Filtration is one of the significant separation processes employed in wastewater and water treatment for extracting organic pollutants. The process can be also used for removing pollutants from air. In case of water treatment, filtration is used for purifying the water for potable use. Industrial waste water contains different impurities, the purpose of implementing proper sewage treatment is to eliminate the undesired impurities and restore the natural quality of water to utilize it for various purposes.
A Brief Overview on Biofiltration
This method came into practice in the year 1893 in England, and from the very moment, it has been effectively applied for treating of both industrial and domestic wastewater. Any sort of filter that comes with fixed biomass on filter media can be named as biofilter. At the initial stage it was developed employing slag or rock as filter media, but with the advancement of technology, different type and shapes of FRP media has also come into use. Regardless of its different names imposed on it depending upon the operational mode, the prime principle of biofilters is to biodegrade the pollutants with the help of micro-organisms present in the filter media.
Since the dawn of industrial revolution, enormous quantities of pollutants has been discharged to the environment, earlier people were not aware of its negative impact. But with time, the side effects of these pollutants came into focus and people realized the necessity of extracting or suppressing the intensity of these pollutants for a better environment. The bio-filtration units are designed in compliance with the size and space of industrial unit setting and operation spaces. The main advantage of using bio-filtration process is lowering operation cost, minimum combustion source and lower level of chemical usage.
The Function of Bio-Filtration
Microorganisms present on porous medium utilized in the bio-filtration process are used for breaking down pollutants present in the wastewater flow. The microorganism grows bio-film on the surface of the medium. The filter bed comprises of relatively still substances ensuring large surface attachment areas and supplementary nutrient supply. The effectiveness of the biofilter is generally determined by the properties and quality of the support medium including the degree of compaction, porosity, water retention abilities and the capability of hosting microbial populations.
Critical biofilter operational and performance parameters include the microbial inoculation, temperature, medium pH, nutrient content as well as medium moisture. With the progress of the method, microorganisms are slowly developed on the internal ceiling of the filter media and grow a biological film. When biofilter can maintain and control a healthy biomass on the surface of the filter, you can consider that it’s working successfully.
Aside from wastewater treatment, biofiltration is also effective in industrial odor control, and in several cases, it is also proved to be the most effective and least expensive treatment option in comparison to thermal destruction and chemical stripping.