4. Majority
Degradation occurs through most free radical reactions.
Solution, but about 10% is due to thermal reaction.
At the interface (degenerate cavity can be ignored
Due to the small fluctuations in country parks).
Considering the velocity constant k (tert-butanol+Ohio) # 5× 108 [36], potassium (tert-butanol+high) # 105 and
Degree (c 6 H5 OH+ high) # 109 [37], tert-butyl alcohol can be an OH radical scavenger, but it is not an H atom scavenger. Therefore,
The ultrasonic decomposition of 34 hydrogen atoms played a role.
It may be small. It is reported that hydrogen production
H takes away hydrogen atoms to form (molecules).
Only 1/50 hydrogen atoms are composed of hydrogen atoms.
Despite the initial [38] recombinant ultrasonic cracking
Rate constant k(HCOO-+ high) # 1.5× 108 [37], and
Ultrasonic decomposition reduces the purity of silver ions and AuCl-4.
Water is slow [39, 40] (gold (silver ion of H+) and.
Degree (AuCl-4, 3 × 10 10 and 5.7 × 109 of H+ are [37] respectively). These facts mean that a small part of hydrogen.
The holes produced by atoms diffuse in the solution.
And support the above assumptions.
34 of them degenerated from 65438+1October 4th to 65438+1October 2nd.
OH radical formation rate. This shows that,
The recombination of OH radicals will appear considerable.
To a large extent. Reaction of rate constant 34
Mixing with water of OH radical at normal temperature.
In the command 109M- 1- 1 (rate constant of hydroxyl group
Free radicals other than aromatic rings), which is the same.
Order of magnitude of OH radical recombination [36].
Most of the solutions are concentrated in Cambridge Positioning System Co., Ltd..
It is considered to be much higher than the instantaneous hydroxyl group.
Free radicals, therefore, recombinant hydroxyl radicals
In most CAL solutions, it is difficult to find a fair solution.
The amount of locally concentrated OH radical [4 1] can be.
On the reorganized interface.
In order to improve the decomposition efficiency, more
It is hoped that OH radicals can be effectively utilized. it is
It is predicted that iron (Ⅱ) ions will regenerate OH radicals.
From hydrogen peroxide, thus the efficiency of ultrasonic degradation.
A suitable one will be added for 34.
Fe (Ⅱ) ion concentration.
Hydrogen peroxide+iron (II)? ? Iron (III)+ hydroxyl+? Oh (1)
Oh +34? ? Decomposition (2)
OH+ iron (II)? ? Hydroxyl+iron (III) (3)
Figure. Effective Effect of 6Fe (Ⅱ) Ion on Ultrasonic Cracking
3 protein. Degradation of 3-cp and degradation of 3-CP
Existing Fe (Ⅱ): the interest rate is increased to 2.4 times.
1.5 times, and the iron (II) concentration of 2 mm is 0 mmol.
The results show that there is an optimum value of iron (Ⅱ).
34 concentration and maximum efficiency of acoustic solution
In addition, excessive Fe (Ⅱ) will lead to
Reduce the degradation rate caused by removal.
Fe (Ⅱ) ion of OH group in equalizer. ( 3 ) 。
4 。 conclusion
Ultrasonic chemical degradation of three kinds of single cell proteins
Pentachlorobenzene was studied in dilute aqueous solution.
Almost 100% yield was degraded under argon.
Ultrasonic decomposition in atmosphere and 80-90% air 1 hour.
Ultrasonic radiation provides different reaction sites.
Pyrolysis and oxidation. In the ultrasonic method
Will be a favorable destruction method.
Environmental pollutants, such as 34, diluted
If the large-scale acoustic reactor is solved, it will already exist.
Express one's gratitude formally
This research was carried out through Japan Steel Company.
Industrial promotion foundation
Environmental protection technology (September).