Microbial ecology is pivotal in wastewater treatment, where microorganisms play a vital role in breaking down organic matter and ultimately reduce the levels of contaminants in treated water, making it safe for reuse in agriculture, industry, and other applications. The book, Microbial Nexus for Sustainable Wastewater Treatment: Resources, Efficiency, and Reuse, ventures into the dynamic world of microbial ecosystems, unveiling their pivotal role in reshaping wastewater treatment technologies. This book addresses novel microbial techniques related to sustainable efficient technologies of wastewater treatment and wastewater reuse as well as water to obtain high-quality effluents by treatment plants.