CN105481137A - Recycling treatment process for wastewater from chlorpyrifos production - Google Patents

Abstract

The present invention discloses a recycling treatment process for wastewater from chlorpyrifos production. The process comprises the steps of: adding a certain amount of a color remover into the chlorpyrifos wastewater, stirring for 30min and filtering; and then adding a certain amount of activated carbon, adsorbing and filtering to obtain a filtrate of the chlorpyrifos production water. The circulating treatment process of the present invention reduces the chlorpyrifos wastewater treatment by 80% for average production of each ton of product, greatly reduces the waste water treatment capacity; and the wastewater conventional treatment of the enterprises can be conducted orderly manner, so as to effectively protect the normal production of the enterprises.

Description

A kind of chlorpyrifos production waste water recycling treatment process

technical field

The invention belongs to the technical field of waste water treatment, and in particular relates to a recycling treatment process for chlorpyrifos production waste water.

Background technique

Chlorpyrifos is a low-toxicity insecticide and one of the most productive pesticides in the world. 3,5,6-trichloropyridinol or its sodium salt and 3,3-diethyl thiophosphoryl chloride (abbreviated as ethyl chloride) are used in the process of synthesizing chlorpyrifos, which can be divided into organic solvent method, Water-phase method and dual-solvent method, the most important method is the water-phase synthesis method. In the process of synthesizing chlorpyrifos by the aqueous phase method, about 3 to 4 tons of waste water is produced per ton of product, and the waste water is reddish brown in color, containing about 5% to 10% of 3,5,6-triclopyridin sodium, 0.15% (calculated as phosphorus) ), organophosphorus, surfactants and other by-product impurities. The amount of wastewater is large, the composition is complex, the treatment process is cumbersome, and the cost is high, which greatly increases the production cost of chlorpyrifos.

Chinese invention patent (ZL201110420347.8) discloses a treatment method for chlorpyrifos production wastewater, including the following steps: (1) pH adjustment: use sulfhydryl acid wastewater to adjust chlorpyrifos production wastewater to acidity; (2) Fenton oxidation: convert step (1) The wastewater after adjusting the pH value is introduced into the Fenton oxidation tank for oxidation; (3) Neutralization, flocculation and filtration: the wastewater after step (2) oxidation is introduced into the neutralization tank, and quicklime is added to the tank for neutralization; The neutralized waste water is flocculated and precipitated under weak alkaline conditions, and then filtered; (4) activated carbon adsorption: the waste water filtered in step (3) is introduced into an activated carbon adsorption column for adsorption.

Chinese invention patent (publication number is CN103771657A) discloses a kind of treatment method of chlorpyrifos waste water, it is characterized in that comprising the following steps: (1) add the hydrochloric acid 18-22 kilogram that mass fraction is 13-15% in every ton of waste water and recycle waste water The sodium clopyridinate of the sodium clopyridinate, solid sodium clopyridinate can be used for reproduction; (2) add the hydrogen peroxide whose quality accounts for 0.5% of the total amount of waste water in the waste water after recovering the sodium clopyridinate, pre-oxidize, pre-oxidize The time is 7-9 hours; (3) adding ferric chloride hexahydrate in an amount of 0.1-0.15% by weight of waste water as a catalyst in the pretreated waste water, stirring evenly, adding a high-pressure reaction device, starting stirring, and heating up to 110 -120°C, keep warm for 6-8 hours; (4) After the reaction is over, lower the temperature to 35-45°C, turn on the waste gas treatment device, and slowly turn on the aeration, the aeration time is 0.5-1 hour; (5) Continue Cool down and take samples, analyze the concentration of total phosphorus and ammonia nitrogen, and put in quantitative magnesium oxide and ammonia water in turn according to the concentration, adjust the pH value to 8.5, stir for 10-13 minutes, and filter after standing still; (6) analyze the salt of the waste water after the reaction According to the concentration, it is diluted with low-salinity wastewater to a biochemical concentration, and it can reach the discharge standard after biochemical treatment with specially cultivated microorganisms; The unit used.

