LT6978B - Method of treatment of wastes contaminated with organic phosphorus compounds - Google Patents

Abstract

The invention describes an industrial method for the treatment of waste contaminated with various types of organic phosphorus compounds. The method involves a sequential process of alkaline (high OH-anion concentration) and peroxide hydrolysis (due to the presence of αnucleophiles) of organic phosphorus compounds in an industrial decontamination column by periodically mixing the treated waste at 18-25 ℃ with a peroxidation activator and a micelleforming agent. After obtaining appropriate results of the analysis of the whole reaction mixture at the level of safe values of contaminants, the mixture is transferred to a neutralization chamber and, neutralized to pH 6.5-7.5, can be used in the production of phosphate fertilizers, industrial detergents, etc.

Description

FIELD OF THE INVENTION

The present invention is directed to the industrial treatment of wastes contaminated with toxic organophosphorus compounds using a decontamination system with a high hydrogen ion activity index value. The method is suitable for use directly at the place of occurrence of toxic waste in the chemical and agricultural industry, farms.

STATE OF THE ART

Irrational use of inappropriate methods of disposal and decontamination of waste contaminated with organic phosphorus compounds, as well as uncontrolled use of organic phosphorus substances as pesticides leads to high-quality soil degradation and a decrease in fertility, a decrease in the safety and nutritional value of plant products, and the pollution of river waters. Such substances can affect humans both through food sources and through direct contact. Residues of organophosphorus pesticides in storage and the increasing use of organophosphorus plant protection products remain a particular problem.

Some existing methods for the destruction of organic phosphorus compounds can be directly applied to companies or farms. Such methods have many significant disadvantages: they require large areas of land for storage, the methods are expensive and not very efficient (Table 1).

table. Disadvantages of pesticide waste disposal methods

The way Disadvantages Land cultivation A large area of land Long decontamination time Disposal pits Low decontamination rate Necessity of using plots Evaporation ponds Low decontamination rate Necessity of using plots Repositories A large area of land High price

Other commonly used thermal, chemical, physical, and biological methods also have many significant drawbacks, the main ones of which are presented in Table 2.

table. General durations of pesticide disposal methods

The way Description Disadvantages Thermal Pyrolysis of contaminated structures High price Non-organic Non-universal Difficult to use Chemical Chemical destruction decomposition reactions High cost High variability of result Potential toxicity of derivatives Physical Adsorption and deposition Lack of destruction of toxins Availability of products for subsequent disposal Biological Destruction by bacteria Large expenses High variability of the result Low process speed

Existing proprietary decontamination methods propose the use of bacterial cultures to convert organic phosphorus to inorganic and/or treatment with various metals to bind toxic components and/or physical treatment (distillation, crystallization) of the waste.

Patent applications JP2000117283A, JPS60166098A and CN104743682A describe a waste treatment procedure using anaerobic biological treatment after primary waste treatment (chemical or physical methods). Patent application JPS5870884A suggests introducing an aluminum flocculant into the system to bind toxic components. Patent application CN107555649A proposes a complex system for deep decontamination of organophosphorus using chemical, physical and biological means of destruction.

Such methods can be used on an industrial scale in specialized companies for the disposal of hazardous waste. Some of them can cause secondary environmental pollution with reaction products.

Our proposed method can be used directly at the place of generation of such waste (farms, pesticide production, etc.). The specified method uses only the chemical method of decomposition of organic phosphorus substances, significantly shortens the time of decontamination, and does not require special temperature conditions. Secondary contamination with toxic products is practically impossible due to the destruction of the decontaminating material to an extremely low level.

ESSENCE OF THE INVENTION

The method of this invention includes a sequential process of alkaline (high concentration of OH-anions) and peroxide hydrolysis (due to the presence of α-nucleophiles) of organic phosphorus compounds in an industrial decontamination column, periodically mixing the treated waste at a temperature of 18-25 T with a peroxidation activator and a micelle-forming substance.

