Target pollutants emitted from laboratories, in accordance with the potential emission intensity and the need for control, sorted as: small molecule gaseous pollutants, specific organic pollutants (formaldehyde, xylene, methanol), biological dirt (pathogenic microorganisms and their aerosols), odor, other TVOCs (ether, benzene and other large molecules of organic matter), particulate matter. Exhaust gas of various types, can not be simple uniform use of a method to deal with, for different types of exhaust gas should be used in the appropriate treatment methods and devices. Exhaust gas treatment processes include high-efficiency filtration, activated carbon adsorption, photocatalytic decomposition, water spraying, wet chemical, combustion method. Considering the inherent characteristics of the laboratory, high-efficiency filtration, wet chemistry, combustion method is not applicable, and more activated carbon, spraying, photocatalytic exhaust gas treatment process.
(a) activated carbon adsorption technology
For organic exhaust gas adsorption or absorption of activated carbon ten activated carbon treatment, activated carbon loading must ensure that the main organic emissions (non-methane hydrocarbons, aniline) removal rate of more than 90%, the equipment wind resistance of not more than 400Pa, the activated carbon loading method to facilitate the removal of replacement or regeneration, the box material, the box, the box, the box, the box, the box, the box, the box, the box, the box, the box and the box. The activated carbon should be filled in a way that is easy to take out and replace or regenerate, and the box material is made of flame-retardant PP or 304 stainless steel.
(2) spray adsorption technology
For inorganic waste gas horizontal water spray tower or spray washing box for alkali absorption treatment, exhaust fan into the spray tower, through the disturbing effect of the disturbance of the ball to form a micro-vortex, and the downward dispersal of the atomized spray liquid fully mingled with the pollutants in the waste gas from the gas phase into the liquid phase, thus achieving the purpose of purifying the air. The pollutants in the exhaust gas are transferred from the gas phase to the liquid phase, thus achieving the purpose of purifying the air. After purification of exhaust emissions to meet the GB162971996 "Comprehensive Emission Standards for Air Pollutants", the wind resistance of the equipment is not greater than 400Pa, the box material is flame retardant PP or 304 stainless steel, the device material must be strong, corrosion-resistant, fire-resistant.
(C) mixed waste gas adsorption technology
Mixed waste gas should be used in water washing (alkali) + activated carbon adsorption treatment, the main organic emissions (non-methane hydrocarbons, aniline) removal rate of more than 90%, purified exhaust emissions to meet the national standards, the wind resistance of the equipment is not greater than 400Pa, the device must be The device must be strong and corrosion-resistant. Water washing device and activated carbon device must have an effective mist removal measures.
(4) regeneration treatment device
In order to reduce operating costs, the use of activated carbon regeneration treatment device is encouraged to ensure that the activated carbon can be regenerated and recycled more than five times, and the re-life process does not produce secondary pollution
(5) nano-semiconductor photocatalyst technology
The use of nano-semiconductor photocatalyst technology is a good way to ensure that the activated carbon can be recycled more than five times.
The MnOx-TiO2 complex is used as the catalyst, which is attached to the titanium mesh by sol-gel method, and the vacuum ultraviolet lamp of specific wavelength is chosen as the catalytic light source. Through photocatalysis to generate electron-hole pairs, oxidation decomposition of large molecules in the airflow of organic matter, so as to remove pathogenic microorganisms, so that part of the large molecules that are difficult to dissolve in water decomposition into soluble small molecules.
(F) building exhaust treatment centralized control and monitoring system
In the exhaust emission system outlet terminal appropriate location to install TVOC monitoring facilities, online monitoring of TVOC indicators and exceeding the alarm, before and after the installation of activated carbon pressure sensing device, real-time measurement of the resistance of activated carbon and exceeding the alarm, the installation of the spraying device pH The installation of pH controller and electronic bit controller for spraying device can control and adjust the main parameters of the operation process of waste gas treatment device and abnormal alarm.
(VII) laboratory indoor exhaust equipment and accessories
Laboratory exhaust equipment commonly used are: fume cupboards, atomic absorption hoods, universal exhaust hoods, ceiling exhaust hoods, exhaust hoods, desktop exhaust hoods and so on.