Polluted air is becoming a growing threat to the environment and nutrition. Act to control air pollution emissions has multiplied. Presently, biological methods have been applied all the more as often as possible to control these emissions, on the grounds that they kill a considerable lot of the disadvantages of old style physical–chemical procedures. Diverse waste gases require various systems for ideal and practical cleansing. Biological treatment gives a growing variety of chances for practical and ecologically friendly answers for some waste gas outflows. A critical knowledge and expertise in the field of biological gas purification has been produced in Europe. The developers claim that there are likely to be more than 6.500 frameworks and related frameworks developed in Europe in the field of biological waste gas processing, half of which are used in wastewater treatment and soil fertilization plants. In the most recent five years, this document introduces instances of some interesting developments and new applications of the biological waste gas treatment systems in Europe.