Microbial Ecology of Wastewater Treatment Plants presents different methods and techniques used in microbial ecology to study the interactions and evolution of microbial populations in WWTPs, particularly the new molecular tools developed in the last decades. These molecular biology-based methods (e.g. studies of DNA, RNA and proteins) provide a high resolution of information compared to traditional ways of studying microbial wastewater populations, such as microscopic examination and culture-based methods. In addition, this book addresses the ability of microorganisms to degrade environmental pollutants.