ABSTRACT
The content of such gases as CH4, H2, and H2S in the atmosphere significantly depends on the microbial activity of corresponding bacteria on the Earth. A bioaerosol is a collection of airborne biological particles including viruses, bacteria, and spores of fungi. The sources of bioaerosols are: (1) natural sources include coughing, sneezing, shedding of human skin, and disturbance of soil and aquatic environments by wind action; (2) production sources such as agricultural practices (e.g. cleaning of silos), processing of diseased animals in abattoirs, laboratory operations (blending and sonicating), and wastewater treatment operations. Bioaerosols in outdoor environments are fungal spores, bacterial cells, viruses, and pollen. In clean rooms, concentrations of culturable agents are from 102 to103 cfu/m3, but in certain industrial or agricultural sites the concentration may be from 105 to 1010 cfu/m3. There are many airborne infectious diseases. Legionnaires’ disease and tuberculosis are examples of illnesses resulting from exposure to aerosol with specific microorganisms. Steps for the prevention of odor from wastewater treatment plants include mechanical cleaning of collection systems, frequent washing to remove grit and organic debris, frequent scraping to remove scum and grease, keeping vents clear in trickling filters to keep biofilms aerobic, keeping tank walls, air pipes, and diffusers clean in activated sludge systems, collection and absorption, and chemical or biological exhaust air treatment. Odorous gases can be treated in wet scrubbers and by combustion, adsorption, chemical oxidation, and biofiltration. A tutorial with solutions and a quiz bank are added to this chapter.
