Forever chemicals, including microplastics (MPs; <5 mm) and per- and polyfluoroalkyl substances (PFASs), have been produced and utilized for more than seven decades. Megatons of plastic and fluoropolymeric goods is produced yearly, and most of them are released into the environment without proper disposal, leading to the widespread distribution of toxic particles, including those in aquatic environments. MPs act as sources and carriers for PFAS and increase the transport of PFAS in aquatic ecosystems. Despite the development of various strategies for diagnosing and treating these contaminants, significant challenges remain in applying these techniques under real conditions, and there is a need to improve the detection and treatment technologies for these contaminants. This chapter aims to provide a comprehensive overview of the current detection techniques and treatment methodologies and focuses on identifying research gaps and future directions for the above contaminants. Additionally, this chapter highlights the challenges and future recommendations for effectively addressing and treating MPs and PFASs at a large scale in aquatic environments.