RU1768875C - Method of toxic matter disposal - Google Patents

Abstract

Usage: in ecology, namely the destruction of pesticides, i.e. It can be used to neutralize filled or unfilled chlorine, nitrogen, sulfur or organophosphorus chemical plant protection products or other toxic substances that have become unusable or banned for use. SUMMARY OF THE INVENTION: in a glass charge of the following composition, wt.%: Silica 40-60, carbonate or sodium hydroxide 15-25, pesticide in an amount of 5-25 wt.% Is added. In the case of the destruction of unfilled pesticides, the mixture additionally contains carbonate or calcium oxide in an amount of 5-10 wt.%. 1 s.p. crystals, 3 tab.

Description

The invention relates to ecology, and in particular, to a new method for the destruction of pesticides, which can be used to neutralize the use of filled or unfilled chlorine, nitrogen, sulfur, or organophosphorus chemical plant protection products or other toxic substances.

A known method for the neutralization of waste by introducing it into a glass charge followed by glass melting. This method is used to destroy radioactive substances.

The purpose of the invention is the destruction of pesticides.

The invention consists in the thermal decomposition of filled or unfilled chloro-, nitrogen-, sulfur- or phospho-organic pesticides in a glass-forming mixture of the following composition, wt.%:

Pesticide 5-25

Silicon Dioxide 40-60

Carbonate or Calcium Oxide 5-10

Sodium carbonate or caustic soda 15-25 Before starting the heat treatment, the mixture is mixed with water or spent working fluid from the stage of absorption of exhaust gases containing chloride, phosphate or sodium sulfate, in an amount necessary to form a thick dough (May 15-20. Parts liquid on May 100. parts of the charge). The composition of the mixture used to destroy pesticides is presented in table. 1.

The specified composition of the charge provides a complete chemical and thermal decomposition of the active substance of pesticides during their interaction, first with a hot aqueous solution of alkaline components of the mixture (hydrolysis), and then, after evaporation of water, with a mass of molten mixture with the formation of a solid solid ecologically safe after cooling residue (glass). The mineral fillers of the pesticide formulations are involved in the chemical process of glass formation.

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The pesticides destruction process was investigated in a batch laboratory apparatus consisting of a series-connected muffle furnace, a sanitary flare furnace for burning off gaseous neutralization products, an acid gas absorption scrubber irrigated with 10% aqueous sodium hydroxide solution, and a sanitary water scrubber. The mixture with the destroyed pesticide in special trays made of refractory bricks is placed in the working area of the muffle furnace with a temperature of 1000-1500 ° C, where it is kept for 1-8 hours. Gaseous decomposition products of the charge components pass through a sanitary flare afterburning furnace with an operating temperature of 900-1100 ° C, for a scrubber and are discharged into the atmosphere. The content of hydrogen chloride, chlorine, nitrogen oxides, phosphorus pentoxide and dust did not exceed the values of the corresponding MPC in the air of the working zone. Solid pesticide killing products were analyzed for hydrolytic stability and, optionally, for the content of pesticides to be destroyed. At the same time, for the selected experiments, an analysis was made of the pesticide content in the working fluid of the last sanitary scrubber, which made it possible to estimate the emissions of non-destroyed pesticides into the atmosphere. For testing, the standard methodology of the Research Institute of Glass was used. Glass testing for hydrolytic stability by the grain method. In the table. Figure 2 presents the technological parameters of the destruction of pesticides and data on the hydrolytic stability of solid neutralization products.

In the table. Figure 3 presents the results of sample analyzes of the content of the destroyed pesticides in the solid residue of neutralization, its aqueous extract and the working fluid (water) of the last sanitary scrubber. Water extract get

by boiling 10 kg of the crushed solid neutralization residue in 250 ml of distilled water for 1 hour. The determination of pesticides is carried out by gas-liquid and thin-layer chromatography by methods.

The trace content of hexachloran in the working fluid of the last sanitary absorber (less than mg / l), which is determined by the sensitivity of the analysis method used) corresponds to the maximum pesticide content in gas emissions into the atmosphere, taking into account the flow rate of the gas and working fluid of the absorber in one cycle

neutralization less than mg / m. Chlorophos in gas emissions into the atmosphere is not detected.

Thus, the proposed method for the destruction of pesticides provides a complete decomposition of the active substances of the pesticides, as well as the binding of mineral filler and solid products of chemical and thermal decomposition into an inert, water-insoluble glassy

a mass free of parent pesticides and safe for the environment in case of disposal or other practical use.

Claims (2)

1. A method of destroying toxic substances by introducing them into a glass charge and subsequent high-temperature processing, characterized in that, in order to destroy pesticides, the pesticide is introduced into a mixture containing silicon dioxide and sodium carbonate or hydroxide in the following ratio, wt.%: Silicon dioxide 40-60 Carbonate or sodium hydroxide 15-25 Pesticide 5-25 2. The method according to p. 1, characterized in that the mixture further comprises carbonate or calcium oxide in an amount 5-10 wt.%. Table 1 Technological parameters of the destruction of pesticides and the properties of the forming glass Pesticide content in neutralization products Table 2 Tabl and tsaz