Biotechnology offers the most economical and environmentally benign method for air pollution control when dealing with the removal of odorous and toxic contaminants from industrial and municipal airstreams
Odours are emitted from agricultural and industrial activities, such as wastewater treatment plants, waste treatment or disposal facilities, animal farms, rendering plants, paint facilities, petroleum refineries, pulp and paper mills, plastics and resin manufacturing, and various chemical industries.
Effects of this kind of air pollution may include: impairment of the quality of the environment; interference with business activities; discomfort, harm or impairment of the safety of any person; rendering any property, plant or animal unsuitable for human use.
Bioaction odour treatment technologies can be classified into three categories:
- biological (using biofilters, biotrickling filters)
- physical (adsorption, absorption)
- oxidation (oxidisation)
An important advantage of biological treatment methods over physical and chemical technologies is that the biological microbial degradation processes are generally oxidative in nature and their end products – carbon dioxide, water, sulphate and nitrate – are ecologically safe.
biofiltrationBiofiltration are fixed-bed bioreactors, in which degrading microorganisms are immobilized. The contaminated gases flow through the porous material and biological oxidation of pollutants occurs after they have diffused into the biofilm synthesized by the microflora.
Biotrickling filters, the gases are carried through a packed bed made of some synthetic or inert material, which is continuously irrigated with an aqueous solution containing essential nutrients required by the biological system. Microorganisms grow as biofilm on the packing material. The pollutants to be treated are initially absorbed by the aqueous film that surrounds the biofilm and then the biodegradation takes place within the biofilm.