The target pollutants emitted by the laboratory are ranked in the order of potential emission intensity and control necessity: small molecular gas pollutants, specific organic pollutants (formaldehyde, xylene, methanol), biological pollutants (pathogenic microorganisms and their aerosols) ), odor, other TVOCs (ether, benzene and other macromolecular organic substances), particulate matter. There are many kinds of waste gas, and one method cannot be used for treatment. Appropriate treatment methods and devices should be used for different types of waste gas. The waste gas treatment process includes high-efficiency filtration, activated carbon adsorption, photocatalytic decomposition, water spray, wet chemistry, combustion method, etc. Considering the inherent characteristics of the laboratory, high-efficiency filtration, wet chemistry, and combustion methods are not suitable, and exhaust gas treatment processes such as activated carbon, spraying, and photocatalysis are mostly used.

1. Activated carbon adsorption technology

For organic waste gas, activated carbon adsorption or absorption liquid + activated carbon treatment methods are mostly used. The activated carbon filling amount must ensure that the removal rate of main organic emissions (non-methane total hydrocarbons, anilines) is greater than 90%, and the wind resistance of the equipment is not greater than 400Pa. The activated carbon filling method To facilitate removal, replacement or regeneration, the box is made of flame-retardant PP or 304 stainless steel.

2. Spray adsorption technology

For inorganic waste gas, a horizontal wet scrubber or a spray water washing box is used for lye absorption treatment. The waste gas is introduced into the waste gas scrubber through the exhaust fan, and the micro-vortex is formed by the disturbance of the spoiler ball, and the atomized spray is scattered downward. The liquid is fully blended, and the pollutants in the exhaust gas are transferred from the gas phase to the liquid phase, so as to achieve the purpose of purifying the air. The exhaust emission after purification meets the "Comprehensive Emission Standard of Air Pollutants", the wind resistance of the equipment is not more than 400Pa, the material of the box body is made of flame-retardant PP or 304 stainless steel, and the material of the device must be strong, corrosion-resistant and fire-resistant.

3. Mixed exhaust gas adsorption technology

Mixed waste gas should be treated by water washing (lye) + activated carbon adsorption, the removal rate of main organic emissions (non-methane total hydrocarbons, anilines) is greater than 90%, the purified exhaust gas emissions meet the national standards, and the wind resistance of the equipment is not greater than 400Pa, the device must be strong and corrosion-resistant. There must be effective demisting measures between the water washing device and the activated carbon device.

4. Regeneration treatment device

In order to reduce operating costs, the use of activated carbon regeneration treatment devices is encouraged to ensure that activated carbon can be recycled for more than five times, and the regeneration and activation process does not produce secondary pollution

5. Nano-semiconductor photocatalysis technology

The MnOx-TiO2 composite was used as the catalyst, and the catalyst was attached to the titanium mesh by the sol-gel method, and a vacuum ultraviolet lamp with a specific wavelength was used as the catalytic light source. Through photocatalysis, electron-hole pairs are generated to oxidize and decompose macromolecular organic matter in the airflow, thereby removing pathogenic microorganisms and decomposing some insoluble macromolecules into soluble small molecules.

6. Central control and monitoring system for building exhaust gas treatment

TVOC monitoring facilities are installed at the appropriate position of the outlet terminal of the exhaust gas emission system, which can monitor TVOC indicators online and exceed the standard alarm, install pressure sensing devices before and after the activated carbon, measure the resistance of the activated carbon in real time and alarm when it exceeds the standard, and install a pH controller and electronic position on the spray device. The controller controls and adjusts the main parameters and abnormal alarms of the operation process of the exhaust gas treatment device.

7. Laboratory indoor exhaust equipment and accessories

The commonly used exhaust equipment in the laboratory mainly include: fume hood, atomic absorption hood, universal exhaust hood, ceiling-type exhaust hood, table-top exhaust hood, etc.

For more details about laboratory waste gas treatment, please consult us or leave a message at the bottom to discuss laboratory waste gas treatment methods.