Treatment method for high-sulfur pesticide chemical residual liquid

Abstract

The invention relates to a high-sulfur pesticide chemical raffinate disposal method which comprises the following steps: fixing raffinate in a packaging container, connecting the raffinate with an alkaline washing tower to form a negative pressure environment, selecting low-calorific-value waste liquid which is non-combustible in a combustion test, is water-based in pH detection and passes through a small reactivity test, injecting a small amount of the raffinate in batches for hydrolysis reaction, and monitoring and controlling the reaction progress according to the wall temperature of the container; after hydrolysis is completed and curing is conducted, upper-layer liquid is subjected to liquid sealing and suction filtration and then subjected to spray incineration, and lower-layer solid is crushed in an alkaline environment, cleaned and then fed into a kiln to be incinerated. Through multi-link cooperative control, the problems of reaction safety, pollution prevention and control and harmlessness in residual liquid disposal are solved, and the method has the advantages of being safe, controllable, environmentally friendly and efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial waste liquid disposal, and particularly to a method for disposing high-sulfur pesticide chemical waste liquid. Background Art

[0002] High-sulfur pesticide chemical waste liquid is a by-product in the process of producing ethyl chloride (chemical name: 0,0-diethylthiophosphoryl chloride, an intermediate for organophosphorus pesticides such as chlorpyrifos, phoxim, triazophos, diazinon, ethyl parathion, and suhua 203) by the phosphorus pentasulfide method in the pesticide industry. It includes undistilled ethanol, residual ethyl chloride, and unseparated sulfur, and is rich in high concentrations of hydrogen sulfide and sodium hydrosulfide. This waste liquid is highly toxic and strongly irritating. Traditional disposal methods have problems such as reaction runaway, secondary pollution, and incomplete disposal. If conventional incineration disposal is used, its high toxicity and strong irritation make it difficult to carry out compatibility pretreatment, seriously affecting the working environment and operation safety. At the same time, high sulfur will cause corrosion of the refractory materials in the incineration system and consumption of alkali liquor for flue gas disposal. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for disposing high-sulfur pesticide chemical waste liquid, aiming to solve technical problems such as safety control of the hydrolysis reaction of the waste liquid, effective absorption of harmful gases, solid-liquid separation, and subsequent harmless disposal.

[0004] To achieve the above purpose, the present invention provides the following technical solutions: A method for disposing high-sulfur pesticide chemical waste liquid, comprising the following steps: Fix the high-sulfur pesticide chemical waste liquid contained in a packaging container to a hydrolysis reaction device, open the first opening on the packaging container, connect it to an alkali scrubber through a suction hose, and maintain a negative pressure state inside the container; Select a water-based low calorific value waste liquid that has been verified non-flammable through a combustion test, has a water-like pH detected by a pH test paper and is not strongly acidic, and the water-based low calorific value waste liquid and the high-sulfur pesticide chemical waste liquid have been pre-tested for reactivity for 24 hours to ensure the reaction is controllable. Use a liquid extraction device to transfer the waste liquid to a storage container as a hydrolysis reaction medium; Open the second opening on the packaging container, install a diversion funnel, and slowly inject the low calorific value waste liquid into the packaging container through a ladling tool to mix it with the high-sulfur pesticide chemical waste liquid for hydrolysis reaction. After injecting the liquid, slightly cover the packaging container lid; Add the water-based low calorific value waste liquid in a fractional and small amount, with a single addition amount of 3 - 5 L. After the reaction starts, use a non-contact temperature measuring device to monitor the container wall temperature every half hour. When the wall temperature drops below 55 °C, continue to add the waste liquid to continue the reaction until the temperature no longer rises after adding, and determine that the hydrolysis reaction is completed; After the hydrolysis reaction is completed, wait for the residual liquid to cool to ambient temperature, remove the suction hose, seal the packaging container, and transfer it to an independent storage area for aging treatment; During the hydrolysis reaction, continuously monitor the pH value of the liquid in the caustic scrubber, and replenish the alkaline neutralizer in a timely manner when the pH is below 7.

