Challenges and Fate of Microplastics in Wastewater Treatment Processes

The existence of microplastics (MPs) is a serious environmental and ecological concern globally. The MPs enter in water bodies through different ways such as surface overflow, wind advection, and effluent from wastewater treatment processes (WWTPs), etc. Since the WWTPs cause a supplementary threat in scattering of the MPs, it is necessary to treat the MPs before they enter into the environment. Understanding the presence, detection, and fate of MPs at each step of the WWTP process is a key challenge for the scientific community. The available technologies for removal of MPs during wastewater treatment are expensive, difficult to install in existing facilities, and used only in the presence of high-quality standards. Membrane technology has shown remarkable results in the removal of the MPs, but membrane blocking and fouling have been detected in large-scale applications. Another challenge is the lack of standard protocol for precisely recognition and well-organized removal of the MPs. In the fate of MPs coming from households, the WWTPs play a crucial role because 99% reduction of the MPs is revealed by efficiently treating wastewater. The pre-treatment together with a primary clarifier has the highest impact while the secondary treatment has shown no significant effect on the reduction of MPs. Therefore, the challenges and fate of MPs in WWTPs are described in the present chapter.