Biodiversity conservation, ecosystem, and public health are negatively triggered by plastics used in all areas of modern life. Micro and nano plastics, one of them, are widely occurring pollutants that have great interest. The increasing levels of micro-nano plastics such as polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), and polyethylene terephthalate (PET) in the ecosystem negatively affecting environmental health and living organisms globally because of undeniable prevalence in the air, soil and especially aquatic ecosystem. Microplastics, which have very slow decomposition rates, stay and accumulate for a long time in the environment where they can interact with organisms. Wastewater treatment plants (WWTPs) are considered point sources of micro-nano plastics released into the environment and the last line of defense that creates a barrier between microplastics and the environment. Although microbial species such as bacteria, algae, and fungi can break down plastic, they can not completely mineralize plastic due to various factors such as enzymatic mechanisms, substrates and co-substrates concentration, temperature, pH, and oxidative stress. Therefore, the underlying mechanism of micro-nano plastic formation and specifying the factors affecting their transport, distribution, and deterioration is very important. So far, no specific treatment technology has been developed to specifically remove MPs and NPs from wastewater and sludge, apart from existing conventional treatment techniques. So, the main purpose of this book chapter focusing on current evidence of microplastic accumulation in the aquatic environment and soil, we will emphasize the harmful effects, fate, and remediation processes of existing and potential microplastic types on living things to protect the environment and life on earth. Also, to fill the information gap, recent research innovations regarding the development of purification technologies targeting MPs and NPs will be discussed.
