tailieunhanh - AIR POLLUTION CONTROL EQUIPMENT SELECTION GUIDE - CHAPTER 3

Lọc sinh học sử dụng các thuộc địa sinh học cư trú trên một chất nền hỗ trợ (sinh khối) và được lựa chọn cho khả năng sản xuất enzyme làm giảm hấp thu các chất ô nhiễm hữu cơ ít độc hại hoặc ít hơn các hình thức dễ bay hơi. Lọc sinh học tự nó là một sự kết hợp của adsorber (các phương tiện truyền thông mà trên đó các vi khuẩn cư cung cấp một bề mặt hấp phụ) và hấp thụ (màng sinh học ẩm trên bề mặt phương tiện truyền thông hấp thụ các. | chapter 3 Biofilters Device type Biofilters use biologic colonies that reside on a supporting substrate biomass and are selected for their ability to produce enzymes that reduce absorbed organic pollutants to less hazardous or less volatile forms. The biofilter itself is a combination of adsorber the media on which the bacteria colonize provides an adsorption surface and absorber the moist biofilm on the media surface absorbs the contaminants . Biofilters are considered by some to be green technology that is environmentally friendly. In reality the organic chemical action that occurs within a biofilter is often more complex than that of inorganic chemisorption systems. Typical applications and uses Biofilters are often used to control the emissions of water-soluble or condensable hydrocarbons such as alcohols phenols aldehydes such as formaldehyde odorous mercaptans organic acids and similar compounds. They are used to control emissions from aerosol propellant manufacture and filling operations meat processing and packing processes pharmaceutical manufacture fermenter emissions and fish and other food processing sources. Candidate pollutants that can be controlled by biofilters in general must be water soluble because the biodegradation occurs in the moist biofilm layer supported in the biofilter. Aliphatic hydrocarbons are generally more easily degraded than aromatic hydrocarbons. Halogenated hydrocarbons show an increased resistance to this method as their halogen content increases although some exceptions exist. A typical biofilter is shown in cutaway format in Figure . The basic components consist of a humidification system to produce a saturated gas stream to the lower left a substrate to support the biomass a containing vessel and some means such as a fan upper right to move the gases through the biofilter. 2002 by CRC Press LLC Figure Biofilter Monsanto Enviro-Chem Systems Inc. . Biofilters have also been used to control the emissions of propane and .