CN1513569A - Method of eliminating organic sulfur and ethyl carbamate pesticide residue - Google Patents

Abstract

A method for removing the residual agricultural chemical including organophosphorus and amino formate features that the solution of hydrogen peroxide is sprayed onto plant or the plant is soaked in said solution.

Description

Remove the method for organophosphor and carbamate chemicals residual

Technical field

The present invention relates to the improvement of environmental protection, especially to the removal method of residues of pesticides.

Technical background

China is one of country that uses the earliest in the world pesticide control crops harmful organism, and output is big, and is wide in variety.The agricultural chemicals " three wastes " of China is seriously polluted simultaneously.Domestic medicament administration technical merit is low lavishment, heavy dressing phenomenon often to occur, causes serious ecological environmental pollution.It is the main pollution by pesticides source of China that organophosphor and carbamate chemicals residual pollute.

The governing problem that remains of pesticide pollutes is an emphasis of green technology research always.Now, mainly be to concentrate by biological treatment to administer pollution by pesticides waste water.These industrial methods have superiority for the waste water that focuses on various factories, have also obtained suitable achievement.In the middle of new light-catalysed method is also being tested, suitable prospect is arranged for controllable pollution processing.Yet, to pollute for majority, the scope of artificial control is quite limited, but seems powerless for the pollution by pesticides problem of farmland, current water and plant surface.The someone utilizes H at present ₂O ₂Make washing agent decontamination, sterilization.The present invention is further finding H ₂O ₂After the degradation to agricultural chemical compound, use it for the removal of removing crops and cutting surface residues of pesticides thereof, reach the purpose of safety food.

Summary of the invention

Purpose of the present invention provides a kind of method with organophosphor and carbamate chemicals residual amount in the hydrogenperoxide steam generator removal plant, pollutes with the remains of pesticide of eliminating these non-controllable environments to greatest extent.

Feature of the present invention is: H ₂O ₂Solution spray maybe will be subjected to the cutting of pollution by pesticides to be soaked in H on the surface of the crops that polluted by organophosphor or carbamate pesticide ₂O ₂In the solution, the agricultural chemicals organic matter on contaminated thing surface is at H ₂O ₂Under the strong oxidizer effect, be degraded to non-poisonous material, thereby remove the residual of organophosphor or mephenesin Carbamate agricultural chemicals.

For the processing of field crops organophosphor or carbamate chemicals residual, before crop harvesting 0-8 days, use 0.1-3%, the pH value is that the hydrogenperoxide steam generator of 9-11 is done spraying and handled.Spray amount is that fog makes plant surface drenched, obviously sees having fog to drip from plant surface, the crops after handling through spraying, the residual safety standard that reaches of its organophosphor or carbamate.

When the residues of pesticides of the organophosphor of handling vegetables or fruits or carbamate, it is 1-5% that pending thing is dipped in concentration, the pH value is behind hydrogenperoxide steam generator 10-60 minute of 9-11, cleans 2-3 time with clear water, and its organophosphor or carbamic residues of pesticides just can be removed.

When spraying is handled, select finely, the sun-drenched time, select the morning spray effect good.Regulate the material of pH value and will select edible alkali compounds for use.

Hydrogen peroxide (H ₂O ₂) very strong oxidability is arranged, be one of the strongest oxidant.It decomposes generation hydroxyl radical free radical (OH), and latter's oxidisability is stronger.Its mechanism of action is degraded to inorganic matter by its strong oxidizing property with oxidation operation exactly, and degradation efficiency is higher under the ultraviolet lighting.Improve its concentration and the pH value can be accelerated degradation of pesticide, prolong the processing time also can obtain good effect.Through behind the hydrogen peroxide degradation, there is not catabolite residual substantially, toxicity is eliminated.

Through efficient liquid phase chromatographic analysis (HPLC) (HP-1100 high performance liquid chromatograph and UV-detector, chromatographic column: HPODS Hypersil 5 μ m, 125 * 4mm, flow velocity: 1mL/min) show, under the indoor conditions, with 0.3% hydrogen peroxide degradation acephatemet, chlopyrifos, three kinds of organophosphorus pesticides of Azodrin and Methomyl, two kinds of carbamate pesticides of carbofuran, the degradation rate of its degradation rate when not adding hydrogen peroxide improved 5～13 times (table 1).