Using the proposed method of cleaning waste contaminated with organic phosphorus compounds, there is no need to store waste in warehouses and to ensure proper storage or disposal conditions, which significantly increases the speed of decontamination, the efficiency of the cleaning process and environmental friendliness (there is no reversible emission of A into the atmosphere). The cost of the technological process decreases. It becomes possible to use the products of the destruction of toxic compounds in the production of phosphate fertilizers, industrial detergents, etc.

DESCRIPTION OF DRAWINGS

The invention will now be described with reference to the explanatory drawings in which:

Fig. is a diagram of an industrial plant for the cleaning process;

and Figure 3. experimental results confirming the effectiveness of the process are presented.

DESCRIPTION OF IMPLEMENTATION OF THE INVENTION

The invention describes an industrial method of cleaning waste contaminated with various types of organic phosphorus compounds. Purification is carried out under high pH conditions in the decontamination column. The destruction of organic phosphorus compounds occurs under the influence of alkaline hydrolysis and peroxide hydrolysis in the micellar system.

Waste decontamination is carried out in a column (Fig. 1), which, according to the technological scheme, consists of three mixing chambers 2, 6, 10, three exposure chambers 4, 8, 12 and one neutralization chamber 14. Decontamination substances (Table 3) are sequentially fed to the mixing chambers.

table. General composition of the system

Input sequence Component Ratio, in parts - Waste 25-30 1 Charm 2.0-3.0 2 Hydrogen peroxide 0.5-1.5 2 Boric acid 0.8-1.7 3 Micelle-forming substance 0.8-1.7 4 Neutralizer until the pH of the mixture is neutralized

The process is as follows:

1. Wastewater contaminated with organic phosphorus compounds is supplied through pipeline 1 to the alkaline chamber of the decontamination column 2. The whole process takes place at an ambient temperature of 18-25 T.

2. While constantly stirring with a paddle mixer 18, alkali is fed through hatch 3 (any alkali is suitable) and stirred for 15 to 60 minutes, until the alkali is completely dissolved, but not shorter and not longer than the specified time. Time is determined empirically, everything depends on technological regulations, i.e. from the amount of material and waste contamination. Specific conditions of use are selected for a specific case.

3. After mixing, the reaction mixture is poured into the exposure chamber 4 and kept for 15-60 min. In the exposure chamber, exposure to the solution takes place, and a chemical reaction occurs. Sampling port 5 is used to control the pH of the reaction mixture. The pH should be in the range of 10.5-12.5. The indicator is adjusted by diluting the solution with water or increasing the amount of alkali, which is added through the waste pipe 1 or through hatch 3. Until the pH value in chamber 4 is determined and adjusted, no waste is added to chamber 2.

4. At the end of the reaction, the reaction mixture is transferred to the peroxide chamber 6, where a freshly prepared mixture of hydrogen peroxide and boric acid is fed through the pipeline 7. Mixing continues for 15-60 minutes, depending on the amount of waste and contamination. At this stage, peroxoanions are formed, and pollutants are destroyed not only by alkaline hydrolysis, but also by peroxide hydrolysis.

5. After mixing, the reaction mixture is transferred to exposure chamber 8, where it is kept for 1560 min.

6. After exposure in chamber 8, the reaction mixture is transferred to the micellar chamber 10. With constant stirring, the micelle-forming substance is fed through hatch 11 and stirred for 1560 min. At this stage, micelles are formed to increase the efficiency of the destruction reaction taking place.

