On the Influence of Environmental Conditions on Microplastic Sorption Dynamics and Mechanisms of Pharmaceuticals in Aquatic Ecosystems

Microplastics are well-known vectors of hydrophilic toxic substances, such as pharmaceuticals, and there are increasing concerns about their negative impacts on aquatic organisms, the environment, and human health. Due to their widespread consumption, pharmaceuticals are ubiquitous and can readily adsorb onto microplastic surfaces. Antibiotics such as amoxicillin, tetracycline, sulfadiazine, ciprofloxacin, and trimethoprim are among these organic contaminants. They have shown differing binding capacity in a variety of environmental conditions, including pH, salinity, and temperature. The goal of this mini-review is to critically examine the environmental factors governing the adsorption, fate, and transport of pharmaceuticals on microplastics in the environment. Environmental factors including salinity, pH, ionic strength, and polymeric and pharmaceuticals properties, as well as their interactions with sorption phenomena and mechanisms, are briefly discussed. This paper summarizes previous experiments to elucidate the importance of environmental factors on antibiotics adsorption onto MPs, thus creating further understanding on the transport, fate, and ecological risk of pharmaceuticals in natural environments.