Table 1 hydrogen peroxide is to the degraded of agricultural chemicals

The degradation rate of organophosphorus pesticide (%) carbamate pesticide degradation rate (%)

Locate 10 μ g/mL, 10 μ g/mL, 100 μ g/mL, 10 μ g/mL, 10 μ g/mL

Reason acephatemet chlopyrifos Azodrin Methomyl carbofuran

X±SE X±SE X±SE X±SE X±SE

H ₂O ₂ 30.43± 10.89± 37.53± 9.41±0.73** 21.76±

1.66** 0.99* 1.81** 1.02**

CK 2.87±0.35 1.89±0.49 2.80±0.28 2.16±0.53 1.76±0.35

1) above result is 3 repetition mean values.

2) (P＜0.05=indicates extremely significantly (P＜0.01=of " * * " expression difference through t check significant difference compared with the control to indicate " * " expression after the data.

Illumination condition particularly ultraviolet lighting can improve the efficient of hydrogen peroxide degradation remains of pesticide.Under ultraviolet lighting, can in 12 hours, make organophosphor and carbamic acid acid agricultural chemicals in the water be degraded to inorganic matter fully with 0.3% hydrogen peroxide, improve 3～9 times, improve 10～20 times (table 2) according to handling than unglazed than the degradation rate under the natural daylight.For the field environment, as long as sunnyly just can reach treatment effect preferably.

Table 2 is not shared the same light to H ₂O ₂The influence of degrading pesticide

Handle organic phosphorus pesticide degradation rate (%) carbamate pesticide degradation rate (%)

10μg/mL 10μg/mL 100μg/mL 10μg/mL 10μg/mL

Acephatemet chlopyrifos Azodrin Methomyl carbofuran

X±SE X±SE X±SE X±SE X±SE

95.22±

Ultraviolet light 100 ± 0a 100.0 ± 0a 100.0 ± 0a 100.0 ± 0a

0.96a

10.89± 37.53± 9.41± 21.76±

Normal optical 30.43 ± 1.66b

0.99b 1.81b 0.73b 1.02b

6.00±

Dark 4.63 ± 0.26c, 7.63 ± 0.26c, 4.09 ± 0.55c, 9.45 ± 0.47c

0.19c

1) above result is 3 repetition mean values.

2) indicate same letter in the table after the same column data and be illustrated in 5% level difference not remarkable (DMRT method).

The concentration that improves hydrogen peroxide just can be accelerated the degraded of agricultural chemicals.Work as H ₂O ₂Concentration is 0.03%, and acephatemet, chlopyrifos and Azodrin degradation rate are respectively 84.50%, 80.60% and 78.25%; And H ₂O ₂Concentration is 0.3% o'clock, and its degradation rate then reaches 100%, 95.23% and 100% respectively, and the carbofuran degradation rate is being 0.003% o'clock, and degradation rate is 59.24%, and H ₂O ₂Then be 98.73% during concentration 0.03%.For the processing on field crops surface, concentration of hydrogen peroxide is unsuitable too high, in case produce poisoning, but the too low expected effect that do not reach again of concentration.Wherein proper between 0.1～3% with concentration.

The pH value of reactant liquor is big more, and hydrogen peroxide degradation agricultural chemicals speed is fast more.The for example degraded of chlopyrifos, Azodrin and carbofuran, under the solutions of weak acidity of pH4～6, degradation rate is lower, and degraded is all higher under highly acid pH2 and alkaline pH11, wherein strong alkaline condition is generally than strong acidic condition good (table 3).For our required these non-controllable environments to be processed, pH9～11st, proper.

