The detection and persistence of micropollutants such as pharmaceuticals, personal care products, pesticides, and industrial chemicals in wastewater has become a significant environmental challenge due to their potential toxicity, bioaccumulation, and adverse effects on aquatic ecosystems and human health. While conventional biological wastewater treatment processes effectively remove organic contaminants, they often fail to degrade these low-concentration, chemically diverse micropollutants. This chapter provides an in-depth analysis of the challenges associated with biological treatment of micropollutants, exploring factors such as the chemical properties of contaminants, microbial degradation pathways, and the limitations of existing treatment technologies. The chapter discusses the role of microbial communities, the influence of environmental conditions, and process optimization techniques in enhancing biodegradation rates. Additionally, it examines novel approaches, including engineered microbial consortia, advanced bioreactors, and hybrid treatment systems that combine biological treatment with technologies like activated carbon adsorption and advanced oxidation processes.