7. After finishing the mixing process, the mixture is kept in the exposure chamber 12 for 15-60 minutes.

8. After receiving the appropriate results of the analysis of the entire reaction mixture at the level of safe values of the amount of pollutants (sampling hole 13 is used for this), the mixture is transferred to the neutralization chamber 14. Safe values for each individual substance are determined by the state regulator or the company, taking into account the specifics of production. The required amount of neutralizer is added to the chamber through hatch 15. Any substance with acidic properties, safe for the environment, can act as a neutralizer. Its amount depends on how much it is needed to neutralize the alkaline reaction of the solution to pH 6.5-7.5. The solution is stirred continuously until it is completely neutralized to pH 6.5-7.5. The control is carried out by taking samples through the sampling hole 16.

9. After complete neutralization (pH 6.5-7.5), the purified solution is poured through pipeline 17.

The loading of waste into the neutralization column takes place from the top sequentially, as the previous charge enters the next chamber. Mixing is not used in the exposure chambers, so if there is no recyclable waste in chambers 2, 6, 10 and 14, the mixer 18 can be turned off to save energy.

and Figure 3. the presented experimental results confirm that the described technological process for the decomposition of organic phosphorus compounds in washing water is characterized by high efficiency (k[ = 8.39 χ 10 ^-3 s ^-1 ; Δ^ = 2.42 χ 10 ^-3 s ^-1 , dimethoate). After degradation, residues are equal to or below the quantitative value (< 15 ppm). This indicator is an order of magnitude lower than the emission values of existing disposal methods.

Fig. shows the change in the observed reaction rate constant during the deactivation process of dimethoate (as an example). The maximum rate is reached after 20 minutes and is 8.39 χ 10 ^-3 s ^-1 . At the end of the reaction, when the pollutant level falls below the quantitative limit, the observed rate constant decreases to 2.42 χ 10 ^-3 s ^-1 .

Fig. shows the dependence of pollutant concentration on the duration of the decontamination process and the trend line. The trend line shows the trend of decreasing analyte concentration over time with exposure to the decontamination formulation.

Claims (1)

The method of cleaning waste contaminated with organic phosphorus compounds, which includes the chemical decomposition of organic phosphorus compounds, differs in that the cleaning of organic phosphorus compounds is carried out in a deactivation column under the influence of alkaline hydrolysis and peroxide hydrolysis in a micellar system, applying the following technological sequence of the process: - wastewater contaminated with organic phosphorus compounds through a pipeline (1 ) is fed into the alkaline chamber (2) of the deactivation column, maintaining an ambient temperature of 18-25 ℃; - while constantly stirring with a paddle mixer (18), alkali is fed through the hatch (3) and stirred for 15 to 60 min.; - after mixing, the reaction mixture is transferred to the reaction chamber (4) and kept for 15-60 minutes, the pH of the reaction mixture is measured and, if necessary, adjusted by diluting the solution with water or increasing the amount of alkali so that the pH indicator is within 10.5 -12.5; - after the end of the reaction in the chamber (4), the reaction mixture is transferred to the peroxide chamber (6) and, with constant stirring, a freshly prepared mixture of hydrogen peroxide and boric acid is fed through the pipe (7) and the stirring is continued for 1560 min until peroxoanions are formed and the pollutants are destroyed only due to alkaline, but also peroxide hydrolysis; - after mixing, the reaction mixture is transferred to the exposure chamber (8) and kept for 15-60 min. - after the reaction in the chamber (8), the reaction mixture is transferred to the micellar chamber (10) and, with constant stirring, the micelle-forming substance is fed through the hatch (11) and mixing continues for 15-60 minutes until micelles are formed, increasing the efficiency of the ongoing reaction; - after completing the mixing process, keep the mixture in the exposure chamber (12) for 15-60 minutes and perform an analysis of the amount of pollutants in the reaction mixture; - after receiving the appropriate results of the analysis of the entire reaction mixture at the level of safe values of the amount of pollutants, the mixture is transferred to the neutralization chamber (14) and, with constant mixing, through the hatch (15) the necessary amount of acid neutralizing substance is added, effective to neutralize the alkaline reaction of the solution to pH 6.5 -7.5; - after complete neutralization, the purified solution is poured through the pipeline (17).