BIOFILTRATION OF AIR
Sustainable process-product development & green chemistry
Sustainable & Clean Technologies-I: Extraction & Remediation (T1-4P)
Keywords: Key words: bio filtration, odour, biofilm.
Bio-filtration is an attractive technique for elimination of malodorous gas emission of low concentration of volatile organic compounds. A bio-filters main function is to bring micro-organisms into contact with pollutants contained in air stream. The micro-organisms live in a thin layer of moisture called “BIO-FILM”, which surrounds the particles that make up the filter media. Odorous air emissions contain low pollutant concentrations like hydrogen sulfide, mercaptons and other reduced sulfur compounds.Bio-filter can be used to remove a wide variety of air contaminants like aliphatic and aromatic hydrocarbons, alcohols, aldehydes, organic solids, acrylate, carboxylic acids, amines and ammonia.
The moist filter medium provides physical and chemical conditions appropriate for the transfer of contaminants from air to liquid phase and biodegradation of contaminants in the biofilm layer. The mechanism of the bio-filtration process includes a contaminant of adsorption and microbial degradation. Biofilter media includes compost
Based materials, earth, leather, plastic or wood-product based material.Its purpose is to provide larger surface area for adsorption and absorption of contaminants. Some types of media lack proper nutrients and will require manual addition nutrients such as nitrogen and phosphorous compounds in order to sustain microbial life.
Certain parameters like residence3 time, concentration, humidity, filter media, pressure drop should be considered in the design of a bio-filter. The main advantages of using bio-filters are lower capita costs, lower operating costs, lower chemical usage and no combustion source. Bio-filtration is versatile enough to treat odors, toxic compounds and vocs. Bio-filters are mainly used in chemical and petro-chemical industries, pharmaceutical industries, soil and ground water remediation,waste and waste water treatment for the removal of vocs and for odor abatement applications. It is used in industries such as sewage treatment, agriculture and meat processing, flavor and fragrance, tobacco, cocoa and sugar industries.