The initial pH of table 3 is to the influence of degradation of pesticide

Organic phosphorus pesticide degradation rate (%) carbamate pesticide degradation rate (%)

The pH value

Chlopyrifos Azodrin carbofuran

2 64.63 39.44 99.45

4 54.89 37.44 69.83

6 68.64 37.25 83.11

9 80.37 71.86 89.88

11 93.74 92.82 100

Prolong the processing time, hydrogen peroxide degradation agricultural chemicals effect improves.Under indoor conditions, the degradation rate of agricultural chemicals such as the acephatemet that tries, Azodrin, carbofuran all reaches 100% degraded (Fig. 1) after handling 12h.For the processing of field remains of pesticide, because field environment uncertain factor is many, therefore needs are grown the time of a bit, and general one all left and right sides are proper; Processing for indoor processing such as fruits and vegetables remained on surface agricultural chemicals then can make the processing time about 10-60 minute by regulating concentration of hydrogen peroxide.

Fig. 1 is H ₂O ₂The graph of a relation in photocatalytic degradation agricultural chemicals and processing time

Find that by analyzing the HPLC collection of illustrative plates for the hydrogen peroxide degradation agricultural chemicals, it can not only make the target agricultural chemicals one It is interior degradable to fix time, and the intermediate product preferably degradation also to producing in degradation process. Indoor After processing 12h, do not have material to be detected in the solution, namely do not have catabolite residual.

Find also that by bioassay method hydrogen peroxide can not only make agricultural chemicals degradable, and it is several that toxicity is dropped to Be zero. For example choose H₂O ₂The initial reaction liquid of degrading pesticide (0h degradation solution), 6h degradation solution and 12h degraded Liquid is studied its toxicity. With the blade immersion method (medicament is made into desired concn, the cabbage leaves dish of diameter 2cm at medicine Soak 30s in the liquid, dry at filter paper then, put into the culture dish of diameter 9cm, insert the examination of hungry 4h Worm, and splash into the clear water moisturizing. Each situation of being poisoned to death of processing of investigation in observing time. ) processing leaf dish, every processing Use 2 age 15 of silkworms, every processing repeats for four times, establishes the clear water contrast, checks 6h and the 24h death rate.

Table 4 degradation of pesticide liquid is to the toxicity of silkworm

The silkworm death rate (%)

Give birth to survey and fall

             10μg/mL   10μg/mL  100μg/mL  100μg/mL   250μg/mL

Process and separate

Acephatemet chlopyrifos Azodrin Methomyl carbofuran

The time interstitial fluid

             X±SE      X±SE      X±SE       X±SE      X±SE

      12h    0±0a      0±0a      0±0c       0±0b      0±0c

                                   25.00±                                  35.00±

      6h     0±0a      0±0a                  0±0b

6h                                 3.19b                  3.19b

             1.67±                                 95.00±            86.67±          96.67±

      0h                0±0a

             1.67a                 3.19a       2.91a      3.33a

                                   5.00±

      12h    0±0c      0±0b                  0±0b      0±0b

                                   5.00b

             11.67±                                                       1.67±            98.33±

24h   6h                0±0b      100±0a

             4.19b                             1.67b      1.67a

                                               98.33±

      0h     60±3.85a  100±0a    100±0a                100±0a

                                               1.67a

1) above result is 4 repetition mean values

2) survey in the processing time all one's life together in the table, be illustrated in 5% level difference not remarkable (DMRT method) with indicating same letter behind the column data

As can be seen from the results, after hydrogen peroxide was processed, for tetchy silkworm, the death rate was all below 5%, Be bordering on nontoxicly, show that the hydrogen peroxide degradation agricultural chemicals is the degraded of a kind of toxicity reduction, can improve to greatest extent the processing security, Reducing the pesticide poisoning event takes place. Result's consistent with silkworm (table 4) that phyllotreta striolata is measured.

In sum, the advantage of hydrogen peroxide degradation remains of pesticide is to make farmland, water body, soil and plant table The degrading pesticide residue of face, and it is residual not have catabolite, can significantly reduce its residual toxicity; Using method is simple, Only aqueous hydrogen peroxide solution need to be sprayed to process and just can achieve the goal.

