Thermal oxidation treatment system of heat desorption gas extracted from soil contaminated with persistent organic pollutants

摘要

The present invention relates to a treatment system for removing persistent organic pollutants contained in soil discharged by treating persistent organic pollutants (dioxin) and steam as harmless gases through a thermal oxidation system, and condensation step (S10), oil Separation step (S20), heating step (S30), cooling step (S40), collecting step (S50), dust collecting step (S60), of cooling the gas by the latent heat of evaporated water by spraying water into the inside of the rapid cooling device, The white smoke reduction step (S70) proceeds sequentially to remove dioxin contained in the contaminated soil, convert it into a harmless gas, and discharge it, but in the condensation step (S10), the dioxin and moisture thermally desorbed from the soil are condensed in the form of extracted steam. When flowing into the condenser, the condensate is separated into gas, water, and condensed water containing oil, and discharged to a heating device and an oil-water separator, respectively.In the oil separation step (S20), the water from which the oil content of the condensed water stored in the oil-water separator is removed is an active adsorption tower. After discharged to the water treatment facility, the oil containing the dioxin component separated by the condenser is stored in an oil storage unit, and in the heating step (S30), gaseous dioxins volatilized and extracted from the soil and supplied from the oil storage unit Dioxins are removed by complete decomposition through a thermal oxidation process in which the oil component containing dioxin is sprayed into the heating device as fine particles, and caustic soda is used in the Wet Scrubber in which the collecting step (S50) is performed. Sodium hydroxide (caustic soda) required for neutralization through the tank is automatically injected according to the pH, and dioxin absorbs hydrogen chloride (HCL) gas generated after thermal oxidation and neutralizes it.In the dust collection step (S60), water is supplied to the upper water tank. A continuous water film type eczema electrostatic precipitator that flows evenly to the dust collecting electrode by the water film forming nozzle as the level rises and cools down by the dust collector, which is a continuous water film type eczema electrostatic precipitator. The dust is removed, and in the white smoke reduction step (S70), the high-temperature and high-humidity exhaust gas is transferred through the heat exchanger 2 using a white smoke reduction device. The wastewater additionally generated in the cooling step (S40), the dust collecting step (S60), and the white smoke reduction step (S70) is discharged to the outside by mitigating the white smoke phenomenon caused by the discharge of water vapor by mixing and discharging after heat exchange with outside air. It is recovered through (S42) and fed back to the heating step (S30) to completely remove dioxins that may be weakly contained in wastewater. A thermal oxidation treatment system for thermal desorption gas is proposed. Therefore, in the present invention, residual pollutants (dioxin) and water vapor extracted through thermal desorption are thermally oxidized at high temperature by heating, and through a rapid cooling process, collection and adsorption and wet electrostatic precipitating processes are performed, all residual dioxin and process by-products are removed. It works. In addition, by applying a rapid cooling device, the residence time in the temperature range in which dioxin is recombined is minimized, and even if a very small amount is recombined, there is an advantage that it can be completely removed through a wet electrostatic precipitator. In addition, the process gas finally discharged to the outside is heat-exchanged using a white smoke reduction device and then finally discharged, and energy efficiency is improved by applying a heat exchange device and a cooling water generating device in the cooling process of thermal oxidizing gas.