Thereare many physical and chemical methods to treat air pollution.
Bioprocesseshave been very efficient for the treatment of air pollution. The most popularbioreactor configuration is the conventional biofilter. Biofilters wereinitially designed for odour control at wastewater treatment plants, but nowthey are becoming renowned for the treatment of volatile organic compounds(VOCs) and other organic compounds. These gases have bad odour and aredangerous for humans and animals.
Biofiltrationprocess is preferred over other air pollution control techniques and has gainedpopularity because it has economic advantages,as the energy requirement is significantly low and avoids cross media transferof pollutants. This technology can be mainly applied to waste gases to controlair pollution, which have low concentration and readily biodegradablepollutants. Biofilters utilizes microorganisms to reduce air pollution. Airpollutants come in contact with microorganisms inside the biofilter, wheremicroorganisms demean pollutants to produce energy and by-products (C02 andH20). Biofilterincludes a filter material, where microorganisms breed. Biofilm is a veryimportant part of the biofilter.
Biofilm is a thin layer of moisture where themicroorganisms reside. Inthe process of biofilteration polluted air is pushed inside the biofilterslowly thereby, the pollutants in the air get absorbed in the filter media,then as a result the polluted gas is dispersed in the biofliter and absorbedonto the biofilm. After the escalation of the conventional biofilter, a newcomposition was developed for air pollution control which is known asbootlicking filter. The new set of technologies were also introduced for airpollution control such as membrane bioreactor and rotating biologicalcontractor. Alot of industries use this new technology for example the food industry,pharmaceuticals, wood products manufacturing, paint and coatings applicationetc.
Pollutedair stream comprises VOCs and many sulfur compounds. Biofilters require a largewhile treating large airflows, which is as big as a basketball court. Recentresearch shows that biofilters can be used to remove a variety of airbornecontaminants which includes aliphatic and aromatic hydrocarbons, alcohols,aldehydes, organic acids, acrylate, carbolic acids, amines and ammonia.