[0005] Preferably, it further includes a liquid spraying and burning step: After completing the hydrolysis reaction of the high-sulfur pesticide chemical residue liquid and fully aging it, conduct solid-liquid separation and disposal. Pre-inject low-calorific-value aqueous waste liquid into the storage container to form a liquid seal layer. Pump the hydrolyzed liquid on the upper layer through filtration to the incineration workshop and pump it to the waste liquid storage tank for closed spray incineration. Crush the solid materials in the lower layer and dispose of them in a pit.

[0006] Preferably, the step of crushing the solid materials and disposing of them in a pit includes: Before the solid crushing operation, empty the materials in the crushing pit, inject low-calorific-value waste liquid and add slaked lime, and adjust the pH of the liquid in the crushing pit to above 12; Conduct continuous crushing operation on the target solid materials. During the operation, it is prohibited to mix other materials. After the crushing is completed, use sludge and slaked lime to clean the crusher in sequence, and then use low-calorific-value aqueous waste liquid twice for crushing and cleaning; Detect the pH of the liquid in the crushing pit the next day. If it is below 7, supplement slaked lime to adjust it to 12. After the reaction is complete, mix and stir it with other compatible materials in batches, and grab and put it into the incineration kiln for disposal through the overhead crane.

[0007] Preferably, when the suction hose is connected to the caustic scrubber, a one-way check valve is provided to prevent the liquid in the caustic scrubber from flowing back into the packaging container.

[0008] Preferably, the selection criteria for the low-calorific-value aqueous waste liquid also include: the density range of the waste liquid is 0.9 - 1.1 g / cm³, and the chloride ion content does not exceed 500 mg / L.

[0009] Preferably, during the hydrolysis reaction, when the temperature of the container wall exceeds 80 °C, suspend adding low-calorific-value waste liquid and start the external water cooling device to cool down the packaging container.

[0010] Compared with the prior art, the technical solution of the present application has the following technical effects: A method for disposing of high-sulfur pesticide chemical residue liquid provided by the present invention. The residue liquid undergoes a hydrolysis reaction under the entire negative pressure system. The hydrogen sulfide released can be neutralized and disposed of through caustic scrubbing. A large amount of hydrogen sulfide in the residue liquid can be volatilized, and the volatilized hydrogen sulfide can be absorbed by the alkaline waste liquid to eliminate the high toxicity and strong irritation of the residue liquid, while reducing the sulfur content in the residue liquid, greatly reducing the disposal difficulty and disposal cost of the residue liquid. Detailed implementation mode

[0011] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0012] As a preferred embodiment of the present invention, this embodiment provides a method for disposing of high-sulfur pesticide chemical waste liquid, including the following steps: Fix the high-sulfur pesticide chemical waste liquid contained in the packaging container to the hydrolysis reaction device, open the first opening on the packaging container, connect it to the alkali washing tower through the suction hose, and keep the inside of the container in a negative pressure state; Select a water-based low-calorific value waste liquid that has been verified non-flammable through combustion tests, has a water-like pH value detected by pH test paper and is not strongly acidic, and the water-based low-calorific value waste liquid and the high-sulfur pesticide chemical waste liquid have been pre-tested for reactivity for 24 hours to ensure controllable reaction. Use liquid extraction equipment to transfer the waste liquid to a storage container as the hydrolysis reaction medium; Open the second opening on the packaging container, install a diversion funnel, and slowly inject the low-calorific value waste liquid into the packaging container through a ladling tool to mix with the high-sulfur pesticide chemical waste liquid for hydrolysis reaction. After injecting the liquid, slightly cover the packaging container lid; Add the water-based low-calorific value waste liquid in a small amount in batches, with a single addition amount of 3-5 L. After the reaction starts, use a non-contact temperature measuring device to monitor the wall temperature of the container every half hour. When the wall temperature drops below 55 °C, continue to add the waste liquid to continue the reaction until the temperature no longer rises after adding, and determine that the hydrolysis reaction is completed; After the hydrolysis reaction is completed, wait for the waste liquid to cool to the ambient temperature, remove the suction hose, seal the packaging container, and transfer it to an independent storage area for aging treatment; During the hydrolysis reaction process, continuously monitor the pH value of the liquid in the alkali washing tower, and promptly supplement the alkaline neutralizer when the pH is lower than 7.

