Microplastics and nanoplastics: Occurrence, fate, and persistence in wastewater treatment plants

Nanoplastics (NPs) and microplastics (MPs) in wastewater treatment plants (WWTPs) and their specific properties such as shape, color, functional groups, molecular arrangement, hydrophobicity, high surface area, surface charges, variety in size, etc. are alarming as they have the potential to create toxic pollutants by forming a complex coil. Therefore, a full-fledged study on the occurrence and removal of NPs and MPs in WWTPs has been described in this chapter. The necessity of identifying index factors to remove NPs and MPs in the WWTPs are also discussed. Furthermore, the behavior and mechanism of the creation of toxic pollutants through NPs and MPs are critically highlighted and their threat to the performance of WWTPs is summarized. Although many reviewers cited the presence of NPs and MPs in WWTPs, the technology to reduce those in wastewater is always in debate. Particularly, the impact of NPs and MPs on the effectiveness of different wastewater treatment processes has been discussed. To date, no comprehensive treatment technology has been identified to remove these pollutants from sludge and the effluent of sewage. Therefore, this chapter presents a critical review of the latest research findings on the possible treatment technologies. In this regard, the details of the published technologies are critically assessed, which will not only help develop the most reliable and efficient technologies to remove NPs and MPs from the water stream but also fill the knowledge shortfall/major challenges in combating pollution.