Prevalence of microplastics and fate in wastewater treatment plants: a review

Microplastics have multidimensional traits, as compared to other emerging contaminants, presenting a concern to terrestrial, aquatic life and humans through inhalation or ingestion. Hazardous chemicals adsorbed on microplastics could potentially be transferred to the environment or consumed by living organisms. We review the transformation of plastic waste in the environment, the origin and transportation of microplastics, the regulatory measures for plastic and microplastic pollution, and the fate of microplastics in wastewater treatment plants. Plastic debris is building up in the environment despite legislative attempts by many countries. Accumulated plastic waste from a range of sources breaks down into smaller fragments and microplastics through chemical, physiochemical and biodegradation mechanisms. This review also discusses personal protective equipment in relation to COVID-19 as a source of microplastics. Millions of microplastics are discharged into the environment through effluents and biosolids. Daily microplastic emissions to the environment from effluent range about 0.46 million to 140 billion. Previous studies had only explored the existence of microplastics in wastewater treatment plants, with limited visualization of how microplastics interact with the various treatment technologies used in wastewater treatment plants.