[0013] When implementing the above embodiments, by connecting under negative pressure, adding the low-calorific value waste liquid in small amounts multiple times and monitoring the temperature in real time, the violent out-of-control of the reaction can be avoided; the reactivity test is carried out in advance to ensure the controllability of the reaction degree.

[0014] In the above embodiments, it further includes a liquid spraying and burning step: After completing the hydrolysis reaction of the high-sulfur pesticide chemical waste liquid and fully aging it, carry out solid-liquid separation disposal. Pre-inject the low-calorific value water-based waste liquid into the storage container to form a liquid seal layer. Pump the hydrolyzed liquid on the upper layer to the incineration workshop by suction filtration, and pump it to the waste liquid storage tank for closed spray incineration. The solid materials on the lower layer are crushed and put into the pit for disposal.

[0015] In a preferred embodiment, the step of crushing the solid material and disposing it in a pit comprises: Before the solid crushing operation, empty the materials in the crushing pit, inject low calorific value waste liquid and add slaked lime, and adjust the pH of the liquid in the crushing pit to above 12; Continuously crush the target solid material. It is forbidden to mix other materials during the operation. After the crushing is completed, the crusher is cleaned with sludge and slaked lime in turn, and then the crushing and cleaning is carried out twice with aqueous low calorific value waste liquid; The next day, the pH value of the liquid in the crushing pit is tested. If it is lower than 7, slaked lime is added to adjust it to 12. After the reaction is complete, it is mixed and stirred with other matching materials in batches, and then grabbed by a crane and put into the incineration kiln for disposal.

[0016] In the above embodiment, the alkaline washing tower monitors the pH in real time and replenishes the alkaline waste liquid to ensure that the hydrogen sulfide is completely neutralized; a water seal is set before the liquid is sprayed to prevent the volatilization of harmful gases; the solid crushing pit adjusts the pH to allow the solid to fully react and reduce pollutant emissions.

[0017] In some preferred embodiments, in order to reduce disposal risks, a one-way check valve is provided when the suction hose is connected to the alkali washing tower to prevent the liquid in the alkali washing tower from flowing back into the packaging container.

[0018] In some preferred embodiments, the selection criteria of the aqueous low calorific value waste liquid also include: the density range of the waste liquid is 0.9-1.1g / cm³, and the chloride ion content does not exceed 500mg / L. In the liquid spraying process, low calorific value aqueous waste liquid needs to be poured into the ton barrel to form a water seal. This density range can ensure that the waste liquid floats on the upper liquid after the residual liquid is hydrolyzed, effectively blocking the volatilization of harmful gases and avoiding secondary pollution before incineration. During the hydrolysis reaction, waste liquid and residual liquid of similar density are easier to mix naturally, reducing the problem of stratification or uneven local reaction caused by excessive density differences, and improving the hydrolysis efficiency.

[0019] In the above embodiment, during the hydrolysis reaction, when the container wall temperature exceeds 80° C., the addition of low calorific value waste liquid is suspended, and an external water cooling device is started to cool the packaging container.

[0020] The hydrolysis reaction of high-sulfur pesticide residue is an exothermic process. If the temperature continues to rise, the reaction rate may accelerate sharply, causing violent boiling or sudden and large-scale release of harmful gases (such as hydrogen sulfide). In the above embodiment, when the container wall temperature exceeds 80°C, suspending the addition of low calorific value waste liquid can cut off the supply of reaction raw materials and slow down the reaction process; the heat in the container is quickly removed through water-cooled heat exchange, and the temperature is controlled within the safety threshold to prevent safety accidents caused by high temperature.

[0021] On the other hand, in a high-temperature environment, some components in the residual liquid may undergo thermal decomposition or polymerization reactions, generating more complex harmful by-products (such as highly toxic organic sulfides). These by-products not only increase the difficulty of subsequent treatment but may also reduce the overall disposal efficiency. By controlling the temperature, it is possible to ensure that the reaction proceeds along the preset path, maintaining the controllability and harmlessness of the hydrolysis reaction.