Embodiment 1:

With 10 μ g/mL acephatemets or 10 μ g/mL chlopyrifos pesticides and mixed solution of hydrogen peroxide 0.25L (containing hydrogen peroxidase 10 .3%), regulate pH9～11, carrying out routine with manual sprayer, to sparge area be 4m ², on 45 days cabbage hearts of plantation 45d, soup is sprayed the positive and negative that is distributed in blade equably, till covering fumulus on the blade.Spray back the 1st, 3,7d gets the cabbage heart blade and carries out remains of pesticide extraction (GB14876-94, GB/T 17331-1998), air feed analysis of hplc (capillary column: HP-530m * 0.32mm * 0.25 μ m, injector temperature: 200 ℃; Detector: 260 ℃, column temperature: 100 ℃ (1min), 20 ℃/min are warming up to 220 ℃ (keeping 5min), carrier gas: hydrogen 3mL/min; Air: 60mL/min; Make-up gas: 2mL/min, post flow: 5mL/min; Sample size: 0.5 μ l).Identical pesticide concentration, no H are established in test ₂O ₂Processing compare.Result such as Fig. 2, Fig. 3.

Fig. 2 is the field residual quantity result of the test figure of 10 μ g/mL acephatemets

Fig. 3 is the field residual quantity result of the test figure of 10 μ g/mL chlopyrifos

Add H₂O ₂The acephatemet field residual quantity of processing obviously reduces. 0.3%H₂O ₂When processing 1 day, acephatemet residual Allowance is 2.62 μ g, and the persticide residue of contrast has descended 10.57%, processes 3 days, and residual quantity is 1.54 μ g, Contrast reduces 39.62%, processes 7 days residual quantities and only has 0.93 μ g, reduces 45.21%. Add 0.3%H₂O ₂Residual than not adding H on the dish leaf of field of the 10 μ g/mL chlopyrifos of processing₂O ₂Chlopyrifos residual few, And temporal evolution, difference is more and more obvious. The persticide residue of processing 1 day is 0.84 μ g, contrasts residual Amount reduces 16.95%, processes and is reduced to 0.30 μ g after 3 days, and contrast descends 30.49%, processes and poisons with poison after 7 days The residual quantity of tick only remains 0.12 μ g, and its residual quantity rate of descent is 64.05%.

Embodiment 2:

300 μ g/mL Methomyl devices are sprayed on the taro leaves dish, and (2cm * 2cm), tow sides respectively spray 1mL, after drying, use 0.6%H ₂O ₂Immersion treatment is taken out after 10 minutes, 30 minutes, 60 minutes and is dried.With the leaf dish put into be equipped with 10 3 age Spodoptera litura larvae the 9cm culture dish, every processing repeats 3 times, establishes the clear water contrast and does not have the blank of immersion treatment.24 hours death rates of procuratorial work.H ₂O ₂Immersion treatment and clear water immersion treatment more than 30 minutes the time Methomyl remarkable to the mortality difference of Spodoptera litura larvae.Its H ₂O ₂The death rate of immersion treatment 30 minutes and 60 minutes is respectively 48.49%, 29.99%, significantly is lower than the death rate of clear water immersion treatment, shows H ₂O ₂Immersion treatment can significantly reduce the methomyl residue amount of plant surface.

Claims (3)

1, removes the method for organophosphor and carbamate chemicals residual, its feature H ₂O ₂Solution spray maybe will be subjected to the crops cutting of pollution by pesticides to be soaked in H on the crops surface that polluted by organophosphor or carbamate pesticide ₂O ₂In the solution, the pesticide activity on contaminated thing surface is at H ₂O ₂Under the strong oxidizer effect, be degraded to non-poisonous material, thereby remove the residual of organophosphor or mephenesin Carbamate agricultural chemicals.

2, according to the said method of claim 1, when it is characterized in that handling field crops organophosphor or carbamate chemicals residual, before crop harvesting, use 0.1-3%, the pH value is that the hydrogenperoxide steam generator of 9-11 is done the spraying processing, spray amount is that fog makes plant surface drenched, obviously sees having fog to drip from plant surface.

3, according to the said method of claim 1, it is characterized in that when the residues of pesticides of the organophosphor of handling vegetables or fruits or carbamate, it is 1-5% that pending thing is dipped in concentration, the pH value is behind hydrogenperoxide steam generator 10-60 minute of 9-11, clean 2-3 time with clear water, organophosphor that it is surperficial or carbamic residues of pesticides just can be removed.

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