## 1 Introduction  
With the increasingly serious environmental pollution, sewage treatment has become a worldwide research hotspot, and the technology of microplastics adsorbing harmful substances to purify sewage has become a prominent choice [1]. Adsorption technology is developing rapidly, and the development of large-scale and sustainable hybrid technologies can overcome the shortcomings of traditional technologies. Microplastics have the advantages of large surface area and low cost [2], thus, leading to applications in the field of sewage treatment. The American Association of Marine Conservation Scientists defines plastic as a synthetic water-insoluble polymer. According to the relevant literature, plastics are divided into thermosetting and thermoplastic plastics. The high abundance of microplastics (MPs) can be attributed to three factors: first, human activity, such as tourism waste, or waste nets from fishing can degrade to produce MPs [3]; second, industrial supplies, such as beverage cans, plastic bags, and plastic water cans. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for the COVID-19 pandemic. Since it emerged, the disease has led to high mortality and morbidity [4]. In the process of testing for the SARS-CoV-2, a large of plastic products flowed into the environment. In addition, there are some modern products, such as the increased of using cosmetics [5] and textiles [3]. MPs are emerging pollutants that have been shown to provide toxic contaminants [6]. For example, the pathways by which the environment or its inherent toxic monomers and additives enter the aquatic food web were MPs [7]. MPs can enter agroecosystems with toxic effects [8] but also enter organisms [9] to cause cellular internalization and affect intracellular target organelles [10]. Moreover, there are many difficulties in fully solving nano plastics due to the limited methodologies for selectively recognizing nano plastics [11]. Traditional sewage treatment technology is complex in operation; has high costs, slow adsorption, limited capacity, and high regeneration costs; and may cause the risk of secondary pollution. Thus, finding a cheap and simple treatment method has become an urgent problem. Based on the principle of green environmental protection, waste utilization is the best way. Microplastics have been used to make electrospun micro/nanofibers (in the waste recycling) [12], PET nanoparticles (in the biological systems) [13], and antimicrobial coatings (in the healthcare sector) [14]. The unique structures of microplastics with benzene rings or carbon chains make them a good material choice for sewage treatment. As microplastics also contain rich functional groups, they have a strong affinity for pollutants under the action of chemical bonds, such as hydrogen bonds and van der Waals forces, and are suitable for sewage treatment [15]. Although pollutants are adsorbed on plastics and cause certain harm to the environment [16], we can achieve simultaneous removal of pollutants and microplastics through this method, which is a good water source treatment method [17]. Microplastics have attracted extensive attention due to their large specific surface area and stable properties [18]. Sewage treatment by microplastics mainly depends on adsorption, and the advantage of microplastics in the specific surface area greatly increases the contact area with pollutants. In addition, the resin carbon structure is stable and easy to separate. Therefore, after treating sewage, plastic can be separated from sewage by centrifugation or sedimentation. Under the influence of the environment, light, weathering [19], breakage, corrosion, grafting, abrasion, single loading, aging [20], and other effects will not only hinder the treatment of sewage by microplastics but also increase the specific surface area of microplastics. When microplastics react with pollutants in the environment, modified microplastics can show strong adsorption performance for some contaminants under this influence [21].