A review on biofilm-based reactors for wastewater treatment: Recent advancements in biofilm carriers, kinetics, reactors, economics, and future perspectives

Industrialization plays an important role in the growth of a nation. But it is also added to the deteriorating condition of our ecosystem. Pollution, be it aquatic, terrestrial, or airborne, has affected our environment drastically and the surge of industries and growing population plays a major role in it. Innumerable basic and advanced techniques degrade the contaminants in wastewater. Most of these techniques are efficient but have several drawbacks too. The biological technique is one such viable approach in which there are no eminent downsides. This article presents a brief investigation of the biological treatment of wastewater, namely biofilm technology. Recently biofilm treatment technology has garnered a lot of attention due to its efficiency, inexpensiveness, and ease of incorporation into various conventional treatment techniques. A succinct analysis is provided about the mechanism of biofilm formation and its application in various systems in fixed, suspended, or submerged conditions. Details of the application of biofilm technology in lab-scale and pilot-scale treatment of industrial effluents are also discussed. This study is crucial to understand the competency of biofilms and to utilize the idea for further development of the technology for better management of wastewater. Pollutants such as BOD, COD can be removed up to 98 % with the help of Biofilm reactor technologies, making it one of the most efficient systems for wastewater treatment.