Micro- and nano-plastic pollution: Behavior, microbial ecology, and remediation technologies

An abrupt rise in plastic waste has become one of the most serious global environmental problems during the past five decades, and many strategies have been suggested to control the increasing levels of contaminants associated with plastic waste. Although many studies have focused on the fate, transport, ecotoxicity, and health risks of plastic waste contaminants, only a few studies have investigated microbial remediation of contaminants using cutting edge nanoscience. This review aims at addressing the environmental problems caused by micro-plastic (MP) and nano-plastic (NP) particles in the context of nanoscience (e.g., synthetic nanoparticle–plastic integrated research), microbial ecology, and remediation technologies to help elucidate their environmental fate, behavior, transport, eco-toxicity, and management. Interactions between plastic and microbes generally cause biofilm formation, which has biological effects that range from genes (by influencing horizontal gene transfer) to whole ecosystems (by influencing biogeochemical cycling, carbon (C) sequestration, and climate). Plastic waste remediation via chemical and bio-nanotechnologies (e.g., coagulation, membrane bioreactors, biodegradation, and phytoremediation) are also reviewed. In this respect, thermochemical conversion of plastic waste into energy is a promising management option. Further, molecular and -omics technologies can also facilitate the microbial biodegradation of MPs/NPs by enhancing enzymatic activity levels. A strategy based on proper incorporation of such interdisciplinary researches with robust sustainable policy measures is expected to offer effective management tools for the plastic wastes in the environment.