[0022] In the above-described embodiments of the present invention, from the hydrolysis reaction, aging to the classified disposal of solid and liquid, incineration, and crushing and cleaning, etc., each link is closely linked to ensure that the harmful substances in the residual liquid are maximally converted and harmlessly treated; the material dosage, operation method, and monitoring frequency are clearly defined for each step, ensuring the standardization and regularization of the disposal process and reducing the risk of human operation.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for disposing of high-sulfur pesticide chemical waste liquid, characterized in that, It includes the following steps: Fix the high-sulfur pesticide chemical waste liquid contained in the packaging container to the hydrolysis reaction device, open the first opening on the packaging container, connect it to the alkali scrubber through the suction hose, and maintain a negative pressure state inside the container; Select a water-based low-calorific value waste liquid that has been verified non-flammable through a combustion test, has a water-like property detected by a pH test paper and is not strongly acidic, and the water-based low-calorific value waste liquid and the high-sulfur pesticide chemical waste liquid have been pre-tested for reactivity for 24 hours to ensure controllable reaction. Use liquid extraction equipment to transfer the waste liquid to a storage container as the hydrolysis reaction medium; Open the second opening on the packaging container, install a diversion funnel, slowly pour the low-calorific value waste liquid into the packaging container through a ladling tool to mix with the high-sulfur pesticide chemical waste liquid for hydrolysis reaction, and leave the packaging container lid slightly ajar after pouring the liquid; Add the water-based low-calorific value waste liquid in a small amount in batches, with a single addition amount of 3 - 5 L. After the reaction starts, use a non-contact temperature measurement device to monitor the container wall temperature every half hour. When the wall temperature drops below 55 °C, continue to add the waste liquid to continue the reaction until the temperature no longer rises after adding, and determine that the hydrolysis reaction is completed; After the hydrolysis reaction ends, wait for the residual liquid to cool to the ambient temperature, remove the suction hose, seal the packaging container, and transfer it to an independent storage area for aging treatment; During the hydrolysis reaction process, continuously monitor the pH value of the liquid in the alkali scrubber, and promptly supplement the alkaline neutralizer when the pH is below 7.

2. The method for disposing of high-sulfur pesticide chemical waste liquid according to claim 1, wherein, It also includes a liquid spraying and burning step: After completing the hydrolysis reaction and sufficient aging of the high-sulfur pesticide chemical waste liquid, perform solid-liquid separation disposal. Pre-inject a low-calorific value water-based waste liquid into the storage container to form a liquid seal layer. Pump the hydrolyzed liquid on the upper layer to the incineration workshop through suction filtration, and then pump it to the waste liquid storage tank for closed spray incineration. Dispose of the solid materials in the lower layer by crushing and putting them into a pit.

3. The method for disposing of high-sulfur pesticide chemical waste liquid according to claim 2, wherein, The step of disposing of the solid materials by crushing and putting them into a pit includes: Before the solid crushing operation, empty the materials in the crushing pit, inject a low-calorific value waste liquid and add slaked lime, and adjust the pH of the liquid in the crushing pit to above 12; Perform continuous crushing operation on the target solid materials. During the operation, it is prohibited to mix other materials. After the crushing is completed, use sludge and slaked lime to clean the crusher in sequence, and then use the water-based low-calorific value waste liquid to clean the crusher twice; The next day, detect the pH of the liquid in the crushing pit. If it is below 7, supplement slaked lime to adjust it to 12. After the reaction is complete, mix it with other compatible materials in batches and stir, and then grab and put it into the incineration kiln for disposal by a crane.

4. The method for disposing of high-sulfur pesticide chemical waste liquid according to claim 1, wherein, When the suction hose is connected to the alkali scrubber, a one-way check valve is set to prevent the liquid in the alkali scrubber from flowing back into the packaging container.

5. The method for disposing of high-sulfur pesticide chemical waste liquid according to claim 1, characterized in that, The selection criteria for the water-based low-calorific value waste liquid also include: the density range of the waste liquid is 0.9 - 1.1 g / cm³, and the chloride ion content does not exceed 500 mg / L.

6. The method for disposing of high-sulfur pesticide chemical waste liquid according to claim 1, wherein, During the hydrolysis reaction process, when the container wall temperature exceeds 80 °C, suspend adding the low-calorific value waste liquid and start the external water cooling device to cool the packaging container.