The Chinese invention patent (publication number is CN102765850A) discloses a treatment process of sodium clopyridinate and chlorpyrifos production wastewater, which belongs to the field of environmental protection technology and includes process steps such as evaporation, incineration, and biochemical methods. It is characterized in that the specific steps of the process are as follows: (1) After evaporating sodium clopyridinate and chlorpyrifos waste water is filtered through a grid to remove coarse dirt, it enters a neutralization tank and adjusts its pH value to be neutral through an acid-base neutralizer; The destructive wastewater enters the evaporator and is concentrated and then enters the crystallization tank to precipitate sodium chloride crystals; the waste liquid (also called mother liquor) from which sodium chloride crystals are precipitated enters the evaporator and is further concentrated into high-concentration organic waste liquid (also called (2) incineration The residue liquid coming out from the wiped film evaporator is sent into the incinerator and is burned into water, carbon dioxide, ashes together with the still residue of triclopyridyl sodium, and releases heat energy; from The high-temperature flue gas from the incinerator goes through the high-temperature dust collector to remove solid particles and then enters the waste heat boiler for full heat exchange to produce steam; the high-temperature flue gas after heat exchange by the waste heat boiler enters the alkali washing tower to wash away the sulfide contained in the gas and carbon dioxide, etc.; the gas from the alkali washing tower is further purified by a water film dust collector to remove the dust particles entrained in it; the finally purified gas is discharged to high altitude through the chimney through the induced draft fan; (3) the biochemical method is passed through the grid The domestic sewage and other low COD sewage and the condensate from the multi-effect evaporator and wiped film evaporator are sent to the regulating tank to adjust the water volume to ensure the balance of the subsequent biochemical treatment, and adjust the pH by adding acid or alkali value; the sewage in the regulating tank is lifted to the anaerobic reactor by the lifting pump; the anaerobic reactor integrates biological reaction, sedimentation and gas separation; the anaerobic reactor can remove most organic matter and increase the biodegradability of wastewater, making the The sewage reaches the water inlet standard of the contact oxidation tank; the contact oxidation tank mainly uses the biofilm method to treat the organic matter in the wastewater, so as to achieve the purpose of treatment; the effluent of the contact oxidation tank enters the sedimentation tank, and the sedimentation tank mainly solidifies the effluent of the contact oxidation tank Liquid separation; the effluent from the sedimentation tank is sent to the air flotation device, and the air flotation device is mainly to separate the activated sludge brought out of the contact oxidation tank, and further remove various impurities in the water; the effluent of the air flotation device is pressurized by a pipeline pump to pressure filtration The pressure filter can remove tiny suspended solids as a guarantee of effluent water quality; the sewage filtered from the pressure filter is sent to the sump for easy reuse or discharge after reaching the standard.

The treatment processes of the above-mentioned several chlorpyrifos production wastewater can all meet the national wastewater discharge standard, and can be used directly as production water. From the above-mentioned process treatment process, it can be seen that the process of various processes for treating chlorpyrifos production wastewater is relatively complicated. It takes a long time from the beginning to the end of the treatment of each ton of wastewater. Generally, it takes at least 1-2 days. With the company's current output, each ton of product produces 3 to 4 tons of wastewater. If the above-mentioned treatment processes are used, the wastewater will be treated in a centralized manner. On the one hand, the company's wastewater storage capacity is limited, and on the other hand, it cannot complete the treatment in a short period of time, which affects the company's normal production.

Contents of the invention

In order to overcome the defects of the prior art, the purpose of the present invention is to provide a recycling treatment process for chlorpyrifos production wastewater, reduce the amount of wastewater treatment, and ensure the normal production of the company.

A kind of chlorpyrifos production waste water recycling process is characterized in that it comprises the following steps:

(1) Add a certain amount of color remover to the chlorpyrifos production wastewater, stir for 30min, and filter to obtain a filtrate;

(2) Add a certain amount of activated carbon to the primary filtrate, heat up to 70-90° C., stir for 30 minutes, cool to room temperature and filter to obtain the secondary filtrate, which is used as chlorpyrifos production water again;

(3) Repeat the above steps (1), (2). After multiple cycles, the salt content in the waste water is too high, which will affect the purity of the product. This batch of waste water is subjected to conventional processing.

The present invention is further improved, and the color removing agent is one or a mixture of sulfur dioxide, sulfurous acid, sulfite, and thionyl chloride.

The present invention is further improved, the dosage of the color removing agent is 1%-5% of the weight of chlorpyrifos production wastewater.

The present invention is further improved, the dosage of the activated carbon is 1%-3% of the weight of the chlorpyrifos production wastewater.

The present invention is further improved, the number of cycles in the step (3) is 3-5.

The beneficial effects of the present invention are:

1) After the cyclic treatment process of the present invention, on average every ton of product produced, the wastewater treatment capacity of chlorpyrifos production is reduced by 80%, the wastewater treatment capacity is greatly reduced, and the company's wastewater routine treatment can be carried out in an orderly manner, thereby effectively ensuring the company's normal production;

2) The secondary filtrate contains a small amount of ethyl chloride and 3,5,6-trichloropyridinol, which can increase the conversion rate of raw materials, and the yield of chlorpyrifos crude oil has increased by 0.1-0.3% accordingly;

3) The color remover remaining in the secondary filtrate can effectively reduce the chroma of chlorpyrifos products, improve the quality of chlorpyrifos crude oil, and the synthetic chlorpyrifos crude oil can reach the standard of chlorpyrifos crude oil of Maxim Agan Company (referred to as Maxim standard), The problem of high chroma and difficult treatment of chlorpyrifos is solved.

detailed description

In order to better understand the present invention, the present invention will be further described below in conjunction with the examples, but the present invention is not limited thereto.

The chlorpyrifos production wastewater of our company is used as the water to be treated in the following multiple embodiments.

Example 1

The waste water after crude oil is separated from the chlorpyrifos synthetic liquid in this embodiment is a red-black turbid system, which is alkaline.

