Microbial Roles and Dynamics in Wastewater Treatment Systems: An Overview

ABSTRACT The quality of wastewater effluents is responsible for the degradation of receiving water bodies, such as lakes, rivers, streams. The two main processes for the removal of impurities from wastewater influents are chemical and biological treatment but due to some drawbacks of the chemical treatment, biological treatment is now employed. Microorganisms are of major importance in industrial wastewater treatment, agricultural and aquaculture. They reside in the sediment and other substrates, and in the water of aquaculture facilities. Microorganisms may have positive or negative effects on the outcome of aquaculture operations. Positive microbial activities include elimination of toxic materials such as ammonia, nitrite, and hydrogen sulfide, degradation of uneaten feed, and nutrition of aquatic animals such as shrimp, fishes. These and other functions make microorganisms the key players in the health and sustainability of aquaculture. The role of the different microbial groups present in the waste water treatment systems with particular importance of bacteria and protozoa in the removal process of nitrogen and phosphorus indicate that the biological treatment system is very effective in the wastewater treatment systems