CN106018026A - Air humidification device applied to determination of soil-air distribution coefficient of semi-volatile organic contaminants - Google Patents

Abstract

An air humidifying device applied to the determination of the soil-air partition coefficient of semi-volatile organic pollutants can be applied to the determination of the soil-air partition coefficient of semi-volatile organic pollutants. It consists of an air inlet, a gas-liquid separation zone and an air outlet. A ring-shaped glass protrusion is processed at the air inlet and air outlet, so that it can be more tightly combined with the PTFE tube and enhance the airtightness of the place; the liquid filled in the gas-liquid separation area is high-purity water or saturated CaCl ₂ solution. A filling tube with a glass stopper is added to the spherical area, which not only shortens the distribution equalization time, but also avoids frequent disassembly of the air humidification unit. When measuring the soil-air partition coefficient of semi-volatile organic pollutants, the invention can simplify the air humidification method, and has the characteristics of fast and easy operation.

Description

An air humidifying device used in the determination of the soil-air partition coefficient of semi-volatile organic pollutants

technical field

The invention relates to an air humidifying device in the experimental field of pollutant environmental distribution behavior, in particular to a humidifying device required for measuring the soil-air partition coefficient of semi-volatile organic pollutants.

Background technique

When measuring the soil-air partition coefficient of semi-volatile organic pollutants, it is necessary to pre-humidify the air so that when it passes through the polluted soil, it will humidify the soil so that the relative humidity (RH) of the soil reaches 100%. This is because the adsorption process of pollutants in the soil is affected by temperature, soil organic matter, etc. When the soil RH>99%, under the action of capillary force, water occupies a large part of the soil pore space, which greatly reduces The adsorption of pollutants at the air/water interface is prevented, and the mineral surface is completely covered by water molecules, so that the adsorption of pollutants at the mineral/water interface is almost non-existent. So in moist soils (RH=100%), soil organic matter determines the adsorption capacity of the overall soil. Soil RH is always kept at 100%, so that the soil-air partition coefficient of semi-volatile organic pollutants in the experiment is only affected by the content of soil organic matter and temperature, so as to ensure the reliability and consistency of the obtained data, and the experimental results will not be affected by soil Changes in humidity have a series of consequences.

At present, in the existing research, when measuring the soil-air partition coefficient of semi-volatile organic pollutants at a temperature greater than 0°C, air is usually used to humidify the contaminated soil by passing air through a closed container filled with high-purity water, and the temperature is less than 0°C. Under the temperature condition of ℃, the polluted soil is humidified by passing the air through the quartz sand covered with ice sand. These humidification methods have no fixed instruments or devices, and there are the following technical problems:

(1) When the water in the container or the smoothie in the quartz sand is exhausted, it is necessary to remove the ports at both ends to inject high-purity water, or to replace the container with the soil with smoothies. The reaction is carried out in a constant temperature preservation box, which is inevitable The temperature in the box will change greatly and affect the experiment, so it takes a long time for the soil temperature to equilibrate to make the temperature reach the measured value. In this way, the experiment time is greatly increased, and the parallelism of the experiment will also be affected to a certain extent.

(2) Under low temperature conditions, the replacement and production of quartz sand with sorbet are more troublesome.

(3) Existing containers such as the ports of the porous glass plate absorption tubes all have smooth glass surfaces, so the combination of it and the polytetrafluoroethylene tube has poor airtightness and easy air leakage, resulting in inaccurate experimental results.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the existing air humidification device, and provide a more effective and convenient air humidifier than the previous equipment, which can be applied to the calculation of the soil-air partition coefficient of semi-volatile organic pollutants under high temperature and low temperature conditions. Determination.

Technical scheme of the present invention:

An air humidifying device used in the determination of the soil-air partition coefficient of semi-volatile organic pollutants, which consists of an air inlet, a gas-liquid separation area, and an air outlet. The gas end and the gas outlet are each processed with a ring-shaped glass protrusion. When connecting, the combination of the ring-shaped glass protrusion and the polytetrafluoroethylene tube is tighter, which solves the problem of poor airtightness and prevents air leakage.

The spherical area of the gas-liquid separation area is also equipped with a liquid filling tube with a glass stopper, which is convenient for adding the required liquid, shortens the distribution balance time and avoids air leakage caused by frequent disassembly processes.

The liquid filled in the gas-liquid separation area is high-purity water (temperature ≥ 0°C) or saturated CaCl ₂ solution (temperature < 0°C). When the gas passes through the aqueous solution, it can be humidified to make the soil RH reach 100%. The device is placed in a constant temperature preservation box In order to ensure the stability of the temperature during the experiment.

The advantages of the present invention are:

(1) Easy to operate: After the solution in the device is consumed, you only need to quickly pull out the glass plug and inject the required liquid into it, avoiding multiple disassembly of the humidifying device and reducing the leak detection steps when installing the humidifying device.

(2) Shorten the test time: Avoid the problem that the device is exposed to the external environment for too long when the container is removed and installed, which causes the temperature in the storage box and the soil to change too much, and the problem that the temperature needs to be balanced for a long time, thus effectively The experiment time is shortened.

(3) Good airtightness: On the one hand, the ring-shaped glass protrusions at the inlet and outlet ends will enhance the airtightness when connected with the PTFE tube; on the other hand, the nozzle and glass plug of the liquid filling pipe are made of frosted material , Increased friction, has a good sealing ability.

Description of drawings

Figure 1 is a schematic diagram of the structure of the new experiment.

1 Inlet port; 2 Gas outlet port; 3 Gas-liquid separation area; 4 High-purity water or saturated CaCl2 solution; 5 Glass plug;

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in FIG. 1 , the present invention is an air humidifying device, which consists of an air inlet 1 , a gas-liquid separation zone 2 and an air outlet 3 . In order to be more tightly combined with the polytetrafluoroethylene tube 8 and prevent air leakage, the air inlet end 1 and the air outlet end 2 are processed with annular glass protrusions 7 . The liquid filled in the gas-liquid separation zone 2 is high-purity water when the temperature is ≥0°C, and is a saturated CaCl ₂ solution 4 when the temperature is <0°C.

The air enters from the inlet port 1, disperses through the glass sand plate 9, fully contacts with the solution 4 in the gas-liquid separation zone 3, and then discharges from the outlet port 2, so as to achieve the humidification effect. When the solution 4 is consumed, the glass stopper 5 is pulled out, and the required solution is added into the liquid feeding tube 6, and the experiment is resumed and continued in a short time.

Claims (3)

1. An air humidifying device used in the determination of the soil-air partition coefficient of semi-volatile organic pollutants, which consists of an air inlet, a gas-liquid separation area, and an air outlet; the air inlet and the air outlet are connected to a polytetrafluoroethylene tube ; The air inlet end and the air outlet end are each processed with a ring-shaped glass protrusion. 2. The air humidifier according to claim 1, characterized in that a liquid feeding pipe with a glass plug is installed on the spherical area of the gas-liquid separation area. 3. The air humidifier according to claim 1 or 2, characterized in that the solution for humidifying the air in the gas-liquid separation zone is high-purity water when the temperature is ≥0°C or higher, and is saturated CaCl ₂ when the temperature is 0<°C or higher solution.