Nanostructured Materials for Removal of Microplastics from Water

Worldwide, plastics have made their way into all commercial sectors viz. food packaging, farming, healthcare, construction, automobiles, electronic devices, etc. leading to the age of plastic (Plastics Europe 2019). The usage of plastic in every phase of life has increased many folds over the last three decades owing to faster lifestyles and changing consumption patterns (Sarkar et al. 2019). In the last 40 years, plastic use has expanded 25-fold due to its lightweight, durability, low cost, and elasticity (Sutherland et al. 2016). However, misuse of plastics and especially mismanagement of plastic waste has led them to sink into aquatic resources causing threats to numerous aquatic species and the balance of aquatic life. According to a recent report by WWF (WWF 2019), nearly 75% of the total plastic produced becomes waste and about 87% of mismanaged solid wastes from uncontrolled landfills are dripped into the natural environment contributing to plastic pollution. Out of 2.5 billion tonnes of solid waste generated globally, coastal countries generate nearly 275 million tonnes of plastic and simultaneously oceans receive 4.8-12 7 million tonnes (Jambeck et al. 2015). Not only marine system but freshwater rivers are also now found to be heavily contaminated with MPs (Sarkar et al. 2019, 2020a, b). After entering into the natural stream, these plastics are reported to be broken down to small pieces due to various environmental processes viz. photodegradation, oxidation, biodegradation, etc. (Sarkar et al. 2021c). Besides aquatic biota, these plastic pieces have also become a real threat to terrestrial species including humans due to exposure through drinking water. They are also reported to act as vectors for various other toxicants including, heavy metal, antibiotics, pesticides, etc. (Sarkar et al. 2021b). It was reported that approximately 5 g of plastic is consumed by an average person through food and beverage depending upon consumption practice whereas, consumption through drinking water (both tap and bottled) is as much as 1769 particles of plastic on a weekly basis (WWF 2019). These tiny plastic particles, christened as microplastics (MPs < 5 mm), are produced from larger plastic items through several environmental physical or chemical processes and have invaded every nook and corner of the planet.