According to the above treatment steps: (1) take 1 L of chlorpyrifos production wastewater, add 50 g of sodium bisulfite, and after fully stirring for 30 minutes, filter to obtain the primary filtrate; (2) add 2% activated carbon to the primary filtrate, heat up to 80 ° C, fully Stir for 30min, filter to obtain secondary filtrate 0.86L after cooling to room temperature, secondary filtrate is colorless and clear, the secondary filtrate after processing is used for chlorpyrifos crude oil synthesis; (3) repeat above-mentioned steps (1), (2), after After 3 cycles, the reaction titer between ethyl chloride and 3,5,6-trichloropyridinol decreased, and the batch of wastewater was treated by conventional process.

Example 2

According to the above-mentioned treatment steps: (1) add 80g sodium bisulfite in the three-necked flask, the flask is inserted into the Erlenmeyer flask with 1L of chlorpyrifos production waste water after being connected with the air guide tube with a rubber tube, the air guide tube is submerged below the liquid level, and the flask is Heating to 50°C, adding a certain amount of 50% sulfuric acid solution dropwise, stirring fully for 30 minutes, and filtering to obtain a primary filtrate; (2) adding 3% activated carbon to the primary filtrate, raising the temperature to 80°C, fully stirring for 30 minutes, and cooling to Filtration after room temperature obtains secondary filtrate 0.89L, and secondary filtrate is colorless and clear, and the waste liquid after treatment is used for chlorpyrifos crude oil synthesis; (3) repeat above-mentioned steps (1), (2), after 5 cycles, B The reaction titer between base chloride and 3,5,6-trichloropyridinol decreased, and the batch of wastewater was treated by conventional process.

Example 3

According to the above treatment steps: (1) take 1 L of waste water, add 100 g of 10% thionyl chloride aqueous solution, stir thoroughly for 30 minutes, and filter to obtain the primary filtrate; (2) add 3% activated carbon to the primary filtrate, and heat up to 80 ° C , stirred for 30min, cooled to room temperature and filtered to obtain 0.81L of secondary filtrate, the secondary filtrate was colorless and clear, and the waste liquid after treatment was used for chlorpyrifos crude oil synthesis; (3) Repeat the above steps (1), (2), after After 4 cycles, the reaction titer between ethyl chloride and 3,5,6-trichloropyridinol decreased, and the batch of wastewater was treated by conventional process.

Example 4

According to the above treatment steps: (1) take 1 L of waste water, add 20 g of sodium bisulfite and 50 g of aqueous solution of thionyl chloride with a content of 10%, and after fully stirring for 30 min, filter to obtain a primary filtrate; (2) add 2% of Activated carbon, heated up to 90°C, stirred for 30min, cooled to room temperature and filtered to obtain 0.88L of the secondary filtrate, the secondary filtrate was colorless and clear, and the treated waste liquid was used for the synthesis of chlorpyrifos crude oil; (3) Repeat the above steps (1) , (2), after 3 cycles, the reaction titer between ethyl chloride and 3,5,6-trichloropyridinol decreases, and the batch of wastewater is subjected to conventional process treatment.

After the chlorpyrifos production wastewater is treated, it is used as a solvent for the production of chlorpyrifos products by the company. The quality of the produced product is compared with the quality of the product produced with standard water, the conversion rate of raw materials, and the yield of chlorpyrifos crude oil, as shown in Table 1.

Table 1 Comparison of the quality of the product produced by the treated chlorpyrifos production wastewater with the quality of the product produced with standard water and the conversion rate of the raw material

As can be seen from the data in Table 1, the secondary filtrate obtained by the treatment process of this invention contains a small amount of ethyl chloride and 3,5,6-trichloropyridinol, which can continuously improve the conversion rate of raw materials, and the yield of chlorpyrifos crude oil is correspondingly improved 0.1 to 0.3%; the residual color remover in the secondary filtrate can effectively reduce the color of chlorpyrifos products and improve the quality of chlorpyrifos crude oil. Hum standard), which solves the problem of high chroma and difficult handling of chlorpyrifos crude oil.

Claims (4)

1. A chlorpyrifos production waste water recycling process is characterized in that, comprising the following steps: (1) Add a certain amount of color remover to the chlorpyrifos production waste water, filter after fully stirring to obtain a filtrate; (2) Add a certain amount of activated carbon to the primary filtrate, heat up to 70-90° C., fully stir, filter to obtain the secondary filtrate after cooling to room temperature, and use the secondary filtrate as chlorpyrifos production water again; (3) Repeat the above steps (1), (2). After multiple cycles, the salt content in the waste water is too high, which will affect the purity of the product. This batch of waste water is subjected to conventional processing. 2. The chlorpyrifos production waste water recycling treatment process according to claim 1, is characterized in that, described color removing agent is the mixture of one or more in sulfur dioxide, sulfurous acid and sulfite, thionyl chloride . 3. The chlorpyrifos production waste water recycling treatment process according to claim 1, characterized in that the amount of the decolorizer is 1-5% of the weight of the chlorpyrifos production waste water. 4. The chlorpyrifos production waste water recycling process according to claim 1, characterized in that the number of cycles in the step (3) is 3-5.