Odorous compounds from most of the food-processing plants are emitted
generally in low concentrations and are simultaneously hydrosoluble and biodegradable.
Hence, for such pollutants, simultaneously highly soluble and degradable,
such as methanol, butanol, tetrahydrofurane, aldehydes, formaldehyde,
carbonic acids, and butyric acid, biological treatment technology appears very
attractive, as its investment and running costs are often lower by a factor of 2 to
10 than the physical–chemical technologies.