Biological Mitigation of Malodorous Emissions in Sewage: A Comprehensive Review

Malodorous gases generated from sewage systems represent a significant environmental and public health challenge due to their offensive nature, toxicity, and persistence. Conventional odor control methods such as adsorption and chemical scrubbing are widely applied but are often associated with high operational costs, secondary pollution, and limited sustainability. Bioremediation has emerged as a promising alternative, utilizing microbial metabolism to degrade, transform, or mineralize odor-causing compounds into less harmful products. This review critically examines the sources and impacts of malodorous gases, conventional control technologies and their limitations, and advances in bioremediation strategies. Particular emphasis is placed on microbial diversity, degradation mechanisms, influencing environmental factors, and emerging molecular approaches such as omics technologies, bioaugmentation, and biostimulation. The integration of advanced biotechnological tools with microbial systems offers significant potential for sustainable odor management in sewage treatment systems.